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Sample records for monovalent flavobacterium columnare

  1. Parasitism enhances tilapia susceptibility to Flavobacterium columnare

    Science.gov (United States)

    Flavobacterium columnare, a Gram-negative bacterium, is the causative agent of columnaris disease. Many commercially important freshwater fish worldwide are susceptible to columnaris disease that can result in high fish mortality. Ichthyophthirius multifiliis (Ich) is a protozoan parasite in many ...

  2. Water hardness influences Flavobacterium columnare pathogenesis in channel catfish

    Science.gov (United States)

    Studies were conducted to determine aspects of water chemistry responsible for large differences in pathogenesis and mortality rates in challenges of channel catfish Ictalurus punctatus with Flavobacterium columnare; challenges were conducted in water supplying the Stuttgart National Aquaculture Res...

  3. Multiplex PCR for rapid genotyping of Flavobacterium columnare

    Science.gov (United States)

    Columnaris disease, caused by the Gram-negative bacterium Flavobacterium columnare, is one of the leading causes of disease losses to the catfish industry in the Southeast USA. Recent research in our laboratory has deciphered the genetic diversity among F. columnare isolates through whole genome seq...

  4. Parasite treatment reduced Flavobacterium columnare infection in tilapia

    Science.gov (United States)

    Bacterium Flavobacterium columnare and parasite Trichodina are common pathogens of cultured fish. The authors conducted a study to evaluate whether treatment of Trichodina parasitized tilapia with formalin would improve fish survival and reduce F. columnare infection in fish. Tilapia parasitized by...

  5. Ungeremine and its hemisynthetic analogues as bactericides against Flavobacterium columnare

    Science.gov (United States)

    The Gram-negative bacterium Flavobacterium columunare is the cause of colmunaris disease in channel catfish (Ictalurus punctatus). In a previous study, the betaine-type alkaloid ungeremine, 1 obtained from Pancratium maritimum L. was found to have strong antibacterial activity against F. columnare. ...

  6. Antibacterial activity of acylglucinol derivatives against Flavobacterium columnare

    Science.gov (United States)

    Columnaris disease is one of the most common bacterial diseases of pond-raised channel catfish (Ictalurus punctatus) in the southeastern United States of America. The Gram-negative, rod-shaped bacterium Flavobacterium columnare is the cause of columnaris disease. Direct economic losses to catfish pr...

  7. Parasitism by Ich enhanced susceptibility of tilapia to Flavobacterium columnare

    Science.gov (United States)

    In aquaculture systems, fish are commonly infected by two or more pathogens. Bacterium Flavobacterium columnare and parasite Ichthyophthirius multifiliis (Ich) are two common pathogens of cultured fish and result in heavy economic losses for aquaculture. There is no published information available ...

  8. Identification of an iron acquisition machinery in Flavobacterium columnare.

    Science.gov (United States)

    Guan, Lingyu; Santander, Javier; Mellata, Melha; Zhang, Yuangxing; Curtiss, Roy

    2013-10-11

    Flavobacterium columnare, a fastidious Gram-negative pathogen and the causative agent of columnaris disease, is one of the most harmful pathogens in the freshwater fish-farming industry. Nevertheless the virulence mechanisms of F. columnare are not well understood. Bacterial iron uptake from the host during infection is an important mechanism of virulence. Here we identified and analyzed part of the iron uptake machinery of F. columnare. Under iron-limited conditions during in vitro growth, synthesis of an outer membrane protein of ~86 kDa was upregulated. This protein was identified as a TonB-dependent ferrichrome-iron receptor precursor (FhuA). Synthesis of siderophores in F. columnare was corroborated by chrome azurol S assays. A putative ferric uptake regulator (Fur) protein was also identified in the F. columnare genome. Structural analysis of the F. columnare Fur protein revealed that it was similar to Fur proteins involved in iron uptake regulation of other bacteria. Furthermore, Salmonella enterica serovar Typhimurium (S. Typhimurium) Δfur mutants were partially complemented by the F. columnare fur gene. We conclude that a siderophore-mediated iron uptake system exists in F. columnare, and fur from F. columnare could partially complement S. Typhimurium Δfur mutant.

  9. Phenotypic characterization and genetic diversity of Flavobacterium columnare isolated from red tilapia, Oreochromis sp. in Thailand

    Science.gov (United States)

    Flavobacterium columnare is the etiologic agent of columnaris disease and severely affects various freshwater aquaculture fish species worldwide. The objectives of this study were to determine the phenotypic characteristics and genetic variability among F. columnare isolates isolated from red tilapi...

  10. Complete genome sequence of the fish pathogen Flavobacterium columnare strain C#2

    Science.gov (United States)

    Flavobacterium columnare is a Gram-negative bacterial pathogen that causes columnaris disease of freshwater fish. Flavobacterium columnare strain C#2 was isolated from a diseased warm water fish and is typed as genomovar II. The genome consists of a single 3.33 Mb circular chromosome with 2,689 pred...

  11. Walleye Autochthonous Bacteria as Promising Probiotic Candidates against Flavobacterium columnare

    Directory of Open Access Journals (Sweden)

    Hamza Seghouani

    2017-07-01

    Full Text Available Walleye (Sander vitreus is the second most fished freshwater species in Canada. While much sought by anglers, walleye also supports substantial commercial fisheries. To cope with the recent decline of wild walleye populations, fish farmers produce juveniles for lake stocking. However, walleye breeding is particularly tedious, mostly due to high disease susceptibility at larval and juvenile developmental stages. The main threat is the columnaris disease, which is caused by Flavobacterium columnare, an opportunistic bacteria. As F. columnare strains exhibit increasing antibiotic resistance, there is a strong need to develop efficient and sustainable alternative strategies to control columnaris disease. Bacterial probiotics have been shown to mitigate infections either by enhancing host immune response or by inhibiting pathogen growth. Being successfully assessed in many fish/pathogen combinations, we developed a tailored probiotic strategy for walleye to prevent and treat columnaris disease. Thirty-seven endogenous bacterial strains were isolated from healthy walleye’s skin and gut, were tested in vitro against F. columnare. Significant antagonistic effect against F. columnare was measured for 2 out of 37 endogenous strains. These two probiotic strains were identified as Pseudomonas fluorescens. The antagonistic effect of these two successful probiotics was further validated in vivo during a 2-month stress trial: groups receiving probiotic treatments showed on average 53.74% survival improvement.

  12. Formalin treatment of Trichondina sp. reduced Flavobacterium columnare infection in tilapia

    Science.gov (United States)

    Bacterium Flavobacterium columnare and protozoan Trichodina spp. are common pathogens of cultured fish. Recent studies on parasite-bacterium interaction show evidence that concurrent infections increase severity of some infectious diseases, especially bacterial diseases. The effect of parasite treat...

  13. Sickeningly sweet: L-rhamnose stimulates Flavobacterium columnare biofilm formation and virulence

    Science.gov (United States)

    Flavobacterium columnare, the causative agent of columnaris disease causes substantial mortality worldwide in numerous freshwater finfish species. Due to its global significance and impact on the aquaculture industry continual efforts to better understand basic mechanisms that contribute to disease ...

  14. The carbohydrate L-rhamnose promotes biofilm formation which enhances Flavobacterium columnare virulence

    Science.gov (United States)

    Flavobacterium columnare, the causative agent of columnaris disease causes substantial mortality worldwide in numerous freshwater finfish species. Due to its global significance and impact on the aquaculture industry, continual efforts to better understand basic mechanisms that contribute to disease...

  15. Ungeremine and Its hemisynthesized analogues as bactericides against Flavobacterium columnare.

    Science.gov (United States)

    Schrader, Kevin K; Avolio, Fabiana; Andolfi, Anna; Cimmino, Alessio; Evidente, Antonio

    2013-02-13

    The Gram-negative bacterium Flavobacterium columnare is the cause of columnaris disease, which can occur in channel catfish ( Ictalurus punctatus ). In a previous study, the betaine-type alkaloid ungeremine, 1, obtained from Pancratium maritimum L. was found to have strong antibacterial activity against F. columnare. In this study, analogues of 1 were evaluated using a rapid bioassay for activity against F. columnare to determine if the analogues might provide greater antibacterial activity and to determine structure-activity relationships of the test compounds. Several ungeremine analogues were prepared by hydrochlorination of the alkaloid and by selenium dioxide oxidation of both lycorine, 7, and pseudolycorine, 8, which yielded the isomer of ungeremine, 3, and zefbetaine, 4, respectively. The treatment of lycorine with phosphorus oxychloride allowed the synthesis of an anhydrolycorine lactam, 5, showing, with respect to 1, the deoxygenation and oxygenation of C-2 and C-7 of the C and B rings, respectively. The results of the structure-activity relationship studies showed that the aromatization of the C ring and the oxidation to an azomethine group of C-7 of the B ring are structural features important for antibacterial activity. In addition, the position of the oxygenation of the C ring as well as the presence of the 1,3-dioxole ring joined to the A ring of the pyrrolo[de]phenanthridine skeleton also plays a significant role in imparting antibacterial activity. On the basis of 24-h 50% inhibition concentration (IC(50)) results, ungeremine hydrochloride, 2, was similar in toxicity to 1, whereas 5 had the lowest activity. Analogue 2 is soluble in water, which may provide the benefit for use as an effective feed additive or therapeutant compared to ungeremine.

  16. Enhanced susceptibility of hybrid tilapia to Flavobacterium columnare after parasitism by Ichthyophthirius multifiliis

    Science.gov (United States)

    Bacterium Flavobacterium columnare and protozoan Ichthyophthirius multifiliis are two common pathogens of cultured fish. The objective of this study was to evaluate the susceptibility of hybrid tilapia (Oreochromis spp.) to the bacterium F. columnare, including fish mortality and bacterial loads in ...

  17. Composition of Extracellular Polymeric Substances (EPS) produced by Flavobacterium columnare isolated from tropical fish in Brazil.

    Science.gov (United States)

    de Alexandre Sebastião, Fernanda; Pilarski, Fabiana; Lemos, Manoel Victor Franco

    2013-01-01

    Thirty nine isolates of Flavobacterium columnare from Brazilian fish farms had their carbohydrate composition of EPS evaluated by high efficiency liquid chromatography, using the phenol-sulfuric acid method of EPS. The occurrence of capsules on F. columnare cells was not directly related to biofilm formation, and the predominant monosaccharide is glucose.

  18. Isolation and characterization of Flavobacterium columnare strains infecting fishes inhabiting the Laurentian Great Lakes basin

    Science.gov (United States)

    Flavobacterium columnare, the etiological agent of columnaris disease, causes significant losses in fish worldwide. In this study, F. columnare infection prevalence was assessed in representative Great Lakes fish species. Over 2,000 wild, feral, and hatchery-propagated salmonids, percids, centrarc...

  19. Growth and survival of the fish pathogenic bacterium, Flavobacterium columnare, in tilapia mucus and porcine gastric mucin

    Science.gov (United States)

    Flavobacterium columnare is an economically important gram negative bacterium that infects most freshwater farmed fish worldwide. Flavobacterium columnare colonizes the skin and gills of fish in the initial steps of pathogenesis. The fish’s surface is coated with mucus made up of high molecular we...

  20. Construction of two selectable markers for integrative/conjugative plasmids in Flavobacterium columnare

    Institute of Scientific and Technical Information of China (English)

    ZHANG Jin; ZOU Hong; WANG Liangfa; HUANG Bei; LI Nan; WANG Guitang; NIE Pin

    2012-01-01

    Flavobacterium columnare,the etiological agent of columnaris disease,is one of the most important and widespread bacterial pathogens of freshwater fish.In this study,we constructed two artificial selectable markers (chloramphenicol and spectinomycin resistance) for gene transfer in F.columnare.These two new artificial selectable markers,which were created by placing the chloramphenicol or spectinomycin resistance gene under the control of the native acs regulatory region of F.columnare,were functional in both F.columnare and Escherichia coli.The integrative/conjugative plasmids constructed by using these markers were introduced into F.columnare G4 via electroporation or conjugation.The integrated plasmid DNA was confirmed by Southem blotting and PCR analysis.These two markers can be employed in future investigations into gene deletion and the pathogenicity of virulence factors in F.columnare.

  1. Evaluation of the antibody response to the LV-359-01 strain of flavobacterium columnare

    Science.gov (United States)

    Flavobacterium columnare, the causative agent of columnaris disease produces substantial mortality worldwide among numerous freshwater farmed finfish species. As aquaculture production continues to increase the frequency of columnaris disease will only continue to rise. Add to this an increase in re...

  2. Draft genome sequence of the fish pathogen Flavobacterium columnare strain CSF-298-10

    Science.gov (United States)

    We announce the genome assembly of Flavobacterium columnare strain CSF-298-10, a strain isolated from an outbreak of Columnaris disease at a commercial trout farm in Snake River Valley Idaho, USA. The complete genome consists of 13 contigs totaling 3,284,579 bp, average G+C content of 31.5% and 2933...

  3. Quality control ranges for testing broth microdilution susceptibility of Flavobacterium columnare and F. psychrophilium to nine antimicrobials

    Science.gov (United States)

    A multi-laboratory broth microdilution method trial was performed to standardize the specialized test conditions required for fish pathogens Flavobacterium columnare and F. pyschrophilum. Nine laboratories tested the quality control (QC) strains Escherichia coli ATCC 25922 and Aeromonas salmonicid...

  4. Isolation and characterization of Flavobacterium columnare (Bernardet et al. 2002) from four tropical fish species in Brazil

    OpenAIRE

    Pilarski, F. [UNESP; ROSSINI, AJ.; CECCARELLI, PS.

    2008-01-01

    Flavobacterium columnare is the causative agent of columnaris disease in freshwater fish, implicated in skin and gill disease, often causing high mortality. The aim of this study was the isolation and characterization of Flavobacterium columnare in tropical fish in Brazil. Piracanjuba (Brycon orbignyanus), pacu (Piaractus mesopotamicus), tambaqui (Colossoma macropomum) and cascudo (Hypostomus plecostomus) were examined for external lesions showing signs of colunmaris disease such as greyish w...

  5. Impact of oral and waterborne administration of rhamnolipids on the susceptibility of channel catfish (Ictalurus punctatus) to Flavobacterium columnare infection

    Science.gov (United States)

    Flavobacterium columnare is the causative agent of columnaris disease and causes tremendous morbidity and mortality of farmed fish globally. Previously, we identified a potential lectin-mediator (a rhamnose-binding lectin; RBL1a) of F. columnare adhesion and showed higher RBL1a expression in suscept...

  6. First identification of Flavobacterium columnare infection in farmed freshwater striped catfish Pangasianodon hypophthalmus.

    Science.gov (United States)

    Tien, Nguyen Thi; Dung, Tu Thanh; Tuan, Nguyen Anh; Crumlish, Mags

    2012-08-13

    The bacterium Flavobacterium columnare was recovered and identified as the aetiological agent causing freshwater columnaris infection in farmed striped catfish Pangasianodon hypophthalmus (Sauvage) fingerlings that had suffered high mortality rates within commercial hatchery ponds in Vietnam. The gross clinical signs were typical of columnaris-infected fish. Histological examination found numerous Gram-negative, filamentous bacteria present on the skin, muscle and gill tissues of affected fish. The yellow-pigmented bacteria were isolated and identified as F. columnare using primary, biochemical and PCR methods. An experimental immersion-challenge study with 2 strains was also performed. It fulfilled Koch's postulates and showed a median lethal concentration (LC50) of 4.27 × 105 and 1.66 × 106 cfu ml-1 for the F. columnare strains FC-HN and FC-CT, respectively. To the best of our knowledge this is the first report of freshwater columnaris infection in P. hypophthalmus.

  7. Isolation and characterization of Flavobacterium columnare from freshwater ornamental goldfish Carassius auratus.

    Science.gov (United States)

    Verma, Dev Kumar; Rathore, Gaurav; Pradhan, Pravata Kumar; Sood, Neeraj; Punia, Peyush

    2015-03-01

    Filamentous bacteria overlaying ulcerated area on the body surface were observed in the wet-mout preparation from a moribund goldfish with saddle back appearance. The causative agent was identified as Flavobacterium columnrae, on the basis of biochemical test, species-specific polymerase chain reaction (PCR) and sequencing of 16S rDNA gene with the universal bacterial primers. Furthermore, the strain (ING-1) attributed to genomovar II in 16S rDNA PCR-restriction fragment length polymorphism (PCR-RFLP) and sequence analysis. In phylogenetic analysis, the strain ING-1, produced typical columnaris disease symptoms in rohu (Labeo rohita) fingerlings within 10 days. This is a new record about molecular detection and identification of Flavobacterium columnare, occurring naturally on a new host Carassius auratusin India.

  8. Susceptibility of zebra fish Danio rerio to infection by Flavobacterium columnare and F. johnsoniae.

    Science.gov (United States)

    Moyer, Thomas R; Hunnicutt, David W

    2007-06-07

    Flavobacterium columnare is a serious pathogen in a wide range of fish species. F. johnsoniae is an opportunistic pathogen of certain fish. Both are gliding bacteria. These species were tested for their ability to infect the zebra fish Danio rerio. Both injection and bath infection methods were tested. The results indicate that F. johnsoniae is not an effective pathogen in D. rerio, but that F. columnare is an effective pathogen. F. johnsoniae did not cause increased death rates following bath infection, but did cause increased death rates following injection, with an LD50 (mean lethal dose) of approximately 3 x 10(10) cfu (colony-forming units). Non-motile mutants of F. johnsoniae produced a similar LD50. F. columnare caused increased death rates following both injection and bath infections. There was considerable strain variation in LD50, with the most lethal strain tested producing an LD50 of 3.2 x 10(6) cfu injected and 1.1 x 10(6) cfu ml(-1) in bath experiments, including skin damage. The LD50 of F. columnare in zebra fish without skin damage was > 1 x 10(8), indicating an important effect of skin damage.

  9. Intragenomic heterogeneity in the 16S rRNA genes of Flavobacterium columnare and relevance to genomovar assignment

    Science.gov (United States)

    Flavobacterium columnare is the causative agent of columnaris disease which severely impacts channel catfish production in the USA and may be emerging as an important pathogen in the rainbow trout industry. The 16S rRNA gene is a housekeeping gene commonly used for bacterial taxonomy and genotyping...

  10. Intragenomic heterogeneity in the 16S rRNA genes of Flavobacterium columnare and standard protocol for genomovar assignment

    Science.gov (United States)

    Genetic variability in 16S rRNA gene sequences has been demonstrated among isolates of Flavobacterium columnare and a restriction fragment length polymorphism (RFLP) assay is available for genetic typing this important fish pathogen. Interpretation of restriction patterns can be difficult due to th...

  11. Isolation and characterization of Flavobacterium columnare (Bernardet et al. 2002) from four tropical fish species in Brazil.

    Science.gov (United States)

    Pilarski, F; Rossini, A J; Ceccarelli, P S

    2008-05-01

    Flavobacterium columnare is the causative agent of columnaris disease in freshwater fish, implicated in skin and gill disease, often causing high mortality. The aim of this study was the isolation and characterization of Flavobacterium columnare in tropical fish in Brazil. Piracanjuba (Brycon orbignyanus), pacu (Piaractus mesopotamicus), tambaqui (Colossoma macropomum) and cascudo (Hypostomus plecostomus) were examined for external lesions showing signs of colunmaris disease such as greyish white spots, especially on the head, dorsal part and caudal fin of the fish. The sampling comprised 50 samples representing four different fish species selected for study. Samples for culture were obtained by skin and kidney scrapes with a sterile cotton swabs of columnaris disease fish and streaked onto Carlson and Pacha (1968) artificial culture medium (broth and solid) which were used for isolation. The strains in the liquid medium were Gram negative, long, filamentous, exhibited flexing movements (gliding motility), contained a large number of long slender bacteria and gathered into columns'. Strains on the agar produced yellow-pale colonies, rather small, flat that had rhizoid edges. A total of four Flavobacterium columnare were isolated: 01 Brycon orbignyanus strain, 01 Piaractus mesopotamicus strain, 01 Colossoma macropomum strain, and 01 Hypostomus plecostomus strain. Biochemical characterization, with its absorption of Congo red dye, production of flexirubin-type pigments, H2S production and reduction of nitrates proved that the isolate could be classified as Flavobacterium columnare.

  12. Intragenomic heterogeneity in the 16S rRNA genes of Flavobacterium columnare and relevance to genomovar assignment

    Science.gov (United States)

    Genetic variability in 16S rRNA gene sequences has been demonstrated among isolates of Flavobacterium columnare and a restriction fragment length polymorphism (RFLP) assay is available for genetic typing this important fish pathogen. Interpretation of restriction patterns can be difficult due to th...

  13. Identification of genes encoding the type IX secretion system and secreted proteins in Flavobacterium columnare IA-S-4

    Science.gov (United States)

    Flavobacterium columnare, a member of the phylum Bacteroidetes, causes columnaris disease in wild and aquaculture-reared freshwater fish. The mechanisms responsible for columnaris disease are not known. Many members of the phylum Bacteroidetes use type IX secretion systems (T9SSs) to secrete enzymes...

  14. DNAk is a dominant epitope in the humoral immune response of channel catfish (Ictalurus punctatus) to Flavobacterium columnare

    Science.gov (United States)

    Vaccination remains a viable alternative for bacterial disease protection in fish; however additional work is required to understand the mechanisms of adaptive immunity in the channel catfish. To assess the humoral immune response to Flavobacterium columnare; a group of channel catfish were first im...

  15. Gene deletion strategy to examine the involvement of the two chondroitin lyases in Flavobacterium columnare virulence.

    Science.gov (United States)

    Li, Nan; Qin, Ting; Zhang, Xiao Lin; Huang, Bei; Liu, Zhi Xin; Xie, Hai Xia; Zhang, Jin; McBride, Mark J; Nie, Pin

    2015-11-01

    Flavobacterium columnare is an important bacterial pathogen of freshwater fish that causes high mortality of infected fish and heavy economic losses in aquaculture. The pathogenesis of this bacterium is poorly understood, in part due to the lack of efficient methods for genetic manipulation. In this study, a gene deletion strategy was developed and used to determine the relationship between the production of chondroitin lyases and virulence. The F. johnsoniae ompA promoter (PompA) was fused to sacB to construct a counterselectable marker for F. columnare. F. columnare carrying PompA-sacB failed to grow on media containing 10% sucrose. A suicide vector carrying PompA-sacB was constructed, and a gene deletion strategy was developed. Using this approach, the chondroitin lyase-encoding genes, cslA and cslB, were deleted. The ΔcslA and ΔcslB mutants were both partially deficient in digestion of chondroitin sulfate A, whereas a double mutant (ΔcslA ΔcslB) was completely deficient in chondroitin lyase activity. Cells of F. columnare wild-type strain G4 and of the chondroitin lyase-deficient ΔcslA ΔcslB mutant exhibited similar levels of virulence toward grass carp in single-strain infections. Coinfections, however, revealed a competitive advantage for the wild type over the chondroitin lyase mutant. The results indicate that chondroitin lyases are not essential virulence factors of F. columnare but may contribute to the ability of the pathogen to compete and cause disease in natural infections. The gene deletion method developed in this study may be employed to investigate the virulence factors of this bacterium and may have wide application in many other members of the phylum Bacteroidetes.

  16. Putative roles for a rhamnose binding lectin in Flavobacterium columnare pathogenesis in channel catfish Ictalurus punctatus.

    Science.gov (United States)

    Beck, Benjamin H; Farmer, Bradley D; Straus, David L; Li, Chao; Peatman, Eric

    2012-10-01

    Columnaris disease, caused by the bacterial pathogen Flavobacterium columnare, continues to be a major problem worldwide and commonly leads to tremendous losses of both wild and cultured freshwater fish, particularly in intensively farmed aquaculture species such as channel catfish. Despite its ecologic and economic impacts, the fundamental molecular mechanisms of the host immune response to this pathogen remain unclear. While F. columnare can induce marked pathologic changes in numerous ectopic tissues, the adhesion of F. columnare to the gill in particular is strongly associated with pathogen virulence and host susceptibility. Recently, in this regard, using RNA-seq expression profiling we found that a rhamnose-binding lectin (RBL) was dramatically upregulated in the gill of fish infected with F. columnare (as compared to naïve fish). Thus, in the present study we sought to further characterize and understand the RBL response in channel catfish (Ictalurus punctatus). We first identified two distinct catfish families with differential susceptibilities to columnaris disease; one family was found to be completely resistant while the other was susceptible (0% mortality versus 18.3% respectively, P catfish RBL that persisted for at least 24 h (P catfish to different doses of the putative RBL ligands l-rhamnose and d-galactose, and found that these sugars, protected channel catfish against columnaris disease, likely through competition with F. columnare binding of host RBL. Finally, we examined the role of nutritional status on RBL regulation and found that RBL expression was upregulated (>120-fold; P < 0.05) in fish fasted for 7 d (as compared to fish fed to satiation daily), yet expression levels returned to those of satiated fish within 4 h after re-feeding. Collectively, these findings highlight putative roles for RBL in the context of columnaris disease and reveal new aspects linking RBL regulation to feed availability.

  17. Adaptive response to starvation in the fish pathogen Flavobacterium columnare: cell viability and ultrastructural changes

    Directory of Open Access Journals (Sweden)

    Arias Covadonga R

    2012-11-01

    Full Text Available Abstract Background The ecology of columnaris disease, caused by Flavobacterium columnare, is poorly understood despite the economic losses that this disease inflicts on aquaculture farms worldwide. Currently, the natural reservoir for this pathogen is unknown but limited data have shown its ability to survive in water for extended periods of time. The objective of this study was to describe the ultrastructural changes that F. columnare cells undergo under starvation conditions. Four genetically distinct strains of this pathogen were monitored for 14 days in media without nutrients. Culturability and cell viability was assessed throughout the study. In addition, cell morphology and ultrastructure was analyzed using light microscopy, scanning electron microscopy, and transmission electron microscopy. Revival of starved cells under different nutrient conditions and the virulence potential of the starved cells were also investigated. Results Starvation induced unique and consistent morphological changes in all strains studied. Cells maintained their length and did not transition into a shortened, coccus shape as observed in many other Gram negative bacteria. Flavobacterium columnare cells modified their shape by morphing into coiled forms that comprised more than 80% of all the cells after 2 weeks of starvation. Coiled cells remained culturable as determined by using a dilution to extinction strategy. Statistically significant differences in cell viability were found between strains although all were able to survive in absence of nutrients for at least 14 days. In later stages of starvation, an extracellular matrix was observed covering the coiled cells. A difference in growth curves between fresh and starved cultures was evident when cultures were 3-months old but not when cultures were starved for only 1 month. Revival of starved cultures under different nutrients revealed that cells return back to their original elongated rod shape upon

  18. Molecular typing of isolates of the fish pathogen, Flavobacterium columnare, by single-strand conformation polymorphism analysis.

    Science.gov (United States)

    Olivares-Fuster, Oscar; Shoemaker, Craig A; Klesius, Phillip H; Arias, Covadonga R

    2007-04-01

    Flavobacterium columnare intraspecies diversity was revealed by analyzing the 16S rRNA gene and the 16S-23S internal spacer region (ISR). Standard restriction fragment length polymorphism (RFLP) of these sequences was compared with single-strand conformation polymorphism (SSCP). Diversity indexes showed that both 16S-SSCP and ISR-SSCP improved resolution (D>or=0.9) when compared with standard RFLP. ISR-SSCP offered a simpler banding pattern than 16S-SSCP while providing high discrimination between isolates. SSCP analysis of rRNA genes proved to be a simple, rapid, and cost-effective method for routine fingerprinting of F. columnare.

  19. Flavobacterium columnare isolated from red tilapia (Oreochromis sp.): emphasis on genetic characterization and virulence of rhizoid and non-rhizoid morphotypes

    Science.gov (United States)

    Flavobacterium columnare is the causative agent of columnaris disease and severely affects various freshwater fish species worldwide. Here, we described the phenotypic and genetic characterization of F. columnare isolates isolated from farmed red tilapia in Thailand. Additionally, the virulence as w...

  20. Involvement of two glycoside hydrolase family 19 members in colony morphotype and virulence in Flavobacterium columnare

    Science.gov (United States)

    Zhang, Xiaolin; Li, Nan; Qin, Ting; Huang, Bei; Nie, Pin

    2016-12-01

    Flavobacterium columnare is the pathogenic agent of columnaris disease in aquaculture. Using a recently developed gene deletion strategy, two genes that encode the Glyco_hydro_19 domain (GH19 domain) containing proteins, ghd-1 and ghd-2, were deleted separately and together from the F. columnare G4 wild type strain. Surprisingly, the single-, Δghd-1 and Δghd-2, and double-gene mutants, Δghd-1 Δghd -2, all had rhizoid and non-rhizoid colony morphotypes, which we named Δghd-1, Δghd-2, Δghd-1 Δghd-2, and NΔghd-1, NΔghd-2, and NΔghd-1 Δghd-2. However, chitin utilization was not detected in either these mutants or in the wild type. Instead, skimmed milk degradation was observed for the mutants and the wild type; the non-rhizoid strain NΔghd-2 exhibited higher degradation activity as revealed by the larger transparent circle on the skimmed milk plate. Using zebrafish as the model organism, we found that non-rhizoid mutants had higher LD50 values and were less virulent because zebrafish infected with these survived longer. Transcriptome analysis between the non-rhizoid and rhizoid colony morphotypes of each mutant, i.e., NΔ ghd -1 versus (vs) Δghd-1, NΔghd-2 vs Δghd-2, and NΔghd-1 Δghd-2 vs Δghd-1 Δghd-2, revealed a large number of differentially expressed genes, among which 39 genes were common in three of the pairs compared. Although most of these genes encode hypothetical proteins, a few molecules such as phage tail protein, rhs element Vgr protein, thiol-activated cytolysin, and TonB-dependent outer membrane receptor precursor, expression of which was down-regulated in non-rhizoid mutants but up-regulated in rhizoid mutants, may play a role F. columnare virulence.

  1. Extremophile extracts and enhancement techniques show promise for the development of a live vaccine against Flavobacterium columnare

    Science.gov (United States)

    Powell, D.B.; Palm, R.C.; MacKenzie, A.P.; Winton, J.R.

    2009-01-01

    The effects of temperature, ionic strength, and new cryopreservatives derived from polar ice bacteria were investigated to help accelerate the development of economical, live attenuated vaccines for aquaculture. Extracts of the extremophile Gelidibacter algens functioned very well as part of a lyophilization cryoprotectant formulation in a 15-week storage trial. The bacterial extract and trehalose additives resulted in significantly higher colony counts of columnaris bacteria (Flavobacterium columnare) compared to nonfat milk or physiological saline at all time points measured. The bacterial extract combined with trehalose appeared to enhance the relative efficiency of recovery and growth potential of columnaris in flask culture compared to saline, nonfat milk, or trehalose-only controls. Pre-lyophilization temperature treatments significantly affected F. columnare survival following rehydration. A 30-min exposure at 0 ??C resulted in a 10-fold increase in bacterial survival following rehydration compared to mid-range temperature treatments. The brief 30 and 35 ??C pre-lyophilization exposures appeared to be detrimental to the rehydration survival of the bacteria. The survival of F. columnare through the lyophilization process was also strongly affected by changes in ionic strength of the bacterial suspension. Changes in rehydration constituents were also found to be important in promoting increased survival and growth. As the sodium chloride concentration increased, the viability of rehydrated F. columnare decreased. ?? 2009 Elsevier Inc.

  2. Computer-aided vaccine designing approach against fish pathogens Edwardsiella tarda and Flavobacterium columnare using bioinformatics softwares

    Directory of Open Access Journals (Sweden)

    Mahendran R

    2016-05-01

    Full Text Available Radha Mahendran,1 Suganya Jeyabaskar,1 Gayathri Sitharaman,1 Rajamani Dinakaran Michael,2 Agnal Vincent Paul1 1Department of Bioinformatics, 2Centre for Fish Immunology, School of Life Sciences, Vels University, Pallavaram, Chennai, Tamil Nadu, India Abstract: Edwardsiella tarda and Flavobacterium columnare are two important intracellular pathogenic bacteria that cause the infectious diseases edwardsiellosis and columnaris in wild and cultured fish. Prediction of major histocompatibility complex (MHC binding is an important issue in T-cell epitope prediction. In a healthy immune system, the T-cells must recognize epitopes and induce the immune response. In this study, T-cell epitopes were predicted by using in silico immunoinformatics approach with the help of bioinformatics tools that are less expensive and are not time consuming. Such identification of binding interaction between peptides and MHC alleles aids in the discovery of new peptide vaccines. We have reported the potential peptides chosen from the outer membrane proteins (OMPs of E. tarda and F. columnare, which interact well with MHC class I alleles. OMPs from E. tarda and F. columnare were selected and analyzed based on their antigenic and immunogenic properties. The OMPs of the genes TolC and FCOL_04620, respectively, from E. tarda and F. columnare were taken for study. Finally, two epitopes from the OMP of E. tarda exhibited excellent protein–peptide interaction when docked with MHC class I alleles. Five epitopes from the OMP of F. columnare had good protein–peptide interaction when docked with MHC class I alleles. Further in vitro studies can aid in the development of potential peptide vaccines using the predicted peptides. Keywords: E. tarda, F. columnare, edwardsiellosis, columnaris, T-cell epitopes, MHC class I, peptide vaccine, outer membrane proteins 

  3. Bioassay-directed isolation and evaluation of Harmine from the terrestrial plant Peganum harmala L. for antibacterial activity against Flavobacterium columnare

    Science.gov (United States)

    The antibacterial activities of crude extracts obtained from the aerial portions and roots of Peganum harmala L. were evaluated against the common fish pathogenic bacteria species Edwardsiella ictaluri, Flavobacterium columnare, and Streptococcus iniae using a rapid bioassay. Enteric septicemia of c...

  4. Intragenomic heterogeneity in the 16S rRNA genes of Flavobacterium columnare and standard protocol for genomovar assignment.

    Science.gov (United States)

    LaFrentz, B R; Waldbieser, G C; Welch, T J; Shoemaker, C A

    2014-07-01

    Genetic variability in 16S rRNA gene sequences has been demonstrated among isolates of Flavobacterium columnare, and a restriction fragment length polymorphism (RFLP) assay is available for genetic typing of this important fish pathogen. Interpretation of restriction patterns can be difficult due to the lack of a formal description of the expected number and sizes of DNA fragments generated for each of the described genomovars. In this study, partial 16S rRNA gene sequences (ca. 1250-bp fragment) from isolates representing each described genomovar and isolates generating unique restriction patterns were cloned and sequenced. The results demonstrated that some isolates contained up to three different 16S rRNA genes whose sequences generate different RFLP patterns due to intragenomic heterogeneity within HaeIII restriction sites. The occurrence of HaeIII restriction sites within the portion of the 16S rRNA gene used for typing the F. columnare isolates and intragenomic heterogeneity within these sites explained the restriction patterns observed following RFLP analyses. This research provides a standard protocol for typing isolates of F. columnare by RFLP and a formal description of the expected restriction patterns for the previously described genomovars I, II, II-B and III. Additionally, we describe a new genomovar, I/II.

  5. Effect of dietary supplementation with Echinacea purpurea on vaccine efficacy against infection with Flavobacterium columnare in zebrafish (Danio rerio).

    Science.gov (United States)

    Guz, L; Puk, K; Walczak, N; Oniszczuk, T; Oniszczuk, A

    2014-01-01

    The effect of dietary Echinacea purpurea (EP) on the response of zebrafish (Danio rerio) to a Flavobacterium columnare vaccine was investigated. Two hundred D. rerio with an average weight of 290 ± 40 g were selected and fed different levels of E. purpurea (5 g kg(-1) diet--group 1, 10 g kg(-1) diet--group 2, 20 g kg(-1) diet--group 3, 30 g kg(-1) diet--group 4, and 0 g kg(-1) diet--group 5). Experimental feeding was begun 3 weeks prior to bath immunization and continued until the end of the experiment. Twenty-eight days after immunization the fish were challenged by bath immersion with F. columnare at a concentration of 1 x 10(6) CFU/ml. The relative percent survival of the experimental groups (1, 2, 3, 4 and 5) was 5.0, 6.0, 30.0, 36.0 and 5.0, respectively. In conclusion, diet supplementation with E. purpurea may effectively enhance the response of zebrafish to a F. columnare vaccine.

  6. Colorimetric Method of Loop-Mediated Isothermal Amplification with the Pre-Addition of Calcein for Detecting Flavobacterium columnare and its Assessment in Tilapia Farms.

    Science.gov (United States)

    Suebsing, Rungkarn; Kampeera, Jantana; Sirithammajak, Sarawut; Withyachumnarnkul, Boonsirm; Turner, Warren; Kiatpathomchai, Wansika

    2015-03-01

    Flavobacterium columnare, the causative agent of columnaris disease in fish, affects many economically important freshwater fish species. A colorimetric method of loop-mediated isothermal amplification with the pre-addition of calcein (LAMP-calcein) was developed and used to detect the presence of F. columnare in farmed tilapia (Nile Tilapia Oreochromis niloticus and red tilapia [Nile Tilapia × Mozambique Tilapia O. mossambicus]) and rearing water. The detection method, based on a change in color from orange to green, could be performed within 45 min at 63°C. The method was highly specific, as it had no cross-detections with 14 other bacterial species, including other fish pathogens and two Flavobacterium species. The method has a minimum detection limit of 2.2 × 10(2) F. columnare CFU; thus, it is about 10 times more sensitive than conventional PCR. With this method, F. columnare was detected in gonad, gill, and blood samples from apparently healthy tilapia broodstock as well as in samples of fertilized eggs, newly hatched fry, and rearing water. The bacteria isolated from the blood were further characterized biochemically and found to be phenotypically identical to F. columnare. The amplified products from the LAMP-calcein method had 97% homology with the DNA sequence of F. columnare.

  7. Laboratory challenges with the bacterial pathogen, Flavobacterium columnare and infection of juvenile lost river suckers (Deltistes luxatus) during their exposure to sublethal ammonia concentrations at pH 9.5

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — Three Flavobacterium columnare isolates which had been obtained from dying adult suckers at Upper Klamath Lake during a fish kill in August, 1996 and stored by...

  8. Immunogenicity and protective role of antigenic regions from five outer membrane proteins of Flavobacterium columnare in grass carp Ctenopharyngodon idella

    Science.gov (United States)

    Luo, Zhang; Liu, Zhixin; Fu, Jianping; Zhang, Qiusheng; Huang, Bei; Nie, Pin

    2016-11-01

    Flavobacterium columnare causes columnaris disease in freshwater fish. In the present study, the antigenic regions of five outer membrane proteins (OMPs), including zinc metalloprotease, prolyl oligopeptidase, thermolysin, collagenase and chondroitin AC lyase, were bioinformatically analyzed, fused together, and then expressed as a recombinant fusion protein in Escherichia coli. The expressed protein of 95.6 kDa, as estimated by 10% sodium dodecyl sulfate-polyacrylamide gel electrophoresis, was consistent with the molecular weight deduced from the amino acid sequence. The purified recombinant protein was used to vaccinate the grass carp, Ctenopharyngodon idella. Following vaccination of the fish their IgM antibody levels were examined, as was the expression of IgM, IgD and IgZ immunoglobulin genes and other genes such as MHC Iα and MHC IIβ, which are also involved in adaptive immunity. Interleukin genes ( IL), including IL-1β, IL-8 and IL-10, and type I and type II interferon ( IFN) genes were also examined. At 3 and 4 weeks post-vaccination (wpv), significant increases in IgM antibody levels were observed in the fish vaccinated with the recombinant fusion protein, and an increase in the expression levels of IgM, IgD and IgZ genes was also detected following the vaccinations, thus indicating that an adaptive immune response was induced by the vaccinations. Early increases in the expression levels of IL and IFN genes were also observed in the vaccinated fish. At four wpv, the fish were challenged with F. columnare, and the vaccinated fish showed a good level of protection against this pathogen, with 39% relative percent survival (RPS) compared with the control group. It can be concluded, therefore, that the five OMPs, in the form of a recombinant fusion protein vaccine, induced an immune response in fish and protection against F. columnare.

  9. Quality control ranges for testing broth microdilution susceptibility of Flavobacterium columnare and F. psychrophilum to nine antimicrobials

    DEFF Research Database (Denmark)

    Gieseker, Charles M.; Mayer, Tamara D.; Crosby, Tina C.

    2012-01-01

    . These data and their associated QC ranges have been approved by the Clinical and Laboratory Standards Institute (CLSI), and will be included in the next edition of the CLSI M49-A Guideline. This method represents the first standardized reference method for testing fish pathogenic Flavobacterium spp....

  10. Generation of Biotechnology-Derived Flavobacterium columnare Ghosts by PhiX174 Gene E-Mediated Inactivation and the Potential as Vaccine Candidates against Infection in Grass Carp

    Directory of Open Access Journals (Sweden)

    Wenxing Zhu

    2012-01-01

    Full Text Available Flavobacterium columnare is a bacterial pathogen causing high mortality rates for many freshwater fish species. Fish vaccination with a safe and effective vaccine is a potential approach for prevention and control of fish disease. Here, in order to produce bacterial ghost vaccine, a specific Flavobacterium lysis plasmid pBV-E-cat was constructed by cloning PhiX174 lysis gene E and the cat gene with the promoter of F. columnare into the prokaryotic expression vector pBV220. The plasmid was successfully electroporated into the strain F. columnare G4cpN22 after curing of its endogenous plasmid. F. columnare G4cpN22 ghosts (FCGs were generated for the first time by gene E-mediated lysis, and the vaccine potential of FCG was investigated in grass carp (Ctenopharyngodon idellus by intraperitoneal route. Fish immunized with FCG showed significantly higher serum agglutination titers and bactericidal activity than fish immunized with FKC or PBS. Most importantly, after challenge with the parent strain G4, the relative percent survival (RPS of fish in FCG group (70.9% was significantly higher than FKC group (41.9%. These results showed that FCG could confer immune protection against F. columnare infection. As a nonliving whole cell envelope preparation, FCG may provide an ideal alternative to pathogen-based vaccines against columnaris in aquaculture.

  11. Lack of association between Flavobacterium columnare genomovar and virulence in hybrid tilapia Oreochromis niloticus (L.) x Oreochromis aureus (Steindachner)

    Science.gov (United States)

    Columnaris disease can be problematic in tilapia (Oreochromis spp.) production. An understanding of the pathogenesis and virulence of F. columnare is needed for the development of prevention strategies. The objective of this study was to determine the virulence of genetically defined isolates of Fl...

  12. Transcriptomic analysis of the head kidney of Topmouth culter (Culter alburnus) infected with Flavobacterium columnare with an emphasis on phagosome pathway.

    Science.gov (United States)

    Zhao, Lijuan; Tu, Jiagang; Zhang, Yulei; Wang, Jinfu; Yang, Ling; Wang, Weimin; Wu, Zaohe; Meng, Qinglei; Lin, Li

    2016-10-01

    Flavobacterium columnare (FC) has caused worldwide fish columnaris disease with high mortality and great economic losses in cultured fish, including Topmouth culter (Culter alburnus). However, the knowledge about the host factors involved in FC infection is little known. In this study, the transcriptomic profiles of the head kidney from Topmouth culter with or without FC infection were obtained using HiSeq™ 2500 (Illumina). Totally 79,641 unigenes with high quality were obtained. Among them, 4037 differently expressed genes, including 1217 up-regulated and 2820 down-regulated genes, were identified and enriched using databases of Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG). The differently expressed genes were mainly associated with pathways such as immune response, carbohydrate metabolism, amino acid metabolism, and lipid metabolism. Since phagocytosis is a central mechanism of innate immune response by host cells to defense against infectious agents, genes related to the phagosome pathway were scrutinized and 9 differently expressed phagosome-related genes were identified including 3 up-regulated and 6 down-regulated genes. Five of them were further validated by quantitative real-time polymerase chain reaction (qRT-PCR). This transcriptomic analysis of host genes in response to FC infection provides data towards understanding the infection mechanisms and will shed a new light on the prevention of columnaris.

  13. 柱状黄杆菌乙酰辅酶A合成酶基因及其上游调控序列分析%Acetyl-coenzyme A synthetase gene and its upstream promoter in the bacterial pathogen Flavobacterium columnare

    Institute of Scientific and Technical Information of China (English)

    张金; 邹红; 姚卫建; 聂品

    2011-01-01

    Flavobacterium columnare, the etiological agent of columnaris disease, is one of the most important bacterial pathogens of freshwater fish in the world. However, suitable genetic manipulation of this bacterium which has been challenging and producing genetic mutations in this bacterium has not been reported. Therefore, isolation of an effective promoter in F. Columnare may provide tools for the development of a genetic manipulation system in the bacterium. In this study, the acetyl-coenzyme A synthetase gene (acs) and flanking sequences were analyzed to determine promoter function. The acs gene is 2 323 bp long, encoding a protein of 635 amino acids. A TAAAA motif was identified as the conserved sequence for ribosome binding site (RBS) and TATTTTCG and TTG were determined to be -7 and -33 promoter motifs, upstream of the acs start codon. When a plasmid was constructed containing the acs upstream regulation sequence (Pacs) fused upstream of the chloramphenicol ace-tyltransferase (cat) gene and was introduced into F. Columnare G4 strain, the host cells gained chloramphenicol (Cm) resistance. The transcriptional start position (TSP) of acs and cat was both determined to be T locating 46 bp upstream of the start codon. Deletion analysis of the promoter showed that at least 164 bp nucleotides upstream of the start codon were required for promoter activity and for the expression of CAT to sufficiently confer the resistance in F. Columnare. Nucleotide analysis and alignment of the putative RBS for 32 protein-coding genes in F. Columnare G4 revealed the conserved RBS consensus, TAAAA, in Flavobacterium located 10 bp upstream of start codon of acs. The current study described the first successful construction of a plasmid that was able to express cloned genes in F. Columnare, which will allow further studies of the important columnaris disease in fish.%柱状黄杆菌(Flavobacterium columnare)是世界范围内危害淡水鱼类的柱形病的病原.目前对该病原菌

  14. 黄颡鱼源柱状黄杆菌的分离鉴定及其对翘嘴鳜的致病性%Characterization and pathogenicity of a strain of Flavobacterium columnare isolated from Pelteobagrus fulvidraco

    Institute of Scientific and Technical Information of China (English)

    张玉蕾; 赵丽娟; 周伟东; 艾桃山; 林蠡

    2016-01-01

    In this report,we isolated and identified a strain of Flavobacterium columnare (named Pf1 strain)from a diseased yellow Chinese catfish,Pelteobagrus fulvidraco .Subsequently,the drug sensitive tests and the pathogenicity of Pf1 on yellow Chinese catfish and mandarin fish (Siniperca chuatsi )were carried out and the results showed that Pf1 was pathogenic.Pf1 infection could cause nec-rosis and inflammation of several tissues,especially the liver,trunk kidney and gill in mandarin fish.In the infected mandarin fish,liver cells were swollen,vacuolar and necrotic.Necrosis of renal tubular and extensive inflammatory cells infiltration were observed.Gill lamellae capillaries were swollen and hyper-emic,and respiratory epithelia were swollen and degenerated.The lesioned gill lead to the higher breathing rate,slower swimming,and eventually mass mortality of the infected mandarin fish.%从患病黄颡鱼上分离出1株柱状黄杆菌(Pf1),对其进行分类鉴定和药物敏感试验。用 Pf1感染黄颡鱼和翘嘴鳜,发现 Pf1对2种鱼均有致病性。Pf1可导致翘嘴鳜多个组织细胞坏死和炎症反应,严重损伤肝、体肾和鳃。被感染翘嘴鳜肝细胞肿胀、空泡化坏死;肾小管广泛坏死和大量炎症细胞浸润;鳃小片毛细血管充血,呼吸上皮细胞肿胀变性,鳃的呼吸功能衰退。鳃部病变导致感染鳜呼吸频率加快、游动缓慢,最后大量死亡。

  15. Treatment of Trichodina sp. reduced load of Flavobacterium colummnare and improved survival of hybrid tilapia

    Science.gov (United States)

    Parasites and bacteria are common inhabitants in water of fish farms. The effect of parasite treatment on Flavobacterium columnare infection in tilapia is currently unknown. This study evaluated whether treatment of Trichodina sp. parasitized hybrid tilapia (Oreochromis niloticus × O. aureus) would...

  16. Multivalent Protein Assembly Using Monovalent Self-Assembling Building Blocks

    Directory of Open Access Journals (Sweden)

    Katja Petkau-Milroy

    2013-10-01

    Full Text Available Discotic molecules, which self-assemble in water into columnar supramolecular polymers, emerged as an alternative platform for the organization of proteins. Here, a monovalent discotic decorated with one single biotin was synthesized to study the self-assembling multivalency of this system in regard to streptavidin. Next to tetravalent streptavidin, monovalent streptavidin was used to study the protein assembly along the supramolecular polymer in detail without the interference of cross-linking. Upon self-assembly of the monovalent biotinylated discotics, multivalent proteins can be assembled along the supramolecular polymer. The concentration of discotics, which influences the length of the final polymers at the same time dictates the amount of assembled proteins.

  17. Monovalent plasmonic nanoparticles for biological applications

    Science.gov (United States)

    Seo, Daeha; Lee, Hyunjung; Lee, Jung-uk; Haas, Thomas J.; Jun, Young-wook

    2016-03-01

    The multivalent nature of commercial nanoparticle imaging agents and the difficulties associated with producing monovalent nanoparticles challenge their use in biology, where clustering of target biomolecules can perturb dynamics of biomolecular targets. Here, we report production and purification of monovalent gold and silver nanoparticles for their single molecule imaging application. We first synthesized DNA-conjugated 20 nm and 40 nm gold and silver nanoparticles via conventional metal-thiol chemistry, yielding nanoparticles with mixed valency. By employing an anion-exchange high performance liquid chromatography (AE-HPLC) method, we purified monovalent nanoparticles from the mixtures. To allow efficient peak-separation resolution while keeping the excellent colloidal stability of nanoparticles against harsh purification condition (e.g. high NaCl), we optimized surface properties of nanoparticles by modulating surface functional groups. We characterized the monovalent character of the purified nanoparticles by hybridizing two complementary conjugates, forming dimers. Finally, we demonstrate the use of the monovalent plasmonic nanoprobes as single molecule imaging probes by tracking single TrkA receptors diffusing on the cell membrane and compare to monovalent quantum dot probes.

  18. Antibacterial compounds from Rutaceae with activities against Flavobacterium columnare and Streptococcus iniae

    Science.gov (United States)

    Bioassay-guided fractionation of the ethyl acetate extract of Murraya koenegii (Rutaceae) leaves yielded isomahanine (1) and mahanine (2) with antibacterial activity towards bacteria species that cause columnaris disease and streptococcosis, common diseases in pond-raised channel catfish (Ictalurus ...

  19. Hematology and productive performance of nile tilapia (Oreochromis niloticus naturally infected with Flavobacterium columnare

    Directory of Open Access Journals (Sweden)

    F. A Sebastião

    2011-03-01

    Full Text Available Columnaris disease is one of the main causes of mortality in tilapia rearing and is responsible for large economic losses worldwide. Hematology is a tool that makes it possible to study organisms' physiological responses to pathogens. It may assist in making diagnoses and prognoses on diseases in fish populations. The hematological variables of nile tilapia were studied in specimens with a clinical diagnosis of columnaris disease and in specimens that were disease-free. The total erythrocyte count, hemoglobin rate, hematocrit percentage, mean corpuscular hemoglobin (MCH, mean corpuscular hemoglobin concentration (MCHC, mean corpuscular volume (MCV, organic defense blood cell percentages (leukocytes and thrombocytes and hepatosomatic and splenosomatic index were determined. The results showed that there were changes in the erythrocytic series and in organic defense blood cells, in the fish infected with the bacterium, with reductions in erythrocytic variables and significant increases in the numbers of circulating lymphocytes and neutrophils.

  20. Flavobacterium ceti sp. nov., isolated from beaked whales (Ziphius cavirostris).

    Science.gov (United States)

    Vela, A I; Fernandez, A; Sánchez-Porro, C; Sierra, E; Mendez, M; Arbelo, M; Ventosa, A; Domínguez, L; Fernández-Garayzábal, J F

    2007-11-01

    Three isolates of a Gram-negative, catalase- and oxidase-positive, rod-shaped bacterium, isolated from the lung and liver of two beaked whales, were characterized by phenotypic and molecular genetic methods. Based on cellular morphology and biochemical criteria, the isolates were tentatively assigned to the family Flavobacteriaceae, although they did not appear to correspond to any recognized species. Comparative 16S rRNA gene sequencing showed that the three new isolates shared 100% sequence similarity. The unknown bacterium was phylogenetically closely related to, but distinct from the type strains of Flavobacterium johnsoniae (93.7% sequence similarity), Flavobacterium frigidimaris (93.4%), Flavobacterium aquidurense (93.4%), Flavobacterium hibernum (93.4%) and Flavobacterium degerlachei (93.4%). The novel isolates were readily distinguished from these and other related Flavobacterium species by physiological and biochemical tests. On the basis of phenotypic and phylogenetic evidence, it is proposed that the unknown isolates from whales are classified as a novel species of the genus Flavobacterium, Flavobacterium ceti sp. nov. The type strain is 454-2T (=CECT 7184T=CCUG 52969T).

  1. Electron transport through monovalent atomic wires

    DEFF Research Database (Denmark)

    Lee, Y. J.; Brandbyge, Mads; Puska, M. J.

    2004-01-01

    Using a first-principles density-functional method we model electron transport through linear chains of monovalent atoms between two bulk electrodes. For noble-metal chains the transport resembles that for free electrons over a potential barrier whereas for alkali-metal chains resonance states...... at the chain determine the conductance. As a result, the conductance for noble-metal chains is close to one quantum of conductance, and it oscillates moderately so that an even number of chain atoms yields a higher value than an odd number. The conductance oscillations are large for alkali-metal chains...

  2. Production and targeting of monovalent quantum dots.

    Science.gov (United States)

    Seo, Daeha; Farlow, Justin; Southard, Kade; Jun, Young-Wook; Gartner, Zev J

    2014-10-23

    The multivalent nature of commercial quantum dots (QDs) and the difficulties associated with producing monovalent dots have limited their applications in biology, where clustering and the spatial organization of biomolecules is often the object of study. We describe here a protocol to produce monovalent quantum dots (mQDs) that can be accomplished in most biological research laboratories via a simple mixing of CdSe/ZnS core/shell QDs with phosphorothioate DNA (ptDNA) of defined length. After a single ptDNA strand has wrapped the QD, additional strands are excluded from the surface. Production of mQDs in this manner can be accomplished at small and large scale, with commercial reagents, and in minimal steps. These mQDs can be specifically directed to biological targets by hybridization to a complementary single stranded targeting DNA. We demonstrate the use of these mQDs as imaging probes by labeling SNAP-tagged Notch receptors on live mammalian cells, targeted by mQDs bearing a benzylguanine moiety.

  3. 21 CFR 866.3270 - Flavobacterium spp. serological reagents.

    Science.gov (United States)

    2010-04-01

    ... disease caused by bacteria belonging to the genus Flavobacterium and provides epidemiological information on diseases caused by these microorganisms. Most members of this genus are found in soil and...

  4. Monovalent copper-activated oxygenated insulators

    Science.gov (United States)

    Parent, C.; Boutinaud, P.; Flem, G. Le; Moine, B.; Pedrini, C.; Garcia, D.; Faucher, M.

    1994-12-01

    The photoluminescence of monovalent copper in oxygenated insulators has been extensively studied. The spectroscopy and the excited states dynamics of Cu + ions were investigated as a function of the copper concentration and temperature in various glassy and crystallized materials, essentially borates and phosphates. The broad band fluorescences observed in the visible range under UV excitation arise from two main emitting centers: isolated Cu + ions and (Cu +) 2 pairs. The spectroscopic characteristics of isolated Cu + depend strongly on the local structure, whereas those of the copper pairs remain nearly unaltered whatever the host-matrix. Energy diagrams are proposed for both centers, using ab initio LCAO calculations, in connection with structural investigations involving XRD, ND and EXAFS spectroscopies. Borate glasses can be considered as potential laser sources for tunable output in the whole visible range.

  5. Attraction between like-charged monovalent ions

    Science.gov (United States)

    Zangi, Ronen

    2012-05-01

    Ions with like-charges repel each other with a magnitude given by the Coulomb law. The repulsion is also known to persist in aqueous solutions albeit factored by the medium's dielectric constant. In this paper, we report results from molecular dynamics simulations of alkali halides salt solutions indicating an effective attraction between some of the like-charged monovalent ions. The attraction is observed between anions, as well as between cations, leading to the formation of dimers with lifetimes on the order of few picoseconds. Two mechanisms have been identified to drive this counterintuitive attraction. The first is exhibited by high-charge density ions, such as fluoride, at low salt concentrations, yielding effective attractions with magnitude up to the order of 1-2 kT. In this case, the stronger local electric field generated when the two ions are in contact augments the alignment of neighboring waters toward the ions. This results in a gain of substantial favorable ion-water interaction energy. For fluorides, this interaction constitutes the major change among the different energy components compensating for the anion-anion repulsion, and therefore, rendering like-charge association possible. The second mechanism involves mediation by counterions, the attractions increase with salt concentration and are characterized by small magnitudes. In particular, clusters of ion triplets, in which a counterion is either bridging the two like-charged ions or is paired to only one of them, are formed. Although these two mechanisms may not yield net attractions in many cases, they might still be operational and significant, explaining effective repulsions between like-charged ions with magnitudes much smaller than expected based on continuum electrostatics.

  6. Attraction between like-charged monovalent ions.

    Science.gov (United States)

    Zangi, Ronen

    2012-05-14

    Ions with like-charges repel each other with a magnitude given by the Coulomb law. The repulsion is also known to persist in aqueous solutions albeit factored by the medium's dielectric constant. In this paper, we report results from molecular dynamics simulations of alkali halides salt solutions indicating an effective attraction between some of the like-charged monovalent ions. The attraction is observed between anions, as well as between cations, leading to the formation of dimers with lifetimes on the order of few picoseconds. Two mechanisms have been identified to drive this counterintuitive attraction. The first is exhibited by high-charge density ions, such as fluoride, at low salt concentrations, yielding effective attractions with magnitude up to the order of 1-2 kT. In this case, the stronger local electric field generated when the two ions are in contact augments the alignment of neighboring waters toward the ions. This results in a gain of substantial favorable ion-water interaction energy. For fluorides, this interaction constitutes the major change among the different energy components compensating for the anion-anion repulsion, and therefore, rendering like-charge association possible. The second mechanism involves mediation by counterions, the attractions increase with salt concentration and are characterized by small magnitudes. In particular, clusters of ion triplets, in which a counterion is either bridging the two like-charged ions or is paired to only one of them, are formed. Although these two mechanisms may not yield net attractions in many cases, they might still be operational and significant, explaining effective repulsions between like-charged ions with magnitudes much smaller than expected based on continuum electrostatics.

  7. Flavobacterium panacis sp. nov., isolated from rhizosphere of Panax ginseng.

    Science.gov (United States)

    Kim, Dong Hyun; Singh, Priyanka; Farh, Mohamed El-Agamy; Kim, Yeon-Ju; Nguyen, Ngoc-Lan; Lee, Hyun A; Yang, Deok-Chun

    2016-09-01

    A novel bacterial strain, designated DCY106(T), was isolated from soil collected from the rhizosphere of ginseng (Panax ginseng), in Gochang, Republic of Korea. Strain DCY106(T) is Gram-negative, yellow-pigmented, non-flagellate, motile, non-spore-forming, rod-shaped, and strictly aerobic. The strain grows optimally at 25-30 °C and pH 6.5-7.5. Phylogenetically, strain DCY106(T) is closely related to Flavobacterium arsenitoxidans KCTC 22507(T) (98.41 %), followed by Flavobacterium cutihirudini LMG 26922(T) (97.67 %), Flavobacterium nitrogenifigens LMG 28694(T) (97.59 %), Flexibacter auranticus LMG 3987(T) (97.38 %), Flavobacterium defluvi KCTC 12612(T) (97.21 %) and Flavobacterium chilense LMG 26360(T) (97.05 %). The 16S rRNA gene sequence similarities to all other Flavobacterium species were below 97 %. The DNA G+C content of strain DCY106(T) is 34.2 mol% and the DNA-DNA relatedness between strain DCY106(T) and F. cutihirudini LMG 26922(T), F. auranticus LMG 3987(T), F. defluvi KCTC 12612(T) and F. chilense LMG 26360(T) were below 40.0 %. The menaquinone of the type MK-6 was found to be the predominant respiratory quinone. The major polar lipids were identified as phosphatidylethanolamine, phosphatidylserine, two unidentified aminolipids (APL1, APL6) and one unidentified lipid L2. C15:0, iso-C15:0 and summed feature 3 (iso-C15:0 2OH/C16:1 ω7c) were identified as the major fatty acids present in DCY106(T). The results of physiological and biochemical tests allowed strain DCY106(T) to be differentiated phenotypically from other recognized species belonging to the genus Flavobacterium. Therefore, it is suggested that the newly isolated organism represents a novel species, for which the name Flavobacterium panacis sp. nov. is proposed with the type strain designated as DCY106(T) (= JCM 31468(T)= KCTC 42747(T)).

  8. Recent results on some columnar paramagnetic metallomesogens

    Indian Academy of Sciences (India)

    W Haase; S Wrobel; K Falk

    2003-08-01

    The liquid crystalline and selected physical properties of some vanadyl and manganese(III)-porphyrin-TCNE complexes are discussed. These materials form linear chains from a magnetic point of view and columnar discotic LC phases. Some of the manganese complexes exhibit a bulk magnetic phase below ∼ 20 K. The discussed materials are studied by means of DSC, X-ray powder diffraction, dielectric spectroscopy, reversal current characterization and magnetic susceptibility measurements. A broader view on some physical properties of columnar paramagnetic metallomesogens is given.

  9. Columnar structure of SV40 minichromosome

    Directory of Open Access Journals (Sweden)

    Edward N Trifonov

    2015-07-01

    Full Text Available Like the sequence of the strongest 601 clone nucleosome of Lowary and Widom, the SV40 genome sequence contains tracks of YR dinucleotides separated by small integers of the 10.4n base series (10, 11, 21 and 30 bases. The tracks, however, substantially exceed the nucleosome DNA size and, thus, correspond to more extended structure - columnar chromatin. The micrococcal nuclease digests of the SV40 chromatin do not show uniquely positioned individual nucleosomes. This confirms the columnar structure of the minichromosome, as well as earlier electron microscopy studies.

  10. Complete genome sequence of the fish pathogen Flavobacterium branchiophilum.

    Science.gov (United States)

    Touchon, Marie; Barbier, Paul; Bernardet, Jean-François; Loux, Valentin; Vacherie, Benoit; Barbe, Valérie; Rocha, Eduardo P C; Duchaud, Eric

    2011-11-01

    Members of the genus Flavobacterium occur in a variety of ecological niches and represent an interesting diversity of lifestyles. Flavobacterium branchiophilum is the main causative agent of bacterial gill disease, a severe condition affecting various cultured freshwater fish species worldwide, in particular salmonids in Canada and Japan. We report here the complete genome sequence of strain FL-15 isolated from a diseased sheatfish (Silurus glanis) in Hungary. The analysis of the F. branchiophilum genome revealed putative mechanisms of pathogenicity strikingly different from those of the other, closely related fish pathogen Flavobacterium psychrophilum, including the first cholera-like toxin in a non-Proteobacteria and a wealth of adhesins. The comparison with available genomes of other Flavobacterium species revealed a small genome size, large differences in chromosome organization, and fewer rRNA and tRNA genes, in line with its more fastidious growth. In addition, horizontal gene transfer shaped the evolution of F. branchiophilum, as evidenced by its virulence factors, genomic islands, and CRISPR (clustered regularly interspaced short palindromic repeats) systems. Further functional analysis should help in the understanding of host-pathogen interactions and in the development of rational diagnostic tools and control strategies in fish farms.

  11. Deformation strain inhomogeneity in columnar grain nickel

    DEFF Research Database (Denmark)

    Wu, G.L.; Godfrey, A.; Juul Jensen, D.

    2005-01-01

    A method is presented for determination of the local deformation strain of individual grains in the bulk of a columnar grain sample. The method, based on measurement of the change in grain area of each grain, is applied to 12% cold rolled nickel. Large variations are observed in the local strain...

  12. Dressed counterions: Polyvalent and monovalent ions at charged dielectric interfaces

    Science.gov (United States)

    Kanduč, Matej; Naji, Ali; Forsman, Jan; Podgornik, Rudolf

    2011-07-01

    We investigate the ion distribution and overcharging at charged interfaces with dielectric inhomogeneities in the presence of asymmetric electrolytes containing polyvalent and monovalent ions. We formulate an effective “dressed counterion” approach by integrating out the monovalent salt degrees of freedom and show that it agrees with results of explicit Monte Carlo simulations. We then apply the dressed counterion approach within the framework of the generalized strong-coupling theory, valid for polyvalent ions at low concentrations, which enables an analytical description for salt effects as well as dielectric inhomogeneities in the limit of strong Coulomb interactions. Limitations and applicability of this theory are examined by comparing the results with simulations.

  13. Torsional fluctuations in columnar DNA assemblies

    CERN Document Server

    Lee, D J

    2005-01-01

    In columnar assemblies of helical bio-molecules the azimuthal degrees of freedom, i.e. rotations about the long axes of molecules, may be important in determining the structure of the assemblies especially when the interaction energy between neighbouring molecules explicitly depends on their relative azimuthal orientations. For DNA this leads to a rich variety of mesophases for columnar assemblies, each categorized by a specific azimuthal ordering. In a preceding paper [A. Wynveen, D. J. Lee, and A. A. Kornyshev, Eur. Phys. J. E, 16, 303 (2005)] a statistical mechanical theory was developed for the assemblies of torsionally rigid molecues in order to determine how thermal fluctuations influence the structure of these mesophases. Here we extend this theory by including torsional fluctuations of the molecules, where a DNA molecule may twist about its long axis at the cost of torsional elastic energy. Comparing this with the previous study, we find that inclusion of torsional fluctuations further increases the d...

  14. Pathogenesis of columnar-lined esophagus

    Institute of Scientific and Technical Information of China (English)

    Kamal E Bani-Hani; Bayan K Bani-Hani

    2006-01-01

    Since its initial description, the pathogenesis of the columnar-lined esophagus (CLE) has been surrounded by many controversies. The first controversy is related to the existence of the condition itself. The second controversy centers on whether the CLE is a congenital or an acquired condition. In this article, we review the congenital and acquired theories of development of CLE and discuss the various factors in acquisition of CLE. The bulk of evidence in the literature suggests that CLE is an acquired condition.

  15. Potential of Flavobacterium as Biofertilizer to Increase Wheat Yield

    Directory of Open Access Journals (Sweden)

    H. Asadi Rahmani

    2016-10-01

    Full Text Available Intoduction: Plant growth promoting rhizobacteria (PGPR are a diverse group of bacteria consisting different species like Pseudomonas, Azotobacter, Azospirillum, Flavobacterium, Bacillus and Serratia with ability of enhancing plant growth and yield by different mechanisms. Flavobacteria are aerobic, gram negative, rod shape bacteria with more than 100 species living in different habitats ranging from soil and water to the foods. There are reports indicating that Flavobacteria are of dominant rhizosphere bacteria with beneficial effects on agricultural crops. Studies in Iran showed that six species of Flavobacterium were isolated and identified from rhizosphere of wheat. The aim of this study was to evaluate the effect of four strains of Flavobacterium on growth and yield of wheat under field conditions. Materials and Methods: In this study four strains of Flavobacterium F9, F11, F21 and F40 were used. Bacterial strains were propagated in liquid NB growth medium and were used in field experiments. Fields were prepared in Khorasan Razavi, Khuzestan, Fars, Mazandran and Kermanshah and wheat seeds were inoculated with strains and sowed in a randomized complete block design (RCBD with five treatments (four strains and a un-inoculated control with four replications. Wheat varieties were Pishtaz in Khorasan and Fars, Marvdasht in Kermanshah, Chamran in Khuzestan and Milan in Mazandaran. Chemical fertilizers were used based on soil analysis. The rate of inoculation was 10 ml of bacteria per kg of seed. Plants were harvested at the end of the experiment and seed yield, total shoot biomass, 1000-seed weight, plant height, number of panicles per m2, number of seeds per panicle and panicle length were measured. Data analysis was performed by SPSS software, and the means were compared at α꞊5% by Duncan test. Results and discussion: Results of the study showed that bacterial strains increased growth and yield of wheat in all provinces. In Mazandaran, all

  16. Reversal mechanism in perpendicular media with columnar structure

    NARCIS (Netherlands)

    Wielinga, T.; Lodder, J.C.

    1986-01-01

    A contribution is given to the discussion concerning the nature of the magnetization reversal process in sputtered CoCr recording media with columnar morphology. The paper is restricted to the additional effects on the total perpendicular anisotropy by studying the columnar shape anisotropy and the

  17. High-frequency micromechanical columnar resonators

    Directory of Open Access Journals (Sweden)

    Jenny Kehrbusch, Elena A Ilin, Peter Bozek, Bernhard Radzio and Egbert Oesterschulze

    2009-01-01

    Full Text Available High-frequency silicon columnar microresonators are fabricated using a simple but effective technological scheme. An optimized fabrication scheme was invented to obtain mechanically protected microcolumns with lateral dimensions controlled on a scale of at least 1 μm. In this paper, we investigate the influence of the environmental conditions on the mechanical resonator properties. At ambient conditions, we observed a frequency stability δf/f of less than 10−6 during 5 h of operation at almost constant temperature. However, varying the temperature shifts the frequency by approximately −173 Hz °C− 1. In accordance with a viscous damping model of the ambient gas, we perceived that the quality factor of the first flexural mode decreased with the inverse of the square root of pressure. However, in the low-pressure regime, a linear dependence was observed. We also investigated the influence of the type of the immersing gas on the resonant frequency.

  18. Polarized spectral complexes of optical functions of monovalent mercury iodide

    Science.gov (United States)

    Sobolev, V. V.; Sobolev, V. Val.; Anisimov, D. V.

    2015-12-01

    Spectral complexes of optical functions of monovalent mercury iodide Hg2I2 were determined for E ⊥ c and E || c polarizations in the range from 2 to 5.5 eV at 4.2 K. The permittivity and characteristic electron energy loss spectra were expanded in simple components with the determination of their main parameters, including the energy of the maximum and the oscillator strength. The calculations were performed based on known reflectance spectra. Computer programs based on Kramers-Kronig relations and the improved parameter-free method of Argand diagrams were used.

  19. Comparative Genome Analysis Provides Insights into the Pathogenicity of Flavobacterium psychrophilum

    DEFF Research Database (Denmark)

    Castillo, Daniel; Christiansen, Rói Hammershaimb; Dalsgaard, Inger

    2016-01-01

    Flavobacterium psychrophilum is a fish pathogen in salmonid aquaculture worldwide that causes cold water disease (CWD) and rainbow trout fry syndrome (RTFS). Comparative genome analyses of 11 F. psychrophilum isolates representing temporally and geographically distant populations were used to des...

  20. CARACTERIZACION DE CEPAS CHILENAS DE FLAVOBACTERIUM PSYCHROPHILUM Y SENSIBILIDAD A ANTIMICROBIANOS.

    OpenAIRE

    RIOFRIO MONTERO, ANDRES PATRICIO

    2002-01-01

    Flavobacterium psychrophilum (Bernardet y col., 1996), anteriormente denominada Flexibacter psychrophilus (Bernardet y Grimont, 1989) y Cytophaga psychrophila (Baudin-Laurencin y col., 1989), es un importante patógeno de peces de agua dulce, ampliamente d 146p.

  1. Lyotropic hexagonal columnar liquid crystals of large colloidal gibbsite platelets

    NARCIS (Netherlands)

    Mourad, M.C.D.; Petukhov, A.V.; Vroege, G.J.; Lekkerkerker, H.N.W.

    2010-01-01

    We report the formation of hexagonal columnar liquid crystal phases in suspensions of large (570 nm diameter), sterically stabilized, colloidal gibbsite platelets in organic solvent. In thin cells these systems display strong iridescence originating from hexagonally arranged columns that are

  2. Antimicrobial resistance patterns in Danish isolates of Flavobacterium psychrophilum

    DEFF Research Database (Denmark)

    Bruun, Morten Sichlau; Schmidt, A.S.; Madsen, Lone

    2000-01-01

    were tested and the resulting antibiograms were used to predict the theoretical therapeutic efficacy and to evaluate if resistance had changed as a course of time. Antimicrobial agents included in this investigation were oxolinic acid (OXA), amoxicillin (AMX), potentiated sulfadiazine, oxytetracycline......The resistance pattern of Flavobacterium psychrophilum to the antimicrobial agents used in fish farming in Denmark was assessed in vitro using an agar dilution method. After identification of 387 isolates from clinical outbreaks of rainbow trout fry syndrome (RTFS) and the environment, the isolates...... (OTC) and florfenicol (FLO). We found that F. psychrophilum isolates divided in susceptible and resistant clusters reflecting the reduced efficacy in practice when using OTC and AMX. The most recent isolates were less susceptible to AMX and OXA, whereas resistance to OTC seemed stable over the last 5...

  3. Purification and properties of elastolytic enzyme from Flavobacterium immotum.

    Science.gov (United States)

    Ozaki, H; Shiio, I

    1975-01-01

    Elastolytic enzyme was purified and crystallized from culture fluid of Flavobacterium immotum No. 9-35. The purified enzyme was homogeneous on polyacrylamide gel electrophoresis. The molecular weight was determined by Sephadex G-100 gel filtration to be 13,000. The isoelectric point was between pH 8.3 and 8.9. The optimum pH of the enzyme was 7.2 for elastolytic activity. The purified enzyme showed not only elastolytic activity, but also non-specific proteolytic activity against various other proteins. Milk-clotting activity was also observed. The enzyme did not act on keratin, collagen, or fourteen amino acid esters, including N-benzoyl-L-alanine methyl ester, N-benzoyl-L-arginine ethyl ester, and N-acetyl-L-tyrosine ethyl ester, which were typical substrates of pancreatic elastase [EC 3.4.21.11], trypsin [EC 3.4.21.4], and chymotrypsin [EC 3.4.21.1], respectively. However, the enzyme selectively hydrolyzed elastin when both elastin and albumin were present in the reaction mixture. The enzyme was inhibited by o-phenanthroline and various heavy metals such as cadmium, lead, zinc, and mercury. Various inhibitors, such as diisopropyl phosphofluoridate, tosyl-L-lysine chloromethyl ketone, tosyl-L-phenylalanine chloromethyl ketone, trypsin inhibitor, iodoacetamide, etc., had no effect on the elastolytic activity.

  4. Genomic diversity of bacteriophages infecting the fish pathogen Flavobacterium psychrophilum.

    Science.gov (United States)

    Castillo, Daniel; Middelboe, Mathias

    2016-12-01

    Bacteriophages infecting the fish pathogen Flavobacterium psychrophilum can potentially be used to prevent and control outbreaks of this bacterium in salmonid aquaculture. However, the application of bacteriophages in disease control requires detailed knowledge on their genetic composition. To explore the diversity of F. pyschrophilum bacteriophages, we have analyzed the complete genome sequences of 17 phages isolated from two distant geographic areas (Denmark and Chile), including the previously characterized temperate bacteriophage 6H. Phage genome size ranged from 39 302 to 89 010 bp with a G+C content of 27%-32%. None of the bacteriophages isolated in Denmark contained genes associated with lysogeny, whereas the Chilean isolates were all putative temperate phages and similar to bacteriophage 6H. Comparative genome analysis showed that phages grouped in three different genetic clusters based on genetic composition and gene content, indicating a limited genetic diversity of F. psychrophilum-specific bacteriophages. However, amino acid sequence dissimilarity (25%) was found in putative structural proteins, which could be related to the host specificity determinants. This study represents the first analysis of genomic diversity and composition among bacteriophages infecting the fish pathogen F. psychrophilum and discusses the implications for the application of phages in disease control. © FEMS 2016. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

  5. Production of viable cultures of Flavobacterium psychrophilum: approach and control.

    Science.gov (United States)

    Michel, C; Antonio, D; Hedrick, R P

    1999-06-01

    Although the fish pathogen Flavobacterium psychrophilum is a major source of concern in salmonid hatcheries, few studies have been conducted on its pathogenicity. Difficulties are often experienced when trying to control or quantify standard procedures for in vitro culture of the bacterium. Plate enumeration and counting chamber enumeration combined with epifluorescent microscopy with fluorescent dyes determined that no more than 25% of the bacterial cells present in the cultures were able to produce colonies on agar media. This was strongly dependent upon different medium components. Tryptone-enriched Anacker and Ordal medium proved more suitable than tryptone-yeast extract-salts with skimmed milk. Adding horse serum and trace elements in controlled proportions offered the most reproducible results. Viable but nonculturable forms were apparently not responsible for the difficulties in production of F. psychrophilum, but the cells were highly susceptible to osmotic conditions. Improvements in the media and careful handling of the bacteria in isotonic suspension media resulted in predictable production of viable bacteria and allowed an absorbance/colony-forming-units relation curve to be established.

  6. Population Structure of the Fish-Pathogenic Bacterium Flavobacterium psychrophilum▿

    Science.gov (United States)

    Nicolas, Pierre; Mondot, Stanislas; Achaz, Guillaume; Bouchenot, Catherine; Bernardet, Jean-François; Duchaud, Eric

    2008-01-01

    Flavobacterium psychrophilum is currently one of the main bacterial pathogens hampering the productivity of salmonid farming worldwide, and its control mainly relies on antibiotic treatments. To better understand the population structure of this bacterium and its mode of evolution, we have examined the nucleotide polymorphisms at 11 protein-coding loci of the core genome in a set of 50 isolates. These isolates were selected to represent the broadest possible diversity, originating from 10 different host fish species and four continents. The nucleotide diversity between pairs of sequences amounted to fewer than four differences per kilobase on average, corresponding to a particularly low level of diversity, possibly indicative of a small effective-population size. The recombination rate, however, seemed remarkably high, and as a consequence, most of the isolates harbored unique combinations of alleles (33 distinct sequence types were resolved). The analysis also showed the existence of several clonal complexes with worldwide geographic distribution but marked association with particular fish species. Such an association could reflect preferential routes of transmission and/or adaptive niche specialization. The analysis provided no clues that the initial range of the bacterium was originally limited to North America. Instead, the historical record of the expansion of the pathogen may reflect the spread of a few clonal complexes. As a resource for future epidemiological surveys, a multilocus sequence typing website based on seven highly informative loci is available. PMID:18424537

  7. Solute distribution in columnar crystal zone of continuous casting billets

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    The periodic bending deformation in the direction of casting occurs at the liquid/solid interface of billet due to the roller supporting force and the pressure of molten metal in the process of continuous casting. Based on this fact, a qualitative expression of solute concentration in columnar crystal zone for continuous casting billet is established, which agrees with the experimental results basically. Therefore, it is favorable to gain a columnar structure with less segregation by adopting a caster with compactly distributed small rollers and enhancing the cooling intensity in secondary-cooling zone.

  8. Mid-Esophagus Columnar Metaplasia: What Is the Biopathogenic Pathway?

    Science.gov (United States)

    Rolim, Inês; Rodrigues, Rita Vale; Bettencourt, António; Barros, Rita; Camilo, Vânia; Dias Pereira, António; Almeida, Raquel; Chaves, Paula

    2016-10-05

    We report a case of metaplastic columnar epithelium in the mid-esophagus in a patient with history of caustic ingestion. A cardiac-type gastric phenotype, with early signs of intestinalization, was confirmed by immunohistochemistry studies (MUC5AC, MUC6, SOX2, and CDX2). Nonmetaplastic mucosa had histologic evidence of gastroesophageal reflux. In this case, esophageal reepithelization seems to have been modulated by acidic gastroesophageal reflux, which might activate transcription factors leading to phenotypic reprogramming of the regenerative epithelium. Most interestingly, it is a clinical example showcasing the origin of columnar metaplasia from stem cells located within the esophageal epithelium.

  9. Activation and inhibition of histone deacetylase 8 by monovalent cations.

    Science.gov (United States)

    Gantt, Stephanie L; Joseph, Caleb G; Fierke, Carol A

    2010-02-26

    The metal-dependent histone deacetylases (HDACs) catalyze hydrolysis of acetyl groups from acetyllysine side chains and are targets of cancer therapeutics. Two bound monovalent cations (MVCs) of unknown function have been previously observed in crystal structures of HDAC8; site 1 is near the active site, whereas site 2 is located > 20 A from the catalytic metal ion. Here we demonstrate that one bound MVC activates catalytic activity (K(1/2) = 3.4 mM for K(+)), whereas the second, weaker-binding MVC (K(1/2) = 26 mM for K(+)) decreases catalytic activity by 11-fold. The weaker binding MVC also enhances the affinity of the HDAC inhibitor suberoylanilide hydroxamic acid by 5-fold. The site 1 MVC is coordinated by the side chain of Asp-176 that also forms a hydrogen bond with His-142, one of two histidines important for catalytic activity. The D176A and H142A mutants each increase the K(1/2) for potassium inhibition by > or = 40-fold, demonstrating that the inhibitory cation binds to site 1. Furthermore, the MVC inhibition is mediated by His-142, suggesting that this residue is protonated for maximal HDAC8 activity. Therefore, His-142 functions either as an electrostatic catalyst or a general acid. The activating MVC binds in the distal site and causes a time-dependent increase in activity, suggesting that the site 2 MVC stabilizes an active conformation of the enzyme. Sodium binds more weakly to both sites and activates HDAC8 to a lesser extent than potassium. Therefore, it is likely that potassium is the predominant MVC bound to HDAC8 in vivo.

  10. Numerical simulation and rational design of optically anisotropic columnar films

    Science.gov (United States)

    Leontyev, Viktor A.; Hawkeye, Matthew M.; Wakefield, Nicholas G.; Tabunshchyk, Kyrylo; Sit, Jeremy C.; Kovalenko, Andriy; Brett, Michael J.

    2011-03-01

    Optical anisotropy is an inherent property of columnar dielectric films, such as those fabricated by the glancing angle deposition (GLAD) technique. This process utilizes physical vapor deposition combined with computer-controlled substrate motion to finely tune the direction of column growth and vital morphological parameters such as column cross-section and inter-columnar spacing. Control over the anisotropic properties of the porous film provides an opportunity to design polarization-selective photonic devices and films with improved band gap properties. Anisotropic defects in multilayer films also result in a polarization-sensitive position of resonant transmission modes. We employed the finite-difference time-domain and frequency-domain methods to theoretically analyze and design columnar films with unique band-gap properties. The following morphologies were considered: (i) S-shaped columnar films with polarization-dependent band-gap position and width. Using numerical simulations we have shown that the competitive effect of different sources of anisotropy can be used to engineer photonic band gaps with strong selectivity to linearly-polarized light; (ii) Rugate thin films with an anisotropic defect, which exhibit resonant mode splitting. Optical devices were fabricated using titanium dioxide because it has good transparency in the visible range of the optical spectrum and a large bulk refractive index. Experimental results were compared to simulations to verify the designs and understand the limitations of the fabrication process.

  11. Columnar architecture improves noise robustness in a model cortical network.

    Directory of Open Access Journals (Sweden)

    Paul C Bush

    Full Text Available Cortical columnar architecture was discovered decades ago yet there is no agreed upon explanation for its function. Indeed, some have suggested that it has no function, it is simply an epiphenomenon of developmental processes. To investigate this problem we have constructed a computer model of one square millimeter of layer 2/3 of the primary visual cortex (V1 of the cat. Model cells are connected according to data from recent paired cell studies, in particular the connection probability between pyramidal cells is inversely proportional both to the distance separating the cells and to the distance between the preferred parameters (features of the cells. We find that these constraints, together with a columnar architecture, produce more tightly clustered populations of cells when compared to the random architecture seen in, for example, rodents. This causes the columnar network to converge more quickly and accurately on the pattern representing a particular stimulus in the presence of noise, suggesting that columnar connectivity functions to improve pattern recognition in cortical circuits. The model also suggests that synaptic failure, a phenomenon exhibited by weak synapses, may conserve metabolic resources by reducing transmitter release at these connections that do not contribute to network function.

  12. Loading-unloading test analysis of anisotropic columnar jointed basalts

    Institute of Scientific and Technical Information of China (English)

    Zhi-gang SHAN; Sheng-jie DI

    2013-01-01

    To evaluate the columnar jointed basalts in the dam site of Baihetan hydropower station in southwest China,we developed a basic conceptual model of single jointed rock mass.Considering that the rock mass deformation consists of rock block deformation and joints deformation,the linear mechanical characteristics of the cell(including the elastic joints and the nonlinear mechanical behaviors of the cell)with a combined frictional-elastic interface were analyzed.We developed formulas to calculate the rock block deformation,which can be adapted for multiple jointed rock mass and columnar jointed basalts.The formulas are effective in calculating the equivalent modulus of multiple jointed rock mass,and precisely reveal the anisotropic properties of columnar jointed basalts.Furthermore,the in situ rigid bearing plate tests were analyzed and calculated,and the types of loading-unloading curves and the equivalent modulus along different directions of columnar jointed basalts were obtained.The analytical results are in close compliance with the test results.

  13. Flavobacterium ahnfeltiae sp. nov., a new marine polysaccharide-degrading bacterium isolated from a Pacific red alga.

    Science.gov (United States)

    Nedashkovskaya, Olga I; Balabanova, Larissa A; Zhukova, Natalia V; Kim, So-Jeong; Bakunina, Irina Y; Rhee, Sung-Keun

    2014-10-01

    A Gram-negative, aerobic, rod-shaped, motile by gliding and yellow-pigmented bacterium, designated strain 10Alg 130(T), that displayed the ability to destroy polysaccharides of red and brown algae, was isolated from the red alga Ahnfeltia tobuchiensis. The phylogenetic analysis based on 16S rRNA gene sequence placed the novel strain within the genus Flavobacterium, the type genus of the family Flavobacteriaceae, the phylum Bacteroidetes, with sequence similarities of 96.2 and 95.7 % to Flavobacterium jumunjiense KCTC 23618(T) and Flavobacterium ponti CCUG 58402(T), and 95.3-92.5 % to other recognized Flavobacterium species. The prevalent fatty acids of strain 10Alg 130(T) were iso-C15:0, iso-C15:0 3-OH, iso-C17:0 3-OH, C15:0 and iso-C17:1ω9c. The polar lipid profile consisted of phosphatidylethanolamine, two unknown aminolipids and three unknown lipids. The DNA G+C content of the type strain was 34.3 mol%. The new isolate and the type strains of recognized species of the genus Flavobacterium could strongly be distinguished by a number of phenotypic characteristics. A combination of the genotypic and phenotypic data showed that the algal isolate represents a novel species of the genus Flavobacterium, for which the name Flavobacterium ahnfeltiae sp. nov. is proposed. The type strain is 10Alg 130(T) (=KCTC 32467(T) = KMM 6686(T)).

  14. Selective removal of arsenic and monovalent ions from brackish water reverse osmosis concentrate.

    Science.gov (United States)

    Xu, Pei; Capito, Marissa; Cath, Tzahi Y

    2013-09-15

    Concentrate disposal and management is a considerable challenge for the implementation of desalination technologies, especially for inland applications where concentrate disposal options are limited. This study has focused on selective removal of arsenic and monovalent ions from brackish groundwater reverse osmosis (RO) concentrate for beneficial use and safe environmental disposal using in situ and pre-formed hydrous ferric oxides/hydroxides adsorption, and electrodialysis (ED) with monovalent permselective membranes. Coagulation with ferric salts is highly efficient at removing arsenic from RO concentrate to meet a drinking water standard of 10 μg/L. The chemical demand for ferric chloride however is much lower than ferric sulfate as coagulant. An alternative method using ferric sludge from surface water treatment plant is demonstrated as an efficient adsorbent to remove arsenic from RO concentrate, providing a promising low cost, "waste treat waste" approach. The monovalent permselective anion exchange membranes exhibit high selectivity in removing monovalent anions over di- and multi-valent anions. The transport of sulfate and phosphate through the anion exchange membranes was negligible over a broad range of electrical current density. However, the transport of divalent cations such as calcium and magnesium increases through monovalent permselective cation exchange membranes with increasing current density. Higher overall salt concentration reduction is achieved around limiting current density while higher normalized salt removal rate in terms of mass of salt per membrane area and applied energy is attained at lower current density because the energy unitization efficiency decreases at higher current density.

  15. Enrichment and isolation of Flavobacterium strains with tolerance to high concentrations of cesium ion.

    Science.gov (United States)

    Kato, Souichiro; Goya, Eri; Tanaka, Michiko; Kitagawa, Wataru; Kikuchi, Yoshitomo; Asano, Kozo; Kamagata, Yoichi

    2016-02-17

    Interest in the interaction of microorganisms with cesium ions (Cs(+)) has arisen, especially in terms of their potent ability for radiocesium bioaccumulation and their important roles in biogeochemical cycling. Although high concentrations of Cs(+) display toxic effects on microorganisms, there have been only limited reports for Cs(+)-tolerant microorganisms. Here we report enrichment and isolation of Cs(+)-tolerant microorganisms from soil microbiota. Microbial community analysis revealed that bacteria within the phylum Bacteroidetes, especially Flavobacterium spp., dominated in enrichment cultures in the medium supplemented with 50 or 200 mM Cs(+), while Gammaproteobacteria was dominant in the control enrichment cultures (in the presence of 50 and 200 mM K(+) instead of Cs(+)). The dominant Flavobacterium sp. was successfully isolated from the enrichment culture and was closely related to Flavobacterium chungbukense with 99.5% identity. Growth experiments clearly demonstrated that the isolate has significantly higher tolerance to Cs(+) compared to its close relatives, suggesting the Cs(+)-tolerance is a specific trait of this strain, but not a universal trait in the genus Flavobacterium. Measurement of intracellular K(+) and Cs(+) concentrations of the Cs(+)-tolerant isolate and its close relatives suggested that the ability to maintain low intracellular Cs(+) concentration confers the tolerance against high concentrations of external Cs(+).

  16. Combining Suppression Subtractive Hybridization and Microarrays To Map the Intraspecies Phylogeny of Flavobacterium psychrophilum

    OpenAIRE

    Soule, Marilyn; Cain, Kenneth; Lafrentz, Stacey; Douglas R. Call

    2005-01-01

    Reciprocal subtractive libraries were prepared for two strains of Flavobacterium psychrophilum, one virulent and the other avirulent in a trout challenge model. Unique clones were sequenced and their distribution assessed among 34 strains. The analysis showed that F. psychrophilum is composed of two genetic lineages, possibly reflecting host specificity.

  17. Effect of Bacteriophages on the Growth of Flavobacterium psychrophilum and Development of Phage-Resistant Strains

    DEFF Research Database (Denmark)

    Christiansen, Rói Hammershaimb; Madsen, Lone; Dalsgaard, Inger;

    2016-01-01

    The controlling effect of single and multiple phages on the density of Flavobacterium psychrophilum at different initial multiplicity of infection (MOI) was assessed in batch cultures to explore the potential for phage-based treatment of this important fish pathogen. A high initial phage concentr...

  18. Utilization of oligo- and polysaccharides at microgram-per-litre levels in freshwater by Flavobacterium johnsoniae

    NARCIS (Netherlands)

    Sack, E.L.W.; Wielen, van der P.W.J.J.; Kooij, van der D.

    2010-01-01

    Aims: To obtain a bacterial strain that can be used to quantify biodegradable polysaccharides at concentrations of a few micrograms per litre in freshwater. Methods and Results: Flavobacterium johnsoniae strain A3 was isolated from tap water supplemented with laminarin, pectin or amylopectin at 100

  19. A thermostable serralysin inhibitor from marine bacterium Flavobacterium sp. YS-80-122

    Science.gov (United States)

    Liang, Pengjuan; Li, Shangyong; Wang, Kun; Wang, Fang; Xing, Mengxin; Hao, Jianhua; Sun, Mi

    2017-06-01

    Serralysin inhibitors have been proposed as potent drugs against many diseases and may help to prevent further development of antibiotic-resistant pathogenic bacteria. In this study, a novel serralysin inhibitor gene, lupI, was cloned from the marine bacterium Flavobacterium sp. YS-80-122 and expressed in Escherichia coli. The deduced serralysin inhibitor, LupI, shows infections.

  20. Complete Genome Sequence of the Fish Pathogen Flavobacterium branchiophilum▿†

    Science.gov (United States)

    Touchon, Marie; Barbier, Paul; Bernardet, Jean-François; Loux, Valentin; Vacherie, Benoit; Barbe, Valérie; Rocha, Eduardo P. C.; Duchaud, Eric

    2011-01-01

    Members of the genus Flavobacterium occur in a variety of ecological niches and represent an interesting diversity of lifestyles. Flavobacterium branchiophilum is the main causative agent of bacterial gill disease, a severe condition affecting various cultured freshwater fish species worldwide, in particular salmonids in Canada and Japan. We report here the complete genome sequence of strain FL-15 isolated from a diseased sheatfish (Silurus glanis) in Hungary. The analysis of the F. branchiophilum genome revealed putative mechanisms of pathogenicity strikingly different from those of the other, closely related fish pathogen Flavobacterium psychrophilum, including the first cholera-like toxin in a non-Proteobacteria and a wealth of adhesins. The comparison with available genomes of other Flavobacterium species revealed a small genome size, large differences in chromosome organization, and fewer rRNA and tRNA genes, in line with its more fastidious growth. In addition, horizontal gene transfer shaped the evolution of F. branchiophilum, as evidenced by its virulence factors, genomic islands, and CRISPR (clustered regularly interspaced short palindromic repeats) systems. Further functional analysis should help in the understanding of host-pathogen interactions and in the development of rational diagnostic tools and control strategies in fish farms. PMID:21926215

  1. Deciphering the biodiversity of fish-pathogenic Flavobacterium spp. recovered from the Great Lakes basin.

    Science.gov (United States)

    Loch, Thomas P; Faisal, Mohamed

    2014-11-13

    Flavobacterial diseases negatively impact wild and cultured fishes worldwide. We recently reported on the presence of a large and diverse group of flavobacteria, many of which were associated with lesions in a number of Great Lakes fish species. Herein, we report on the characterization of 65 fish-associated Flavobacterium spp. isolates using 16S rRNA gene sequence analysis and phylogenetic analyses based upon neighbor-joining and Bayesian methodologies. Thirteen isolates were identified as the newly described fish-associated F. plurextorum, F. spartansii, and F. tructae, while 3 isolates were similar to F. frigidimaris; however, the remaining Flavobacterium spp. isolates did not conclusively match any described Flavobacterium spp. and thus were suspected as comprising novel flavobacterial species. A more comprehensive polyphasic characterization was undertaken on 6 isolates, representing a range of association with disease signs in hatchery-raised or free-ranging fish and genetic distinctness. Polyphasic characterization included physiological, morphological, and biochemical analyses, as well as additional phylogenetic analyses based upon near-complete sequencing of the 16S rRNA gene. Our findings demonstrated that that at least 5 of the 6 isolates are most likely novel species within the genus Flavobacterium that have never before been reported from fish. Pilot experimental challenge studies suggested that some of these Flavobacterium spp. can cause pathological lesions in fish and were re-isolated from the brains, spleens, livers, and kidneys of experimentally infected fish. The findings underscore the growing number and heterogeneity of flavobacteria now known to be capable of infecting fish.

  2. Neutralizing capacity of a new monovalent anti-Bothrops atrox antivenom: comparison with two commercial antivenoms

    Directory of Open Access Journals (Sweden)

    R. Otero

    1997-03-01

    Full Text Available Three horse-derived antivenoms were tested for their ability to neutralize lethal, hemorrhagic, edema-forming, defibrinating and myotoxic activities induced by the venom of Bothrops atrox from Antioquia and Chocó (Colombia. The following antivenoms were used: a polyvalent (crotaline antivenom produced by Instituto Clodomiro Picado (Costa Rica, b monovalent antibothropic antivenom produced by Instituto Nacional de Salud-INS (Bogotá, and c a new monovalent anti-B. atrox antivenom produced with the venom of B. atrox from Antioquia and Chocó. The three antivenoms neutralized all toxic activities tested albeit with different potencies. The new monovalent anti-B. atrox antivenom showed the highest neutralizing ability against edema-forming and defibrinating effects of B. atrox venom (41 ± 2 and 100 ± 32 µl antivenom/mg venom, respectively, suggesting that it should be useful in the treatment of B. atrox envenomation in Antioquia and Chocó

  3. Predicting 3D Structure, Flexibility, and Stability of RNA Hairpins in Monovalent and Divalent Ion Solutions

    Science.gov (United States)

    Shi, Ya-Zhou; Jin, Lei; Wang, Feng-Hua; Zhu, Xiao-Long; Tan, Zhi-Jie

    2015-01-01

    A full understanding of RNA-mediated biology would require the knowledge of three-dimensional (3D) structures, structural flexibility, and stability of RNAs. To predict RNA 3D structures and stability, we have previously proposed a three-bead coarse-grained predictive model with implicit salt/solvent potentials. In this study, we further develop the model by improving the implicit-salt electrostatic potential and including a sequence-dependent coaxial stacking potential to enable the model to simulate RNA 3D structure folding in divalent/monovalent ion solutions. The model presented here can predict 3D structures of RNA hairpins with bulges/internal loops (RNA hairpins with bulge loops of different lengths at several divalent/monovalent ion conditions. In addition, the model successfully predicts the stability of RNA hairpins with various loops/stems in divalent/monovalent ion solutions. PMID:26682822

  4. Columnar mesophases of hexabenzocoronene derivatives. II. Charge carrier mobility

    Science.gov (United States)

    Kirkpatrick, James; Marcon, Valentina; Kremer, Kurt; Nelson, Jenny; Andrienko, Denis

    2008-09-01

    Combining atomistic molecular dynamic simulations, Marcus-Hush theory description of charge transport rates, and master equation description of charge dynamics, we correlate the temperature-driven change of the mesophase structure with the change of charge carrier mobilities in columnar phases of hexabenzocoronene derivatives. The time dependence of fluctuations in transfer integrals shows that static disorder is predominant in determining charge transport characteristics. Both site energies and transfer integrals are distributed because of disorder in the molecular arrangement. It is shown that the contributions to the site energies from polarization and electrostatic effects are of opposite sign for positive charges. We look at three mesophases of hexabenzocoronene: herringbone, discotic, and columnar disordered. All results are compared to time resolved microwave conductivity data and show excellent agreement with no fitting parameters.

  5. Periodically patterned columnar thin films as Blazed gratings

    CERN Document Server

    Dutta, Jhuma; Lakhtakia, Akhlesh

    2012-01-01

    Periodically patterned columnar thin films (PP-CTFs) were made by evaporating CaF2 and directing the vapor flux obliquely towards lithographically fabricated micrometer/sub-micrometer gratings. The growth of the PP-CTFs was controlled by the deposition rate to form prismatic air cavities within them and they function like blazed diffraction gratings with asymmetric diffraction patterns and diffraction efficiencies upto 52% in transmission at visible wavelengths. Scalar diffraction theory qualitatively explained the measured diffraction efficiencies.

  6. Form Birefringence in Thin Films with Oblique Columnar Structures

    Institute of Scientific and Technical Information of China (English)

    WANG Jian-Guo; SHAO Jian-Da; WANG Su-Mei; HE Hong-Bo; FAN Zheng-Xiu

    2005-01-01

    @@ Effective medium theory is useful for designing optical elements with form birefringent subwavelength structures. Thinfilms fabricated by oblique deposition are similar to the two-dimensional surface relief subwavelength gratings. We use the effective medium theory to calculate the anisotropic optical properties of the thin films with oblique columnar structures. The effective refractive indices and the directions are calculated from effective medium theory. It is shown that optical thin films with predetermined refractive indices and birefringence may be engineered.

  7. Large-scale columnar vortices in rotating turbulence

    Science.gov (United States)

    Yokoyama, Naoto; Takaoka, Masanori

    2016-11-01

    In the rotating turbulence, flow structures are affected by the angular velocity of the system's rotation. When the angular velocity is small, three-dimensional statistically-isotropic flow, which has the Kolmogorov spectrum all over the inertial subrange, is formed. When the angular velocity increases, the flow becomes two-dimensional anisotropic, and the energy spectrum has a power law k-2 in the small wavenumbers in addition to the Kolmogorov spectrum in the large wavenumbers. When the angular velocity decreases, the flow returns to the isotropic one. It is numerically found that the transition between the isotropic and anisotropic flows is hysteretic; the critical angular velocity at which the flow transitions from the anisotropic one to the isotropic one, and that of the reverse transition are different. It is also observed that the large-scale columnar structures in the anisotropic flow depends on the external force which maintains a statistically-steady state. In some cases, small-scale anticyclonic structures are aligned in a columnar structure apart from the cyclonic Taylor column. The formation mechanism of the large-scale columnar structures will be discussed. This work was partially supported by JSPS KAKENHI.

  8. Diversity of Flavobacterium psychrophilum and the potential use of its phages for protection against bacterial cold water disease in salmonids

    DEFF Research Database (Denmark)

    Castillo, D.; Higuera, G.; Villa, M.

    2012-01-01

    Flavobacterium psychrophilum causes rainbow trout fry syndrome (RTFS) and cold water disease (CWD) in salmonid aquaculture. We report characterization of F. psychrophilum strains and their bacteriophages isolated in Chilean salmonid aquaculture. Results suggest that under laboratory conditions ph...

  9. Evolution of interleukin-1 receptor-like 1 and its role in rainbow trout (Oncorhynchus mykiss) resistance to Flavobacterium psychrophilum

    Science.gov (United States)

    Rainbow trout exhibit extensive phenotypic variation in innate disease resistance and we have divergently selected lines with either increased or reduced survival following exposure to the gram-negative bacterium, Flavobacterium psychrophilum (Fp). Following five generations of selection, gene expr...

  10. The Mrp system: a giant among monovalent cation/proton antiporters?

    Science.gov (United States)

    Swartz, Talia H; Ikewada, Sayuri; Ishikawa, Osamu; Ito, Masahiro; Krulwich, Terry Ann

    2005-10-01

    Mrp systems are a novel and broadly distributed type of monovalent cation/proton antiporter of bacteria and archaea. Monovalent cation/proton antiporters are membrane transport proteins that catalyze efflux of cytoplasmic sodium, potassium or lithium ions in exchange for external hydrogen ions (protons). Other known monovalent cation antiporters are single gene products, whereas Mrp systems have been proposed to function as hetero-oligomers. A mrp operon typically has six or seven genes encoding hydrophobic proteins all of which are required for optimal Mrp-dependent sodium-resistance. There is little sequence similarity of Mrp proteins to other antiporters but three of these proteins have significant sequence similarity to membrane embedded subunits of ion-translocating electron transport complexes. Mrp antiporters have essential roles in the physiology of alkaliphilic and neutralophilic Bacillus species, nitrogen-fixing Sinorhizobium meliloti and in the pathogen Staphylococcus aureus, although these bacteria contain multiple monovalent cation/proton antiporters. The wide distribution of Mrp systems leads to the anticipation of important roles in an even wider variety of pathogens, extremophiles and environmentally important organisms. Here, the distribution, established physiological roles and catalytic activities of Mrp systems are reviewed, hypotheses regarding their complexity are discussed and major open questions about their function are highlighted.

  11. Monovalent RIVM meningococcal B OMP vesicle F91 vaccines in toddlers

    NARCIS (Netherlands)

    Lafeber AB; Limpt CJP van; Labadie J; Berbers GAM; Kleijn ED de; Groot R de; Rumke HC; Alphen AJW; Sophia Kinderziekenhuis /; LVO

    2001-01-01

    This report gives the results of a randomised phase-II clinical study into the safety and immunogenicity of a monovalent MenB OMV vaccine expressing P1.7h,4 PorA (MonoMen) in toddlers. Safety and immunogenicity are compared for two types of vaccine that are differently adjuvated (either aluminium ph

  12. Physiological and phenotypic variations between columnar and standard apple (Malus x domestica Borkh.) trees

    DEFF Research Database (Denmark)

    Talwara, Susheela

    Columnar apple trees have very determined growth habit, short internodes, nearly absent branching and can be planted densely in the orchards to obtain higher yields. Such tree architecture provides a possibility for automation and mechanization in agriculture and hence lowering the labour cost...... the variations between columnar and standard apple trees. This knowledge provides a better insight on the production abilities of the columnar apple trees which may be useful for future crop improvement strategies....

  13. Isolation and characterization of an Antarctic Flavobacterium strain with agarase and alginate lyase activities

    Directory of Open Access Journals (Sweden)

    Lavín Paris

    2016-09-01

    Full Text Available Several bacteria that are associated with macroalgae can use phycocolloids as a carbon source. Strain INACH002, isolated from decomposing Porphyra (Rhodophyta, in King George Island, Antarctica, was screened and characterized for the ability to produce agarase and alginate-lyase enzymatic activities. Our strain INACH002 was identified as a member of the genus Flavobacterium, closely related to Flavobacterium faecale, using 16S rRNA gene analysis. The INACH002 strain was characterized as psychrotrophic due to its optimal temperature (17ºC and maximum temperature (20°C of growth. Agarase and alginate-lyase displayed enzymatic activities within a range of 10°C to 50°C, with differences in the optimal temperature to hydrolyze agar (50°C, agarose (50°C and alginate (30°C during the first 30 min of activity. Strain Flavobacterium INACH002 is a promising Antarctic biotechnological resource; however, further research is required to illustrate the structural and functional bases of the enzymatic performance observed during the degradation of different substrates at different temperatures.

  14. Validation of simulated point response of columnar phosphor screens

    Science.gov (United States)

    Badano, Aldo; Kyprianou, Iacovos S.; Tang, Katherine H.; Saha, Anindita

    2007-03-01

    Typical methods to measure the resolution properties of x-ray detectors use slit or edge devices. However, complete models of imaging systems for system optimization require knowledge of the point-response function of the detector. In this paper, we report on the experimental methods developed for the validation of the point-response function of an indirect columnar CsI:Tl detector predicted by Monte Carlo using mantis. We describe simulation results that replicate experimental resolution measurements using edge and pinhole devices. The experimental setup consists of a high-resolution CCD camera with a 1-to-1fiber optic faceplate that allows measurements for different scintillation screens. The results of these experiments and simulations constitute a resource for the development and validation of the columnar models of phosphor screens proposed as part of previous work with mantis. We compare experimental high-resolution pinhole responses of two different CsI(Tl) screens to predictions from mantis. The simulated response matches reasonably well the measurements at normal and off-normal x-ray incidence angle when a realistic pinhole is used in the simulation geometry. Our results will be combined with results on Swank factors determined from Monte Carlo pulse-height spectra to provide a comprehensive validation of the phosphor models, therefore allowing their use for in silico system optimization.

  15. Columnar domains and anisotropic growth laws in dipolar systems

    Science.gov (United States)

    Bupathy, Arunkumar; Banerjee, Varsha; Puri, Sanjay

    2017-06-01

    Magnetic and dielectric solids are well-represented by the Ising model with dipolar interactions (IM+DI). The latter are long-ranged, fluctuating in sign, and anisotropic. Equilibrium studies have revealed novel consequences of these complicated interactions, but their effect on nonequilibrium behavior is not explored. We perform a deep temperature quench to study the kinetics of domain growth in the d =3 IM+DI. Our main observations are (i) the emergence of columnar domains along the z axis (Ising axis) with a transient periodicity in the x y plane; (ii) anisotropic growth laws: ℓρ(t ) ˜tϕ ; ℓz(t ) ˜tψ , where ρ ⃗=(x ,y ) and ℓ is the characteristic length scale; (iii) generalized dynamical scaling for the correlation function: C (ρ ,z ;t ) =g (ρ /ℓρ,z /ℓz) ; and (iv) an asymptotic Porod tail in the corresponding structure factor: S (kρ,0 ;t ) ˜kρ-3 ; S (0 ,kz;t ) ˜kz-2 . Our results explain the experimentally observed columnar morphologies in a wide range of dipolar systems, and they have important technological implications.

  16. Columnar molecular aggregation in the aqueous solutions of disodium cromoglycate

    Science.gov (United States)

    Agra-Kooijman, Dena M.; Singh, Gautam; Lorenz, Alexander; Collings, Peter J.; Kitzerow, Heinz-S.; Kumar, Satyendra

    2014-06-01

    Stack, chimneylike, and threadlike assemblies have previously been proposed for the structure of disodium cromoglycate (DSCG) aggregates in aqueous solutions. The results of the synchrotron x-ray scattering investigations reported here reveal the formation of simple columnar assemblies with π-π stacking at a separation of 3.4 Å between the DSCG molecules. Lateral separation between the assemblies is concentration and temperature dependent, varying from ˜35 to 42 Å in the orientationally ordered nematic (N) phase and from 27 to 32 Å in the columnar or middle (M) phase having long range lateral positional order. The assemblies' length depends on concentration and consists of ˜23 molecules in the N phase, becoming three to ten times larger in the M phase. The scission energy is concentration dependent in the N phase with values ˜7.19 ± 0.14 kBT (15 wt %), 2.73 ± 0.4 kBT (20 wt %), and 3.05 ± 0.2 kBT (25 wt %). Solutions of all concentrations undergo a spinodal decomposition at temperatures above ˜40 °C, resulting in DSCG-rich regions with the M phase and water-rich regions in the N and isotropic phases.

  17. Phenotypic and molecular characterisation of fish-borne Flavobacterium johnsoniae-like isolates from aquaculture systems in South Africa.

    Science.gov (United States)

    Flemming, Leonard; Rawlings, Douglas; Chenia, Hafizah

    2007-01-01

    Fish infections caused by pathogenic Flavobacterium species are a major problem in the aquaculture industry worldwide, often leading to large economic losses. Thirty-two Flavobacterium spp. isolates, obtained from various diseased fish species and biofilm growth, were characterised genetically using 16S rDNA PCR restriction fragment length polymorphism (RFLP), randomly amplified polymorphic DNA (RAPD) PCR, repetitive extragenic palindromic (REP) element PCR, plasmid profiling, whole cell protein (WCP) and outer membrane protein (OMP) analyses. Although the Flavobacterium spp. isolates displayed a high degree of genetic heterogeneity when differentiated by RAPD-PCR, REP-PCR and OMP fingerprinting techniques, isolates appeared very homogeneous by plasmid profiling and WCP analysis. No specific correlation was observed between the RAPD, REP and/or OMP profiles and fish host, site of isolation, geographic location or date of isolation of the Flavobacterium spp. isolates. Experimental infection of tilapia fish revealed variable levels of virulence and pathogenicity by isolates following handling stress and could not be linked to specific molecular types. This is the first reported isolation and characterisation of Flavobacterium johnsoniae-like spp. isolated from diseased fish in Southern Africa.

  18. Columnar cell lesions of the breast: clinical significance and molecular background

    NARCIS (Netherlands)

    Verschuur-Maes, A.H.J.

    2012-01-01

    Columnar cell lesions (CCLs) of the breast have since long been regarded as possible precursor lesions of breast cancer. CCLs are cystically dilated ducts lined by columnar cell epithelium, with or without atypia. Intraluminal secretions and microcalcifications are frequently seen and the microcalci

  19. Towards identification of the gene responsible for the columnar phenotype of 'McIntosh 'Wijcik" apple

    NARCIS (Netherlands)

    Wolters, P.J.; Schouten, H.J.; Velasco, R.; Salvi, S.; Komjanc, M.; Si-Ammour, A.; Baldi, P.

    2015-01-01

    The 'Wijcik' mutant of the apple cultivar 'McIntosh' shows columnar-type growth, characterized by altered branching and a thick stem. Instead of normal branches, spur-like branches are produced on 'Wijcik' trees, leading to apples produced close to the stem. Columnar-type growth is a desirable tr

  20. Relaxation dynamics in the columnar liquid crystal phase of hard platelets

    NARCIS (Netherlands)

    patti, A; Belli, S; van Roij, R.H.H.G.; Dijkstra, M.

    2011-01-01

    We perform Monte Carlo simulations to analyze the equilibrium dynamics and the long-time structural relaxation decay of columnar liquid crystals of disk-like colloidal particles. In the wake of recent studies on the columnar mesophase of hard calamitic (rod-like) colloids, we now focus on the

  1. SAXS reveals the magnetic alignment pathway of the goethite columnar liquid crystal phase

    NARCIS (Netherlands)

    Leferink op Reinink, Anke B G M; van den Pol, Esther; Vroege, Gert Jan; Petukhov, Andrei V.

    2014-01-01

    The alignment of board-like colloidal goethite particles in the dense rectangular centred columnar liquid crystal phase in an external magnetic field is studied using small angle X-ray scattering (SAXS). Transient SAXS-patterns show broadening of the columnar reflections in specific directions. Whil

  2. A novel serrated columnar phased array ultrasonic transducer

    Science.gov (United States)

    Zou, Cheng; Sun, Zhenguo; Cai, Dong; Song, Hongwei; Chen, Qiang

    2016-02-01

    Traditionally, wedges are required to generate transverse waves in a solid specimen and mechanical rotation device is needed for interrogation of a specimen with a hollow bore, such as high speed railway locomotive axles, turbine rotors, etc. In order to eliminate the mechanical rotation process, a novel array pattern of phased array ultrasonic transducers named as serrated columnar phased array ultrasonic transducer (SCPAUT) is designed. The elementary transducers are planar rectangular, located on the outside surface of a cylinder. This layout is aimed to generate electrically rotating transverse waveforms so as to inspect the longitudinal cracks on the outside surface of a specimen which has a hollow bore at the center, such as the high speed railway locomotive axles. The general geometry of the SCPAUT and the inspection system are illustrated. A FEM model and mockup experiment has been carried out. The experiment results are in good agreement with the FEM simulation results.

  3. Gold nanoparticles in columnar matrix of discotic liquid crystal

    Science.gov (United States)

    Supreet, Kumar, Rishi; Pratibha, R.; Kumar, Sandeep; Raina, K. K.

    2013-06-01

    Hexanethiolate-stabilized gold nanoparticles (GNP) were synthesized by the method adopted by Song et al.[2]. Average size of GNPs was determined by scanning transmission electron microscopy (STEM). This method yielded nanoparticles with average particle size of 1.5 nm. In the present work, we have incorporated GNPs in columnar matrix of discotic liquid crystal. The thermo-physical properties of these mixtures were investigated using polarizing optical micrography (POM), differential scanning calorimetry (DSC) and dielectric spectroscopy. Results show GNPs does not affect the hexagonal arrangement of columns of DLC. However, there is decrease in mesophase to crystallization temperature as confirmed by DSC. This approach of crossing of the field of nanotechnology with DLC may lead to novel materials with interesting properties that are useful for many device applications.

  4. Anisoptropic Bruggeman Effective Medium Approaches for Slanted Columnar Thin Films

    CERN Document Server

    Schmidt, Daniel

    2013-01-01

    Two different formalisms for the homogenization of composite materials containing ellipsoidal inclusions based on Bruggeman's original formula for spherical inclusions can be found in the literature. Both approximations determine the effective macroscopic permittivity of such an idealized composite assuming randomly distributed dielectric particles of equal shape and differ only in the definition of the depolarization factors. The two approaches are applied to analyze ellipsometric Mueller matrix spectra acquired in the visible and near-infrared spectral region from metal and semiconductor slanted columnar thin films. Furthermore, the effective dielectric function tensor generated by the two Bruggeman formalisms is compared to effective major axes dielectric functions individually determined with a homogeneous biaxial layer approach. Best-match model parameters of all three model approaches are discussed and compared to estimates from scanning electron microscope images. The structural parameters obtained fro...

  5. Interobserver reproducibility in pathologist interpretation of columnar-lined esophagus.

    Science.gov (United States)

    Mastracci, Luca; Piol, Nataniele; Molinaro, Luca; Pitto, Francesca; Tinelli, Carmine; De Silvestri, Annalisa; Fiocca, Roberto; Grillo, Federica

    2016-02-01

    Confirmation of endoscopically suspected esophageal metaplasia (ESEM) requires histology, but confusion in the histological definition of columnar-lined esophagus (CLE) is a longstanding problem. The aim of this study is to evaluate interpathologist variability in the interpretation of CLE. Thirty pathologists were invited to review three ten-case sets of CLE biopsies. In the first set, the cases were provided with descriptive endoscopy only; in the second and the third sets, ESEM extent using Prague criteria was provided. Moreover, participants were required to refer to a diagnostic chart for evaluation of the third set. Agreement was statistically assessed using Randolph's free-marginal multirater kappa. While substantial agreement in recognizing columnar epithelium (K = 0.76) was recorded, the overall concordance in clinico-pathological diagnosis was low (K = 0.38). The overall concordance rate improved from the first (K = 0.27) to the second (K = 0.40) and third step (K = 0.46). Agreement was substantial when diagnosing Barrett's esophagus (BE) with intestinal metaplasia or inlet patch (K = 0.65 and K = 0.89), respectively, in the third step, while major problems in interpretation of CLE were observed when only cardia/cardia-oxyntic atrophic-type epithelium was present (K = 0.05-0.29). In conclusion, precise endoscopic description and the use of a diagnostic chart increased consistency in CLE interpretation of esophageal biopsies. Agreement was substantial for some diagnostic categories (BE with intestinal metaplasia and inlet patch) with a well-defined clinical profile. Interpretation of cases with cardia/cardia-oxyntic atrophic-type epithelium, with or without ESEM, was least consistent, which reflects lack of clarity of definition and results in variable management of this entity.

  6. Population genetic structure of Venezuelan chiropterophilous columnar cacti (Cactaceae).

    Science.gov (United States)

    Nassar, Jafet M; Hamrick, J L; Fleming, Theodore H

    2003-11-01

    We conducted allozyme surveys of three Venezuelan self-incompatible chiropterophilous columnar cacti: two diploid species, Stenocereus griseus and Cereus repandus, and one tetraploid, Pilosocereus lanuginosus. The three cacti are pollinated by bats, and both bats and birds disperse seeds. Population sampling comprised two spatial scales: all Venezuelan arid zones (macrogeographic) and two arid regions in northwestern Venezuela (regional). Ten to 15 populations and 17-23 loci were analyzed per species. Estimates of genetic diversity were compared with those of other allozyme surveys in the Cactaceae to examine how bat-mediated gene dispersal affects the population genetic attributes of the three cacti. Genetic diversity was high for both diploid (P(s) = 94.1-100, P(p) = 56.7-72.3, H(s) = 0.182-0.242, H(p) = 0.161-0.205) and tetraploid (P(s) = 93.1, P(p) = 76.1, H(s) = 0.274, H(p) = 0.253) species. Within-population heterozygote deficit was detected in the three cacti at macrogeographic (F(IS) = 0.145-0.182) and regional (F(IS) = 0.057-0.174) levels. Low genetic differentiation was detected at both macrogeographic (G(ST) = 0.043-0.126) and regional (G(ST) = 0.009-0.061) levels for the three species, suggesting substantial gene flow among populations. Gene exchange among populations seems to be regulated by distance among populations. Our results support the hypothesis that bat-mediated gene dispersal confers high levels of genetic exchange among populations of the three columnar cacti, a process that enhances levels of genetic diversity within their populations.

  7. Evolving fracture patterns: columnar joints, mud cracks, and polygonal terrain

    Science.gov (United States)

    Goehring, L.

    2012-12-01

    Contraction cracks can form captivating patterns, such as the artistic craquelure sometimes found in pottery glazes, to the cracks in dried mud, or the polygonal networks covering the polar regions of Earth and Mars. Two types are frequently encountered: those with irregular rectilinear patterns, such as that formed by an homogeneous slurry when dried (or cooled) uniformly, and more regular hexagonal patterns, such as those typified by columnar joints. Once cracks start to form in a thin contracting layer, they will sequentially break the layer into smaller and smaller pieces. A rectilinear crack pattern encodes information about the order of cracks, as later cracks tend to intersect with earlier cracks at right angles. In this manner they relieve the stresses perpendicular to the pre-existing crack. In a hexagonal pattern, in contrast, the angles between all cracks at a vertex are near 120°. In this presentation it will be shown how both types of pattern can arise from identical forces, and that a rectilinear, T-junction dominated pattern will develop into to a hexagonal pattern, with Y-junctions, if allowed to. Such an evolution can be explained as the result of three conditions: (1) if cracks advance through space, or heal and recur, that the previous positions of a crack tip acts as a line of weakness, guiding the next iteration of cracking; (2) that the order of opening of cracks can change in each iteration; and (3) that crack tips curve to maximise the local strain energy release rate. The ordering of crack patterns are seen in a number of systems: columnar joints in starch and lava; desiccation cracks in clays that are repeatedly wetted and dried; cracks in eroding gypsum-cemented sand layers; and the cracks in permafrost known as polygonal terrain. These patterns will each be briefly explored, in turn, and shown to obey the above principles of crack pattern evolution.

  8. New host record of five Flavobacterium species associated with tropical fresh water farmed fishes from North India.

    Science.gov (United States)

    Verma, Dev Kumar; Rathore, Gaurav

    2015-01-01

    Yellow pigmented, filamentous, Gram-negative bacteria belonging to genus Flavobacterium are commonly associated with infections in stressed fish. In this study, inter-species diversity of Flavobacterium was studied in apparently healthy freshwater farmed fishes. For this, ninety one yellow pigmented bacteria were isolated from skin and gill samples (n = 38) of three farmed fish species i.e. Labeo rohita, Catla catla and Cyprinus carpio. Among them, only twelve bacterial isolates (13.18%) were identified as Flavobacterium spp. on the basis of morphological, biochemical tests, partial 16S rDNA gene sequencing and phylogenetic analysis. On the basis of 16S rDNA gene sequencing, all the 12 isolates were 97.6-100% similar to six different formally described species of genus Flavobacterium. The 16S rDNA based phylogenetic analysis grouped these strains into six different clades. Of the 12 isolates, six strains (Fl9S1-6) grouped with F. suncheonense, two strains (Fl6I2, Fl6I3) with F. indicum and the rest four strains (Fl1A1, Fl2G1, Fl3H1 and Fl10T1) clustered with F. aquaticum, F. granuli, F. hercynium and F. terrae, respectively. None of these species except, F. hercynium were previously reported from fish. All the isolated Flavobacterium species possessed the ability of adhesion and biofilm formation to colonize the external surface of healthy fish. The present study is the first record of tropical freshwater farmed fishes as hosts to five environmentally associated species of the Flavobacterium.

  9. Evidence for regulation of columnar habit in apple encodes a putative 2og-fe(ii) oxygenase

    NARCIS (Netherlands)

    Wolters, P.; Schouten, H.J.; Riccardo, V.; Si-Ammour, A.; Baldi, P.

    2013-01-01

    Understanding the genetic mechanisms controlling columnar-type growth in the apple mutant Wijcik will provide insights on how tree architecture and growth are regulated in fruit trees. In apple, columnar-type growth is controlled by a single major gene at the Columnar (Co) locus. By comparing the ge

  10. Flavobacterium faecale sp. nov., an agarase-producing species isolated from stools of Antarctic penguins.

    Science.gov (United States)

    Kim, Jin Ho; Choi, Bo Hyun; Jo, Minho; Kim, Sun Chang; Lee, Pyung Cheon

    2014-08-01

    Taxonomic studies were performed on an agarase-producing strain, designated WV33(T), isolated from faeces of Antarctic penguins. Cells of strain WV33(T) were Gram-staining-negative, strictly aerobic, orange and rod-shaped. Strain WV33(T) displayed agarase activity and was able to utilize galactose as a sole carbon source. 16S rRNA gene sequence analysis revealed that strain WV33(T) was closely related to Flavobacterium algicola TC2(T) (98.0% similarity), F. frigidarium ATCC 700810(T) (96.9%) and F. frigoris LMG 21922(T) (96.1%). The predominant cellular fatty acids were iso-C(15 : 1) G, iso-C(15 : 0), C(15 : 0), C(16 : 0) and summed feature 3 (comprising iso-C(15 : 0) 2-OH and/or C(16 : 1)ω7c). Menaquinone 6 (MK-6) was the sole quinone identified, and the major pigment was zeaxanthin. The major polar lipid was phosphatidylethanolamine. DNA-DNA relatedness of strain WV33(T) with respect to its closest phylogenetic neighbours was 25% for F. algicola NBRC 102673(T), 23% for F. frigidarium DSM 17623(T) and 21% for F. frigoris DSM 15719(T). The DNA G+C content of strain WV33(T) was 37±0.6 mol%. Based on the phenotypic, chemotaxonomic and phylogenetic data, strain WV33(T) is concluded to represent a novel species of the genus Flavobacterium, for which the name Flavobacterium faecale sp. nov. is proposed. The type strain is WV33(T) ( = KCTC 32457(T) = CECT 8384(T)).

  11. Role of fatty acids in cold adaptation of Antarctic psychrophilic Flavobacterium spp.

    Science.gov (United States)

    Králová, Stanislava

    2017-09-01

    Cold-loving microorganisms developed numerous adaptation mechanisms allowing them to survive in extremely cold habitats, such as adaptation of the cell membrane. The focus of this study was on the membrane fatty acids of Antarctic Flavobacterium spp., and their adaptation response to cold-stress. Fatty acids and cold-response of Antarctic flavobacteria was also compared to mesophilic and thermophilic members of the genus Flavobacterium. The results showed that the psychrophiles produced more types of major fatty acids than meso- and thermophilic members of this genus, namely C15:1 iso G, C15:0 iso, C15:0 anteiso, C15:1ω6c, C15:0 iso 3OH, C17:1ω6c, C16:0 iso 3OH and C17:0 iso 3OH, summed features 3 (C16:1ω7cand/or C16:1ω6c) and 9 (C16:0 10-methyl and/or C17:1 iso ω9c). It was shown that the cell membrane of psychrophiles was composed mainly of branched and unsaturated fatty acids. The results also implied that Antarctic flavobacteria mainly used two mechanisms of membrane fluidity alteration in their cold-adaptive response. The first mechanism was based on unsaturation of fatty acids, and the second mechanism on de novo synthesis of branched fatty acids. The alteration of the cell membrane was shown to be similar for all thermotypes of members of the genus Flavobacterium. Copyright © 2017 Elsevier GmbH. All rights reserved.

  12. Reproducible methods for experimental infection with Flavobacterium psychrophilum in rainbow trout Oncorhynchus mykiss

    DEFF Research Database (Denmark)

    Madsen, Lone; Dalsgaard, Inger

    1999-01-01

    Experiments were done in order to achieve a reproducible method that can be used to infect rainbow trout Oncorhynchus mykiss with Flavobacterium psychrophilum, the causal agent of coldwater disease and rainbow trout fry syndrome. The main method investigated was intraperitoneal injection......, and this method was tested using isolates with different elastin- degrading profiles and representing different serotypes. Injecting trout, average weight 1 g, with 10(4) CFU (colony- forming units) per fish caused cumulative mortalities around 60 to 70%. The virulent strains belonged to certain serotypes...

  13. Columnar cell lesions of the canine mammary gland: pathological features and immunophenotypic analysis

    Directory of Open Access Journals (Sweden)

    Cassali Geovanni D

    2010-02-01

    Full Text Available Abstract Background It has been suggested that columnar cell lesions indicate an alteration of the human mammary gland involved in the development of breast cancer. They have not previously been described in canine mammary gland. The aim of this paper is describe the morphologic spectrum of columnar cell lesions in canine mammary gland specimens and their association with other breast lesions. Methods A total of 126 lesions were subjected to a comprehensive morphological review based upon the human breast classification system for columnar cell lesions. The presence of preinvasive (epithelial hyperplasia and in situ carcinoma and invasive lesions was determined and immunophenotypic analysis (estrogen receptor (ER, progesterone receptor (PgR, high molecular weight cytokeratin (34βE-12, E-cadherin, Ki-67, HER-2 and P53 was perfomed. Results Columnar cell lesions were identified in 67 (53.1% of the 126 canine mammary glands with intraepithelial alterations. They were observed in the terminal duct lobular units and characterized at dilated acini may be lined by several layers of columnar epithelial cells with elongated nuclei. Of the columnar cell lesions identified, 41 (61.2% were without and 26 (38.8% with atypia. Association with ductal hyperplasia was observed in 45/67 (67.1%. Sixty (89.5% of the columnar cell lesions coexisted with neoplastic lesions (20 in situ carcinomas, 19 invasive carcinomas and 21 benign tumors. The columnar cells were ER, PgR and E-cadherin positive but negative for cytokeratin 34βE-12, HER-2 and P53. The proliferation rate as measured by Ki-67 appeared higher in the lesions analyzed than in normal TDLUs. Conclusions Columnar cell lesions in canine mammary gland are pathologically and immunophenotypically similar to those in human breast. This may suggest that dogs are a suitable model for the comparative study of noninvasive breast lesions.

  14. Genomic structure of bacteriophage 6H and its distribution as prophage in Flavobacterium psychrophilum strains

    DEFF Research Database (Denmark)

    Castillo Bermúdez, Daniel Elías; Espejo, Romilio; Middelboe, Mathias

    2014-01-01

    Flavobacterium psychrophilum is currently one of the most devastating fish pathogens worldwide causing considerable economic losses in salmonid aquaculture. Recently, attention has been drawn to the use of phages for controlling F. psychrophilum, and phages infecting the pathogen have been isolat...

  15. Effect of hydrogen peroxide and/or Flavobacterium psychrophilum on the gills of rainbow trout, Oncorhynchus mykiss (Walbaum)

    DEFF Research Database (Denmark)

    Henriksen, Maya Maria Mihályi; Kania, P. W.; Buchmann, K.

    2015-01-01

    The immune response and morphological changes in the gills of rainbow trout fry after immersion in hydrogen peroxide (H2O2), Flavobacterium psychrophilum or combined exposure were examined. The gills were sampled 4, 48, 125 and 192 h after exposure, and the regulation of expression of the following...

  16. Phage-Host Interactions in Flavobacterium psychrophilum and the Potential for Phage Therapy in Aquaculture

    DEFF Research Database (Denmark)

    Christiansen, Rói Hammershaimb

    Abstract The disease rainbow trout fry syndrome (RTFS) is caused by the bacterial fish pathogen Flavobacterium psychrophilum, which for decades has been the cause of great losses of rainbow trout in aquacultures both in Denmark and around the world. Disease outbreaks are typically seen at water...

  17. Mixed polyvalent-monovalent metal coating for carbon-graphite fibers

    Science.gov (United States)

    Harper-Tervet, J.; Tervet, F. W.; Humphrey, M. F. (Inventor)

    1982-01-01

    An improved coating of gasification catalyst for carbon-graphite fibers is provided comprising a mixture of a polyvalent metal such as calcium and a monovalent metal such as lithium. The addition of lithium provides a lighter coating and a more flexible coating when applied to a coating of a carboxyl containing resin such as polyacrylic acid since it reduces the crosslink density. Furthermore, the presence of lithium provides a glass-like substance during combustion which holds the fiber together resulting in slow, even combustion with much reduced evolution of conductive fragments. The coated fibers are utilized as fiber reinforcement for composites.

  18. Coupled-cluster calculations of properties of Boron atom as a monovalent system

    CERN Document Server

    Gharibnejad, H

    2015-01-01

    We present relativistic coupled-cluster (CC) calculations of energies, magnetic-dipole hyperfine constants, and electric-dipole transition amplitudes for low-lying states of atomic boron. The trivalent boron atom is computationally treated as a monovalent system. We explore performance of the CC method at various approximations. Our most complete treatment involves singles, doubles and the leading valence triples. The calculations are done using several approximations in the coupled-cluster (CC) method. The results are within 0.2-0.4% of the energy benchmarks. The hyperfine constants are reproduced with 1-2% accuracy.

  19. Columnar ordering properties of fluorinated and non-fluorinated tris(hexaalkoxytriphenylene)tristriazolotriazines

    NARCIS (Netherlands)

    Umesh, C.P.; Marcelis, A.T.M.; Zuilhof, H.

    2015-01-01

    Two new series of columnar discotic liquid crystalline materials based on a tristriazolotriazine (TTT) core connected to three pendant hexyloxytriphenylene or pentafluoropentyloxytriphenylene groups via a flexible alkyl spacer are synthesised and investigated. It is found that the mesophase

  20. Innovative Columnar Type of Grid Array SJ BIST HALT Method Project

    Data.gov (United States)

    National Aeronautics and Space Administration — Ridgetop will develop a superior method for testing and qualifying columnar type of grid arrays such as field programmable gate arrays (FPGAs) packaged in column...

  1. Columnar Aerosol Optical Properties during "El Arenosillo 2004 Summer Campaign"

    Energy Technology Data Exchange (ETDEWEB)

    Prats, N.; Cachorro, V. E.; Sorribas, M.; Mogo, S.; Berjon, A.; Toledano, C.; de Frutos, A. M.; de la Rosa, J.; Laulainen, Nels S.; de la Morena, B. A.

    2008-04-14

    A detailed analysis of the microphysical and radiative columnar aerosol parameters has been carried out for data collected during the “El Arenosillo 2004” summer campaign. These data are derived from a Cimel sun-photometer, as part of the PHOTONS-AERONET network at the El Arenosillo site in south-western Spain, over the period 1 June to 31 October 2004. The aim of this campaign was to obtain a more complete set of data on aerosol microphysical, optical/radiative, and chemical properties for use in closure studies. Previous papers addressed the climatology of the AOD-alpha parameters at this site. In this paper, we focus on the characterization of the particle size distribution and associated microphysical parameters, such as volume concentration, effective radius, etc., in order to define the features and ranges of these physical parameters associated with both fine and coarse particle modes. The requirement of high AOD values for using the optical inversion technique puts significant constraints on the estimation of these parameters and, thus, necessitates great care in the analysis. As a result, only the characterizations for desert dust events are considered reliable. Moreover, summer 2004 had the most frequent desert dust intrusions, including the most intense event, ever recorded at the El Arensillo site. We summarize the results for the intensive summer campaign in terms of the range of values of the physical and optical parameters of the mixed aerosol types present in this area of Spain.

  2. Engineering of Ground for Liquefaction Mitigation Using Granular Columnar Inclusions: Recent Developments

    Directory of Open Access Journals (Sweden)

    A. M. Krishna

    2009-01-01

    Full Text Available Problem statement: Liquefaction was the most hazardous damage during an earthquake. Ground improvement techniques were employed to mitigate liquefaction hazards. Most common methods to improve engineering properties of soils are densification, reinforcement, grouting/mixing and drainage. Among various remedial measures available, installation of columnar granular inclusions is the most widely adopted method for liquefaction mitigation. Approach: Columnar granular inclusions function as drains and permit rapid dissipation of earthquake induced pore pressures by virtue of their high permeability. Results: One of the chief benefits of ground treatment with granular piles is the densification of in situ ground by which the in-situ properties of the ground get modified to mitigate liquefaction potential. Further, the very high deformation modulus and stiffness of the granular pile material provide reinforcement for the in situ soil and offer another mechanism to mitigate liquefaction. The study described briefly the phenomenon of liquefaction and the associated features. A short discussion on various ground improvement methods available for liquefaction mitigation was presented highlighting the importance of columnar inclusions. Construction methods of different granular columnar inclusions like sand compaction piles/ granular piles were discussed briefly. Recent developments in the research of columnar granular inclusions as liquefaction counter measures were presented in relation to physical, numerical and analytical model studies. Conclusion/Recommendations: Columnar granular inclusions were demonstrated to be very effective for liquefaction mitigation in different case studies and research investigations.

  3. Effect of film thickness on the columnar packing structures of discotic supramolecules in thin films.

    Science.gov (United States)

    Kim, Hyo-Sik; Choi, Sung-Min; Pate, Brian D; Park, Po Gyu

    2009-10-19

    The effects of film thickness on the columnar packing structure of discotic supramolecules in a thin supported film have been investigated by grazing-incidence small-angle X-ray scattering technique using magnetically aligned cobalt octa(n-decylthio)porphyrazine (CoS10) films on octadecyltrichlorosilane (OTS)-functionalized substrates as model systems. Magnetically aligned CoS10 films with a range of film thicknesses (49-845 nm) form uniaxially oriented 'edge-on' columnar superstructures with their columnar directors perpendicular to the applied magnetic field. However, the orientational ordering of the columnar packing in the plane perpendicular to the applied magnetic field is strongly dependent on the film thickness. While being damped by the elasticity of the side chains of CoS10, the strong interfacial interaction at the film-substrate interface propagates up to 50-100 nm from the substrate, maintaining the orientation of columnar packing in the plane perpendicular to the applied magnetic field. When the distance from the film-substrate interface becomes larger than about 100 nm, symmetric tilting of columnar layer orientation, which saturates at 11.5 degrees , occurs due to longitudinal edge dislocations induced by accumulated elastic deformation.

  4. Serial incorporation of a monovalent GalNAc phosphoramidite unit into hepatocyte-targeting antisense oligonucleotides.

    Science.gov (United States)

    Yamamoto, Tsuyoshi; Sawamura, Motoki; Wada, Fumito; Harada-Shiba, Mariko; Obika, Satoshi

    2016-01-01

    The targeting of abundant hepatic asialoglycoprotein receptors (ASGPR) with trivalent N-acetylgalactosamine (GalNAc) is a reliable strategy for efficiently delivering antisense oligonucleotides (ASOs) to the liver. We here experimentally demonstrate the high systemic potential of the synthetically-accessible, phosphodiester-linked monovalent GalNAc unit when tethered to the 5'-terminus of well-characterised 2',4'-bridged nucleic acid (also known as locked nucleic acid)-modified apolipoprotein B-targeting ASO via a bio-labile linker. Quantitative analysis of the hepatic disposition of the ASOs revealed that phosphodiester is preferable to phosphorothioate as an interunit linkage in terms of ASGPR binding of the GalNAc moiety, as well as the subcellular behavior of the ASO. The flexibility of this monomeric unit was demonstrated by attaching up to 5 GalNAc units in a serial manner and showing that knockdown activity improves as the number of GalNAc units increases. Our study suggests the structural requirements for efficient hepatocellular targeting using monovalent GalNAc and could contribute to a new molecular design for suitably modifying ASO.

  5. Poisson-Helmholtz-Boltzmann model of the electric double layer: analysis of monovalent ionic mixtures.

    Science.gov (United States)

    Bohinc, Klemen; Shrestha, Ahis; Brumen, Milan; May, Sylvio

    2012-03-01

    In the classical mean-field description of the electric double layer, known as the Poisson-Boltzmann model, ions interact exclusively through their Coulomb potential. Ion specificity can arise through solvent-mediated, nonelectrostatic interactions between ions. We employ the Yukawa pair potential to model the presence of nonelectrostatic interactions. The combination of Yukawa and Coulomb potential on the mean-field level leads to the Poisson-Helmholtz-Boltzmann model, which employs two auxiliary potentials: one electrostatic and the other nonelectrostatic. In the present work we apply the Poisson-Helmholtz-Boltzmann model to ionic mixtures, consisting of monovalent cations and anions that exhibit different Yukawa interaction strengths. As a specific example we consider a single charged surface in contact with a symmetric monovalent electrolyte. From the minimization of the mean-field free energy we derive the Poisson-Boltzmann and Helmholtz-Boltzmann equations. These nonlinear equations can be solved analytically in the weak perturbation limit. This together with numerical solutions in the nonlinear regime suggests an intricate interplay between electrostatic and nonelectrostatic interactions. The structure and free energy of the electric double layer depends sensitively on the Yukawa interaction strengths between the different ion types and on the nonelectrostatic interactions of the mobile ions with the surface.

  6. Effects of monovalent cations on folding kinetics of G-quadruplexes.

    Science.gov (United States)

    You, Jing; Li, Hui; Lu, Xi-Ming; Li, Wei; Wang, Peng-Ye; Dou, Shuo-Xing; Xi, Xu-Guang

    2017-08-31

    G-quadruplexes are special structures existing at the ends of human telomeres, the folding kinetics of which are essential for their functions, such as in the maintenance of genome stability and the protection of chromosome ends. In the present study, we investigated the folding kinetics of G-quadruplex in different monovalent cation environments and determined the detailed kinetic parameters for Na(+)- and K(+)-induced G-quadruplex folding, and for its structural transition from the basket-type Na(+) form to the hybrid-type K(+) form. More interestingly, although Li(+) was often used in previous studies of G-quadruplex folding as a control ion supposed to have no effect, we have found that Li(+) can actually influence the folding kinetics of both Na(+)- and K(+)-induced G-quadruplexes significantly and in different ways, by changing the folding fraction of Na(+)-induced G-quadruplexes and greatly increasing the folding rates of K(+)-induced G-quadruplexes. The present study may shed new light on the roles of monovalent cations in G-quadruplex folding and should be useful for further studies of the underlying folding mechanism. © 2017 The Author(s).

  7. [Safety and tolerability of monovalent measles and combined measles, mumps, rubella, and varicella vaccines].

    Science.gov (United States)

    Mentzer, D; Meyer, H; Keller-Stanislawski, B

    2013-09-01

    Although effective monovalent and combined measles vaccines have been available for several decades in Germany, measles outbreaks continue to occur leading to severe cases of measles and even death. Possible reasons for the low acceptance of the measles vaccination are concerns about adverse events and serious complications following vaccination. In this report, we have summarized and assessed all adverse events reported in Germany from 2001 to 2012 after vaccination with monovalent- and combined measles-containing vaccines. A total of 1,696 suspected adverse reaction reports describing 5,297 adverse events were sent to the Paul Ehrlich Institute (PEI) between 1 January 2001 and 31 December 2012. The calculated mean reporting rate was 5.7 reports per 100,000 vaccine doses released by the PEI. Analysis of the reports indicates that measles-containing vaccines are well tolerated with a constantly low rate of adverse events reported. Compared to the high rate of serious complications following wild-type measles infection, the benefit of measles-containing vaccines clearly outweighs the anticipated risks of adverse events.

  8. Circular Dichroism is Sensitive to Monovalent Cation Binding in Monensin Complexes.

    Science.gov (United States)

    Nedzhib, Ahmed; Kessler, Jiří; Bouř, Petr; Gyurcsik, Béla; Pantcheva, Ivayla

    2016-05-01

    Monensin is a natural antibiotic that exhibits high affinity to certain metal ions. In order to explore its potential in coordination chemistry, circular dichroism (CD) spectra of monensic acid A (MonH) and its derivatives containing monovalent cations (Li(+) , Na(+) , K(+) , Rb(+) , Ag(+) , and Et4 N(+) ) in methanolic solutions were measured and compared to computational models. Whereas the conventional CD spectroscopy allowed recording of the transitions down to 192 nm, synchrotron radiation circular dichroism (SRCD) revealed other bands in the 178-192 nm wavelength range. CD signs and intensities significantly varied in the studied compounds, in spite of their similar crystal structure. Computational modeling based on the Density Functional Theory (DFT) and continuum solvent model suggests that the solid state monensin structure is largely conserved in the solutions as well. Time-dependent Density Functional Theory (TDDFT) simulations did not allow band-to-band comparison with experimental spectra due to their limited precision, but indicated that the spectral changes were caused by a combination of minor conformational changes upon the monovalent cation binding and a direct involvement of the metal electrons in monensin electronic transitions. Both the experiment and simulations thus show that the CD spectra of monensin complexes are very sensitive to the captured ions and can be used for their discrimination. Chirality 28:420-428, 2016. © 2016 Wiley Periodicals, Inc. © 2016 Wiley Periodicals, Inc.

  9. Predicting 3D structure, flexibility and stability of RNA hairpins in monovalent and divalent ion solutions

    CERN Document Server

    Shi, Ya-Zhou; Wang, Feng-Hua; Zhu, Xiao-Long; Tan, Zhi-Jie

    2015-01-01

    A full understanding of RNA-mediated biology would require the knowledge of three-dimensional (3D) structures, structural flexibility and stability of RNAs. To predict RNA 3D structures and stability, we have previously proposed a three-bead coarse-grained predictive model with implicit salt/solvent potentials. In this study, we will further develop the model by improving the implicit-salt electrostatic potential and involving a sequence-dependent coaxial stacking potential to enable the model to simulate RNA 3D structure folding in divalent/monovalent ion solutions. As compared with the experimental data, the present model can predict 3D structures of RNA hairpins with bulge/internal loops (<77nt) from their sequences at the corresponding experimental ion conditions with an overall improved accuracy, and the model also makes reliable predictions for the flexibility of RNA hairpins with bulge loops of different length at extensive divalent/monovalent ion conditions. In addition, the model successfully pred...

  10. Feral livestock threatens landscapes dominated by columnar cacti

    Science.gov (United States)

    Malo, J. E.; Acebes, P.; Giannoni, S. M.; Traba, J.

    2011-05-01

    The introduction and naturalization of alien species represents a serious threat to many natural protected areas. One such case of worldwide concern is the impact of feral livestock on arid ecosystems. Damage suffered by Echinopsis (= Trichocereus) terscheckii dominating the landscape of rocky slopes was surveyed in seven locations within the Ischigualasto-Talampaya World Heritage Site (Argentina) by measuring the frequency, position on the plant and extent of damage. At the same time we employed transects to estimate the abundance of autochtonous and feral large herbivores ( Lama guanicoe, Bos taurus, Equus asinus) from their dung. Our results show relatively high damage levels (40-77% of individuals damaged, more than 5 dm 3 removed by plant in some sites), particularly within 0.50-1.75 m above the ground, showing herbivores to be the main responsible for them. We also found significant differences between sites in variables measuring damage level and in the intensity of use by the two feral livestock species but not by guanacos. The frequency of damaged cacti below 1.75 m (but not above) was significantly positively correlated among locations with the frequencies of cattle and donkey dung, and the damage suffered by individual cacti was also correlated with donkey and cattle dung in their surroundings after correcting for spatial effects. However, all correlations were non-significant in the case of guanacos. We conclude that the continued presence of feral livestock, particularly donkeys, leads to damages to columnar cacti with potential effects on their populations and the physiognomy of this protected landscape.

  11. Modeling of current distribution on smooth and columnar platinum structures.

    Science.gov (United States)

    Zinola, Carlos F

    2011-01-17

    Studying the growth and stability of anisotropic or isotropic disordered surfaces in electrodeposition is of importance in catalytic electrochemistry. In some cases, the metallic nature of the electrode defines the topography and roughness, which are also controlled by the experimental time and applied external potential. Because of the experimental restrictions in conventional electrochemical techniques and ex situ electron microscopies, a theoretical model of the surface geometry could aid in understanding the electrodeposition process and current distributions. In spite of applying a complex theory such as dynamic scaling method or perturbation theories, the resolution of mixed mass-/charge-transfer equations (tertiary distribution) for the electrodeposition process would give reliable information. One of the main problems with this type of distribution is the mathematics when solving the spatial n-dimensional differential equations. Use of a primary current distribution is proposed here to simplify the differential equations; however it limits wide application of the first assumption. Distributions of concentration profile, current density, and electrode potential are presented here as a function of the distance normal to the surface for the cases of smooth and rough platinum growth. In the particular case of columnar surfaces, cycloid curves are used to model the electrode, from which the concentration profile is presented in a parameterized form after solving a first-type curvilinear integral. The concentration contour results in a combination of a trigonometric inverse function and a linear distribution leading to a negative concavity curve. The calculation of the current density and electrode potential contours also show trigonometric shapes exhibiting forbidden imaginary values only at the minimal values of the trochoid curve.

  12. Detection of Flavobacterium psychrophilum from fish tissue and water samples by PCR amplification

    DEFF Research Database (Denmark)

    Wiklund, T.; Madsen, Lone; Bruun, Morten Sichlau

    2000-01-01

    Rainbow trout fry syndrome and cold-water disease, caused by Flavobacterium psychrophilum, are important diseases in farmed salmonids. Some of the presently available techniques for the detection of Fl. psychrophilum are either time consuming or lack sufficient sensitivity. In the present...... investigation, the possible detection of Fl. psychrophilum from fish tissue and water samples was examined using nested PCR with DNA probes against a sequence of the 16S rRNA genes. The DNA was extracted using Chelex(R) 100 chelating resin. The primers, which were tested against strains isolated from diseased...... to be more sensitive than agar cultivation of tissue samples from the brain of rainbow trout injected with Fl. psychrophilum. In non-sterile fresh water seeded with Fl. psychrophilum the detection limit of the PCR- assay was 1.7 cfu in the PCR tube, corresponding to 110 cfu ml(-1) water. The PCR...

  13. Genomic Characterization of Flavobacterium psychrophilum Serotypes and Development of a Multiplex PCR-Based Serotyping Scheme

    Directory of Open Access Journals (Sweden)

    Tatiana Rochat

    2017-09-01

    Full Text Available Flavobacterium psychrophilum is a devastating bacterial pathogen of salmonids reared in freshwater worldwide. So far, serological diversity between isolates has been described but the underlying molecular factors remain unknown. By combining complete genome sequence analysis and the serotyping method proposed by Lorenzen and Olesen (1997 for a set of 34 strains, we identified key molecular determinants of the serotypes. This knowledge allowed us to develop a robust multiplex PCR-based serotyping scheme, which was applied to 244 bacterial isolates. The results revealed a striking association between PCR-serotype and fish host species and illustrate the use of this approach as a simple and cost-effective method for the determination of F. psychrophilum serogroups. PCR-based serotyping could be a useful tool in a range of applications such as disease surveillance, selection of salmonids for bacterial coldwater disease resistance and future vaccine formulation.

  14. In situ enhanced bioremediation of dichlorvos by a phyllosphere Flavobacterium strain

    Institute of Scientific and Technical Information of China (English)

    Jiying NING; Gang GANG; Zhihui BAI; Qing HU; Hongyan QI; Anzhou MA; Xuliang ZHUAN; Guoqiang ZHUANG

    2012-01-01

    A bacterium capable of degrading dichlorvos was isolated from the rape phyllosphere and designated YD4. The strain was identified as Flavobacterium sp., based on its phenotypic features and 16S rRNA gene sequence. Strain YD4 was able to utilize dichlorvos as the sole source of phosphorus. In situ enhanced bioremedia- tion of dichlorvos by YD4 was hereafter studied. Chlorpyrifos and phoxim could also be degraded by this strain as the sole phosphorus source. A higher degradation rate of dichlorvos was observed after spraying YD4 onto the surface of rape leaves when compared to the sterilized- YD4 and water-treated samples. The results indicated that pesticide-degrading epiphytic bacterium could become a new way for in situ phyllosphere bioremediation where the hostile niche is unsuitable for other pesticide-degrading bacteria isolated from soil and water.

  15. Functional trade-offs in succulent stems predict responses to climate change in columnar cacti.

    Science.gov (United States)

    Williams, David G; Hultine, Kevin R; Dettman, David L

    2014-07-01

    Columnar cacti occur naturally in many habitats and environments in the Americas but are conspicuously dominant in very dry desert regions. These majestic plants are widely regarded for their cultural, economic, and ecological value and, in many ecosystems, support highly diverse communities of pollinators, seed dispersers, and frugivores. Massive amounts of water and other resources stored in the succulent photosynthetic stems of these species confer a remarkable ability to grow and reproduce during intensely hot and dry periods. Yet many columnar cacti are potentially under severe threat from environmental global changes, including climate change and loss of habitat. Stems in columnar cacti and other cylindrical-stemmed cacti are morphologically diverse; stem volume-to-surface area ratio (V:S) across these taxa varies by almost two orders of magnitude. Intrinsic functional trade-offs are examined here across a broad range of V:S in species of columnar cacti. It is proposed that variation in photosynthetic gas exchange, growth, and response to stress is highly constrained by stem V:S, establishing a mechanistic framework for understanding the sensitivity of columnar cacti to climate change and drought. Specifically, species that develop stems with low V:S, and thus have little storage capacity, are expected to express high mass specific photosynthesis and growth rates under favourable conditions compared with species with high V:S. But the trade-off of having little storage capacity is that low V:S species are likely to be less tolerant of intense or long-duration drought compared with high V:S species. The application of stable isotope measurements of cactus spines as recorders of growth, water relations, and metabolic responses to the environment across species of columnar cacti that vary in V:S is also reviewed. Taken together, our approach provides a coherent theory and required set of observations needed for predicting the responses of columnar cacti to

  16. International collaboration to assess the risk of Guillain Barre Syndrome following Influenza A (H1N1) 2009 monovalent vaccines

    NARCIS (Netherlands)

    Dodd, Caitlin N.; Romio, Silvana A.; Black, Steven; Vellozzi, Claudia; Andrews, Nick; Sturkenboom, Miriam; Zuber, Patrick; Hua, Wei; Bonhoeffer, Jan; Buttery, Jim; Crawford, Nigel; Deceuninck, Genevieve; de Vries, Corinne; De Wals, Philippe; Gutierrez-Gimeno, M. Victoria; Heijbel, Harald; Hughes, Hayley; Hur, Kwan; Hviid, Anders; Kelman, Jeffrey; Kilpi, Tehri; Chuang, S. K.; Macartney, Kristine; Rett, Melisa; Lopez-Callada, Vesta Richardson; Salmon, Daniel; Sanchez, Francisco Gimenez; Sanz, Nuria; Silverman, Barbara; Storsaeter, Jann; Thirugnanam, Umapathi; van der Maas, Nicoline; Yih, Katherine; Zhang, Tao; Izurieta, Hector

    2013-01-01

    Background: The global spread of the 2009 novel pandemic influenza A (H1N1) virus led to the accelerated production and distribution of monovalent 2009 Influenza A (H1N1) vaccines (pH1N1). This pandemic provided the opportunity to evaluate the risk of Guillain-Barre syndrome (GBS), which has been an

  17. In vitro neutralisation of rotavirus infection by two broadly specific recombinant monovalent llama-derived antibody fragments

    NARCIS (Netherlands)

    F. Aladin (Farah); A.W.C. Einerhand (Sandra); J. Bouma (Janneke); S. Bezemer (Sandra); P. Hermans (Pim); D. Wolvers (Danielle); K. Bellamy (Kate); L.G.J. Frenken (Leon); J. Gray (Jim); M. Iturriza-Gómara (Miren)

    2012-01-01

    textabstractRotavirus is the main cause of viral gastroenteritis in young children. Therefore, the development of inexpensive antiviral products for the prevention and/or treatment of rotavirus disease remains a priority. Previously we have shown that a recombinant monovalent antibody fragment (refe

  18. Stem biomechanics of three columnar cacti from the Sonoran Desert.

    Science.gov (United States)

    Molina-Freaner, F; Tinoco-Ojanguren, C; Niklas, K

    1998-08-01

    The allometric relationship of stem length L with respect to mean stem diameter D was determined for 80 shoots of each of three columnar cactus species (Stenocereus thurberi, Lophocereus schottii, and S. gummosus) to determine whether this relationship accords with that predicted by each of three contending models purporting to describe the mechanical architecture of vertical shoots (i.e., geometric, stress, and elastic similitude, which predict L proportional to D(alpha), with alpha = 1/1, 1/2, and 2/3, respectively). In addition, anatomical, physical, and biomechanical stem properties were measured to determine how the stems of these three species maintain their elastic stability as they increase in size. Reduced major axis regression of L with respect to D showed that alpha = 2.82 ± 0.14 for S. thurberi, 2.32 ± 0.19 for L. schottii, and 4.21 ± 0.31 for S. gummosus. Thus, the scaling exponents for the allometry of L differed significantly from that predicted by each of the three biomechanical models. In contrast, these exponents were similar to that for the allometry previously reported for saguaro. Analyses of biomechanical data derived from bending tests performed on 30 stems selected from each of the three species indicated that the bulk stem tissue stiffness was roughly proportional to L2, while stem flexural rigidity (i.e., the ability to resist a bending force) scaled roughly as L3. Stem length was significantly and positively correlated with the volume fraction of wood, while regression analysis of the pooled data from the three species (i.e., 90 stems) indicated that bulk tissue stiffness scaled roughly as the 5/3-power of the volume fraction of wood in stems. These data were interpreted to indicate that wood served as the major stiffening agent in stems and that this tissue accumulates at a sufficient rate to afford unusually high scaling exponents tot stem length with respect to stem diameter (i.e., disproportionately large increments of stem length

  19. Polyelectrolyte-like behaviour of poly(ethylene-oxide) solutions with added monovalent salt

    Science.gov (United States)

    Lal, Jyotsana; Hakem, Ilhem-Faiza

    2004-03-01

    Solvent effects on the conformation of poly(ethylene-oxide) (PEO) and complexation of PEO by monovalent cations, have been examined by using small-angle neutron scattering. In methanol and acetonitrile, a big change in interchain interaction, osmotic compressibility and local chain conformation have been observed upon addition of small amounts of potassium iodide. The amplitude of the total intensity decreases significantly and a peak at a certain value of the wavevector q* appears as signature of a polyelectrolyte-like behaviour. With further addition of salt, the ionic strength of the solution increases and potassium binding becomes less favorable: the binding constant decreases with the ionic strength and PEO behaves as a neutral polymer with excluded volume. No association between PEO and potassium iodide was observed in aqueous solutions. Reference: I.F. Hakem and J. Lal. Europhysics letters, 64 (2), 204, 2003

  20. Directed evolution of antibody fragments with monovalent femtomolar antigen-binding affinity.

    Science.gov (United States)

    Boder, E T; Midelfort, K S; Wittrup, K D

    2000-09-26

    Single-chain antibody mutants have been evolved in vitro with antigen-binding equilibrium dissociation constant K(d) = 48 fM and slower dissociation kinetics (half-time > 5 days) than those for the streptavidin-biotin complex. These mutants possess the highest monovalent ligand-binding affinity yet reported for an engineered protein by over two orders of magnitude. Optimal kinetic screening of randomly mutagenized libraries of 10(5)-10(7) yeast surface-displayed antibodies enabled a >1,000-fold decrease in the rate of dissociation after four cycles of affinity mutagenesis and screening. The consensus mutations are generally nonconservative by comparison with naturally occurring mouse Fv sequences and with residues that do not contact the fluorescein antigen in the wild-type complex. The existence of these mutants demonstrates that the antibody Fv architecture is not intrinsically responsible for an antigen-binding affinity ceiling during in vivo affinity maturation.

  1. Mucocele-like tumor and columnar cell hyperplasia of the breast occurring in a morphologic continuum

    Directory of Open Access Journals (Sweden)

    Fadare Oluwole

    2008-04-01

    Full Text Available Abstract Introduction Mucocele-like tumor was originally described in 1986 as a benign breast proliferation consisting of multiple dilated cysts lined by cytologically bland, flat to cuboidal cells. Subsequent reports described the coexistence of, including the morphologic inter-transitions between, mucocele-like tumor and a variety of other breast proliferations, including intraductal carcinoma, invasive carcinoma, atypical ductal hyperplasia, and hyperplasia of the usual type. The spectrum of breast alterations characterized by variably enlarged terminal-ductal lobular units lined by variably hyperplastic and variably atypical columnar cells has been the subject of significant discussion in the recent literature. In one scheme, these lesions may be classified into four groups, that is, columnar cell change with and without atypia and columnar cell hyperplasia with and without atypia. Morphologic and molecular observations suggest an association, perhaps in a nonobligate precursor role, between some columnar cell lesions and a variety of other neoplastic lesions. Case presentation We describe the case of a 43-year-old woman whose breast tumor contained areas diagnostic of mucocele-like tumor and columnar cell hyperplasia, with morphologic transitions in between. Conclusion Our case represents the second broadly similar case that has been reported, and suggests a potential relationship between these two enigmatic lesions.

  2. Mucocele-like tumor and columnar cell hyperplasia of the breast occurring in a morphologic continuum

    Science.gov (United States)

    Fadare, Oluwole; Mariappan, M Rajan

    2008-01-01

    Introduction Mucocele-like tumor was originally described in 1986 as a benign breast proliferation consisting of multiple dilated cysts lined by cytologically bland, flat to cuboidal cells. Subsequent reports described the coexistence of, including the morphologic inter-transitions between, mucocele-like tumor and a variety of other breast proliferations, including intraductal carcinoma, invasive carcinoma, atypical ductal hyperplasia, and hyperplasia of the usual type. The spectrum of breast alterations characterized by variably enlarged terminal-ductal lobular units lined by variably hyperplastic and variably atypical columnar cells has been the subject of significant discussion in the recent literature. In one scheme, these lesions may be classified into four groups, that is, columnar cell change with and without atypia and columnar cell hyperplasia with and without atypia. Morphologic and molecular observations suggest an association, perhaps in a nonobligate precursor role, between some columnar cell lesions and a variety of other neoplastic lesions. Case presentation We describe the case of a 43-year-old woman whose breast tumor contained areas diagnostic of mucocele-like tumor and columnar cell hyperplasia, with morphologic transitions in between. Conclusion Our case represents the second broadly similar case that has been reported, and suggests a potential relationship between these two enigmatic lesions. PMID:18447919

  3. A theoretical study of CsI:Tl columnar scintillator image quality parameters by analytical modeling

    Energy Technology Data Exchange (ETDEWEB)

    Kalyvas, N., E-mail: nkalyvas@teiath.gr; Valais, I.; Michail, C.; Fountos, G.; Kandarakis, I.; Cavouras, D.

    2015-04-11

    Medical X-ray digital imaging systems such as mammography, radiography and computed tomography (CT), are composed from efficient radiation detectors, which can transform the X-rays to electron signal. Scintillators are materials that emit light when excited by X-rays and incorporated in X-ray medical imaging detectors. Columnar scintillator, like CsI:T1 is very often used for X-ray detection due to its higher performance. The columnar form limits the lateral spread of the optical photons to the scintillator output, thus it demonstrates superior spatial resolution compared to granular scintillators. The aim of this work is to provide an analytical model for calculating the MTF, the DQE and the emission efficiency of a columnar scintillator. The model parameters were validated against published Monte Carlo data. The model was able to predict the overall performance of CsI:Tl scintillators and suggested an optimum thickness of 300 μm for radiography applications. - Highlights: • An analytical model for calculating MTF, DQE and Detector Optical Gain (DOG) of columnar phosphors was developed. • The model was fitted to published efficiency and MTF Monte Carlo data. • A good fit was observed for 300 µm columnar CsI:Tl thickness. • The performance of the 300 µm column thickness CsI:Tl was better in terms of MTF and DOG for radiographic applications.

  4. Thermal Cycling Behavior of Quasi-Columnar YSZ Coatings Deposited by PS-PVD

    Science.gov (United States)

    Yang, Jiasheng; Zhao, Huayu; Zhong, Xinghua; Shao, Fang; Liu, Chenguang; Zhuang, Yin; Ni, Jinxing; Tao, Shunyan

    2017-01-01

    Columnar-structured thermal barrier coatings, owing to their high strain tolerance, are expected for their potential possibilities to substantially extend turbine lives and improve engine efficiencies. In this paper, plasma spray-physical vapor deposition (PS-PVD) process was used to deposit yttria partially stabilized zirconia (YSZ) coatings with quasi-columnar structures. Thermal cyclic tests on burner rigs and thermal shock tests by heating and water-quenching method were involved to evaluate the thermal cycling and thermal shock behaviors of such kind of structured thermal barrier coatings (TBCs). Evolution of the microstructures, phase composition, residual stresses and failure behaviors of quasi-columnar YSZ coatings before and after the thermal tests was investigated. The quasi-columnar coating obtained had an average life of around 623 cycles when the spallation area reached about 10% of the total coating surface during burner rig tests with the coating surface temperature of 1250 °C. Failure of the coating is mainly due to the break and pull-out of center columnar segments.

  5. A comparative study on phyllosphere nitrogen fixation by newly isolated Corynebacterium sp. & Flavobacterium sp. and their potentialities as biofertilizer.

    Science.gov (United States)

    Giri, S; Pati, B R

    2004-01-01

    A number of nitrogen fixing bacteria has been isolated from forest phyllosphere on the basis of nitrogenase activity. Among them two best isolates are selected and identified as Corynebacterium sp. AN1 & Flavobacterium sp. TK2 able to reduce 88 and 132 n mol of acetylene (10(8)cells(-1)h(-1)) respectively. They were grown in large amount and sprayed on the phyllosphere of maize plants as a substitute for nitrogenous fertilizer. Marked improvements in growth and total nitrogen content of the plant have been observed by the application of these nitrogen-fixing bacteria. An average 30-37% increase in yield was obtained, which is nearer to chemical fertilizer treatment. Comparatively better effect was obtained by application of Flavobacterium sp.

  6. Monovalent metal ions play an essential role in catalysis and intersubunit communication in the tryptophan synthase bienzyme complex.

    Science.gov (United States)

    Woehl, E U; Dunn, M F

    1995-07-25

    This investigation shows that the alpha 2 beta 2 tryptophan synthase bienzyme complex from Salmonella typhimurium is subject to monovalent metal ion activation. The effects of the monovalent metal ions Na+ and K+ were investigated using rapid scanning stopped-flow (RSSF), single-wavelength stopped-flow (SWSF), and steady-state techniques. RSSF measurements of individual steps in the reaction of L-serine and indole to give L-trytophan (the beta-reaction) as well as the reaction of 3-indole-D-glycerol 3'-phosphate (IGP) with L-serine (the alpha beta-reaction) demonstrate that monovalent metal ions such as Na+ and K+ change the distribution of intermediates in both the transient and steady states. Therefore the metal ion effect alters relative ground-state energies and the relative positions of ground- and transition-state energies. The RSSF spectra and SWSF time courses show that the turnover of indole is significantly reduced in the absence of either Na+ or K+. The alpha-aminoacrylate Schiff base species, E(A-A), is in a less active state in the absence of monovalent metal ions. Na+ decreases the steady-state rate of IGP cleavage (the alpha-reaction) to about 30% of the value obtained in the absence of metal ions. Steady-state investigations show that in the absence of monovalent metal ions the alpha- and alpha beta-reactions have the same activity. Na+ binding gives a 30-fold stimulation of the alpha-reaction when the beta-site is in the E(A-A) form.(ABSTRACT TRUNCATED AT 250 WORDS)

  7. Mutational analysis of pcpA and its role in pentachlorophenol degradation by Sphingomonas (Flavobacterium) chlorophenolica ATCC 39723.

    OpenAIRE

    Chanama, S; Crawford, R L

    1997-01-01

    Sphingomonas (Flavobacterium) chlorophenolica ATCC 39723 degrades pentachlorophenol (PCP) through a catabolic pathway encoded by multiple genes. One gene required for PCP degradation is pcpA, which encodes information for a 30-kDa polypeptide, PcpA, found in the periplasm of the bacterium. The biological role of PcpA has remained unknown. We disrupted pcpA by replacing it with a defective copy through homologous recombination. The pcpA recombinant, mutant strains accumulated 2,6-dichlorohydro...

  8. Simulation of vortex matter two-step melting in an anisotropic superconductor with columnar defects

    Energy Technology Data Exchange (ETDEWEB)

    Viana, Leonardo P. [Laboratorio de Metodos Numericos e Simulacao Computacional, Departamento de Tecnologia da Informacao, Universidade Federal de Alagoas, Maceio, AL 57072-970 (Brazil) and Laboratorio de Fisica Teorica e Computacional, Departamento de Fisica, Universidade Federal de Pernambuco, Recife, PE 50670-901 (Brazil)]. E-mail: lpviana@gmail.com; Raposo, E.P. [Laboratorio de Fisica Teorica e Computacional, Departamento de Fisica, Universidade Federal de Pernambuco, Recife, PE 50670-901 (Brazil)]. E-mail: ernesto@df.ufpe.br; Coutinho-Filho, M.D. [Laboratorio de Fisica Teorica e Computacional, Departamento de Fisica, Universidade Federal de Pernambuco, Recife, PE 50670-901 (Brazil)]. E-mail: mdcf@ufpe.br

    2006-05-15

    Columnar defects in high-temperature superconductors have been object of recent intense experimental and theoretical investigations. We report on the observation of a melting in two steps in a 3D vortex line system with randomly-placed columnar defects. We perform a Monte Carlo simulation using the Lawrence-Doniach model, with Bi{sub 2}Sr{sub 2}CaCu{sub 2}O{sub 8} parameters, in a magnetic field applied perpendicular to the CuO{sub 2} planes and parallel to the columnar defects. The Bose glass phase observed at low temperatures melts, as the temperature increases, through two steps: first it depins to a distorted Abrikosov lattice, in which the vortex matter presents some degree of hexatic order; in the sequence, further increment in the temperature causes the fusion of this distorted lattice.

  9. A 3-phase model for mixed columnar-equiaxed solidification in DC casting of bronze

    Science.gov (United States)

    Hao, J.; Grasser, M.; Wu, M.; Ludwig, A.; Riedle, J.; Eberle, R.

    2012-01-01

    A three-phase Eulerian approach is used to model the columnar-to-equiaxed transition (CET) during solidification in DC casting of technical bronze. The three phases are the melt, the solidifying columnar dendrites and the equiaxed grains. They are considered as spatially interpenetrating and interacting continua by solving the conservation equations of mass, momentum, species and enthalpy for all three phases. The so defined solidification model is applied to a binary CuSn6 DC casting process as a benchmark to demonstrate the model potentials. Two cases are studied: one considering only feeding flow and one including both feeding flow and equiaxed sedimentation. The simulated results of mixed columnar and equiaxed solidification are presented and discussed including the occurrence of CET, phase distribution, feeding flow, equiaxed sedimentation and their influence on macrosegregation.

  10. Columnar order in jammed LiFePO4 cathodes: ion transport catastrophe and its mitigation.

    Science.gov (United States)

    Smith, Kyle C; Mukherjee, Partha P; Fisher, Timothy S

    2012-05-21

    The high-rate, high-capacity potential of LiFePO4-based lithium-ion battery cathodes has motivated numerous experimental and theoretical studies aiming to realize such performance through nano-sizing, tailoring of particle shape through synthesis conditions, and doping. Here, a granular mechanics study of microstructures formed by dense jammed packings of experimentally and theoretically inspired LiFePO4 particle shapes is presented. A strong dependence of the resultant packing structures on particle shapes is observed, in which columnar structures aligned with the [010] direction inhibit diffusion along [010] in anisotropic LiFePO4. Transport limitations are induced by [010] columnar order and lead to catastrophic performance degradation in anisotropic LiFePO4 electrodes. Further, judicious mixing of nanoplatelets with additive nanoparticles can frustrate columnar ordering and thereby enhance the rate capability of LiFePO4 electrodes by nearly an order of magnitude.

  11. Legionella pneumophila persists within biofilms formed by Klebsiella pneumoniae, Flavobacterium sp., and Pseudomonas fluorescens under dynamic flow conditions.

    Directory of Open Access Journals (Sweden)

    Catherine R Stewart

    Full Text Available Legionella pneumophila, the agent of Legionnaires' disease pneumonia, is transmitted to humans following the inhalation of contaminated water droplets. In aquatic systems, L. pneumophila survives much of time within multi-organismal biofilms. Therefore, we examined the ability of L. pneumophila (clinical isolate 130 b to persist within biofilms formed by various types of aquatic bacteria, using a bioreactor with flow, steel surfaces, and low-nutrient conditions. L. pneumophila was able to intercalate into and persist within a biofilm formed by Klebsiella pneumoniae, Flavobacterium sp. or Pseudomonas fluorescens. The levels of L. pneumophila within these biofilms were as much as 4 × 10(4 CFU per cm(2 of steel coupon and lasted for at least 12 days. These data document that K. pneumoniae, Flavobacterium sp., and P. fluorescens can promote the presence of L. pneumophila in dynamic biofilms. In contrast to these results, L. pneumophila 130 b did not persist within a biofilm formed by Pseudomonas aeruginosa, confirming that some bacteria are permissive for Legionella colonization whereas others are antagonistic. In addition to colonizing certain mono-species biofilms, L. pneumophila 130 b persisted within a two-species biofilm formed by K. pneumoniae and Flavobacterium sp. Interestingly, the legionellae were also able to colonize a two-species biofilm formed by K. pneumoniae and P. aeruginosa, demonstrating that a species that is permissive for L. pneumophila can override the inhibitory effect(s of a non-permissive species.

  12. Columnar phases exhibited by some polycatenar ligands and a few related metal complexes

    Indian Academy of Sciences (India)

    B K Sadashiva; V A Raghunathan

    2003-08-01

    The synthesis and characterization of some polycatenar ligands which exhibit hexagonal columnar and cubic phases are reported. A pentacatenar with only four phenyl rings in the core and exhibiting a mesophase is also reported. A few copper (II) and palladium (II) complexes have been synthesized using these ligands and the mesomorphic properties exhibited by them are described. The hexagonal columnar phase exhibited by some of the complexes can be cooled down to room temperature. The mesophases have been characterized using a combination of polarized light microscopy, differential scanning calorimetry and X-ray diffraction methods.

  13. Physiological and phenotypic variations between columnar and standard apple (Malus x domestica Borkh.) trees

    DEFF Research Database (Denmark)

    Talwara, Susheela

    on the physiological and phenotypic characteristics of the columnar apple trees were made by comparing them with the standard traditionally grown non-columnar apple trees. Data from the leaves morphological and anatomical studies and from various physiological investigations have been assembled to compare...

  14. Vulnerabilidad de los sistemas de polinización de cactáceas columnares de México Vulnerability of pollination systems of columnar cacti of Mexico

    Directory of Open Access Journals (Sweden)

    Alfonso Valiente-Banuet

    2002-03-01

    Full Text Available Se presenta un análisis geográfico sobre el grado de vulnerabilidad de los sistemas de polinización de cactáceas columnares de México que muestran un síndrome de polinización quiropterófila. Se partió del supuesto que sistemas especializados de polinización serían más vulnerables a la perturbación humana que los generalistas. Los resultados indican que las especies que se ubican en el límite norte de la distribución de las cactáceas columnares muestran patrones generalistas de polinización que las hace menos vulnerables a las perturbaciones que las que habitan el centro de México que presentan sistemas de interacción especializados. Este patrón contrastante podría estar relacionado con los movimientos migratorios de los murciélagos en el norte de la distribución de las cactáceas que pudo haber restringido la respuesta hacia la especialización, en tanto que poblaciones residentes de murciélagos en el centro de México podrían haber favorecido la especialización localAn analysis of the degree of vulnerability of the pollination systems of Mexican columnar cacti showing a chiropterophyllous pollination syndrome was conducted, assuming that specialized pollination interactions would be more vulnerable to human perturbations. The results indicate that the species inhabiting the northern distribution limit of the columnar cacti show generalized pollination systems whereas species inhabiting central Mexico showing specialized pollination interactions would be more vulnerable to perturbations. This contrasting geographic pattern might be related to the migratory movements of the nectar-feeding bats in the northern limit of distribution of the columnar cacti that restricted local specialization, whereas resident nectar-feeding bat populations in south-central Mexico probably favored local specialization

  15. Ordering properties of columnar discotic triazines containing three pendant triphenylenes with four or five fluorinated trials

    NARCIS (Netherlands)

    Umesh, C.P.; Marcelis, A.T.M.; Zuilhof, H.

    2015-01-01

    Two series of discotic columnar liquid crystals were prepared and investigated, consisting of a triazine core to which three triphenylenes (HATs) are attached, connected via a flexible variable spacer containing a triazole group. The triphenylenes have five pentafluoropentyloxy tails or four

  16. A combined study of mesomorphism, optical, and electronic properties of donor-acceptor columnar liquid crystals

    NARCIS (Netherlands)

    Eichhorn, S.H.; Shuai, C.; Ahmida, M.; Demenev, A.; Kayal, H.; Raad, F.S.; Kaafarani, B.R.; Patwardhan, S.; Grozema, F.C.; Siebbeles, L.D.A.; Taerum, T.; Perepichka, D.F.; Klenkler, R.

    2011-01-01

    Donor-acceptor structures have recently gained great popularity for the design of low band gap polymeric organic semiconductors. Presented here is a first systematic study of organic semiconductors based on columnar liquid crystals that consist of discotic and board-shaped donor-acceptor structures.

  17. Tunnel current through virus particles between columnar structures in mesoporous silicon

    Energy Technology Data Exchange (ETDEWEB)

    Vashpanov, Yuriy; Jung, Jae-Il; Dal Kwack, Kae [Electrical Engineering and Computer Science Division of Hanyang Institute of Technology, Hanyang University, 17 Haengdang-dong, Seongdong-gu, 133-791 Seoul (Korea, Republic of)

    2011-07-15

    Earlier we reported on a tunnel charge transport mechanism in mesoporous silicon with columnar structures under adsorption of plant nematode-transmitted polyhedral (NEPO) viruses at room temperature. Additional experiments are performed in this paper to establish that this observed tunnel current is connected to a conduction path through virus particles. The plant NEPO viruses have an orbicular shape with a diameter of around 25-30 nm. This size is matched well to the porous size distribution in manufactured samples. The tunnel charge transport in semiconductor structures was not observed on loading protein macromolecules of smaller sizes. A physical mechanism of the observed phenomena can be interpreted to be the result of a shunting effect through virus particles between the two closely located columnar silicon structures. This effect is likely to result from double points at virus adsorption under the condition of matching of pore and virus sizes. The magnitudes of the tunnel barrier heights depend on the type of loaded plant viruses. The investigated columnar structures of mesoporous silicon can be used for research on the electrical properties of different viruses with corresponding sizes in the range of 20-30 nm. The existence of a tunnel current between columnar structures in mesoporous silicon under virus adsorption can be used as a simple method for their detection in the environment. (Copyright copyright 2011 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

  18. Formation of columnar baroclinic vortices in thermally stratified nonlinear spin-up

    NARCIS (Netherlands)

    Pacheco, J.R.; Verzicco, R.

    2012-01-01

    We investigate the mechanisms that affect the formation of columnar vortices for spin-up in a cylinder where the temperatures at the horizontal walls are prescribed. Numerical results from the three-dimensional Navier–Stokes equations show that a short-lived instability, suppressed by the combined e

  19. Collective stringlike motion of semiflexible filamentous particles in columnar liquid crystalline phases

    NARCIS (Netherlands)

    Naderi, S.; van der Schoot, P. P. A. M.

    2013-01-01

    We study, by means of Brownian dynamics simulations, heterogeneous dynamics in a dense columnar phase of monodisperse hard filamentous particles, and find that in a background of barely moving particles, some particles occasionally engage in a fast coherent string-type motion similar to what is

  20. Evolution of orientations and deformation structures within individual grains in cold rolled columnar grained nickel

    DEFF Research Database (Denmark)

    Wu, G.L.; Godfrey, A.; Winther, Grethe;

    2011-01-01

    Columnar grained Ni is used as a model material allowing simultaneous non-surface investigations of the evolution of crystallographic orientations and deformation microstructures within individual grains as a function of rolling strain up to ε=0.7. Electron channelling contrast and electron...

  1. Plasmid control of 6-aminohexanoic acid cyclic dimer degradation enzymes of Flavobacterium sp. KI72.

    Science.gov (United States)

    Negoro, S; Shinagawa, H; Nakata, A; Kinoshita, S; Hatozaki, T; Okada, H

    1980-07-01

    Flavobacterium sp. K172, which is able to grow on 6-aminohexanoic acid cyclic dimer as the sole source of carbon and nitrogen, and plasmid control of the responsible enzymes, 6-aminohexanoic acid cyclic dimer hydrolase and 6-aminohexanoic acid linear oligomer hydrolase, were studied. The wild strain of K172 harbors three kinds of plasmid, pOAD1 (26.2 megadaltons), pOAD2 (28.8 megadaltons), and pOAD3 (37.2 megadaltons). The wild strain K172 was readily cured of its ability to grow on the cyclic dimer by mitomycin C, and the cyclic dimer hydrolase could not be detected either as catalytic activity or by antibody precipitation. No reversion of the cured strains was detected. pOAD2 was not detected in every cured strain tested but was restored in a transformant. The transformant recovered both of the enzyme activities, and the cyclic dimer hydrolase of the transformant was immunologically identical with that of the wild strain. All of the strains tested, including the wild, cured, and transformant ones, possessed identical pOAD3 irrespective of the metabolizing activity. Some of the cured strains possessed pOAD1 identical with the wild strain, but the others harbored plasmids with partially altered structures which were likely to be derived from pOAD1 by genetic rearrangements such as deletion, insertion, or substitution. These results suggested that the genes of the enzymes were borne on pOAD2.

  2. Development of a markerless deletion system for the fish-pathogenic bacterium Flavobacterium psychrophilum.

    Science.gov (United States)

    Gómez, Esther; Álvarez, Beatriz; Duchaud, Eric; Guijarro, José A

    2015-01-01

    Flavobacterium psychrophilum is a Gram-negative fish pathogen that causes important economic losses in aquaculture worldwide. Although the genome of this bacterium has been determined, the function and relative importance of genes in relation to virulence remain to be established. To investigate their respective contribution to the bacterial pathogenesis, effective tools for gene inactivation are required. In the present study, a markerless gene deletion system has been successfully developed for the first time in this bacterium. Using this method, the F. psychrophilum fcpB gene, encoding a predicted cysteine protease homologous to Streptococcus pyogenes streptopain, was deleted. The developed system involved the construction of a conjugative plasmid that harbors the flanking sequences of the fcpB gene and an I-SceI meganuclease restriction site. Once this plasmid was integrated in the genome by homologous recombination, the merodiploid was resolved by the introduction of a plasmid expressing I-SceI under the control of the fpp2 F. psychrophilum inducible promoter. The resulting deleted fcpB mutant presented a decrease in extracellular proteolytic activity compared to the parental strain. However, there were not significant differences between their LD50 in an intramuscularly challenged rainbow trout infection model. The mutagenesis approach developed in this work represents an improvement over the gene inactivation tools existing hitherto for this "fastidious" bacterium. Unlike transposon mutagenesis and gene disruption, gene markerless deletion has less potential for polar effects and allows the mutation of virtually any non-essential gene or gene clusters.

  3. Development of a markerless deletion system for the fish-pathogenic bacterium Flavobacterium psychrophilum.

    Directory of Open Access Journals (Sweden)

    Esther Gómez

    Full Text Available Flavobacterium psychrophilum is a Gram-negative fish pathogen that causes important economic losses in aquaculture worldwide. Although the genome of this bacterium has been determined, the function and relative importance of genes in relation to virulence remain to be established. To investigate their respective contribution to the bacterial pathogenesis, effective tools for gene inactivation are required. In the present study, a markerless gene deletion system has been successfully developed for the first time in this bacterium. Using this method, the F. psychrophilum fcpB gene, encoding a predicted cysteine protease homologous to Streptococcus pyogenes streptopain, was deleted. The developed system involved the construction of a conjugative plasmid that harbors the flanking sequences of the fcpB gene and an I-SceI meganuclease restriction site. Once this plasmid was integrated in the genome by homologous recombination, the merodiploid was resolved by the introduction of a plasmid expressing I-SceI under the control of the fpp2 F. psychrophilum inducible promoter. The resulting deleted fcpB mutant presented a decrease in extracellular proteolytic activity compared to the parental strain. However, there were not significant differences between their LD50 in an intramuscularly challenged rainbow trout infection model. The mutagenesis approach developed in this work represents an improvement over the gene inactivation tools existing hitherto for this "fastidious" bacterium. Unlike transposon mutagenesis and gene disruption, gene markerless deletion has less potential for polar effects and allows the mutation of virtually any non-essential gene or gene clusters.

  4. Evaluation of reference genes for real-time quantitative PCR in the marine flavobacterium Zobellia galactanivorans.

    Science.gov (United States)

    Thomas, François; Barbeyron, Tristan; Michel, Gurvan

    2011-01-01

    The marine bacteria Zobellia galactanivorans is an emerging model microorganism for the bioconversion of algal polysaccharides. The sequence analysis of its genome opens the way to in-depth gene expression analysis, such as reverse transcription quantitative PCR (RT-qPCR) studies. The selection and validation of reference genes are a mandatory first step for the accurate quantification of transcripts. We selected fourteen candidate reference genes belonging to distinct pathways, namely replication, transcription, translation, citric acid cycle, amino acid, nucleotide and dihydrofolate metabolisms, and peptidoglycan, FMN and aromatic compounds synthesis. We quantified their expression by RT-qPCR in various culture conditions corresponding to different temperatures, carbon sources or stresses. The applications geNorm and Normfinder allowed ranking the genes according to their stability and gave concordant results. We found that the geometric average of the expression of glyA, icdA and gmkA can be confidently used to normalize the transcript abundance of genes of interest. In conclusion, this work provides a reliable procedure for gene expression analysis in the flavobacterium Z. galactanivorans and a validated set of reference genes to be used in future transcriptomics approaches. The strategy developed could also be the starting point for similar studies in other members of the Flavobacteria class.

  5. Adhesion of smooth and rough phenotypes of Flavobacterium psychrophilum to polystyrene surfaces.

    Science.gov (United States)

    Högfors-Rönnholm, E; Norrgård, J; Wiklund, T

    2015-05-01

    Phenotypic smooth cells of the fish pathogenic bacterium Flavobacterium psychrophilum have previously been reported to be more adhesive to polystyrene surfaces than corresponding rough cells. In this study, the adhesion ability of smooth and rough cells of F. psychrophilum to polystyrene surfaces was investigated in detail with a crystal violet staining method. By treating both polystyrene surfaces with fish mucus and carbohydrates and the bacterial cells with carbohydrates, the involvement of lectins in the adhesion process was investigated. Smooth cells showed significantly higher adhesion ability to untreated polystyrene surfaces compared with corresponding rough cells and increasing water hardness had an inhibitory effect on the adhesion. Treatment of polystyrene surfaces with D-glucose, D-galactose and fish mucus increased the adhesion ability of smooth cells to polystyrene. Furthermore, treatment of the smooth cells with D-glucose, D-galactose and sialic acid decreased the adhesion ability of the cells, indicating that the adhesion is likely mediated by complementary lectins on the surface of the cells. Sodium (meta)periodate treatment of smooth cells also decreased the adhesion ability to polystyrene, suggesting that the lectins, such as the dominating sialic acid-binding lectin, are probably localized in the extracellular polysaccharides surrounding the cells.

  6. Metal-Organic Frameworks (MOFs) as Multivalent Materials: Size Control and Surface Functionalization by Monovalent Capping Ligands.

    Science.gov (United States)

    Rijnaarts, Timon; Mejia-Ariza, Raquel; Egberink, Richard J M; van Roosmalen, Wies; Huskens, Jurriaan

    2015-07-13

    Control over particle size and composition are pivotal to tune the properties of metal organic frameworks (MOFs), for example, for biomedical applications. Particle-size control and functionalization of MIL-88A were achieved by using stoichiometric replacement of a small fraction of the divalent fumarate by monovalent capping ligands. A fluorine-capping ligand was used to quantify the surface coverage of capping ligand at the surface of MIL-88A. Size control at the nanoscale was achieved by using a monovalent carboxylic acid-functionalized poly(ethylene glycol) (PEG-COOH) ligand at different concentrations. Finally, a biotin-carboxylic acid capping ligand was used to functionalize MIL-88A to bind fluorescently labeled streptavidin as an example towards bioapplications. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  7. Core charge distribution and self assembly of columnar phases: the case of triphenylenes and azatriphenylenes

    Directory of Open Access Journals (Sweden)

    Berardi Roberto

    2007-06-01

    Full Text Available Abstract Background The relation betweeen the structure of discotic molecules and columnar properties, a crucial point for the realization of new advanced materials, is still largely unknown. A paradigmatic case is that hexa-alkyl-thio substituted triphenylenes present mesogenic behavior while the corresponding azatriphenylenes, similar in shape and chemical structure, but with a different core charge distribution, do not form any liquid crystalline mesophase. This study is aimed at investigating, with the help of computer simulations techniques, the effects on phase behaviour of changes of the charge distribution in the discotic core. Results We described the shape and the pair, dispersive and electrostatic, interactions of hexa alkyl triphenylenes by uniaxial Gay-Berne discs with embedded point charges. Gay-Berne parameters were deduced by fitting the dispersive energies obtained from an atomistic molecular dynamics simulation of a small sample of hexa-octyl-thio triphenylene molecules in columnar phase, while a genetic algorithm was used to get a minimal set of point charges that properly reproduces the ab anitio electrostatic potential. We performed Monte Carlo simulations of three molecular models: the pure Gay-Berne disc, used as a reference, the Gay-Berne disc with hexa-thio triphenylene point charges, the Gay-Berne disc with hexa-thio azatriphenylene point charges. The phase diagram of the pure model evidences a rich polymorphism, with isotropic, columnar and crystalline phases at low pressure, and the appearance of nematic phase at higher pressure. Conclusion We found that the intermolecular electrostatic potential among the cores is fundamental in sta-bilizing/destabilizing columnar phases; in particular the triphenylene charge distribution stabilizes the columnar structure, while the azatriphenylene distribution suppresses its formation in favor of the nematic phase. We believe the present model could be successfully employed as the

  8. How accurate is Poisson-Boltzmann theory for monovalent ions near highly charged interfaces?

    Science.gov (United States)

    Bu, Wei; Vaknin, David; Travesset, Alex

    2006-06-20

    Surface sensitive synchrotron X-ray scattering studies were performed to obtain the distribution of monovalent ions next to a highly charged interface. A lipid phosphate (dihexadecyl hydrogen-phosphate) was spread as a monolayer at the air-water interface to control surface charge density. Using anomalous reflectivity off and at the L3 Cs+ resonance, we provide spatial counterion (Cs+) distributions next to the negatively charged interfaces. Five decades in bulk concentrations are investigated, demonstrating that the interfacial distribution is strongly dependent on bulk concentration. We show that this is due to the strong binding constant of hydronium H3O+ to the phosphate group, leading to proton-transfer back to the phosphate group and to a reduced surface charge. The increase of Cs+ concentration modifies the contact value potential, thereby causing proton release. This process effectively modifies surface charge density and enables exploration of ion distributions as a function of effective surface charge-density. The experimentally obtained ion distributions are compared to distributions calculated by Poisson-Boltzmann theory accounting for the variation of surface charge density due to proton release and binding. We also discuss the accuracy of our experimental results in discriminating possible deviations from Poisson-Boltzmann theory.

  9. Differences on the conversion of celestite in solutions bearing monovalent ions under hydrothermal conditions

    Science.gov (United States)

    Rendón-Angeles, J. C.; Pech-Canul, M. I.; López-Cuevas, J.; Matamoros-Veloza, Z.; Yanagisawa, K.

    2006-12-01

    The replacement of SO 42- ions by monovalent ions in mineral SrSO 4 crystals was investigated under hydrothermal conditions by using aqueous solutions bearing F - and OH - ions. Experiments were conducted at various temperatures (150-250 °C) for different reaction intervals (1-96 h), with M-/SO 42- molar ratios of 1, 5 and 10, where M-=F - or OH -. The celestite crystals were completely converted into SrF 2 crystals, at 200 °C using a F -/SO 42- molar ratio=5 for 24 h. The morphology of the converted SrF 2 crystals indicated that the heteroionic conversion proceeded by a pseudomorphic replacement process, because the transformed crystals maintained their original shape and dimensions. In contrast, the SrSO 4 crystals were instantaneously converted into the Sr(OH) 2 phase by a bulk dissolution-recrystallization mechanism, resulting in the formation of large transparent acicular Sr(OH) 2 crystals. The differences on the conversion process are mainly associated with the chemical interaction between the mineral crystal and the hydrothermal fluid. In addition, the chemical stability of the converted phase with low solubility is also essential for the heteroionic conversion to proceed by the pseudomorphic replacement process.

  10. Aqueous batteries based on mixed monovalence metal ions: a new battery family.

    Science.gov (United States)

    Chen, Liang; Zhang, Leyuan; Zhou, Xufeng; Liu, Zhaoping

    2014-08-01

    As existing battery technologies struggle to meet the requirements for widespread use in the field of large-scale energy storage, new concepts are urgently needed to build batteries with high energy density, low cost, and good safety. Here, we demonstrate two new aqueous batteries based on two monovalence metal ions (Li(+) /K(+) and Na(+) /K(+) ) as charge-transfer ions, Ni1 Zn1 HCF/TiP2 O7 and Ni1 Zn1 HCF/NaTi2 (PO4 )3 . These new batteries are unlike the conventional "rocking-chair" aqueous metal-ion batteries based on the migration of one type of shuttle ion between cathode and anode. They can deliver specific energy of 46 Wh kg(-1) and 53 Wh kg(-1) based on the total mass of active materials; this is superior to current aqueous battery systems based on sodium-ion and/or potassium-ion technologies. These two new batteries together with the previously developed Li(+) /Na(+) mixed-ion battery not only constitute a new battery family for energy storage, but also greatly broaden our horizons for battery research.

  11. Potent dengue virus neutralization by a therapeutic antibody with low monovalent affinity requires bivalent engagement.

    Directory of Open Access Journals (Sweden)

    Melissa A Edeling

    2014-04-01

    Full Text Available We recently described our most potently neutralizing monoclonal antibody, E106, which protected against lethal Dengue virus type 1 (DENV-1 infection in mice. To further understand its functional properties, we determined the crystal structure of E106 Fab in complex with domain III (DIII of DENV-1 envelope (E protein to 2.45 Å resolution. Analysis of the complex revealed a small antibody-antigen interface with the epitope on DIII composed of nine residues along the lateral ridge and A-strand regions. Despite strong virus neutralizing activity of E106 IgG at picomolar concentrations, E106 Fab exhibited a ∼20,000-fold decrease in virus neutralization and bound isolated DIII, E, or viral particles with only a micromolar monovalent affinity. In comparison, E106 IgG bound DENV-1 virions with nanomolar avidity. The E106 epitope appears readily accessible on virions, as neutralization was largely temperature-independent. Collectively, our data suggest that E106 neutralizes DENV-1 infection through bivalent engagement of adjacent DIII subunits on a single virion. The isolation of anti-flavivirus antibodies that require bivalent binding to inhibit infection efficiently may be a rare event due to the unique icosahedral arrangement of envelope proteins on the virion surface.

  12. Higher cytotoxicity of divalent antibody-toxins than monovalent antibody-toxins

    Energy Technology Data Exchange (ETDEWEB)

    Won, JaeSeon; Nam, PilWon; Lee, YongChan [College of Life Sciences and Graduate School of Biotechnology, Korea University, 5-ga Anam-dong, Sungbuk-gu, Seoul 136-701 (Korea, Republic of); Choe, MuHyeon, E-mail: choemh@korea.ac.kr [College of Life Sciences and Graduate School of Biotechnology, Korea University, 5-ga Anam-dong, Sungbuk-gu, Seoul 136-701 (Korea, Republic of)

    2009-04-24

    Recombinant antibody-toxins are constructed via the fusion of a 'carcinoma-specific' antibody fragment to a toxin. Due to the high affinity and high selectivity of the antibody fragments, antibody-toxins can bind to surface antigens on cancer cells and kill them without harming normal cells [L.H. Pai, J.K. Batra, D.J. FitzGerald, M.C. Willingham, I. Pastan, Anti-tumor activities of immunotoxins made of monoclonal antibody B3 and various forms of Pseudomonas exotoxin, Proc. Natl. Acad. Sci. USA 88 (1991) 3358-3362]. In this study, we constructed the antibody-toxin, Fab-SWn-PE38, with SWn (n = 3, 6, 9) sequences containing n-time repeated (G{sub 4}S) between the Fab fragment and PE38 (38 kDa truncated form of Pseudomonas exotoxin A). The SWn sequence also harbored one cysteine residue that could form a disulfide bridge between two Fab-SWn-PE38 monomers. We assessed the cytotoxicity of the monovalent (Fab-SWn-PE38), and divalent ([Fab-SWn-PE38]{sub 2}) antibody-toxins. The cytotoxicity of the dimer against the CRL1739 cell line was approximately 18.8-fold higher than that of the monomer on the ng/ml scale, which was approximately 37.6-fold higher on the pM scale. These results strongly indicate that divalency provides higher cytotoxicity for an antibody-toxin.

  13. Independent adsorption of monovalent cations and cationic polymers at PE/PG lipid membranes

    Science.gov (United States)

    Khomich, Daria A.; Nesterenko, Alexey M.; Kostritskii, Andrei Yu; Kondinskaia, Diana A.; Ermakov, Yuri A.; Gurtovenko, Andrey A.

    2017-01-01

    Synthetic cationic polymers constitute a wide class of polymeric biocides. Commonly their antimicrobial effect is associated to their interaction with bacterial membranes. In the present study we analyze the interaction of various cationic polymers with model bacterial membranes comprised of a mixture of phosphatidylethanolamine (PE) and phosphatidylglycerol (PG). We describe a polymer-membrane interaction as a process of modification of the surface charge. It is well known that small monovalent inorganic cations (Na+, K+) cannot overcharge the surface of a bilayer containing anionic lipids. In contrast, polycations are able to overcharge anionic membranes and demonstrate a very large input to the electric field distribution at the membrane-water interface. We aimed here to study the electrostatic effects associated with the interaction of polycations of different types with a model lipid membrane whose composition closely resembles that of bacterial membranes (PE:PG = 1:4). Four different cationic polymers (polyvinylamine, polyallylamine, poly-L-lysine and polyethylenimine) were adsorbed at a model PE/PG bilayer in MD simulations. Adsorption of sodium cations was inspected separately for PE/PG bilayers of different composition and cation’s binding parameters were determined. From computational experiments and consequent theoretical analysis we concluded that sodium adsorption at anionic binding sites does not depend on the presence of polycations. Therefore, we hypothesize that antimicrobial activity of the studied cationic polymers should depend on the ionic composition of the medium.

  14. Antigenic specificity of a monovalent versus polyvalent MOMP based Chlamydia pecorum vaccine in koalas (Phascolarctos cinereus).

    Science.gov (United States)

    Kollipara, Avinash; Wan, Charles; Rawlinson, Galit; Brumm, Jacqui; Nilsson, Karen; Polkinghorne, Adam; Beagley, Kenneth; Timms, Peter

    2013-02-06

    Chlamydia continues to be a major pathogen of koalas. The bacterium is associated with ocular, respiratory and urogenital tract infections and a vaccine is considered the best option to limit the decline of mainland koala populations. Over the last 20 years, efforts to develop a chlamydial vaccine in humans have focussed on the use of the chlamydial major outer membrane protein (MOMP). Potential problems with the use of MOMP-based vaccines relate to the wide range of genetic diversity in its four variable domains. In the present study, we evaluated the immune response of koalas vaccinated with a MOMP-based C. pecorum vaccine formulated with genetically and serologically diverse MOMPs. Animals immunised with individual MOMPs developed strong antibody and lymphocyte proliferation responses to both homologous as well as heterologous MOMP proteins. Importantly, we also showed that vaccine induced antibodies which effectively neutralised various heterologous strains of koala C. pecorum in an in vitro assay. Finally, we also demonstrated that the immune responses in monovalent as well as polyvalent MOMP vaccine groups were able to recognise whole chlamydial elementary bodies, illustrating the feasibility of developing an effective MOMP based C. pecorum vaccine that could protect against a range of strains. Crown Copyright © 2013. Published by Elsevier Ltd. All rights reserved.

  15. Impact of universal mass vaccination with monovalent inactivated hepatitis A vaccines – A systematic review

    Science.gov (United States)

    Stuurman, Anke L.; Marano, Cinzia; Bunge, Eveline M.; De Moerlooze, Laurence; Shouval, Daniel

    2017-01-01

    ABSTRACT The WHO recommends integration of universal mass vaccination (UMV) against hepatitis A virus (HAV) in national immunization schedules for children aged ≥1 year, if justified on the basis of acute HAV incidence, declining endemicity from high to intermediate and cost-effectiveness. This recommendation has been implemented in several countries. Our aim was to assess the impact of UMV using monovalent inactivated hepatitis A vaccines on incidence and persistence of anti-HAV (IgG) antibodies in pediatric populations. We conducted a systematic review of literature published between 2000 and 2015 in PubMed, Cochrane Library, LILACS, IBECS identifying a total of 27 studies (Argentina, Belgium, China, Greece, Israel, Panama, the United States and Uruguay). All except one study showed a marked decline in the incidence of hepatitis A post introduction of UMV. The incidence in non-vaccinated age groups decreased as well, suggesting herd immunity but also rising susceptibility. Long-term anti-HAV antibody persistence was documented up to 17 y after a 2-dose primary vaccination. In conclusion, introduction of UMV in countries with intermediate endemicity for HAV infection led to a considerable decrease in the incidence of hepatitis A in vaccinated and in non-vaccinated age groups alike. PMID:27786671

  16. Monovalency Unleashes the Full Therapeutic Potential of the DN-30 Anti-Met Antibody*

    Science.gov (United States)

    Pacchiana, Giovanni; Chiriaco, Cristina; Stella, Maria C.; Petronzelli, Fiorella; De Santis, Rita; Galluzzo, Maria; Carminati, Paolo; Comoglio, Paolo M.; Michieli, Paolo; Vigna, Elisa

    2010-01-01

    Met, the high affinity receptor for hepatocyte growth factor, is one of the most frequently activated tyrosine kinases in human cancer and a validated target for cancer therapy. We previously developed a mouse monoclonal antibody directed against the extracellular portion of Met (DN-30) that induces Met proteolytic cleavage (receptor “shedding”) followed by proteasome-mediated receptor degradation. This translates into inhibition of hepatocyte growth factor/Met-mediated biological activities. However, DN-30 binding to Met also results in partial activation of the Met kinase due to antibody-mediated receptor homodimerization. To safely harness the therapeutic potential of DN-30, its shedding activity must be disassociated from its agonistic activity. Here we show that the DN-30 Fab fragment maintains high affinity Met binding, elicits efficient receptor shedding and down-regulation, and does not promote kinase activation. In Met-addicted tumor cell lines, DN-30 Fab displays potent cytostatic and cytotoxic activity in a dose-dependent fashion. DN-30 Fab also inhibits anchorage-independent growth of several tumor cell lines. In mouse tumorigenesis assays using Met-addicted carcinoma cells, intratumor administration of DN-30 Fab or systemic delivery of a chemically stabilized form of the same molecule results in reduction of Met phosphorylation and inhibition of tumor growth. These data provide proof of concept that monovalency unleashes the full therapeutic potential of the DN-30 antibody and point at DN-30 Fab as a promising tool for Met-targeted therapy. PMID:20833723

  17. Monovalency unleashes the full therapeutic potential of the DN-30 anti-Met antibody.

    Science.gov (United States)

    Pacchiana, Giovanni; Chiriaco, Cristina; Stella, Maria C; Petronzelli, Fiorella; De Santis, Rita; Galluzzo, Maria; Carminati, Paolo; Comoglio, Paolo M; Michieli, Paolo; Vigna, Elisa

    2010-11-12

    Met, the high affinity receptor for hepatocyte growth factor, is one of the most frequently activated tyrosine kinases in human cancer and a validated target for cancer therapy. We previously developed a mouse monoclonal antibody directed against the extracellular portion of Met (DN-30) that induces Met proteolytic cleavage (receptor "shedding") followed by proteasome-mediated receptor degradation. This translates into inhibition of hepatocyte growth factor/Met-mediated biological activities. However, DN-30 binding to Met also results in partial activation of the Met kinase due to antibody-mediated receptor homodimerization. To safely harness the therapeutic potential of DN-30, its shedding activity must be disassociated from its agonistic activity. Here we show that the DN-30 Fab fragment maintains high affinity Met binding, elicits efficient receptor shedding and down-regulation, and does not promote kinase activation. In Met-addicted tumor cell lines, DN-30 Fab displays potent cytostatic and cytotoxic activity in a dose-dependent fashion. DN-30 Fab also inhibits anchorage-independent growth of several tumor cell lines. In mouse tumorigenesis assays using Met-addicted carcinoma cells, intratumor administration of DN-30 Fab or systemic delivery of a chemically stabilized form of the same molecule results in reduction of Met phosphorylation and inhibition of tumor growth. These data provide proof of concept that monovalency unleashes the full therapeutic potential of the DN-30 antibody and point at DN-30 Fab as a promising tool for Met-targeted therapy.

  18. Crash worthy capacity of a hybridized epoxy-glass fiber aluminum columnar tube using repeated axial resistive force

    Energy Technology Data Exchange (ETDEWEB)

    Paruka, Perowansa [Jalan Politeknik, Kota Kinabalu (Malaysia); Siswanto, Waluyo Adi [Universiti Tun Hussein Onn Malaysia, Parit Raja (Malaysia); Maleque, Md Abdul [Universiti Islam Antarabangsa Malaysia, Kuala Lumpur (Malaysia); Shah, Mohd Kamal Mohd [Universiti Malaysia Sabah, Kota Kinabalu (Malaysia)

    2015-05-15

    A combination of aluminum columnar member with composite laminate to form a hybrid structure can be used as collapsible energy absorbers especially in automotive vehicular structures to protect occupants and cargo. A key advantage of aluminum member in composite is that it provides ductile and stable plastic collapse mechanisms with progressive deformation in a stable manner by increasing energy absorption during collision. This paper presents an experimental investigation on the influence of the number of hybrid epoxy glass layers in overwrap composite columnar tubes. Three columnar tube specimens were used and fabricated by hand lay-up method. Aluminum square hollow shape was combined with externally wrapped by using an isophthalic epoxy resin reinforced with glass fiber skin with an orientation angle of 0 .deg. /90 .deg. The aluminum columnar tube was used as reference material. Crushed hybrid-composite columnar tubes were prepared using one, two, and three layers to determine the crash worthy capacity. Quasi-static crush test was conducted using INSTRON machine with an axial loading. Results showed that crush force and the number of layers were related to the enhancement of energy absorption before the collapse of columnar tubes. The energy absorption properties of the crushed hybrid-composite columnar tubes improved significantly with the addition of layers in the overwrap. Microscopic analysis on the modes of epoxy-glass fiber laminate failure was conducted by using scanning electron microscopy.

  19. Characterization of isolates of Flavobacterium psychrophilum associated with coldwater disease or rainbow trout fry syndrome II: serological studies

    DEFF Research Database (Denmark)

    Lorenzen, Ellen; Olesen, Niels Jørgen

    1997-01-01

    The possibility of seroIogical differentiation between isolates of Flavobacterium psychrophilum was analyzed by ELISA and slide agglutination. Twenty-five Danish isolates and 20 isolates from other European countries were studied using polyclonal rabbit antisera and whole-cell preparations...... species with different disease signs, The ELISA showed the existence of different serotypes most distinctly, but slide agglutination supported the ELISA results. Three serotypes were found among the isolates studied: 1 major serotype (serotype Th) represented most of the Danish isolates and isolates from...

  20. Radiological examination of the spinal column in farmed rainbow trout Oncorhynchus mykiss (Walbaum): experiments with Flavobacterium psychrophilum and oxytetracycline

    DEFF Research Database (Denmark)

    Madsen, Lone; Arnbjerg, J.; Dalsgaard, Inger

    2001-01-01

    Flavobacterium psychrophilum and oxytetracycline have both been associated with spinal deformities in salmonids. Experiments were carried out to investigate whether infection with F, psychrophilum or medication with oxytetracycline (OTC) at the fry stage would result in an increased occurrence...... of vertebral column deformities in rainbow trout, Oncorhynchus mykiss (Walbaum). Fish were on-grown for 9 months and examined by radiology at the end of the experiments. There was a relationship between infection by F. psychrophilum and deformities of the spinel column, if fish with more than 10 affected...

  1. Comparative Genome Analysis Provides Insights into the Pathogenicity of Flavobacterium psychrophilum

    Science.gov (United States)

    Castillo, Daniel; Christiansen, Rói Hammershaimb; Dalsgaard, Inger; Madsen, Lone; Espejo, Romilio

    2016-01-01

    Flavobacterium psychrophilum is a fish pathogen in salmonid aquaculture worldwide that causes cold water disease (CWD) and rainbow trout fry syndrome (RTFS). Comparative genome analyses of 11 F. psychrophilum isolates representing temporally and geographically distant populations were used to describe the F. psychrophilum pan-genome and to examine virulence factors, prophages, CRISPR arrays, and genomic islands present in the genomes. Analysis of the genomic DNA sequences were complemented with selected phenotypic characteristics of the strains. The pan genome analysis showed that F. psychrophilum could hold at least 3373 genes, while the core genome contained 1743 genes. On average, 67 new genes were detected for every new genome added to the analysis, indicating that F. psychrophilum possesses an open pan genome. The putative virulence factors were equally distributed among isolates, independent of geographic location, year of isolation and source of isolates. Only one prophage-related sequence was found which corresponded to the previously described prophage 6H, and appeared in 5 out of 11 isolates. CRISPR array analysis revealed two different loci with dissimilar spacer content, which only matched one sequence in the database, the temperate bacteriophage 6H. Genomic Islands (GIs) were identified in F. psychrophilum isolates 950106-1/1 and CSF 259–93, associated with toxins and antibiotic resistance. Finally, phenotypic characterization revealed a high degree of similarity among the strains with respect to biofilm formation and secretion of extracellular enzymes. Global scale dispersion of virulence factors in the genomes and the abilities for biofilm formation, hemolytic activity and secretion of extracellular enzymes among the strains suggested that F. psychrophilum isolates have a similar mode of action on adhesion, colonization and destruction of fish tissues across large spatial and temporal scales of occurrence. Overall, the genomic characterization and

  2. Effect of Bacteriophages on the Growth of Flavobacterium psychrophilum and Development of Phage-Resistant Strains.

    Science.gov (United States)

    Christiansen, Rói Hammershaimb; Madsen, Lone; Dalsgaard, Inger; Castillo, Daniel; Kalatzis, Panos G; Middelboe, Mathias

    2016-05-01

    The controlling effect of single and multiple phages on the density of Flavobacterium psychrophilum at different initial multiplicity of infection (MOI) was assessed in batch cultures to explore the potential for phage-based treatment of this important fish pathogen. A high initial phage concentration (MOI = 0.3-4) was crucial for efficient viral lysis, resulting in a 10(4)-10(5)-fold reduction of phage-sensitive cells (both single phages and phage cocktails), which was maintained throughout the incubation (>10 days). Following cell lysis, regrowth of phage-resistant strains was examined and resistant strains were isolated for further characterization. The application of a mathematical model allowed simulation of phage-host interactions and resistance development, confirming indications from strain isolations that phage-sensitive strains dominated the regrowing population (>99.8%) at low MOI and phage-resistant strains (>87.8%) dominated at high MOI. A cross-infectivity test covering 68 isolated strains and 22 phages resulted in 23 different host susceptibility patterns, with 20 of the isolates being resistant to all the applied phages. Eleven isolated strains with different susceptibility patterns had lower growth rates (0.093 to 0.31 h(-1)) than the host strain (0.33 h(-1)), while 10 of 14 examined strains had lost the ability to take up specific substrates as shown by BIOLOG profiles. Despite increased selection for phage resistance at high MOI, the results emphasize that high initial MOI is essential for fast and effective control of F. psychrophilum infection and suggest that the small populations of resistant clones had reduced competitive abilities relative to the sensitive ancestral strain.

  3. Genomics and physiology of a marine flavobacterium encoding a proteorhodopsin and a xanthorhodopsin-like protein.

    Directory of Open Access Journals (Sweden)

    Thomas Riedel

    Full Text Available Proteorhodopsin (PR photoheterotrophy in the marine flavobacterium Dokdonia sp. PRO95 has previously been investigated, showing no growth stimulation in the light at intermediate carbon concentrations. Here we report the genome sequence of strain PRO95 and compare it to two other PR encoding Dokdonia genomes: that of strain 4H-3-7-5 which shows the most similar genome, and that of strain MED134 which grows better in the light under oligotrophic conditions. Our genome analysis revealed that the PRO95 genome as well as the 4H-3-7-5 genome encode a protein related to xanthorhodopsins. The genomic environment and phylogenetic distribution of this gene suggest that it may have frequently been recruited by lateral gene transfer. Expression analyses by RT-PCR and direct mRNA-sequencing showed that both rhodopsins and the complete β-carotene pathway necessary for retinal production are transcribed in PRO95. Proton translocation measurements showed enhanced proton pump activity in response to light, supporting that one or both rhodopsins are functional. Genomic information and carbon source respiration data were used to develop a defined cultivation medium for PRO95, but reproducible growth always required small amounts of yeast extract. Although PRO95 contains and expresses two rhodopsin genes, light did not stimulate its growth as determined by cell numbers in a nutrient poor seawater medium that mimics its natural environment, confirming previous experiments at intermediate carbon concentrations. Starvation or stress conditions might be needed to observe the physiological effect of light induced energy acquisition.

  4. Paralytic poliomyelitis associated with Sabin monovalent and bivalent oral polio vaccines in Hungary.

    Science.gov (United States)

    Estívariz, Concepción F; Molnár, Zsuzsanna; Venczel, Linda; Kapusinszky, Beatrix; Zingeser, James A; Lipskaya, Galina Y; Kew, Olen M; Berencsi, György; Csohán, Agnes

    2011-08-01

    Historical records of patients with vaccine-associated paralytic poliomyelitis (VAPP) in Hungary during 1961-1981 were reviewed to assess the risk of VAPP after oral polio vaccine (OPV) administration. A confirmed VAPP case was defined as a diagnosis of paralytic poliomyelitis and residual paralysis at 60 days in a patient with an epidemiologic link to the vaccine. Archived poliovirus isolates were retested using polymerase chain reaction and sequencing of the viral protein 1 capsid region. This review confirmed 46 of 47 cases previously reported as VAPP. Three cases originally linked to monovalent OPV (mOPV) 3 and one case linked to mOPV1 presented after administration of bivalent OPV 1 + 3 (bOPV). The adjusted VAPP risk per million doses administered was 0.18 for mOPV1 (2 cases/11.13 million doses), 2.96 for mOPV3 (32 cases/10.81 million doses), and 12.82 for bOPV (5 cases/390,000 doses). Absence of protection from immunization with inactivated poliovirus vaccine or exposure to OPV virus from routine immunization and recent injections could explain the higher relative risk of VAPP in Hungarian children. In polio-endemic areas in which mOPV3 and bOPV are needed to achieve eradication, the higher risk of VAPP would be offset by the high risk of paralysis due to wild poliovirus and higher per-dose efficacy of mOPV3 and bOPV compared with trivalent OPV.

  5. Deposition kinetics of extracellular polymeric substances (EPS) on silica in monovalent and divalent salts.

    Science.gov (United States)

    Zhu, Pingting; Long, Guoyu; Ni, Jinren; Tong, Meiping

    2009-08-01

    The deposition kinetics of extracellular polymeric substances (EPS) on silica surfaces were examined in both monovalent and divalent solutions under a variety of environmentally relevant ionic strength and pH conditions by employing a quartz crystal microbalance with dissipation (DCM-D). Soluble EPS (SEPS) and bound EPS (BEPS) were extracted from four bacterial strains with different characteristics. Maximum favorable deposition rates (k(fa)) were observed for all EPS at low ionic strengths in both NaCl and CaCl2 solutions. With the increase of ionic strength, k(fa) decreased due to the simultaneous occurrence of EPS aggregation in solutions. Deposition efficiency (alpha; the ratio of deposition rates obtained under unfavorable versus corresponding favorable conditions) for all EPS increased with increasing ionic strength in both NaCl and CaCl2 solutions, which agreed with the trends of zeta potentials and was consistent with the classic Derjaguin-Landau-Verwey-Overbeek (DLVO) theory. Comparison of alpha for SEPS and BEPS extracted from the same strain showed that the trends of alpha did not totally agree with trends of zeta potentials, indicating the deposition kinetics of EPS on silica surfaces were not only controlled by DLVO interactions, but also non-DLVO forces. Close comparison of alpha for EPS extracted from different sources showed alpha increased with increasing proteins to polysaccharides ratio. Subsequent experiments for EPS extracted from the same strain but with different proteins to polysaccharides ratios and from activated sludge also showed that alpha were largest for EPS with greatest proteins to polysaccharides ratio. Additional experiments for pure protein and solutions with different pure proteins to pure saccharides ratios further corroborated that larger proteins to polysaccharides ratio resulted in greater EPS deposition.

  6. Discotic columnar liquid crystal studied in the bulk and nanoconfined states by molecular dynamics simulation.

    Science.gov (United States)

    Busselez, Rémi; Cerclier, Carole V; Ndao, Makha; Ghoufi, Aziz; Lefort, Ronan; Morineau, Denis

    2014-10-07

    A prototypical Gay Berne discotic liquid crystal was studied by means of molecular dynamics simulations both in the bulk state and under confinement in a nanoporous channel. The phase behavior of the confined system strongly differs from its bulk counterpart: the bulk isotropic-to-columnar transition is replaced by a continuous ordering from a paranematic to a columnar phase. Moreover, a new transition is observed at a lower temperature in the confined state, which corresponds to a reorganization of the intercolumnar order. It reflects the competing effects of pore surface interaction and genuine hexagonal packing of the columns. The translational molecular dynamics in the different phases has been thoroughly studied and discussed in terms of collective relaxation modes, non-Gaussian behavior, and hopping processes.

  7. The tumor suppressor PTEN and the PDK1 kinase regulate formation of the columnar neural epithelium.

    Science.gov (United States)

    Grego-Bessa, Joaquim; Bloomekatz, Joshua; Castel, Pau; Omelchenko, Tatiana; Baselga, José; Anderson, Kathryn V

    2016-01-26

    Epithelial morphogenesis and stability are essential for normal development and organ homeostasis. The mouse neural plate is a cuboidal epithelium that remodels into a columnar pseudostratified epithelium over the course of 24 hr. Here we show that the transition to a columnar epithelium fails in mutant embryos that lack the tumor suppressor PTEN, although proliferation, patterning and apical-basal polarity markers are normal in the mutants. The Pten phenotype is mimicked by constitutive activation of PI3 kinase and is rescued by the removal of PDK1 (PDPK1), but does not depend on the downstream kinases AKT and mTORC1. High resolution imaging shows that PTEN is required for stabilization of planar cell packing in the neural plate and for the formation of stable apical-basal microtubule arrays. The data suggest that appropriate levels of membrane-associated PDPK1 are required for stabilization of apical junctions, which promotes cell elongation, during epithelial morphogenesis.

  8. Modelling the viscoplastic behavior and the heterogeneous intracrystalline deformation of columnar ice polycrystals

    Energy Technology Data Exchange (ETDEWEB)

    Lebensohn, Ricardo A [Los Alamos National Laboratory; Montagnat, Maurine [LGGE (FRANCE); Mansuy, Philippe [MICHELIN (FRANCE); Duval, Paul [LGGE (FRANCE); Philip, A [LGGE (FRANCE)

    2008-01-01

    A full-field formulation based on Fast Fourier Transforms (FFT) has been adapted and used to predict the micromechanical fields that develop in columnar Ih ice polycrystals deforming in compression by dislocation creep. The predicted intragranular mechanical fields are in qualitative good agreement with experimental observations, in particular those involving the formation of shear and kink bands. These localization bands are associated with the large internal stresses that develop during creep in such anisotropic material, and their location, intensity, morphology and extension are found to depend strongly on the crystallographic orientation of the grains and on their interaction with neighbor crystals. The predictions of the model are also discussed in relation with the deformation of columnar sea and lake ice, and with the mechanical behavior of granular ice of glaciers and polar ice sheets, as well.

  9. Smectic and columnar liquid crystals concepts and physical properties illustrated by experiments

    CERN Document Server

    Oswald, Patrick

    2005-01-01

    Liquid crystals allow us to perform experiments that provide insight into fundamental problems of modern physics, such as phase transitions, frustration, elasticity, hydrodynamics, defects, growth phenomena, and optics. Smectic and Columnar Liquid Crystals: Concepts and Physical Properties Illustrated by Experiments is a result of personal research and of the graduate lectures given by the authors at the École Normale Supérieure de Lyon and the University of Paris VII, respectively. The book examines lamellar (smectic) and columnar liquid crystals, which, in addition to orientational order, possess 1D, 2D or 3D positional order. This volume illustrates original physical concepts using methodically numerous experiments, theoretical developments, and diagrams. Topics include rheology and plasticity, ferroelectricity, analogies with superconductors, hexatic order and 2D-melting, equilibrium shapes, facetting, and the Mullins-Sekerka instability, as well as phase transitions in free films and membrane vibration...

  10. Polar order in columnar phase made of polycatenar bent-core molecules.

    Science.gov (United States)

    Gorecka, Ewa; Pociecha, Damian; Matraszek, Joanna; Mieczkowski, Jozef; Shimbo, Yoshio; Takanishi, Yoichi; Takezoe, Hideo

    2006-03-01

    Columnar phases made of polycatenar molecules with bent-shaped mesogenic cores are studied. The polar order in this system is associated with the change of the column building blocks from flat disks (Colh phase) into cones (Colh PA phase), which allows for axial polarization of the columns. The nature of the Colh and Colh PA phase transition changes from first order for short homologues to continuous for the longest one. This can be attributed to decreasing intercolumnar interactions due to broadening of the columnar scaffold made of partially melted terminal alkyl chains. Decrease of intercolumnar interactions is also responsible for a strong increase of the pretransitional fluctuations in the Colh phase. The mesophase observed for the longest homologues is reminiscent of the relaxor phase observed for solid crystals.

  11. Improved Pinning Center Morphology in HTS with Order-of-Magnitude Increase in Jc and Bpin Compared to Columnar Pinning

    Institute of Scientific and Technical Information of China (English)

    2003-01-01

    The motivation for continuouscolumnar pinning centers has been to provide maximum Upin. It has been assumed that this provides the best Jc and Bpin. Limitations on Jc and Bpin observed for columnar pinning have been attributed to degradation of the order parameter and Tc. We examine columnar pinning by ionic damage and conclude instead that geometrical effects of columnar pinningon percolation path and on the number of pinning centers are the dominant limitations of columnar pinning, leading to a limit of Bpin~4 T. Evidence suggests that multiple-in-line-defects (MILD) are far better suited to increase Jc and Bpin. The morphology of MILD pinning is reviewed. Ion energy loss per unit distance, Se, is found to be most promising in a regime almost diametrically opposite to that sought to maximize Upin. We expect Jc~106 A/cm2 and Bpin>40 T from MILD pinning,despite sharply decreased Upin.Experimental confirmation is proposed.

  12. Long segments of columnar-lined lower esophagus are not always metaplastic

    Directory of Open Access Journals (Sweden)

    Antonio Dias-Pereira

    2015-07-01

    Full Text Available The presence of columnar epithelium in the esophagus is associated with two conditions: Barrett's esophagus and heterotopic gastric mucosa. The former results from the metaplastic replacement of the normal distal squamous esophageal lining, is associated with gastroesophageal reflux and is a pre-neoplastic condition. The second is thought as a congenital condition, resulting from the incomplete squamous epithelialization of the esophagus during embryologic development. It is found mainly in the cervical esophagus. Histologically, Barrett's esophagus is composed of an admixture of cardiac mucosa, oxintocardiac mucosa and intestinal metaplasia. Most of heterotopic gastric mucosa consists of oxyntic mucosa where the mucosal glands are straight and composed of parietal and chief cells. There are few reports of heterotopic gastric mucosa in the lower esophagus, generally presenting as small islands. In the present report, a series of four cases of large lower esophageal heterotopic gastric mucosa is described. All patients were initially misdiagnosed with Barrett's esophagus and referred for surveillance. The correct diagnosis was based in endoscopic and histological features. In all, a circular tiny strip of squamous mucosa was observed at endoscopy between the lower end of the columnar-lined esophagus and the esophagogastric junction, defined as the proximal end of the gastric folds. Biopsy samples taken from the columnar-lined segments of the four patients showed pure oxyntic mucosa. When columnar-lined esophagus is observed in the distal esophagus not in continuity with gastric mucosa, the diagnosis of heterotopic gastric mucosa must be thought and confirmed histologically by the presence of pure oxyntic mucosa.

  13. Organization of columnar inputs in the third optic ganglion of a highly visual crab.

    Science.gov (United States)

    Bengochea, Mercedes; Berón de Astrada, Martín

    2014-01-01

    Motion information provides essential cues for a wide variety of animal behaviors such as mate, prey, or predator detection. In decapod crustaceans and pterygote insects, visual codification of object motion is associated with visual processing in the third optic neuropile, the lobula. In this neuropile, tangential neurons collect motion information from small field columnar neurons and relay it to the midbrain where behavioral responses would be finally shaped. In highly ordered structures, detailed knowledge of the neuroanatomy can give insight into their function. In spite of the relevance of the lobula in processing motion information, studies on the neuroarchitecture of this neuropile are scant. Here, by applying dextran-conjugated dyes in the second optic neuropile (the medulla) of the crab Neohelice, we mass stained the columnar neurons that convey visual information into the lobula. We found that the arborizations of these afferent columnar neurons lie at four main lobula depths. A detailed examination of serial optical sections of the lobula revealed that these input strata are composed of different number of substrata and that the strata are thicker in the centre of the neuropile. Finally, by staining the different lobula layers composed of tangential processes we combined the present characterization of lobula input strata with the previous characterization of the neuroarchitecture of the crab's lobula based on reduced-silver preparations. We found that the third lobula input stratum overlaps with the dendrites of lobula giant tangential neurons. This suggests that columnar neurons projecting from the medulla can directly provide visual input to the crab's lobula giant neurons. Copyright © 2014 Elsevier Ltd. All rights reserved.

  14. Porosity Study of Hybrid Silica Mesostructure in Aluminium Oxide Membrane Columnar by Cyclic Voltammetry Method

    Directory of Open Access Journals (Sweden)

    M.N. Jalil

    2011-12-01

    Full Text Available Silica mesostructure has been grown within with a porous aluminium oxide membrane columnar material (hybrid-AOM. This was prepared using a sol-gel technique with Pluronic P123 triblock copolymer as the structure-directing agent and tetraethyl orthosilicate as the inorganic source. The porosity of the hybrid-AOM after ethanol extraction was calculated from the cyclic voltammetry response of a neutral probe (FcMeOH, using Randles-Sevčik equation.

  15. Use of nanoporous columnar thin film in the wafer-level packaging of MEMS devices

    Science.gov (United States)

    Lee, Byung-Kee; Choi, Dong-Hoon; Yoon, Jun-Bo

    2010-04-01

    This paper presents a new packaging technology that uses a nanoporous columnar thin film to seal microelectromechanical system (MEMS) devices at the wafer level. In the proposed packaging process, the processing temperature is 350 °C. The process is relatively inexpensive compared to wafer level packaging processes, because the wafer-bonding step is eliminated and the die size is shrunk. In the suggested approach, a sputtered columnar thin film at room temperature forms vertical nanopores as etch holes, and an air cavity is formed by the removal of a sacrificial layer through the nanopores in the columnar membrane. Subsequent hermetic vacuum packaging of the cavity is achieved by depositing thin films over the membrane under low pressure. The hermeticity of the packaging was verified by using an optical surface morphology microscope to measure the deflection change of the sealing membrane before and after breaking of the vacuum through an interconnected membrane. The long-term hermeticity was monitored by measuring the maximum central deflection of the PECVD sealing layer over a period of 170 days. The precise pressure (0.7 Torr) and short-term (30 days) pressure change inside the cavity were measured by encapsulated Ni Pirani gauges, representing packaged freestanding MEMS devices.

  16. Immunohistochemical/histochemical double staining method in the study of the columnar metaplasia of the oesophagus

    Directory of Open Access Journals (Sweden)

    D. Cabibi

    2014-03-01

    Full Text Available Intestinal metaplasia in Barrett’s oesophagus (BO represents an important risk factor for oesophageal adenocarcinoma. Instead, few and controversial data are reported about the progression risk of columnar-lined oesophagus without intestinal metaplasia (CLO, posing an issue about its clinical management. The aim was to evaluate if some immunophenotypic changes were present in CLO independently of the presence of the goblet cells. We studied a series of oesophageal biopsies from patients with endoscopic finding of columnar metaplasia, by performing some immunohistochemical stainings (CK7, p53, AuroraA combined with histochemistry (Alcian-blue and Alcian/PAS, with the aim of simultaneously assess the histochemical features in cells that shows an aberrant expression of such antigens. We evidenced a cytoplasmic expression of CK7 and a nuclear expression of Aurora A and p53,  both in goblet cells of BO and in non-goblet cells of CLO, some of which showing mild dysplasia. These findings suggest that some immunophenotypic changes are present in CLO and they can precede the appearance of the goblet cells or can be present independently of them, confirming the conception of BO as the condition characterized by any extention of columnar epithelium. This is the first study in which a combined immunohistochemical/histochemical method has been applied to Barrett pathology.

  17. Rock Cracking Indices for Improved Tunnel Support Design: A Case Study for Columnar Jointed Rock Masses

    Science.gov (United States)

    Feng, Xia-Ting; Hao, Xian-Jie; Jiang, Quan; Li, Shao-jun; Hudson, John A.

    2016-06-01

    Measurements indicate that the development of cracking is a key feature relating to the strength and collapse of a columnar jointed rock mass. In this context, a new support design method utilising rock cracking indices for columnar jointed rock mass under high stress is proposed to restrain the development of cracking in the surrounding rock mass. The method involves limiting the cracking evolution of the surrounding rock mass by designing the appropriate parameters and time of installation of the support system. Two indices are suggested: the allowable depth of the excavation damaged zone (EDZ); and the allowable damage extent of the rock mass in the EDZ. The method involves limiting the evolution of cracking in the surrounding rock mass by designing the parameters and time of installation of the support system. The support system should have a suitable stiffness and installation time so as to restrain the evolution of the depth and damage extent of the EDZ within the surrounding rock. Therefore, the depth and damage extent of the EDZ, as well as the axial stress in the anchor bolts, are calculated at different distances between the support location and the tunnel working face to find the appropriate stiffness and installation time of the support system. The method has been successfully adopted to determine the thickness of shotcrete, the arrangement and installation time of rockbolts, and other parameters, for five large diversion tunnels at the Baihetan hydropower station, China, which were excavated in columnar jointed rock masses.

  18. Preparation and characterization of vertically columnar boron doped diamond array electrode

    Energy Technology Data Exchange (ETDEWEB)

    Zhao, Yang; Yu, Hongtao; Quan, Xie, E-mail: quanxie@dlut.edu.cn; Chen, Shuo; Zhao, Huimin; Zhang, Yaobin

    2014-06-01

    A vertically columnar boron doped diamond (BDD) array electrode was fabricated by microwave plasma chemical vapor deposition. Observed by scanning electron microscopy, the fabricated samples were structured with aligned columns whose diameter and height was 8 μm and 12 μm, respectively, and the minimum interval of neighboring columns was 2 μm. The results of electrochemistry measurement showed that the columnar BDD array electrode possessed high oxygen evolution potential and low background current. Besides that, comparing with flat BDD electrode, the columnar BDD array electrode showed higher electrochemical activity (due to its inner active surface being up to 4.25 cm{sup 2}), lower impedance of electric double layer, and especially enhanced electrical response signal (2.12 μA/μM, 4 times of flat BDD in glucose detection as a sample). These excellent performances may open the door for the BDD materials to be applied in wide areas including electrochemical detection, electrochemistry degradation, electrochemical synthesis, and so on.

  19. Diversity and Geographical Distribution of Flavobacterium psychrophilum Isolates and Their Phages: Patterns of Susceptibility to Phage Infection and Phage Host Range

    DEFF Research Database (Denmark)

    Castillo, Daniel; Christiansen, Rói Hammershaimb; Espejo, Romilio

    2014-01-01

    Flavobacterium psychrophilum is an important fish pathogen worldwide that causes cold water disease (CWD) or rainbow trout fry syndrome (RTFS). Phage therapy has been suggested as an alternative method for the control of this pathogen in aquaculture. However, effective use of bacteriophages in di...

  20. Evaluation of the immune response in rainbow trout fry, Oncorhynchus mykiss (Walbaum), after waterborne exposure to Flavobacterium psychrophilum and/or hydrogen peroxide

    DEFF Research Database (Denmark)

    Henriksen, Maya Maria Mihályi; Kania, P. W.; Buchmann, Kurt;

    2015-01-01

    The immune response in rainbow trout fry against Flavobacterium psychrophilum was elucidated using an immersion-based challenge with or without prior exposure to hydrogen peroxide (H2O2). Samples were taken from the head kidney 4, 48, 125 and 192 h after immersion, and the regulation of several...

  1. Proinflammatory cytokine and cytokine receptor gene expression kinetics following challenge with Flavobacterium psychrophilum in resistant and susceptible lines of rainbow trout (Oncorhynchus mykiss)

    Science.gov (United States)

    Flavobacterium psychrophilum (Fp) is the causative agent of bacterial cold water disease (BCWD) which causes appreciable economic losses in rainbow trout aquaculture. We previously reported development of a genetic line, designated ARS-Fp-R that exhibits higher survival relative to a susceptible lin...

  2. Differential expression of long non-coding RNAs in three genetic lines of rainbow trout (Oncorhynchus mykiss) in response to infection with Flavobacterium psychrophilum

    Science.gov (United States)

    Bacterial cold-water disease caused by Flavobacterium psychrophilum is one of the major causes of mortality of salmonids. Three genetic lines of rainbow trout designated as ARS-Fp-R (resistant), ARS-Fp-C (control) and ARS-Fp-S (susceptible) have significant differences in survival rate following F. ...

  3. Inversion of the haze aerosol sky columnar AVSD in central China by combining multiple ground observation equipment.

    Science.gov (United States)

    Ma, Yingying; Gong, Wei; Wang, Lunche; Zhang, Ming; Chen, Zhongyong; Li, Jun; Yang, Jian

    2016-04-18

    Wuhan is the biggest city in China that has been facing an increasingly serious problem of air pollution in the recent years. In order to understand the mechanism of haze formation and diffusion, it is very important to obtain multiple atmospheric parameters. Columnar aerosol volume size distribution (AVSD) is an important atmospheric parameter in this regard, and utilizing CIMEL sun-photometer data to obtain this parameter has become the most popular method. However, currently, the widely used retrieval algorithms cannot be accessed using an open source code, and thus the retrieval of columnar AVSD is still a challenging task.. In this article, we introduce a new method that combines partial least squares (PLS) and genetic algorithm (GA) for the retrieval of columnar AVSD. By using this new method, we could obtain credible results even during hazy periods, despite the fact that our sun-photometer did not participate in the AERONET program and we did not use an official data processing method. First, it was assumed that columnar AVSD obeys the double logarithmic normal distribution function. Second, the relationship between the columnar AVSD and the AVSD on earth's surface was established using the partial least squares (PLS) method. Finally, the initial distribution parameters were adjusted through GA to obtain an optimal solution. This new method can improve the accuracy and reduce the computational difficulties faced in the retrieval of columnar AVSD in the absence of AREONET-based algorithm.

  4. Photoirradiation Caused Controllable Wettability Switching of Sputtered Highly Aligned c-Axis-Oriented Zinc Oxide Columnar Films

    Directory of Open Access Journals (Sweden)

    P. W. Chi

    2014-01-01

    Full Text Available This study presents the microstructure morphology and UV photoirradiation coupling effects of the c-axis-oriented zinc oxide (ZnO columnar films. Highly aligned c-axis-oriented films have been deposited onto glass substrates at room temperature by radio-frequency (RF magnetron sputtering without introducing any oxygen source under different sputtering powers ranging from 50 to 150 W. Self-assembled ZnO columnar structures that were successfully obtained belong to wurtzite structure, and the corresponding columnar structures and crystalline orientation were confirmed by the FE-SEM and XRD, respectively. All the ZnO columnar films exhibit good transparency with a visible light averaged transmittance over 82%. According to water contact angle (CA measurement, ZnO columnar films exhibit hydrophobic behavior. After exposing to photoirradiation under ultraviolet (UV environment, all the ZnO samples showed remarkable transition from hydrophobic to superhydrophilic surfaces and could return to their original hydrophobicity after being placed in the dark. It is demonstrated that the controllable wettability of ZnO columnar films under changing between the UV photoirradiation and dark storage is due to the surface charges accumulation and discharging processes. As a result, this study could provide important applications for many fields such as ZnO-based hybrid sensors/solar cells functional devices with photoirradiation disinfection surfaces accompanied with reversible wettability switches.

  5. Effects of monovalent and divalent salts on the phospholipid and fatty acid compositions of a halotolerant Planococcus sp.

    Science.gov (United States)

    Miller, K J

    1986-09-01

    The phospholipid headgroup and fatty acid compositions of a halotolerant Planococcus sp. (strain A4a) were examined when cells were grown in the presence of high concentrations of a variety of salts. The fatty acid composition of Planococcus sp. strain A4a was altered primarily as a function of the osmolality of the growth medium. The phospholipid headgroup composition was influenced by both the osmolality of the growth medium and the nature of the cation species present. An increase in the cardiolipin/phosphatidylglycerol molar ratio was detected when cells were grown in the presence of high concentrations of monovalent cations.

  6. Single crystal structures of thallium (I) thorium fluorides and crystal chemistry of monovalent tetravalent cation pentafluorides

    Science.gov (United States)

    Oudahmane, Abdelghani; El-Ghozzi, Malika; Jouffret, Laurent; Avignant, Daniel

    2015-12-01

    Two thallium (I) thorium (IV) fluorides, TlTh3F13 and TlThF5 were obtained by solid state synthesis and their crystal structures determined from single crystal X-ray diffraction data recorded at room temperature with an APEX-II CCD diffractometer. TlTh3F13 is orthorhombic, space group Pmc21, with a=8.1801(2) Å, b=7.4479(2) Å, c=8.6375(2) Å, V=526.24(2) Å3, Z=2 and TlThF5 is monoclinic, space group P21/n, with a=8.1128(5) Å, b=7.2250(4) Å, c=8.8493(6) Å, β=116.683(3)°, V=463.46(5) Å3, Z=4. The structure of TlTh3F13 comprises layers of corner and edge-sharing ThF9 polyhedra further linked by chains of trans connected tricapped trigonal prisms ThF9 through corners and edges. The three dimensional thorium frameworks delimits channels parallel to [0 0 1] where the 11-coordinated Tl+ ions are arranged into double columns located in mirror planes of the structure. TlTh3F13 is isotypic with RbTh3F13, RbU3F13 and with one of the two polymorphs of CsTh3F13. The structure of TlThF5 may be regarded as a layer structure built up from the regular succession of 2∞[ M ‧F5 ] - corrugated layers further held by the Tl+ ions along the [1 0 1 ̅] direction. The layers are built up from edge and corner-sharing thorium polyhedra where each (ThF9)5- monocapped square antiprism is connected to five others by sharing three edges and two corners. TlThF5 is isostructural with β-NH4UF5 and with one of the polymorphs of CsThF5. A comparison of the different structural types of MM‧F5 pentafluorides is presented and a diagram of repartition of their structures is given. From the comparison of the Tl structures with their Rb or Cs homologs, where very similar monovalent cation environments are observed it should be concluded to a stereochemically inactivity of the 6s2 lone pair of Tl(I) in both TlTh3F13 and TlThF5, contrary to what is observed in richer Tl(I) content Tl3ThF7 fluorothorate.

  7. High quality draft genome sequence of Flavobacterium rivuli type strain WB 3.3-2(T) (DSM 21788(T)), a valuable source of polysaccharide decomposing enzymes.

    Science.gov (United States)

    Hahnke, Richard L; Stackebrandt, Erko; Meier-Kolthoff, Jan P; Tindall, Brian J; Huang, Sixing; Rohde, Manfred; Lapidus, Alla; Han, James; Trong, Stephan; Haynes, Matthew; Reddy, T B K; Huntemann, Marcel; Pati, Amrita; Ivanova, Natalia N; Mavromatis, Konstantinos; Markowitz, Victor; Woyke, Tanja; Göker, Markus; Kyrpides, Nikos C; Klenk, Hans-Peter

    2015-01-01

    Flavobacterium rivuli Ali et al. 2009 emend. Dong et al. 2013 is one of about 100 species in the genus Flavobacterium (family Flavobacteriacae, phylum Bacteroidetes) with a validly published name, and has been isolated from the spring of a hard water rivulet in Northern Germany. Including all type strains of the genus Myroides and Flavobacterium into the 16S rRNA gene sequence phylogeny revealed a clustering of members of the genus Myroides as a monophyletic group within the genus Flavobacterium. Furthermore, F. rivuli WB 3.3-2(T) and its next relatives seem more closely related to the genus Myroides than to the type species of the genus Flavobacterium, F. aquatile. The 4,489,248 bp long genome with its 3,391 protein-coding and 65 RNA genes is part of the G enomic E ncyclopedia of B acteria and A rchaea project. The genome of F. rivuli has almost as many genes encoding carbohydrate active enzymes (151 CAZymes) as genes encoding peptidases (177). Peptidases comprised mostly metallo (M) and serine (S) peptidases. Among CAZymes, 30 glycoside hydrolase families, 10 glycosyl transferase families, 7 carbohydrate binding module families and 7 carbohydrate esterase families were identified. Furthermore, we found four polysaccharide utilization loci (PUL) and one large CAZy rich gene cluster that might enable strain WB 3.3-2(T) to decompose plant and algae derived polysaccharides. Based on these results we propose F. rivuli as an interesting candidate for further physiological studies and the role of Bacteroidetes in the decomposition of complex polymers in the environment.

  8. Monovalent Cation Doping of CH3NH3PbI3 for Efficient Perovskite Solar Cells.

    Science.gov (United States)

    Abdi-Jalebi, Mojtaba; Dar, M Ibrahim; Sadhanala, Aditya; Senanayak, Satyaprasad P; Grätzel, Michael; Friend, Richard H

    2017-03-19

    Here, we demonstrate the incorporation of monovalent cation additives into CH3NH3PbI3 perovskite in order to adjust the optical, excitonic, and electrical properties. The possibility of doping was investigated by adding monovalent cation halides with similar ionic radii to Pb(2+), including Cu(+), Na(+), and Ag(+). A shift in the Fermi level and a remarkable decrease of sub-bandgap optical absorption, along with a lower energetic disorder in the perovskite, was achieved. An order-of-magnitude enhancement in the bulk hole mobility and a significant reduction of transport activation energy within an additive-based perovskite device was attained. The confluence of the aforementioned improved properties in the presence of these cations led to an enhancement in the photovoltaic parameters of the perovskite solar cell. An increase of 70 mV in open circuit voltage for AgI and a 2 mA/cm(2) improvement in photocurrent density for NaI- and CuBr-based solar cells were achieved compared to the pristine device. Our work paves the way for further improvements in the optoelectronic quality of CH3NH3PbI3 perovskite and subsequent devices. It highlights a new avenue for investigations on the role of dopant impurities in crystallization and controls the electronic defect density in perovskite structures.

  9. Mimicking the cell membrane: bio-inspired simultaneous functions with monovalent anion selectivity and antifouling properties of anion exchange membrane

    Science.gov (United States)

    Zhao, Yan; Liu, Huimin; Tang, Kaini; Jin, Yali; Pan, Jiefeng; der Bruggen, Bart Van; Shen, Jiangnan; Gao, Congjie

    2016-11-01

    A new bio-inspired method was applied in this study to simultaneously improve the monovalent anion selectivity and antifouling properties of anion exchange membranes (AEMs). Three-layer architecture was developed by deposition of polydopamine (PDA) and electro-deposition of N-O-sulfonic acid benzyl chitosan (NSBC). The innermost and outermost layers were PDA with different deposition time. The middle layer was prepared by NSBC. Fourier transform infrared spectroscopy and scanning electron microscopy confirmed that PDA and NSBC were successfully modified on the surfaces of AEMs. The contact angle of the membranes indicated an improved hydrophilicity of the modified membranes. A series of electrodialysis experiments in which Cl‑/SO42‑ separation was studied, demonstrating the monovalent anion selectivity of the samples. The Cl‑/SO42‑ permselectivity of the modified membranes can reach up to 2.20, higher than that of the commercial membrane (only 0.78) during 90 minutes in electrodialysis (ED). The increase value of the resistance of the membranes was also measured to evaluate the antifouling properties. Sodium dodecyl benzene sulfonate (SDBS) was used as the fouling material in the ED process and the membrane area resistance of modified membrane increase value of was only 0.08 Ωcm2 30 minutes later.

  10. Investigating the efficacy of monovalent and tetravalent dengue vaccine formulations against DENV-4 challenge in AG129 mice.

    Science.gov (United States)

    Fuchs, Jeremy; Chu, Haiyan; O'Day, Peter; Pyles, Richard; Bourne, Nigel; Das, Subash C; Milligan, Gregg N; Barrett, Alan D T; Partidos, Charalambos D; Osorio, Jorge E

    2014-11-12

    Dengue (DEN) is the most important mosquito-borne viral disease, with a major impact on global health and economics, caused by four serologically and distinct viruses termed DENV-1 to DENV-4. Currently, there is no licensed vaccine to prevent DEN. We have developed a live attenuated tetravalent DENV vaccine candidate (TDV) (formally known as DENVax) that has shown promise in preclinical and clinical studies and elicits neutralizing antibody responses to all four DENVs. As these responses are lowest to DENV-4 we have used the AG129 mouse model to investigate the immunogenicity of monovalent TDV-4 or tetravalent TDV vaccines, and their efficacy against lethal DENV-4 challenge. Since the common backbone of TDV is based on an attenuated DENV-2 strain (TDV-2) we also tested the efficacy of TDV-2 against DENV-4 challenge. Single doses of the tetravalent or monovalent vaccines elicited neutralizing antibodies, anti-NS1 antibodies, and cellular responses to both envelope and nonstructural proteins. All vaccinated animals were protected against challenge at 60 days post-immunization, whereas all control animals died. Investigation of DENV-4 viremias post-challenge showed that only the control animals had high viremias on day 3 post-challenge, whereas vaccinated mice had no detectable viremia. Overall, these data highlight the excellent immunogenicity and efficacy profile of our candidate dengue vaccine in AG129 mice.

  11. Establishment of an in vivo potency assay for the recombinant hepatit is B surface antigen in monovalent and combined vaccines

    Directory of Open Access Journals (Sweden)

    Mabel Izquierdo-López

    2014-12-01

    Full Text Available In this paper the development of potency assay in animals (mice was made, with the objective of demonstrating the immunogenic power of the recombinant Hepatitis B surface antigen in monovalent and combined vaccines, produced at the Center of Genetic Engineering and Biotechnology. The potency test is a parameter in quality control and it is also a tool to demonstrate the consistency of the production process. Parameters such as duration of the test, number of animals in the test, as well as different areas for the maintenance of the animals were evaluated. The results on the applicability of the potency test, to two presentations of the vaccines; monovalent Heberbiovac HB and pentavalent liquid in one vial Heberpenta-L are shown, for which specificity studies, evaluating different vaccine lots, the behavior of linearity, and parallelism, as well as establishing quality specification of the test were performed. This assay led to the obtainment of reliable results for the vaccines evaluated, the consistent evaluation of the immunogenic power and the monitoring of different production processes.

  12. 黄杆菌(Flavobacterium sp.)ATCC27551 opd 基因在E.coli中的克隆及表达%Cloning and Expression of Flavobacterium-derived opd gene in Eschrichia coli

    Institute of Scientific and Technical Information of China (English)

    陈亚丽; 张先恩; 刘虹

    2001-01-01

    研究了黄杆菌ATCC27551的opd基因在大肠杆菌中的表达,并对于表达产物进行了胞内定位和酶活测定.通过PCR扩增和PCR产物直接克隆,将黄杆菌质粒上的一段长达1 137 bp的opd基因进行扩增及克隆,然后按正确的读码框亚克隆于表达载体pET28b(+)上,转化宿主菌E.coli BL21(DE3),经IPTG诱导,获得了较高量的基因表达产物.该表达产物以包涵体的形式存在于细胞内,通过分离包涵体可以得到电泳较纯的条带.工程菌的细胞活性达到原始菌株黄杆菌的水平.`%The cloning and expression of a Flavobacterium-derived opd gene in E.coli was studied. The 1137 bp DNA fragment encoding organophosphorus hydrolase was amplified with PCR, then directly cloned into pGEM-T vector. Plasmid pET-opd was constructed by subcloning the opd gene into plasmid pET28b(+) in correct reading frame. The expression product could be observed on an SDS-PAGE gel as a protein band with molecular weight of about 38×103. In the cell lysate induced with IPTG, the target protein located intracellular and aggregated into the inclusion bodies. Compared with the native Flavobacterium, the recombinant E.coli cells showed a similiar activity of organophosphorus hydrolase.

  13. Columnar- Equiaxed Transition in Solidification processing: The ESA-MAP CETSOL project

    Science.gov (United States)

    Billia, Bernard; Gandin, Charles-André; Zimmermann, Gerhard; Browne, David; Dupouy, Marie-Danielle

    2005-03-01

    Many castings are the result of a competition between the growth of columnar and equiaxed grains. Indeed, microstructures are at the center of materials science and engineering, and solidification is the most important processing route for structural materials, especially metals and alloys. Presently, microstructure models remain mostly based on diffusive transport mechanisms so that there is a need of critical benchmark data to test fundamental theories of microstructure formation, which often necessitates to have recourse to solidification experiments in the reduced-gravity environment of space. Accordingly, the CETSOL (Columnar-Equiaxed Transition in SOLidification processing)-MAP project of ESA is gathering together European groups with complementary skills to carry out experiments and model the processes, in particular in view of the utilization of reduced-gravity environment that will be afforded by the International Space Station (ISS) to get benchmark data. The ultimate objective of the CETSOL research program is to significantly contribute to the improvement of integrated modeling of grain structure in industrially important castings. To reach this goal, the approach is devised to deepen the quantitative understanding of the basic physical principles that, from the microscopic to the macroscopic scales, govern microstructure formation in solidification processing under diffusive conditions and with fluid flow in the melt. Pending questions are attacked by well-defined model experiments on technical alloys and/or on model transparent systems, physical modeling at microstructure and mesoscopic scales (e.g. large columnar front or equiaxed crystals) and numerical simulation at all scales, up to the macroscopic scales of casting with integrated numerical models.

  14. Optical response of columnar TiO{sub 2}:Co on Si substrate

    Energy Technology Data Exchange (ETDEWEB)

    Anggraeni, G. P. [Department of Physics, Institut Teknologi Bandung, Ganesha 10 Bandung 40132 (Indonesia); Saripudin, A. [Department of Physics, Universitas Pendidikan Indonesia, Setiabudi 229, Bandung, 40154 Indonesia (Indonesia); Rusydi, A.; Darma, Y., E-mail: yudi@fi.itb.ac.id [Department of Physics, Institut Teknologi Bandung, Ganesha 10 Bandung 40132 (Indonesia); Singapore Synchrotron Light Source, National University of Singapore, 5 Research Link, Singapore 117603 (Singapore); NUSNNI-Nanocore, Department of Physics, National University of Singapore, 2 Science Drive 3, Singapore 117542 (Singapore)

    2015-09-30

    Vertically arranged columnar TiO{sub 2}:Co structure has been deposited on Si (100) substrate using the metal organic chemical vapor deposition (MOCVD) technique. SEM images confirm the columnar structure of the TiO{sub 2}:Co layer on Si (100). Concentration of the Co dopant has been defined by means of the energy dispersive x-ray (EDX) spectra. Co concentrations are varied at 0.18, 0.33, and 0.68 at. % using pure TiO{sub 2} as the reference. X-ray diffraction (XRD) spectra show that the TiO{sub 2}:Co layer have a rutile phase. Further analysis of this structure has been performed by using room temperature spectroscopic ellipsometry (SE) measurements in the energy range of 0.5 - 6.5 eV. This optical response shows the unique feature of significantly high density fringe especially below the band gap energy region (lower than 3.3 eV) in contrast to the conventional TiO{sub 2} thin film structure. This unique feature is interpreted as a dominant contribution of the vertical interfaces at columnar boundaries towards reflected light from the sample. The evolution of Ψ and Δ will be discussed as the function of Co concentration and some optical properties will be extracted after reasonably well data fitting by multilayer modelling. Furthermore, by comparing the SE data from different measurement orientations, it has been shown that TiO{sub 2}:Co tends to be anisotropic. This study enables us to further evaluate structural properties through optical responses given by SE measurement.

  15. The Solar Vortex: Electric Power Generation using Anchored, Buoyancy-Induced Columnar Vortices

    Science.gov (United States)

    Glezer, Ari

    2015-04-01

    Naturally-occurring, buoyancy-driven columnar vortices (``dust devils'') that are driven by the instability of thermally stratified air layers and sustained by the entrainment of ground- heated air, occur spontaneously in the natural environment with core diameters of 1-50 m and heights up to 1 km. These vortices convert low-grade waste heat in the air layer overlying the warm surface into a solar-induced wind with significant kinetic energy. Unlike dust devil vortices that are typically free to wander laterally, the Solar Vortex (SoV) is deliberately triggered and anchored within a cylindrical domain bounded by an azimuthal array of stationary ground-mounted vertical vanes and sustained by continuous entrainment of the ground-heated air through these vanes. The mechanical energy of the anchored vortex is exploited for power generation by coupling the vortex to a vertical-axis turbine. This simple, low-cost electric power generating unit is competitive in cost, intermittency, and capacity factor with traditional solar power technologies. The considerable kinetic energy of the vortex column cannot be explained by buoyancy alone, and the fundamental mechanisms associated with the formation, evolution, and dynamics of an anchored, buoyancy-driven columnar vortex were investigated experimentally and numerically with specific emphasis on flow manipulation for increasing the available kinetic energy and therefore the generated power. These investigations have also considered the dependence of the vortex scaling and strength on the thermal resources and on the flow enclosure in the laboratory and in the natural environment. Preliminary outdoor tests of a two-meter scale prototype successfully demonstrated the ability to engender and anchor a columnar vortex using only solar radiation and couple the flow to a vertical axis wind turbine. A kilowatt-scale outer door prototype will be tested during the summer of 2015.

  16. Fröhlich modes in GaN columnar nanostructures

    Science.gov (United States)

    Tiginyanu, I. M.; Sarua, A.; Irmer, G.; Monecke, J.; Hubbard, S. M.; Pavlidis, D.; Valiaev, V.

    2001-12-01

    GaN columnar nanostructures fabricated by electrochemical dissolution of bulk material have been studied by micro-Raman spectroscopy. The anodization induces an increase in the intensity of Raman scattering accompanied by a breakdown of the polarization selection rules and by the appearance of a new mode at 716 cm-1, i.e., in the frequency gap between the transverse optical and longitudinal optical bulk phonons. We present a Raman line-shape analysis based on the effective dielectric function of a composite that brings to light the Fröhlich character of this mode.

  17. Fixed-film columnar bioreactors for the production of chemicals and fuels from biomass

    Science.gov (United States)

    Scott, C. D.; Shumate, S. E. W., II; Arcuri, E. J.

    1982-12-01

    Fixed films of an active biological agent are maintained on solid surfaces within bioreactor systems to allow high productivity without agent washout during continuous operation. This, coupled with a stagewise columnar arrangement, may allow higher overall reaction rates. Fluidized bed and fixed bed bioreactors with fixed films of microorganisms are studied for the production of chemicals and fuels from biomass derived feed materials. Ethanol production at high rates has been demonstrated with glucose as the feed material; methane and other chemicals are also produced in these advanced systems.

  18. Columnar deformation of human red blood cell by highly localized fiber optic Bessel beam stretcher

    Science.gov (United States)

    Lee, Sungrae; Joo, Boram; Jeon, Pyo Jin; Im, Seongil; Oh, Kyunghwan

    2015-01-01

    A single human red blood cell was optically stretched along two counter-propagating fiber-optic Bessel-like beams in an integrated lab-on-a-chip structure. The beam enabled highly localized stretching of RBC, and it induced a nonlinear mechanical deformation to finally reach an irreversible columnar shape that has not been reported. We characterized and systematically quantified this optically induced mechanical deformation by the geometrical aspect ratio of stretched RBC and the irreversible stretching time. The proposed RBC mechanism can realize a versatile and compact opto-mechanical platform for optical diagnosis of biological substances in the single cell level. PMID:26601005

  19. Stable Isotopic Variations in Columnar Cacti: are Responses to Climate Recorded in Spines?

    Science.gov (United States)

    English, N. B.; Dettman, D. L.; Williams, D. G.

    2004-12-01

    The behavior of the North American monsoon (NAM), particularly with respect to times of continental drought and its relationship to the Pacific-North American (PNA) teleconnection pattern and the El Nino/Southern Oscillation (ENSO) is of great interest to paleoclimatologists and water managers. Long-term instrumental precipitation and tree ring records in the southwestern United States and northwestern Mexico at low elevations are sparse and this has hindered research on NAM variability at interannual timescales. Saguaro cacti (Carnegiea gigantea) and other columnar cacti in North and South America are long-lived and have the potential to record climate variability on land with high temporal and spatial resolution. The vertical sequence of spines on the saguaro's exterior represents a high resolution (4 to 6 per year), and long (over 150 years) record of environmental change. We present results from an experiment where we tracked the oxygen isotopic values in the source waters, stem tissue waters and spine tissue for three treatments over the course of three months. These data are then compared to a previously developed mechanistic model of isotopic variation that reflects the physiological responses of Saguaro to climate variation over seasonal to century long time-scales. We also present the rationale for a new method to determine the growth rate of columnar cacti using the radiocarbon bomb spike. Our measurements reveal that oxygen and hydrogen isotopic variation among the sequentially produced and persistent spines covering the saguaro body record fluctuations in saguaro water balance. The model successfully predicts isotopic variation in spines and constrains controlling variables, yielding a powerful and high-resolution stable isotope index of water stress in the low desert. The development and refinement of an isotopic model for saguaro will serve as the basis for models applied to other species of columnar cacti in North and South America. The role of the

  20. High hydrogen dilution and low substrate temperature cause columnar growth of hydrogenated amorphous silicon

    Energy Technology Data Exchange (ETDEWEB)

    Bronsveld, Paula C.P.; Rath, Jatindra K.; Schropp, Ruud E.I. [Debye Institute for Nanomaterials Science, Nanophotonics - Physics of Devices, Utrecht University, P.O. Box 80000, 3508 TA Utrecht (Netherlands); Mates, Tomas; Fejfar, Antonin; Kocka, Jan [Institute of Physics, Academy of Sciences of the Czech Republic, Cukrovarnicka 10, 162 53 Praha 6 (Czech Republic)

    2010-03-15

    Columnar growth was observed in the amorphous part of mixed phase layers deposited at very low substrate temperatures. The width of the columns and the layer thickness at which they are first distinguishable in a cross-sectional transmission electron microscope (X-TEM) image, about 120 nm, is similar for the substrate temperature range of 40-100 C, but the columns are less well developed when either the substrate temperature is increased or the dilution ratio is lowered. This growth behaviour and the incubation layer are attributed to hydrogen-induced surface diffusion of growth precursors resulting in an amorphous-amorphous roughness transition. (Abstract Copyright [2010], Wiley Periodicals, Inc.)

  1. Fine genetic mapping of the Co locus controlling columnar growth habit in apple.

    Science.gov (United States)

    Bai, Tuanhui; Zhu, Yuandi; Fernández-Fernández, Felicidad; Keulemans, Johan; Brown, Susan; Xu, Kenong

    2012-05-01

    Tree architecture is an important, complex and dynamic trait affected by diverse genetic, ontogenetic and environmental factors. 'Wijcik McIntosh', a columnar (reduced branching) sport of 'McIntosh' and a valuable genetic resource, has been used intensively in apple-breeding programs for genetic improvement of tree architecture. The columnar growth habit is primarily controlled by the dominant allele of gene Co (columnar) on linkage group-10. But the Co locus is not well mapped and the Co gene remains unknown. To precisely map the Co locus and to identify candidate genes of Co, a sequence-based approach using both peach and apple genomes was used to develop new markers linked more tightly to Co. Five new simple sequence repeats markers were developed (C1753-3520, C18470-25831, C6536-31519, C7223-38004 and C7629-22009). The first four markers were obtained from apple genomic sequences on chromosome-10, whereas the last (C7629-22009) was from an unanchored apple contig that contains an apple expressed sequence tag CV082943, which was identified through synteny analysis between the peach and apple genomes. Genetic mapping of these five markers in four F(1) populations of 528 genotypes and 290 diverse columnar selections/cultivars (818 genotypes in total) delimited the Co locus in a genetic interval with 0.37 % recombination between markers C1753-3520 and C7629-22009. Marker C18470-25831 co-segregates with Co in the 818 genotypes studied. The Co region is estimated to be 193 kb and contains 26 predicted gene in the 'Golden Delicious' genome. Among the 26 genes, three are putative LATERAL ORGAN BOUNDARIES (LOB) DOMAIN (LBD) containing transcription factor genes known of essential roles in plant lateral organ development, and are therefore considered as strong candidates of Co, designated MdLBD1, MdLBD2, and MdLBD3. Although more comprehensive studies are required to confirm the function of MdLBD1-3, the present work represents an important step forward to better

  2. Columnar deformation of human red blood cell by highly localized fiber optic Bessel beam stretcher.

    Science.gov (United States)

    Lee, Sungrae; Joo, Boram; Jeon, Pyo Jin; Im, Seongil; Oh, Kyunghwan

    2015-11-01

    A single human red blood cell was optically stretched along two counter-propagating fiber-optic Bessel-like beams in an integrated lab-on-a-chip structure. The beam enabled highly localized stretching of RBC, and it induced a nonlinear mechanical deformation to finally reach an irreversible columnar shape that has not been reported. We characterized and systematically quantified this optically induced mechanical deformation by the geometrical aspect ratio of stretched RBC and the irreversible stretching time. The proposed RBC mechanism can realize a versatile and compact opto-mechanical platform for optical diagnosis of biological substances in the single cell level.

  3. Evidence for regulation of columnar habit in apple by a putative 2OG-Fe(II) oxygenase.

    Science.gov (United States)

    Wolters, Pieter J; Schouten, Henk J; Velasco, Riccardo; Si-Ammour, Azeddine; Baldi, Paolo

    2013-12-01

    Understanding the genetic mechanisms controlling columnar-type growth in the apple mutant 'Wijcik' will provide insights on how tree architecture and growth are regulated in fruit trees. In apple, columnar-type growth is controlled by a single major gene at the Columnar (Co) locus. By comparing the genomic sequence of the Co region of 'Wijcik' with its wild-type 'McIntosh', a novel non-coding DNA element of 1956 bp specific to Pyreae was found to be inserted in an intergenic region of 'Wijcik'. Expression analysis of selected genes located in the vicinity of the insertion revealed the upregulation of the MdCo31 gene encoding a putative 2OG-Fe(II) oxygenase in axillary buds of 'Wijcik'. Constitutive expression of MdCo31 in Arabidopsis thaliana resulted in compact plants with shortened floral internodes, a phenotype reminiscent of the one observed in columnar apple trees. We conclude that MdCo31 is a strong candidate gene for the control of columnar growth in 'Wijcik'.

  4. Specialization clines in the pollination systems of agaves (Agavaceae) and columnar cacti (Cactaceae): A phylogenetically controlled meta-analysis.

    Science.gov (United States)

    Munguía-Rosas, Miguel A; Sosa, Vinicio J; Ojeda, Mario M; De-Nova, J Arturo

    2009-10-01

    The biogeography of plant-animal interactions is a novel topic on which many disciplines converge (e.g., reproductive biology, biogeography, and evolutionary biology). Narrative reviews have indicated that tropical columnar cacti and agaves have highly specialized pollination systems, while extratropical species have generalized systems. However, this dichotomy has never been quantitatively tested. We tested this hypothesis using traditional and phylogenetically informed meta-analysis. Three effect sizes were estimated from the literature: diurnal, nocturnal, and hand cross-pollination (an indicator of pollen limitation). Columnar cactus pollination systems ranged from purely bat-pollinated in the tropics to generalized pollination, with diurnal visitors as effective as nocturnal visitors in extratropical regions; even when phylogenetic relatedness among species is taken into account. Metaregressions identified a latitudinal increase in pollen limitation in columnar cacti, but this increase was not significant after correcting for phylogeny. The currently available data for agaves do not support any latitudinal trend. Nectar production of columnar cacti varied with latitude. Although this variation is positively correlated with pollination by diurnal visitors, it is influenced by phylogeny. The degree of specificity in the pollination systems of columnar cacti is heavily influenced by ecological factors and has a predictable geographic pattern.

  5. Application of the Prague C and M criteria for endoscopic description of columnar-lined esophagus in South Korea

    Institute of Scientific and Technical Information of China (English)

    Jung Wan Choe; Young Choon Kim; Moon Kyung Joo; Hyo Jung Kim; Beom Jae Lee; Ji Hoon Kim; Jong Eun Yeon; Jong-Jae Park; Jae Seon Kim; Kwan Soo Byun; Young-Tae Bak

    2016-01-01

    AIM:To ascertain whether the Prague circumferential(C) length and maximal(M) length criteria for grading the extent of Barrett’s esophagus can be applied prior to its widespread application in South Korea.METHODS:Two hundred and thirteen consecutive cases with endoscopic columnar-lined esophagus(CLE) were included and classified according to the Prague C and M criteria.RESULTS:Of 213 cases with CLE, the distribution of maximum CLE lengths was: 0.5-0.9 cm in 99 cases(46.5%); 1.0-1.4 cm in 63 cases(29.6%); 1.5-1.9 cm in 15 cases(7.0%); 2.0-2.4 cm in 14 cases(6.6%); 2.5-2.9 cm in 1 case(0.5%); and 7.0 cm in 1 case(0.5%). Twenty cases(9.4%) had columnar islands alone. Two hundred and eight cases(97.7%) lacked the circumferential CLE component(C0Mx). Columnar islands were found in 70 cases(32.9%), of which 20 cases(9.4%) had columnar islands alone.CONCLUSION:In regions where most CLE patients display short or ultrashort tongue-like appearance, more detailed descriptions of CLE’s in < 1.0 cm lengths and columnar islands, as well as avoidance of repeating the prefix "C0" need to be considered in parallel with the widespread application of the Prague system in South Korea.

  6. Low-grade ductal carcinoma in situ and invasive mammary carcinoma with columnar cell morphology arising in a complex fibroadenoma in continuity with columnar cell change and flat epithelial atypia.

    Science.gov (United States)

    Petersson, Fredrik; Tan, Puay Hoon; Putti, Thomas Choudary

    2010-10-01

    We describe the clinicopathologic features of a small low-grade invasive mammary carcinoma with cytomorphological columnar cell features arising in a complex fibroadenoma that in addition to sclerosing adenosis, apocrine metaplasia, and usual ductal hyperplasia also displayed columnar cell change with flat epithelial atypia and low-grade ductal carcinoma in situ merging with the invasive carcinoma. There were strong cytomorphological similarities between the invasive carcinoma and the low-grade ductal carcinoma in situ, which also showed significant overlap in the immunohistochemical findings.

  7. Effect of heat treatment of formation of columnar ferrite structure in explosively welded titanium/hypoeutectoid steel joints

    Energy Technology Data Exchange (ETDEWEB)

    Morizono, Y. [Shock Wave and Condensed Matter Research Center, Kumamoto Univ., Kumamoto (Japan); Nishida, M.; Chiba, A.; Yamamuro, T. [Dept. of Mechanical Engineering and Materials Science, Kumamoto Univ., Kumamoto (Japan)

    2004-07-01

    Explosive welding of titanium to hypoeutectoid steel (SS 400, 0.09 mass% C) was carried out, and interfacial aspects of as-welded and heat treated states have been investigated with a focus on microstructures of the steel. In as-welded joint, plastic flow occurred by high velocity collision was observed in the vicinity of the interface. The steel in the joints retained equiaxed structure consisting of ferrite and pearlite even after prolonged heat treatment up to 1173 K. Columnar grains were generated in the steel near the interface by the heat treatment at 1223 K and above. Although the region of the columnar ferrite structure increased with increasing heating temperature and holding time, texture with specific crystal orientation was not confirmed. It was found that such a microstructural change in the steel was closely related to constituent phases formed at the bonding interface. The formation mechanism of the columnar structure was also discussed. (orig.)

  8. Photocatalytic Properties of Columnar Nanostructured TiO2 Films Fabricated by Sputtering Ti and Subsequent Annealing

    Directory of Open Access Journals (Sweden)

    Zhengcao Li

    2012-01-01

    Full Text Available Columnar nanostructured TiO2 films were prepared by sputtering Ti target in pure argon with glancing angle deposition (GLAD and subsequent annealing at 400°C for different hours in air. Compared with sputtering TiO2 target directly, sputtering Ti target can be carried out under much lower base pressure, which contributes to obtaining discrete columnar nanostructures. In the present study, TiO2 films obtained by annealing Ti films for different hours all kept discrete columnar structures as the Ti films deposited in GLAD regime. The longer the annealing time was, the better the phase transition accomplished from Ti to TiO2 (a mixture of rutile and anatase, and the better it crystallized. In addition, those TiO2 films performed photocatalytic decolorization effectively and showed a law changing over annealing time under UV light irradiation towards methyl orange, which demonstrated the potential applications for treatment of effluent.

  9. Topology of ON and OFF inputs in visual cortex enables an invariant columnar architecture.

    Science.gov (United States)

    Lee, Kuo-Sheng; Huang, Xiaoying; Fitzpatrick, David

    2016-05-05

    Circuits in the visual cortex integrate the information derived from separate ON (light-responsive) and OFF (dark-responsive) pathways to construct orderly columnar representations of stimulus orientation and visual space. How this transformation is achieved to meet the specific topographic constraints of each representation remains unclear. Here we report several novel features of ON-OFF convergence visualized by mapping the receptive fields of layer 2/3 neurons in the tree shrew (Tupaia belangeri) visual cortex using two-photon imaging of GCaMP6 calcium signals. We show that the spatially separate ON and OFF subfields of simple cells in layer 2/3 exhibit topologically distinct relationships with the maps of visual space and orientation preference. The centres of OFF subfields for neurons in a given region of cortex are confined to a compact region of visual space and display a smooth visuotopic progression. By contrast, the centres of the ON subfields are distributed over a wider region of visual space, display substantial visuotopic scatter, and have an orientation-specific displacement consistent with orientation preference map structure. As a result, cortical columns exhibit an invariant aggregate receptive field structure: an OFF-dominated central region flanked by ON-dominated subfields. This distinct arrangement of ON and OFF inputs enables continuity in the mapping of both orientation and visual space and the generation of a columnar map of absolute spatial phase.

  10. Does Cell Lineage in the Developing Cerebral Cortex Contribute to its Columnar Organization?

    Science.gov (United States)

    Costa, Marcos R.; Hedin-Pereira, Cecilia

    2010-01-01

    Since the pioneer work of Lorente de Nó, Ramón y Cajal, Brodmann, Mountcastle, Hubel and Wiesel and others, the cerebral cortex has been seen as a jigsaw of anatomic and functional modules involved in the processing of different sets of information. In fact, a columnar distribution of neurons displaying similar functional properties throughout the cerebral cortex has been observed by many researchers. Although it has been suggested that much of the anatomical substrate for such organization would be already specified at early developmental stages, before activity-dependent mechanisms could take place, it is still unclear whether gene expression in the ventricular zone (VZ) could play a role in the development of discrete functional units, such as minicolumns or columns. Cell lineage experiments using replication-incompetent retroviral vectors have shown that the progeny of a single neuroepithelial/radial glial cell in the dorsal telencephalon is organized into discrete radial clusters of sibling excitatory neurons, which have a higher propensity for developing chemical synapses with each other rather than with neighboring non-siblings. Here, we will discuss the possibility that the cell lineage of single neuroepithelial/radial glia cells could contribute for the columnar organization of the neocortex by generating radial columns of sibling, interconnected neurons. Borrowing some concepts from the studies on cell–cell recognition and transcription factor networks, we will also touch upon the potential molecular mechanisms involved in the establishment of sibling-neuron circuits. PMID:20676384

  11. Does cell lineage in the developing cerebral cortex contribute to its columnar organization?

    Directory of Open Access Journals (Sweden)

    Marcos R Costa

    2010-06-01

    Full Text Available Since the pioneer work of Lorente de Nó, Ramón y Cajal, Brodmann, Mountcastle, Hubel and Wiesel and others, the cerebral cortex has been seen as a jigsaw of anatomic and functional modules involved in the processing of different sets of information. In fact, a columnar distribution of neurons displaying similar functional properties throughout the cerebral cortex has been observed by many researchers. Although it has been suggested that much of the anatomical substrate for such organization would be already specified at early developmental stages, before activity-dependent mechanisms could take place, it is still unclear whether gene expression in the ventricular zone could play a role in the development of discrete functional units, such as minicolumns or columns. Cell lineage experiments using replication-incompetent retroviral vectors have shown that the progeny of a single neuroepithelial/radial glial cell in the dorsal telencephalon is organized into discrete radial clusters of sibling excitatory neurons, which have a higher propensity for developing chemical synapses with each other rather than with neighbouring non-siblings. Here, we will discuss the possibility that the cell lineage of single neuroepithelial/radial glia cells could contribute for the columnar organization of the neocortex by generating radial columns of sibling, interconnected neurons. Borrowing some concepts from the studies on cell-cell recognition and transcription factor networks, we will also touch upon the potential molecular mechanisms involved in the establishment of sibling-neuron circuits.

  12. A Columnar Storage Strategy with Spatiotemporal Index for Big Climate Data

    Science.gov (United States)

    Hu, F.; Bowen, M. K.; Li, Z.; Schnase, J. L.; Duffy, D.; Lee, T. J.; Yang, C. P.

    2015-12-01

    Large collections of observational, reanalysis, and climate model output data may grow to as large as a 100 PB in the coming years, so climate dataset is in the Big Data domain, and various distributed computing frameworks have been utilized to address the challenges by big climate data analysis. However, due to the binary data format (NetCDF, HDF) with high spatial and temporal dimensions, the computing frameworks in Apache Hadoop ecosystem are not originally suited for big climate data. In order to make the computing frameworks in Hadoop ecosystem directly support big climate data, we propose a columnar storage format with spatiotemporal index to store climate data, which will support any project in the Apache Hadoop ecosystem (e.g. MapReduce, Spark, Hive, Impala). With this approach, the climate data will be transferred into binary Parquet data format, a columnar storage format, and spatial and temporal index will be built and attached into the end of Parquet files to enable real-time data query. Then such climate data in Parquet data format could be available to any computing frameworks in Hadoop ecosystem. The proposed approach is evaluated using the NASA Modern-Era Retrospective Analysis for Research and Applications (MERRA) climate reanalysis dataset. Experimental results show that this approach could efficiently overcome the gap between the big climate data and the distributed computing frameworks, and the spatiotemporal index could significantly accelerate data querying and processing.

  13. Hierarchical columnar silicon anode structures for high energy density lithium sulfur batteries

    Science.gov (United States)

    Piwko, Markus; Kuntze, Thomas; Winkler, Sebastian; Straach, Steffen; Härtel, Paul; Althues, Holger; Kaskel, Stefan

    2017-05-01

    Silicon is a promising anode material for next generation lithium secondary batteries. To significantly increase the energy density of state of the art batteries with silicon, new concepts have to be developed and electrode structuring will become a key technology. Structuring is essential to reduce the macroscopic and microscopic electrode deformation, caused by the volume change during cycling. We report pulsed laser structuring for the generation of hierarchical columnar silicon films with outstanding high areal capacities up to 7.5 mAh cm-2 and good capacity retention. Unstructured columnar electrodes form a micron-sized block structure during the first cycle to compensate the volume expansion leading to macroscopic electrode deformation. At increased silicon loading, without additional structuring, pronounced distortion and the formation of cracks through the current collector causes cell failure. Pulsed laser ablation instead is demonstrated to avoid macroscopic electrode deformation by initial formation of the block structure. A full cell with lithiated silicon versus a carbon-sulfur cathode is assembled with only 15% overbalanced anode and low electrolyte amount (8 μl mgsulfur-1). While the capacity retention over 50 cycles is identical to a cell with high excess lithium anode, the volumetric energy density could be increased by 30%.

  14. Analysis of form and function in North American columnar cacti (tribe Pachycereeae).

    Science.gov (United States)

    Cornejo, D; Simpson, B

    1997-11-01

    Simple and multivariate linear models were used to demonstrate the influence of mechanical design and climate on stem morphology and branching architecture in 25 species of North American columnar cacti. The effect of phyletic inertia was tested by the method of independent contrasts. Stem girth was found to increase significantly slower with increased height within taxa (cross-sectional stem area ;ps [plant height] 0.603), than across taxon (cross-sectional stem area ;ps [plant height] 1.451). Juveniles are shown to be mechanically overbuilt and subsequently grow into more slender adult forms determined in part by structural limitations and the optimization of other stem functions. We make a structural analogy of relatively rigid columnar cacti to concrete columns and compare plants and models with similar growth forms lacking woody skeletons (barrel cacti). Taxa with woody support achieved a surface-to-volume ratio six times greater than taxa without woody support. Across taxon, cooler winter temperatures were associated with larger stem girths, and greater annual precipitation was associated with less frequent branching. The relationship between total plant surface and volume approaches isometry within taxa, but across taxon average individuals are scaled replicates. We hypothesize that architecture and average plant height are adjusted, in an evolutionary sense, to maintain geometric similitude between surface and volume along a climatic gradient.

  15. A New Columnar CsI(Tl) Scintillator for iQID detectors.

    Science.gov (United States)

    Han, Ling; Miller, Brian W; Barber, H Bradford; Nagarkar, Vivek V; Furenlid, Lars R

    2014-09-12

    A 1650 μm thick columnar CsI(Tl) scintillator for upgrading iQID detectors, which is a high-resolution photon-counting gamma-ray and x-ray detector recently developed at the Center for Gamma-Ray Imaging (CGRI), has been studied in terms of sensitivity, spatial resolution and depth-of-interaction effects. To facilitate these studies, a new frame-parsing algorithm for processing raw event data is also proposed that has more degrees of freedom in data processing and can discriminate against a special kind of noise present in some low-cost intensifiers. The results show that in comparison with a 450 μm-thickness columnar CsI(Tl) scintillator, the 1650 μm thick CsI(Tl) scintillator provides more than twice the sensitivity at the expense of some spatial resolution degradation. The depth-of-interaction study also shows that event size and amplitude vary with scintillator thickness, which can assist in future detector simulations and 3D-interaction-position estimation.

  16. Columnar structured FePt films epitaxially grown on large lattice mismatched intermediate layer

    Science.gov (United States)

    Dong, K. F.; Deng, J. Y.; Peng, Y. G.; Ju, G.; Chow, G. M.; Chen, J. S.

    2016-09-01

    The microstructure and magnetic properties of the FePt films grown on large mismatched ZrN (15.7%) intermediate layer were investigated. With using ZrN intermediate layer, FePt 10 nm films exhibited (001) texture except for some weaker FePt (110) texture. Good epitaxial relationships of FePt (001) //ZrN (001) //TiN (001) among FePt and ZrN/TiN were revealed from the transmission electron microscopy (TEM) results. As compared with TiN intermediate layer, although FePt-SiO2-C films grown on ZrN/TiN intermediate layer showed isotropic magnetic properties, the large interfacial energy and lattice mismatch between FePt and ZrN would lead to form columnar structural FePt films with smaller grain size and improved isolation. By doping ZrN into the TiN layer, solid solution of ZrTiN was formed and the lattice constant is increased comparing with TiN and decreased comparing with ZrN. Moreover, FePt-SiO2-C films grown on TiN 2 nm-20 vol.% ZrN/TiN 3 nm intermediate layer showed an improved perpendicular magnetic anisotropy. Simultaneously, columnar structure with smaller grain size retained.

  17. Immunogenicity and safety of monovalent RIVM meningococcal B OMP vesicle F91 vaccine administered to children that received hexavalent meningococcal B vaccine 2.5 years ago

    NARCIS (Netherlands)

    Lafeber AB; Limpt CJP van; Berbers GAM; Labadie J; Kleijn ED de; Groot R de; Rumke HC; Alphen AJW van; Sophia Kinderziekenhuis /; LVO

    2000-01-01

    This report describes the results with respect to immunogenicity as well as reactogenicity of a monovalent P1.7h,4 OMV vaccine (MonoMen) used as booster vaccination in children previously vaccinated with a hexavalent MenB vaccine. The participants in this study were immunised in 1995-1996 with hexav

  18. International collaboration to assess the risk of Guillain Barré Syndrome following Influenza A (H1N1) 2009 monovalent vaccines

    NARCIS (Netherlands)

    C. Dodd (Caitlin); S.A. Romio (Silvana); S. Black (Steve); C. Vellozzi (Claudia); N.J. Andrews (Nick); M.C.J.M. Sturkenboom (Miriam); P. Zuber (Patrick); W. Hua (Wei); J. Bonhoeffer (Jan); J. Buttery (Jim); N. Crawford (Nigel); G. Deceuninck (Genevieve); C.S. de Vries (Corinne); P. de Wals (Philippe); D. Gimeno (David); H. Heijbel (Harald); H. Hughes (Hayley); K. Hur (Kwan); A. Hviid (Anders); J. Kelman (Jeffrey); T. Kilpi (Tehri); S.K. Chuang (S.); T. Macartney (Thomas); M. Rett (Melisa); V.R. Lopez-Callada (Vesta Richardson); D. Salmon (Daniel); F.G. Sanchez (Francisco Gimenez); N. Sanz (Nuria); B. Silverman (Bernard); J. Storsaeter (Jann); U. Thirugnanam (Umapathi); N.A.T. van der Maas (Nicoline); K. Yih (Katherine); T. Zhang (Teng Fei); H.S. Izurieta (Hector); B.J. Addis; A. Akhtar (Aysha); J. Cope (Judith); R.L. Davis (Robert); P. Gargiullo (Paul); X. Kurz (Xavier); B. Law (Barbara); I. Sahinovic (Isabelle); J. Tokars (Jerry); P. Serrano (Pedro); A. Cheng (Aixin); N.J. Andrews (Nick); P. Charles (Pat); H. Clothier (Hazel); B. Day (Bruce); T. Day (Timothy); P. Gates (Peter); R. MacDonnell (Richard); L. Roberts (Les); V. Rodriguez-Casero (Vic-toria); T. Wijeratne (Tissa); H.A.L. Kiers (Henk); C. Blyth (Christopher); R. Booy (Robert); E. Elliott (Elizabeth); M.R. Gold (Michael); H. Marshall; P. McIntyre (Peter); P. Richmond (Peter); J. Royle (Jenny); N.W. Wood (Nicholas); Y. Zurynski (Yvonne); G. Calvo (Gonzalo); M. Campins (Magda); N. Corominas (Nuria); F. Torres (Ferran); V. Valls; A. Vilella (Ángels); A. Dutra (Amalia); A. Eick-Cost (Angelia); H.M. Jackson (Henry); K. Garman (Katherine); Z. Hu (Zheng); J. Rigo; J. Badoo (Judith); D Cho (David); L.L. Polakowski (Laura); S.K. Sandhu (Sukhminder); G. Sun (Guoying); H.-S.S. Chan (Hoi-Shan Sophelia); K.-Y. Chan (Kwok-Yin); R. Cheung (Raymond); Y-F. Cheung (Yuk-Fai); S. Cherk (Sharon); S.K Chuang (S.); D. Fok (Dennis); B.-H. Fung (Bun-Hey); K.-F. Ko (Kwai-Fu); K.W. Lau (Ka Wing); K.-K. Lau (Kwok-Kwong); P. Li (Pulin); H.-T. Liu (Hui-Tung); S.-H. Liu (Shao-Haei); K. Mok (Kin); J. So (Joanna); W. Wong (Winnie); S.-P. Wu (Shun-Ping); V. Avagyan (Vardan); R. Ball (Robert); D. Burwen (Dale); R.L. Franks (Riley); J.M. Gibbs (Jonathan); R.E. Kliman (Rebecca); S. Kropp (Silke); T.E. MaCurdy (Thomas); D.B. Martin (David); S.-D.K. Sandhu (Sukhmin-Der); B.B. Worrall (Bradford B.); D.E.F. Fuentes (Dra. Elvira Fuentes); P.C.O. González (Paola Carolina Ojeda); V.F. Reyna (Valerie ); M. Kulldorff (Martin); G. Lee (Grace); T.A. Lieu (Tracy); S. Platt; G.D. Serres (Gaston De); K. Jabin (Kamilah); B.L.S. Soh (Bee Leng Sally); L. Arnheim-Dahlström (Lisen); A. Castot (Anne); H.E. de Melker (Hester); J.P. Dieleman (Jeanne); J. Hallgren (Jonal); B.C. Jacobs (Bart); K. Johansen (Kari); P Kramarz (Piotr); M. Lapeyre (Maryse); T. Leino (Tuija); D. Mølgaard-Nielsen (Ditte); M. Mosseveld (Mees); H.K. Olberg (Henning K); C.-M. Sammon (Cor-Mac); C. Saussier (Christel); M.J. Schuemie (Martijn); A. Sommet (Agnès); P. Sparen (Pär); H. Svanström (Henrik); A.M. Vanrolleghem (Ann M.); D.M. Weibel (Daniel); J.D. Domingo (Javier Diez); J.L. Esparza (José LuísMicó); R.M.O. Lucas (Rafael M. Ortí); J.B.M. Maseres (Juan B. Mollar); J.L.A. Sánchez (José Luís Alfonso); M.G. Sánchez (Mercedes Garcés); V.Z. Viguer (Vicente Zanón); F. Cunningham (Francesca); B. Thakkar (Bharat); R. Zhang (Rongping)

    2013-01-01

    textabstractBackground: The global spread of the 2009 novel pandemic influenza A (H1N1) virus led to the accelerated production and distribution of monovalent 2009 Influenza A (H1N1) vaccines (pH1N1). This pandemic provided the opportunity to evaluate the risk of Guillain-Barré syndrome (GBS), which

  19. Immunogenicity and safety of monovalent RIVM meningococcal B OMP vesicle F91 vaccine administered to children that received hexavalent meningococcal B vaccine 2.5 years ago

    NARCIS (Netherlands)

    Lafeber AB; van Limpt CJP; Berbers GAM; Labadie J; de Kleijn ED; de Groot R; Rumke HC; van Alphen AJW; LVO

    2000-01-01

    Dit rapport beschrijft een follow-up studie naar veiligheid en immunogeniciteit van monovalent P1.7h,4 OMV vaccin (MonoMen) gebruikt als boostervaccinatie in kinderen eerder gevaccineerd met hexavalent MenB vaccin. De deelnemers aan deze studie zijn in het kader van een eerdere studie gevaccineerd

  20. International collaboration to assess the risk of Guillain Barré Syndrome following Influenza A (H1N1) 2009 monovalent vaccines

    NARCIS (Netherlands)

    C. Dodd (Caitlin); S.A. Romio (Silvana); S. Black (Steve); C. Vellozzi (Claudia); N.J. Andrews (Nick); M.C.J.M. Sturkenboom (Miriam); P. Zuber (Patrick); W. Hua (Wei); J. Bonhoeffer (Jan); J. Buttery (Jim); N. Crawford (Nigel); G. Deceuninck (Genevieve); C.S. de Vries (Corinne); P. de Wals (Philippe); D. Gimeno (David); H. Heijbel (Harald); H. Hughes (Hayley); K. Hur (Kwan); A. Hviid (Anders); J. Kelman (Jeffrey); T. Kilpi (Tehri); S.K. Chuang (S.); T. Macartney (Thomas); M. Rett (Melisa); V.R. Lopez-Callada (Vesta Richardson); D. Salmon (Daniel); F.G. Sanchez (Francisco Gimenez); N. Sanz (Nuria); B. Silverman (Bernard); J. Storsaeter (Jann); U. Thirugnanam (Umapathi); N.A.T. van der Maas (Nicoline); K. Yih (Katherine); T. Zhang (Teng Fei); H.S. Izurieta (Hector); B.J. Addis; A. Akhtar (Aysha); J. Cope (Judith); R.L. Davis (Robert); P. Gargiullo (Paul); X. Kurz (Xavier); B. Law (Barbara); I. Sahinovic (Isabelle); J. Tokars (Jerry); P. Serrano (Pedro); A. Cheng (Aixin); N.J. Andrews (Nick); P. Charles (Pat); H. Clothier (Hazel); B. Day (Bruce); T. Day (Timothy); P. Gates (Peter); R. MacDonnell (Richard); L. Roberts (Les); V. Rodriguez-Casero (Vic-toria); T. Wijeratne (Tissa); H.A.L. Kiers (Henk); C. Blyth (Christopher); R. Booy (Robert); E. Elliott (Elizabeth); M.R. Gold (Michael); H. Marshall; P. McIntyre (Peter); P. Richmond (Peter); J. Royle (Jenny); N.W. Wood (Nicholas); Y. Zurynski (Yvonne); G. Calvo (Gonzalo); M. Campins (Magda); N. Corominas (Nuria); F. Torres (Ferran); V. Valls; A. Vilella (Ángels); A. Dutra (Amalia); A. Eick-Cost (Angelia); H.M. Jackson (Henry); K. Garman (Katherine); Z. Hu (Zheng); J. Rigo; J. Badoo (Judith); D Cho (David); L.L. Polakowski (Laura); S.K. Sandhu (Sukhminder); G. Sun (Guoying); H.-S.S. Chan (Hoi-Shan Sophelia); K.-Y. Chan (Kwok-Yin); R. Cheung (Raymond); Y-F. Cheung (Yuk-Fai); S. Cherk (Sharon); S.K Chuang (S.); D. Fok (Dennis); B.-H. Fung (Bun-Hey); K.-F. Ko (Kwai-Fu); K.W. Lau (Ka Wing); K.-K. Lau (Kwok-Kwong); P. Li (Pulin); H.-T. Liu (Hui-Tung); S.-H. Liu (Shao-Haei); K. Mok (Kin); J. So (Joanna); W. Wong (Winnie); S.-P. Wu (Shun-Ping); V. Avagyan (Vardan); R. Ball (Robert); D. Burwen (Dale); R.L. Franks (Riley); J.M. Gibbs (Jonathan); R.E. Kliman (Rebecca); S. Kropp (Silke); T.E. MaCurdy (Thomas); D.B. Martin (David); S.-D.K. Sandhu (Sukhmin-Der); B.B. Worrall (Bradford B.); D.E.F. Fuentes (Dra. Elvira Fuentes); P.C.O. González (Paola Carolina Ojeda); V.F. Reyna (Valerie ); M. Kulldorff (Martin); G. Lee (Grace); T.A. Lieu (Tracy); S. Platt; G.D. Serres (Gaston De); K. Jabin (Kamilah); B.L.S. Soh (Bee Leng Sally); L. Arnheim-Dahlström (Lisen); A. Castot (Anne); H.E. de Melker (Hester); J.P. Dieleman (Jeanne); J. Hallgren (Jonal); B.C. Jacobs (Bart); K. Johansen (Kari); P Kramarz (Piotr); M. Lapeyre (Maryse); T. Leino (Tuija); D. Mølgaard-Nielsen (Ditte); M. Mosseveld (Mees); H.K. Olberg (Henning K); C.-M. Sammon (Cor-Mac); C. Saussier (Christel); M.J. Schuemie (Martijn); A. Sommet (Agnès); P. Sparen (Pär); H. Svanström (Henrik); A.M. Vanrolleghem (Ann M.); D.M. Weibel (Daniel); J.D. Domingo (Javier Diez); J.L. Esparza (José LuísMicó); R.M.O. Lucas (Rafael M. Ortí); J.B.M. Maseres (Juan B. Mollar); J.L.A. Sánchez (José Luís Alfonso); M.G. Sánchez (Mercedes Garcés); V.Z. Viguer (Vicente Zanón); F. Cunningham (Francesca); B. Thakkar (Bharat); R. Zhang (Rongping)

    2013-01-01

    textabstractBackground: The global spread of the 2009 novel pandemic influenza A (H1N1) virus led to the accelerated production and distribution of monovalent 2009 Influenza A (H1N1) vaccines (pH1N1). This pandemic provided the opportunity to evaluate the risk of Guillain-Barré syndrome (GBS), which

  1. Monovalent rotavirus vaccine provides protection against an emerging fully heterotypic G9P[4] rotavirus strain in Mexico.

    Science.gov (United States)

    Yen, Catherine; Figueroa, Jesùs Reyna; Uribe, Edgar Sánchez; Carmen-Hernández, Luz Del; Tate, Jacqueline E; Parashar, Umesh D; Patel, Manish M; Richardson López-Collado, Vesta

    2011-09-01

    After the introduction of monovalent rotavirus vaccine (RV1) in Mexico in 2006-2007, diarrhea mortality and morbidity declined substantially among Mexican children under 5 years of age. In January 2010, surveillance identified the emergence of a novel G9P[4] rotavirus strain nationwide. We conducted a case-control study to assess the field effectiveness of RV1 against severe rotavirus gastroenteritis caused by this unusual strain and to determine whether the G9P[4] emergence was related to vaccine failure or failure to vaccinate. RV1 was 94% effective (95% confidence interval, 16%-100%) against G9P[4] rotavirus-related hospitalization, indicating that its emergence was likely unrelated to vaccine pressure.

  2. Draft Genome Sequence of Flavobacterium sp. Strain TAB 87, Able To Inhibit the Growth of Cystic Fibrosis Bacterial Pathogens Belonging to the Burkholderia cepacia Complex

    Science.gov (United States)

    Presta, Luana; Inzucchi, Ilaria; Bosi, Emanuele; Fondi, Marco; Perrin, Elena; Miceli, Elisangela; Tutino, Maria Luisa; Lo Giudice, Angelina

    2016-01-01

    We report here the draft genome sequence of the Flavobacterium sp. TAB 87 strain, isolated from Antarctic seawater during a summer campaign near the French Antarctic station Dumont d’Urville (60°40′S, 40°01′E). It will allow for comparative genomics and the fulfillment of both fundamental and application-oriented investigations. It allowed the recognition of genes associated with the production of bioactive compounds and antibiotic resistance. PMID:27198032

  3. Photocatalytic inactivation of Flavobacterium and E. coli in water by a continuous stirred tank reactor (CSTR) fed with suspended/immobilised TiO2 medium.

    Science.gov (United States)

    Cohen-Yaniv, Vered; Narkis, Nava; Armon, Robert

    2008-01-01

    A photocatalytic continuous stirred tank reactor (CSTR) was built at laboratory scale to inactivate two environmental bacteria strains (Flavobacterium and E. coli) in tap water. Several parameters were found to impact reactor efficiency. Bacterial initial concentration is an important factor in inactivation rate. After 30 minutes of irradiation at 10(8)-10(9) CFU mL(-1) starting concentration, a >5 log reduction was achieved while at 10(4)-10(6) CFU mL(-1) only a 2 log reduction was observed. Water hardness and pH have an important influence on the photocatalytic inactivation process. Soft water, with low Ca(+2) and Mg(+2) at low pH approximately 5.3 resulted in increased inactivation of Flavobacterium reaching >6 orders of magnitude reduction. E. coli and Flavobacterium at pH 5 were inactivated by 3 logs more as compared to pH 7 under similar conditions. pH below TiO2 isoelectric point (approximately 5.6) supports better contact between bacteria and anatase particles resulting in superior inactivation. TiO2 powder suspension was compared with immobilised powder in sol-gel coated glass beads in order to exclude the need for particles separation from the treated water. TiO2 suspension was more effective by 3 orders of magnitude when compared to coated glass beads. An interesting observation was found between the two bacterial strains based on their hydrophobicity/hydrophilicity balance. The more hydrophobic Flavobacterium compared to E. coli was inactivated photocatalytically by >3 logs more then E. coli in the first 30 minutes of irradiation interval. The results indicate the importance of the parameters involved in the contact between TiO2 particles and microorganisms that govern the successful inactivation rate in CSTR.

  4. Detection and quantification of Flavobacterium psychrophilum specific bacteriophages in rainbow trout upon different administration methods: Implications for disease control in aquaculture

    DEFF Research Database (Denmark)

    Christiansen, Rói Hammershaimb; Madsen, Lone; Dalsgaard, Inger

    2013-01-01

    Flavobacterium psychrophilum is the pathogen causing the disease rainbow trout fry syndrome (RTFS), which has important implications for aquaculture production and trade worldwide. RTFS can be treated by antibiotic administration, but with the increasing problem of antibiotic resistant bacteria......, the use of lytic bacteriophages is a promising alternative approach to disease control in aquaculture. Bacteriophage control of bacterial infections depends on efficient delivery of the phages to the infected organs, and in this study we therefore examined the occurrence and persistence of phages...

  5. Ultra-fast in-situ X-ray studies of evolving columnar dendrites in solidifying steel weld pools

    Science.gov (United States)

    Mirihanage, W. U.; Di Michiel, M.; Mathiesen, R. H.

    2015-06-01

    High-brilliance polychromatic synchrotron radiation has been used to conduct in-situ studies of the solidification microstructure evolution during simulated welding. The welding simulations were realized by rapidly fusing ∼ 5 mm spot in Fe-Cr-Ni steel. During the solid- liquid-solid phase transformations, a section of the weld pool was placed in an incident 50-150 keV polychromatic synchrotron X-ray beam, in a near-horizontal position at a very low inclination angle. Multiple high-resolution 2D detectors with very high frame rates were utilized to capture time resolved X-ray diffraction data from suitably oriented solid dendrites evolving in the weld pool. Comprehensive analysis of the diffraction data revealed individual and overall dendritic growth characteristics and relevant melt and solid flow dynamics during weld pool solidification, which was completed within 1.5 s. Columnar dendrite tip velocities were estimated from the experimental data and during early stages of solidification were exceeded 4 mm/s. The most remarkable observation revealed through the time-resolved reciprocal space observations are correlated to significant tilting of columnar type dendrites at their root during solidification, presumably caused by convective currents in the weld pool. When the columnar dendrite tilting are transformed to respective metric linear tilting velocities at the dendrite tip; tilting velocities are found to be in the same order of magnitude as the columnar tip growth velocities, suggesting a highly transient nature of growth conditions.

  6. Leaf micro-environment influence the altered foliar phenotype of columnar apple (Malus x domestica Borkh.) trees

    DEFF Research Database (Denmark)

    Talwara, Susheela; Grout, Brian William Wilson; Toldam-Andersen, Torben Bo

    2015-01-01

    Columnar apple trees (CATs) have radically-altered architecture (significantly shorter internodes and lateral branches) when compared to standard apple trees, attributed to a mutation of the Co gene involved in apical dominance. These changes in architecture have been associated with changes...

  7. Experimental test of the postulate that continuous columnar pinning centers produce the highest J{sub c}

    Energy Technology Data Exchange (ETDEWEB)

    Weinstein, Roy [Texas Center for Superconductivity and Advanced Materials, and Physics Department, University of Houston, Houston, TX 77204-5005 (United States)]. E-mail: weinstein@uh.edu; Gandini, Alberto [Texas Center for Superconductivity and Advanced Materials, and Physics Department, University of Houston, Houston, TX 77204-5005 (United States); Sawh, Ravi-Persad [Texas Center for Superconductivity and Advanced Materials, and Physics Department, University of Houston, Houston, TX 77204-5005 (United States); Mayes, Bill [Texas Center for Superconductivity and Advanced Materials, and Physics Department, University of Houston, Houston, TX 77204-5005 (United States); Parks, Drew [Texas Center for Superconductivity and Advanced Materials, and Physics Department, University of Houston, Houston, TX 77204-5005 (United States)

    2004-10-18

    Continuous columnar pinning centers, created by energetic ions, have been usefully studied theoretically and experimentally to investigate vortex physics in high T{sub c} superconductors. However, along the way, in error, their discontinuities have been downplayed, and they have been anointed as the way to produce high J{sub c}.

  8. FORWARD AND INVERSE BIO-GEOCHEMICAL MODELING OF MICROBIALLY INDUCED PRECIPITATION IN 0.5M COLUMNAR EXPERIMENTS

    Energy Technology Data Exchange (ETDEWEB)

    Tammer Barkouki; Brian Martinez; Brina Mortensen; Tess Weathers; Jason DeJong; Nic Spycher; Tim Ginn; Yoshiko Fujita; Robert Smith

    2009-09-01

    Microbial ureolysis-induced calcite precipitation may offer an in situ remediation for heavy metal and radionuclide contamination, as well as an alternative to traditional soil strengthening techniques. A microbially mediated calcite precipitation model was built in TOUGHREACT v2 and calibrated to batch and columnar experimental data. Kinetic ureolysis and calcite precipitation-rate expressions were parameterized by coupling TOUCHREACT with UCODE.

  9. Orientational packing of a confined discotic mesogen in the columnar phase.

    Science.gov (United States)

    Zheng, Wenjun; Hu, Ya-Ting; Chiang, Cheng-Yan; Ong, Chi Wi

    2010-03-08

    The stacking of discotic molecules (hexakis(alkoxy)diquinoxalino[2,3-a:2',3'-c]phenazines) in the columnar phase sandwiched between two flat glass substrates has been studied. The surface free energy of the substrates, measured by means of sessile drop technique, is found to have significant influence on the way that the discotic molecules anchor on the surface, and a steady thermal state of the system is crucial for a homogenous orientation of the discotic columns. On a surface of high free energy, the discotic molecules anchor with their disc-face toward the surface. A decrease in the surface free energy of the substrate causes the discotic columns to tilt away from the normal of the substrate.

  10. Comparison of Columnar Water-Vapor Measurements from Solar Transmittance Methods

    Science.gov (United States)

    Schmid, Beat; Michalsky, J.; Slater, Donald W.; Barnard, James C.; Halthore, Rangasayi N.; Liljegren, James C.; Holben, Brent N.; Eck, Thomas F.; Livingston, John M.; Russell, Philp B.

    2001-01-01

    The Atmospheric Radiation Measurement program studied water vapor abundance measurement at its southern Great Plains site in the fall of 1997. The program used a large number of instruments, including four solar radiometers. By measuring solar transmittance in the 0.94 micrometer water apor absorption band, they were able to measure columnar water vapor (CWV). In the second round of comparison we used the same radiative transfer model, and the same line-by-line code (which includes recently corrected H2O spectroscopy) to retrieve CWV from all four solar radiometers, thus decreasing the mean CWV by 8 - 13 %. The model was not responsible for the 8 % spread in CWV which remained.

  11. Orientational Packing of a Confined Discotic Mesogen in the Columnar Phase

    Directory of Open Access Journals (Sweden)

    Chi Wi Ong

    2010-03-01

    Full Text Available The stacking of discotic molecules (hexakis(alkoxydiquinoxalino[2,3-a:2’,3’-c]phenazines in the columnar phase sandwiched between two flat glass substrates has been studied. The surface free energy of the substrates, measured by means of sessile drop technique, is found to have significant influence on the way that the discotic molecules anchor on the surface, and a steady thermal state of the system is crucial for a homogenous orientation of the discotic columns. On a surface of high free energy, the discotic molecules anchor with their disc-face toward the surface. A decrease in the surface free energy of the substrate causes the discotic columns to tilt away from the normal of the substrate.

  12. Functional morphology and biomechanics of branch-stem junctions in columnar cacti.

    Science.gov (United States)

    Schwager, Hannes; Masselter, Tom; Speck, Thomas; Neinhuis, Christoph

    2013-12-07

    Branching in columnar cacti features morphological and anatomical characteristics specific to the subfamily Cactoideae. The most conspicuous features are the pronounced constrictions at the branch-stem junctions, which are also present in the lignified vascular structures within the succulent cortex. Based on finite-element analyses of ramification models, we demonstrate that these indentations in the region of high flexural and torsional stresses are not regions of structural weakness (e.g. allowing vegetative propagation). On the contrary, they can be regarded as anatomical adaptations to increase the stability by fine-tuning the stress state and stress directions in the junction along prevalent fibre directions. Biomimetic adaptations improving the functionality of ramifications in technical components, inspired, in particular, by the fine-tuned geometrical shape and arrangement of lignified strengthening tissues of biological role models, might contribute to the development of alternative concepts for branched fibre-reinforced composite structures within a limited design space.

  13. Functional morphology and biomechanics of branch–stem junctions in columnar cacti

    Science.gov (United States)

    Schwager, Hannes; Masselter, Tom; Speck, Thomas; Neinhuis, Christoph

    2013-01-01

    Branching in columnar cacti features morphological and anatomical characteristics specific to the subfamily Cactoideae. The most conspicuous features are the pronounced constrictions at the branch–stem junctions, which are also present in the lignified vascular structures within the succulent cortex. Based on finite-element analyses of ramification models, we demonstrate that these indentations in the region of high flexural and torsional stresses are not regions of structural weakness (e.g. allowing vegetative propagation). On the contrary, they can be regarded as anatomical adaptations to increase the stability by fine-tuning the stress state and stress directions in the junction along prevalent fibre directions. Biomimetic adaptations improving the functionality of ramifications in technical components, inspired, in particular, by the fine-tuned geometrical shape and arrangement of lignified strengthening tissues of biological role models, might contribute to the development of alternative concepts for branched fibre-reinforced composite structures within a limited design space. PMID:24132310

  14. Comparison of columnar water vapor over northern China derived from ground-based measurements and MODIS

    Science.gov (United States)

    Liu, Chaoshun; Shi, Runhe; Gao, Wei; Bai, Kaixu

    2011-09-01

    Water vapor represents a small but environmentally significant constituent of the atmosphere. This study retrieved columnar water vapor (CWV) with the 939.3 nm band of a Multi-filter Rotating Shadowband Radiometer (MFRSR) using the modified Langley technique from September 23, 2004 to June 20, 2005 at the XiangHe site.To improve the credibility, the MFRSR results were compared with those obtained from the AERONET (AErosol RObotic NETwork) CIMEL sun-photometer measurements, co-located at the XiangHe site, and the Moderate Resolution Imaging Spectroradiometer (MODIS) Near-Infrared Total Precipitable Water Product (MOD05), respectively. These comparisons show a good agreement in terms of correlation coefficients, slopes, and offsets, revealing that the accuracy of CWV estimation using the MFRSR instrument is reliable and suitable for extended studies in northern China.

  15. Light-melt adhesive based on dynamic carbon frameworks in a columnar liquid-crystal phase

    Science.gov (United States)

    Saito, Shohei; Nobusue, Shunpei; Tsuzaka, Eri; Yuan, Chunxue; Mori, Chigusa; Hara, Mitsuo; Seki, Takahiro; Camacho, Cristopher; Irle, Stephan; Yamaguchi, Shigehiro

    2016-07-01

    Liquid crystal (LC) provides a suitable platform to exploit structural motions of molecules in a condensed phase. Amplification of the structural changes enables a variety of technologies not only in LC displays but also in other applications. Until very recently, however, a practical use of LCs for removable adhesives has not been explored, although a spontaneous disorganization of LC materials can be easily triggered by light-induced isomerization of photoactive components. The difficulty of such application derives from the requirements for simultaneous implementation of sufficient bonding strength and its rapid disappearance by photoirradiation. Here we report a dynamic molecular LC material that meets these requirements. Columnar-stacked V-shaped carbon frameworks display sufficient bonding strength even during heating conditions, while its bonding ability is immediately lost by a light-induced self-melting function. The light-melt adhesive is reusable and its fluorescence colour reversibly changes during the cycle, visualizing the bonding/nonbonding phases of the adhesive.

  16. Anisotropic and non-heterogeneous continuum percolation in titanium oxynitride thin columnar films

    Energy Technology Data Exchange (ETDEWEB)

    Fabreguette, F. [LPUB, Universite de Bourgogne, Dijon (France); LRRS, Universite de Bourgogne, Dijon (France); Maglione, M.; Sacilotti, M. [LPUB, Universite de Bourgogne, Dijon (France); Clerc, J.P. [IUSTI, Technopole de Chateau-Gombert, Marseille (France); Bourgeois, S. [LRRS, Universite de Bourgogne, Dijon (France)

    2002-09-02

    We report the percolation behaviour of the conductivity of titanium oxynitride films grown by low-pressure metal-organic chemical vapour deposition, composed of TiN{sub x}O{sub y} mixed with TiO{sub 2}. The usual DC parameters (t, s and {phi}{sub c}), obtained from the effective media theory equations, are compared to the universal values (s=s{sub un} while tcolumnar films with chemically similar conducting and insulating units (non-heterogeneous percolation) whose mixing is based upon the growth temperature during the film growth. (author)

  17. Columnar shifts as symmetry-breaking degrees of freedom in molecular perovskites.

    Science.gov (United States)

    Boström, Hanna L B; Hill, Joshua A; Goodwin, Andrew L

    2016-11-23

    We introduce columnar shifts-collective rigid-body translations-as a structural degree of freedom relevant to the phase behaviour of molecular perovskites ABX3 (X = molecular anion). Like the well-known octahedral tilts of conventional perovskites, shifts also preserve the octahedral coordination geometry of the B-site cation in molecular perovskites, and so are predisposed to influencing the low-energy dynamics and displacive phase transitions of these topical systems. We present a qualitative overview of the interplay between shift activation and crystal symmetry breaking, and introduce a generalised terminology to allow characterisation of simple shift distortions, drawing analogy to the "Glazer notation" for octahedral tilts. We apply our approach to the interpretation of a representative selection of azide and formate perovskite structures, and discuss the implications for functional exploitation of shift degrees of freedom in negative thermal expansion materials and hybrid ferroelectrics.

  18. On the frequency-selective features of gold nanorods-based columnar thin film metamaterial absorber

    Science.gov (United States)

    Ghasemi, Masih; Choudhury, P. K.; Baqir, M. A.; Mohamed, M. A.; Zain, A. R. M.; Majlis, B. Y.

    2016-09-01

    Metamaterials have been of great interest owing to multifarious technological applications. Among various applications of scientific need, the perfect absorber kind of property of metamaterials remains prudent. Within the context, this investigation describes the filtering/absorber applications of metasurfaces comprised of columnar nanorods of gold having circular and elliptical cross-sections. The spectral features of such absorbers are investigated in terms of absorptivity in the visible to infrared (IR) regimes. The results indicate of almost perfect absorption corresponding to certain wavelengths in the IR span. Also, multiple absorption peaks would determine the filtering characteristics of the structures under consideration. It has been found that the absorber having circular nanorods exhibits better performance than the one with elliptical nanorods in terms of the magnitude/smoothness of absorption peaks in the entire electromagnetic spectral region of interest; the case of elliptical nanorods makes the absorption spectra to yield too much of flickers in the IR range of wavelength.

  19. Phase field simulation of the columnar dendritic growth and microsegregation in a binary alloy

    Institute of Scientific and Technical Information of China (English)

    Li Jun-Jie; Wang Jin-Cheng; Yang Gen-Cang

    2008-01-01

    This paper applies a phase field model for polycrystalline solidification in binary alloys to simulate the formation and growth of the columnar dendritic array under the isothermal and constant cooling conditions.The solidification process and microsegregation in the mushy zone are analysed in detail.It is shown that under the isothermal condition solidification will stop after the formation of the mushy zone,but dendritic coarsening will progress continuously,which results in the decrease of the total interface area.Under the constant cooling condition the mushy zone will solidify and coarsen simultaneously. For the constant cooling solidification,microsegregation predicted by a modified Brody Flemings model is compared with the simulation results.It is found that the Fourier number which characterizes microsegregation is different for regions with different microstructures.Dendritic coarsening and the larger area of interface should account for the enhanced Fourier number in the region with well developed second dendritic arms.

  20. Crystal structures of 2,3,6,7,10,11-oxytriphenylenes. Implications for columnar discotic mesophases

    DEFF Research Database (Denmark)

    Andresen, T.L.; Krebs, Frederik C; Thorup, Niels;

    2000-01-01

    in the aim that a detailed structural knowledge of the discotic premesogens could be used to infer detailed structural knowledge with respect to known liquid crystal mesogens where little detailed structural knowledge is available. It was found that the crystal structures of the discotic premesogens were......The structures of the oxysubstituted triphenylene premesogens, 2,3,6,7,10,11-hexahydroxy-triphenylene (4), 2,3,6,7,10,11-hexamethoxytriphenylene (5), 2,3,6,7,10,11-hexaethoxytriphenylene (6), and 2,3,6,7,10,11-hexapropoxytriphenylene (7) were determined, and the structural results were investigated...... very different from the structures expected for discotic columnar behavior. These differences allowed us to shed some light on the structural forces that gives rise to the mesophasic behavior observed in such systems as being not due to stacking of the planar aromatic core as inferred hitherto...

  1. Percolation threshold gold films on columnar coatings: characterisation for SERS applications

    CERN Document Server

    Balcytis, Armandas; Wang, Xuewen; Seniutinas, Gediminas; Drazdys, Ramutis; Stoddart, Paul R; Juodkazis, Saulius

    2016-01-01

    Percolation of gold films of ~15 nm thickness was controlled to achieve the largest openings during Au deposition. Gold was evaporated on 300-nm-thick films of nanostructured porous and columnar SiO2, TiO2 and MgF2 which were deposited by controlling the angle, rotation speed during film formation and ambient pressure. The gold films were tested for SERS performance using thiophenol reporter molecules which form a stable self-assembled monolayer on gold. The phase retardation of these SERS substrates was up to 5% for wavelengths in the visible spectral range, as measured by Stokes polarimetry. The SERS intensity on gold percolation films can reach 10^3 counts/(mW.s) for tight focusing in air, while back-side excitation through the substrate has shown the presence of an additional SERS enhancement via the Fresnel near-field mechanism.

  2. One- and two-dimensional fluids properties of smectic, lamellar and columnar liquid crystals

    CERN Document Server

    Jakli, Antal

    2006-01-01

    Smectic and lamellar liquid crystals are three-dimensional layered structures in which each layer behaves as a two-dimensional fluid. Because of their reduced dimensionality they have unique physical properties and challenging theoretical descriptions, and are the subject of much current research. One- and Two-Dimensional Fluids: Properties of Smectic, Lamellar and Columnar Liquid Crystals offers a comprehensive review of these phases and their applications. The book details the basic structures and properties of one- and two-dimensional fluids and the nature of phase transitions. The later chapters consider the optical, magnetic, and electrical properties of special structures, including uniformly and non-uniformly aligned anisotropic films, lyotropic lamellar systems, helical and chiral structures, and organic anisotropic materials. Topics also include typical and defective features, magnetic susceptibility, and electrical conductivity. The book concludes with a review of current and potential applications ...

  3. Neuroarchitecture of the central complex of the desert locust: Intrinsic and columnar neurons.

    Science.gov (United States)

    Heinze, Stanley; Homberg, Uwe

    2008-12-01

    The central complex is a group of neuropils in the center of the insect brain. It consists of four major subunits: the upper and lower divisions of the central body (CBU, CBL), the protocerebral bridge (PB), and the paired noduli. A distinctive feature of the central complex is a modular architecture characterized by rows of 16 columns, intersected in the central body by stacks of layers. Evidence from locusts suggests that the central complex plays a major role in sky compass orientation. To understand signal processing in this brain area further, we have analyzed the morphologies of columnar neurons of the central complex of the locust Schistocerca gregaria. Intracellular dye fills revealed 21 types of columnar neurons that connect columns of different subunits, three types of pontine neurons linking pairs of columns within the CBU, and one amacrine cell. Most neurons appeared to be part of isomorphic sets with cell type-specific heterolateral projection patterns. Evaluation of arborization areas and neuron polarity suggests that these neurons are either intrinsic to the central complex or provide output to the lateral accessory lobes (LALs) or anterior lip region. No direct connections were found between the CBU and CBL. Instead, neurons of either subdivision were connected with the PB, but projected to non-overlapping regions in the LALs and to different layers of the noduli. This study provides novel insights into the functional organization of the central complex, especially with respect to its likely role in right-left signal matching and decision making. (c) 2008 Wiley-Liss, Inc.

  4. Long term analysis of the columnar and surface aerosol relationship at an urban European coastal site

    Science.gov (United States)

    Segura, S.; Estellés, V.; Utrillas, M. P.; Martínez-Lozano, J. A.

    2017-10-01

    Simultaneous PM2.5, PM10 and columnar (ground and satellite based) AOD measurements have been analyzed at Burjassot site in the metropolitan area of Valencia (Spain) during the period 2007-2016. The site is representative of a south European city in the Western Mediterranean coastal area, influenced by local urban pollution but also from frequent Saharan dust events. First, multiannual statistics were performed to characterize the main aerosol burden characteristics. The averages and standard deviations resulted 18 ± 9 μg m-3, 25 ± 19 μg m-3, 0.15 ± 0.11, 0.23 ± 0.17, 0.19 ± 0.15 and 1.2 ± 0.3 for PM2.5, PM10, AERONET AOD, MODIS Terra AOD, MODIS Aqua AOD, and AERONET Ångström exponent AE, respectively. The AOD is always referred to 550 nm. PM10 and AOD showed seasonal patterns with maxima in summer and minima in winter. However, PM2.5 and AE did not show such an evident seasonality. The relationship between surface and columnar measurements show a poor correlation (r down to 0.30) for daily values, although the correlation increases to r up to 0.90 for yearly averages. The relationship between PM and AOD becomes more consistent when the databases are binned in intervals of 0.05 AOD. Results for AERONET and MODIS AOD are very similar, although for daily averages is slightly worse for satellite than ground based measurements. In order to explain some seasonality effects found, the mixing layer height has been included in the analysis. Results show that the correlation is maximum when PM2.5 is used and the mixing layer height is greater than 1 000 m (r > 0.90).

  5. Pollination system of the Pilosocereus leucocephalus columnar cactus (tribe Cereeae) in eastern Mexico.

    Science.gov (United States)

    Munguía-Rosas, M A; Sosa, V J; Jácome-Flores, M E

    2010-07-01

    It has been suggested that there is a geographic dichotomy in the pollination systems of chiropterophilous columnar cacti: in intra-tropical areas they are pollinated almost exclusively by bats, whereas in extratropical areas they are pollinated by bats, birds and bees. However, currently the studies are clumped both taxonomically (mainly Pachycereeae species) and geographically (mainly in the Tehuacan Valley and the Sonoran Desert). This clumping limits the possibility of generalising the pattern to other regions or cactus tribes. Only four of the 36 chiropterophilous cacti in Pilosocereus have been studied. Despite the tropical distribution of two Pilosocereus species, bees account for 40-100% of their fruit set. We examined how specialised is the pollination system of P. leucocephalus in eastern Mexico. As we studied tropical populations, we expected a bat-specialised pollination system. However, previous studies of Pilosocereus suggest that a generalised pollination system is also possible. We found that this cactus is mainly bat-pollinated (bats account for 33-65% of fruit set); although to a lesser degree, diurnal visitors also caused some fruit set (7-15%). Diurnal visitors were more effective in populations containing honeybee hives. P. leucocephalus is partially self-compatible (14-18% of fructification) but unable to set fruit without visitors. Despite the variation in pollination system, P. leucocephalus shows more affinity with other columnar cacti from tropical regions than with those from extratropical regions. Although we report here that a new species of tropical Pilosocereus is relatively bat-specialised, this Cereeae genus is more flexible in its pollination system than the Pachycereeae genera.

  6. High-quality draft genome sequence of Flavobacterium suncheonense GH29-5(T) (DSM 17707(T)) isolated from greenhouse soil in South Korea, and emended description of Flavobacterium suncheonense GH29-5(T).

    Science.gov (United States)

    Tashkandy, Nisreen; Sabban, Sari; Fakieh, Mohammad; Meier-Kolthoff, Jan P; Huang, Sixing; Tindall, Brian J; Rohde, Manfred; Baeshen, Mohammed N; Baeshen, Nabih A; Lapidus, Alla; Copeland, Alex; Pillay, Manoj; Reddy, T B K; Huntemann, Marcel; Pati, Amrita; Ivanova, Natalia; Markowitz, Victor; Woyke, Tanja; Göker, Markus; Klenk, Hans-Peter; Kyrpides, Nikos C; Hahnke, Richard L

    2016-01-01

    Flavobacterium suncheonense is a member of the family Flavobacteriaceae in the phylum Bacteroidetes. Strain GH29-5(T) (DSM 17707(T)) was isolated from greenhouse soil in Suncheon, South Korea. F. suncheonense GH29-5(T) is part of the G enomic E ncyclopedia of B acteria and A rchaea project. The 2,880,663 bp long draft genome consists of 54 scaffolds with 2739 protein-coding genes and 82 RNA genes. The genome of strain GH29-5(T) has 117 genes encoding peptidases but a small number of genes encoding carbohydrate active enzymes (51 CAZymes). Metallo and serine peptidases were found most frequently. Among CAZymes, eight glycoside hydrolase families, nine glycosyl transferase families, two carbohydrate binding module families and four carbohydrate esterase families were identified. Suprisingly, polysaccharides utilization loci (PULs) were not found in strain GH29-5(T). Based on the coherent physiological and genomic characteristics we suggest that F. suncheonense GH29-5(T) feeds rather on proteins than saccharides and lipids.

  7. Effect of Suspension Plasma-Sprayed YSZ Columnar Microstructure and Bond Coat Surface Preparation on Thermal Barrier Coating Properties

    Science.gov (United States)

    Bernard, Benjamin; Quet, Aurélie; Bianchi, Luc; Schick, Vincent; Joulia, Aurélien; Malié, André; Rémy, Benjamin

    2017-08-01

    Suspension plasma spraying (SPS) is identified as promising for the enhancement of thermal barrier coating (TBC) systems used in gas turbines. Particularly, the emerging columnar microstructure enabled by the SPS process is likely to bring about an interesting TBC lifetime. At the same time, the SPS process opens the way to a decrease in thermal conductivity, one of the main issues for the next generation of gas turbines, compared to the state-of-the-art deposition technique, so-called electron beam physical vapor deposition (EB-PVD). In this paper, yttria-stabilized zirconia (YSZ) coatings presenting columnar structures, performed using both SPS and EB-PVD processes, were studied. Depending on the columnar microstructure readily adaptable in the SPS process, low thermal conductivities can be obtained. At 1100 °C, a decrease from 1.3 W m-1 K-1 for EB-PVD YSZ coatings to about 0.7 W m-1 K-1 for SPS coatings was shown. The higher content of porosity in the case of SPS coatings increases the thermal resistance through the thickness and decreases thermal conductivity. The lifetime of SPS YSZ coatings was studied by isothermal cyclic tests, showing equivalent or even higher performances compared to EB-PVD ones. Tests were performed using classical bond coats used for EB-PVD TBC coatings. Thermal cyclic fatigue performance of the best SPS coating reached 1000 cycles to failure on AM1 substrates with a β-(Ni,Pt)Al bond coat. Tests were also performed on AM1 substrates with a Pt-diffused γ-Ni/γ'-Ni3Al bond coat for which more than 2000 cycles to failure were observed for columnar SPS YSZ coatings. The high thermal compliance offered by both the columnar structure and the porosity allowed the reaching of a high lifetime, promising for a TBC application.

  8. Purification, characterization, and overexpression of psychrophilic and thermolabile malate dehydrogenase of a novel antarctic psychrotolerant, Flavobacterium frigidimaris KUC-1.

    Science.gov (United States)

    Oikawa, Tadao; Yamamoto, Noriko; Shimoke, Koji; Uesato, Shinichi; Ikeuchi, Toshihiko; Fujioka, Toru

    2005-11-01

    We purified the psychrophilic and thermolabile malate dehydrogenase to homogeneity from a novel psychrotolerant, Flavobacterium frigidimaris KUC-1, isolated from Antarctic seawater. The enzyme was a homotetramer with a molecular weight of about 123 k and that of the subunit was about 32 k. The enzyme required NAD(P)(+) as a coenzyme and catalyzed the oxidation of L-malate and the reduction of oxalacetate specifically. The reaction proceeded through an ordered bi-bi mechanism. The enzyme was highly susceptible to heat treatment, and the half-life time at 40 degrees C was estimated to be 3.0 min. The k(cat)/K(m) (microM(-1).s(-1)) values for L-malate and NAD(+) at 30 degrees C were 289 and 2,790, respectively. The enzyme showed pro-R stereospecificity for hydrogen transfer at the C4 position of the nicotinamide moiety of the coenzyme. The enzyme contained 311 amino acid residues and much lower numbers of proline and arginine residues than other malate dehydrogenases.

  9. Improved husbandry to control an outbreak of rainbow trout fry syndrome caused by infection with Flavobacterium psychrophilum

    Science.gov (United States)

    Bebak, J.A.; Welch, T.J.; Starliper, C.E.; Baya, A.M.; Garner, M.M.

    2007-01-01

    Case Description - A cohort of 35,200, 13-week-old, female rainbow trout at a fish farm was evaluated because of a 2-week history of anorexia and lethargy and a mortality rate of approximately 100 fish/d. Clinical Findings - Affected fish were lethargic and thin and had disequilibrium, bilateral exophthalmia, pale red gills and kidneys, red-tinged coelomic fluid, and pale brown livers. Some fish were differentially pigmented bilaterally. The presumptive diagnosis was bacterial or viral septicemia. The definitive diagnosis was rainbow trout fry syndrome caused by infection with Flavobacterium psychrophilum. Treatment and Outcome - A strategy for controlling the outbreak based on reducing pathogen numbers in affected tanks and reducing pathogen spread among tanks was developed. The option of treating with antimicrobial-medicated feed was discussed with the farmer, but was declined. After changes were made, mortality rate declined quickly, with no more deaths within 10 days after the initial farm visit. Clinical Relevance - Bacterial coldwater disease is the most common manifestation of infection with F psychrophilum in fingerling and adult rainbow trout. However, the organism can also cause rainbow trout fry syndrome. This condition should be included on a list of differential diagnoses for septicemia in hatchery-reared rainbow trout fry.

  10. Neutrophil Migration in the Activation of the Innate Immune Response to Different Flavobacterium psychrophilum Vaccines in Zebrafish (Danio rerio

    Directory of Open Access Journals (Sweden)

    Camila J. Solís

    2015-01-01

    Full Text Available Flavobacterium psychrophilum is a Gram-negative bacterium, responsible for the bacterial cold-water disease and the rainbow trout fry syndrome in freshwater salmonid fish. At present, there is only one commercial vaccine in Chile, made with two Chilean F. psychrophilum isolates and another licensed in Europe. The present study analyzed neutrophil migration, as a marker of innate immune activation, in zebrafish (Danio rerio in response to different F. psychrophilum bath vaccines, which is the first step in evaluating vaccine effectiveness and efficiency in fish. Results indicated that bacterins of the LM-02-Fp isolate were more immunogenic than those from the LM-13-Fp isolate. However, no differences were observed between the same bacteria inactivated by either formaldehyde or heat. Importantly, the same vaccine formulation without an adjuvant only triggered a mild neutrophil migration compared to the complete vaccine. Observations also found that, after a year of storage at 4°C, the activation of the innate immune system by the different vaccines was considerably decreased. Finally, new vaccine formulations prepared with heat and formaldehyde inactivated LM-02-Fp were significantly more efficient than the available commercial vaccine in regard to stimulating the innate immune system.

  11. Protection against Flavobacterium psychrophilum infection (cold water disease) in Ayu fish (Plecoglossus altivelis) by oral administration of humus extract.

    Science.gov (United States)

    NAKAGAWA, Jun; IWASAKI, Tadashi; KODAMA, Hiroshi

    2009-11-01

    Humic substances are formed during the decomposition of organic matter in humus, and are found in many natural environments in which organic materials and microorganisms have been present. In the present study, oral administration of humus extract to ayu fish (Plecoglossus altivelis) induced effective protection against experimental Flavobacterium psychrophilum infection (cold water disease). Mortality of fish and development of skin lesions, such as erosion and hemorrhages on the skin, gill cover or mouth, were significantly suppressed in fish treated with 10%, 5% or 1% humus extract adsorbed on dry pellets. Although F. psychrophilum was not re-isolated from gills and erosion lesions of the skin of dead fish, bacterial gyrB DNA could be amplified in these specimens from dead fish and surviving control fish using the polymerase chain reaction. The protective effect of the extract was not the results of direct killing of bacteria or antibiotic activity of the extract since no obvious reduction in the bacterial number was observed at 5 times to 5,000 times dilution of the humus extract having pH 5.45 to 7.40. These results clearly show that treating fish with humus extract is effective in preventing cold water disease.

  12. The protective efficacy of cloned Moraxella bovis pili in monovalent and multivalent vaccine formulations against experimentally induced infectious bovine keratoconjunctivitis (IBK).

    Science.gov (United States)

    Lepper, A W; Atwell, J L; Lehrbach, P R; Schwartzkoff, C L; Egerton, J R; Tennent, J M

    1995-07-01

    Calves were vaccinated with cloned Moraxella bovis pili of serogroup C (experiment 1) or B (experiment 2) either as a monovalent formulation or as part of a multivalent preparation with pili of six other serogroups. Within 4 weeks of the second vaccine dose vaccinated calves and non-vaccinated controls were challenged via the ocular route with either virulent M. bovis strain Dal2d (serogroup C) or M. bovis strain 3WO7 (serogroup B) in experiments 1 and 2, respectively. Calves vaccinated with multivalent vaccines had significantly lower antibody titres than those vaccinated with monovalent preparations. Nevertheless, the levels of protection against infectious bovine keratoconjunctivitis (IBK) achieved with multivalent vaccines were 72% and 83% for the groups challenged with M. bovis strains of serogroups B and C, respectively. The serogroup C monovalent vaccine gave 100% protection against experimentally induced IBK and M. bovis isolates cultured from the eyes 6 days post-challenge were identified as belonging solely to serogroup C. Unexpectedly, only 25% protection was achieved against homologous strain challenge of calves that received the monovalent serogroup B vaccine. Furthermore, the majority of M. bovis isolates recovered from calves in this group belonged to serogroup C, as did half of those isolates cultured from the multivalent vaccinates. The remaining bacterial isolates from the latter group, together with all isolates from the non-vaccinated controls, belonged to serogroup B. Results are consistent with the hypothesis that derivatives of the serogroup B challenge inoculum had expressed serogroup C pilus antigen within 6 days of the challenge, possibly as a result of pilus gene inversion occurring in response to the presence of specific antibody in eye tissues and tears.

  13. Non-covalent ligand conjugation to biotinylated DNA nanoparticles using TAT peptide genetically fused to monovalent streptavidin.

    Science.gov (United States)

    Sun, Wenchao; Fletcher, David; van Heeckeren, Rolf Christiaan; Davis, Pamela B

    2012-09-01

    DNA nanoparticles (DNA NPs), which self-assemble from DNA plasmids and poly-L-lysine (pLL)-polyethylene glycol (PEG) block copolymers, transfect several cell types in vitro and in vivo with minimal toxicity and immune response. To further enhance the gene transfer efficiency of DNA NP and control its tropism, we established a strategy to efficiently attach peptide ligands to DNA NPs. The non-covalent biotin-streptavidin (SA) interaction was used for ligand conjugation to overcome problems associated with covalent conjugation methods. A fusion protein of SA with the HIV-1 TAT peptide was cloned, expressed, purified and attached to biotinylated DNA NPs. A modified SA system with tetrameric structure but monovalent biotin binding capacity was adopted and shown to reduce the aggregation of biotinylated DNA NPs compared to neutravidin. Compared to unmodified DNA NPs, TAT modified DNA NPs significantly enhanced in vitro gene transfer, particularly at low DNA concentrations. Studies of cellular uptake and cellular distribution of the DNA NPs indicated that attaching TAT enhanced binding of DNA NPs to cell surface but not internalization at high DNA concentrations. In vivo studies showed that TAT modified DNA NPs mediated equal level of gene transfer to the mouse airways via the luminal route compared to unmodified DNA NPs.

  14. Monovalent Ions and Water Dipoles in Contact with Dipolar Zwitterionic Lipid Headgroups-Theory and MD Simulations

    Directory of Open Access Journals (Sweden)

    Aljaž Velikonja

    2013-01-01

    Full Text Available The lipid bilayer is a basic building block of biological membranes and can be pictured as a barrier separating two compartments filled with electrolyte solution. Artificial planar lipid bilayers are therefore commonly used as model systems to study the physical and electrical properties of the cell membranes in contact with electrolyte solution. Among them the glycerol-based polar phospholipids which have dipolar, but electrically neutral head groups, are most frequently used in formation of artificial lipid bilayers. In this work the electrical properties of the lipid layer composed of zwitterionic lipids with non-zero dipole moments are studied theoretically. In the model, the zwitterionic lipid bilayer is assumed to be in contact with aqueous solution of monovalent salt ions. The orientational ordering of water, resulting in spatial variation of permittivity, is explicitly taken into account. It is shown that due to saturation effect in orientational ordering of water dipoles the relative permittivity in the zwitterionic headgroup region is decreased, while the corresponding electric potential becomes strongly negative. Some of the predictions of the presented mean-field theoretical consideration are critically evaluated using the results of molecular dynamics (MD simulation.

  15. Influence of competing inorganic cations on the ion exchange equilibrium of the monovalent organic cation metoprolol on natural sediment.

    Science.gov (United States)

    Niedbala, Anne; Schaffer, Mario; Licha, Tobias; Nödler, Karsten; Börnick, Hilmar; Ruppert, Hans; Worch, Eckhard

    2013-02-01

    The aim of this study was to systematically investigate the influence of the mono- and divalent inorganic ions Na(+) and Ca(2+) on the sorption behavior of the monovalent organic cation metoprolol on a natural sandy sediment at pH=7. Isotherms for the beta-blocker metoprolol were obtained by sediment-water batch tests over a wide concentration range (1-100000 μg L(-1)). Concentrations of the competing inorganic ions were varied within freshwater relevant ranges. Data fitted well with the Freundlich sorption model and resulted in very similar Freundlich exponents (n=0.9), indicating slightly non-linear behavior. Results show that the influence of Ca(2+) compared to Na(+) is more pronounced. A logarithmic correlation between the Freundlich coefficient K(Fr) and the concentration or activity of the competing inorganic ions was found allowing the prediction of metoprolol sorption on the investigated sediment at different electrolyte concentrations. Additionally, the organic carbon of the sediment was completely removed for investigating the influence of organic matter on the sorption of metoprolol. The comparison between the experiments with and without organic carbon removal revealed no significant contribution of the organic carbon fraction (0.1%) to the sorption of metoprolol on the in this study investigated sediment. Results of this study will contribute to the development of predictive models for the transport of organic cations in the subsurface.

  16. In-vitro Neurotoxicity of Two Malaysian Krait Species (Bungarus candidus and Bungarus fasciatus Venoms: Neutralization by Monovalent and Polyvalent Antivenoms from Thailand

    Directory of Open Access Journals (Sweden)

    Muhamad Rusdi Ahmad Rusmili

    2014-03-01

    Full Text Available Bungarus candidus and Bungarus fasciatus are two species of krait found in Southeast Asia. Envenoming by these snakes is often characterized by neurotoxicity and, without treatment, causes considerable morbidity and mortality. In this study, the in vitro neurotoxicity of each species, and the effectiveness of two monovalent antivenoms and a polyvalent antivenom, against the neurotoxic effects of the venoms, were examined in a skeletal muscle preparation. Both venoms caused concentration-dependent inhibition of indirect twitches, and attenuated responses to exogenous nicotinic receptor agonists, in the chick biventer preparation, with B. candidus venom being more potent than B. fasciatus venom. SDS-PAGE and western blot analysis indicated different profiles between the venoms. Despite these differences, most proteins bands were recognized by all three antivenoms. Antivenom, added prior to the venoms, attenuated the neurotoxic effect of the venoms. Interestingly, the respective monovalent antivenoms did not neutralize the effects of the venom from the other Bungarus species indicating a relative absence of cross-neutralization. Addition of a high concentration of polyvalent antivenom, at the t90 time point after addition of venom, partially reversed the neurotoxicity of B. fasciatus venom but not B. candidus venom. The monovalent antivenoms had no significant effect when added at the t90 time point. This study showed that B. candidus and B. fasciatus venoms display marked in vitro neurotoxicity in the chick biventer preparation and administration of antivenoms at high dose is necessary to prevent or reverse neurotoxicity.

  17. In-vitro neurotoxicity of two Malaysian krait species (Bungarus candidus and Bungarus fasciatus) venoms: neutralization by monovalent and polyvalent antivenoms from Thailand.

    Science.gov (United States)

    Rusmili, Muhamad Rusdi Ahmad; Yee, Tee Ting; Mustafa, Mohd Rais; Othman, Iekhsan; Hodgson, Wayne C

    2014-03-12

    Bungarus candidus and Bungarus fasciatus are two species of krait found in Southeast Asia. Envenoming by these snakes is often characterized by neurotoxicity and, without treatment, causes considerable morbidity and mortality. In this study, the in vitro neurotoxicity of each species, and the effectiveness of two monovalent antivenoms and a polyvalent antivenom, against the neurotoxic effects of the venoms, were examined in a skeletal muscle preparation. Both venoms caused concentration-dependent inhibition of indirect twitches, and attenuated responses to exogenous nicotinic receptor agonists, in the chick biventer preparation, with B. candidus venom being more potent than B. fasciatus venom. SDS-PAGE and western blot analysis indicated different profiles between the venoms. Despite these differences, most proteins bands were recognized by all three antivenoms. Antivenom, added prior to the venoms, attenuated the neurotoxic effect of the venoms. Interestingly, the respective monovalent antivenoms did not neutralize the effects of the venom from the other Bungarus species indicating a relative absence of cross-neutralization. Addition of a high concentration of polyvalent antivenom, at the t90 time point after addition of venom, partially reversed the neurotoxicity of B. fasciatus venom but not B. candidus venom. The monovalent antivenoms had no significant effect when added at the t90 time point. This study showed that B. candidus and B. fasciatus venoms display marked in vitro neurotoxicity in the chick biventer preparation and administration of antivenoms at high dose is necessary to prevent or reverse neurotoxicity.

  18. Purification of a Flavobacterium pentachlorophenol-induced periplasmic protein (PcpA) and nucleotide sequence of the corresponding gene (pcpA).

    OpenAIRE

    Xun, L Y; Orser, C S

    1991-01-01

    A pentachlorophenol (PCP)-induced periplasmic protein (PcpA) with a molecular weight of 30,000 has been identified and purified from Flavobacterium sp. strain ATCC 39723. Results suggest that PcpA may be involved in PCP mineralization. The induction of PcpA correlated with the induction of PCP-degrading activity. When PcpA was released from the periplasmic space by EDTA or osmotic shock treatment, PCP-degrading activity was arrested. Two PCP- mutants of ATCC 39723, which do not degrade PCP, d...

  19. Simulation of thermos-solutal convection induced macrosegregation in a Sn-10%Pb alloy benchmark during columnar solidification

    Science.gov (United States)

    Zheng, Y.; Wu, M.; Kharicha, A.; Ludwig, A.

    2016-03-01

    In order to investigate the effect of thermo-solutal convection on the formation of macrosegregation during columnar solidification, simulations with a liquid-columnar two phase model were carried out on a 2D rectangular benchmark of Sn-10%Pb alloy. The solidification direction in the benchmark is unidirectional: (') downwards from top to bottom or (2) upwards from bottom to top. Thermal expansion coefficient, solutal expansion coefficient and liquid diffusion coefficient of the melt are found to be key factors influencing the final macrosegregation. The segregation range and distribution are also strongly influenced by the benchmark configurations, e.g. the solidifying direction (upwards or downwards) and boundary conditions, et al. The global macrosegregation range increases with the velocity magnitude of the melt during the process of solidification.

  20. [Digestibility of columnar cacti pollen grains in the glosophagine bats Glossophaga longirostris and Leptonycteris curasoae (Chiroptera: Phyllostomidae)].

    Science.gov (United States)

    Muñoz-Romo, Mariana; Sosa, Maricela; Quintero, Yveth Casart

    2005-01-01

    We examined the protoplasmic assimilation of columnar cacti pollen grains in two species of Venezuelan desert glosophagine bats, Glossophaga longirostris and Leptonycteris curasoae, by determining the amount of empty (digested) pollen grains found in their fecal samples. To determine the amount of empty pollen grains, the fecal samples were stained to differ between empty and full (non-digested) pollen grains. The number of empty and full pollen grains observed in the fecal samples were corrected using the amount of aborted pollens present (before anthesis) in flowers of the columnar cacti species (Subpilocereus repandus, Stenocereus griseus and Pilosocereus tillianus) used by bats as food in the study site; G. longirostris and L. curasoae digested 64.2% and 71.3% of all the pollens fed, respectively. These high values confirm the importance of pollen in the diet of these bats, given its high nitrogen level.

  1. Optimizing modulation frequency for structured illumination in a fiber-optic microendoscope to image nuclear morphometry in columnar epithelium.

    Science.gov (United States)

    Keahey, P A; Tkaczyk, T S; Schmeler, K M; Richards-Kortum, R R

    2015-03-01

    Fiber-optic microendoscopes have shown promise to image the changes in nuclear morphometry that accompany the development of precancerous lesions in tissue with squamous epithelium such as in the oral mucosa and cervix. However, fiber-optic microendoscopy image contrast is limited by out-of-focus light generated by scattering within tissue. The scattering coefficient of tissues with columnar epithelium can be greater than that of squamous epithelium resulting in decreased image quality. To address this challenge, we present a small and portable microendoscope system capable of performing optical sectioning using structured illumination (SI) in real-time. Several optical phantoms were developed and used to quantify the sectioning capabilities of the system. Columnar epithelium from cervical tissue specimens was then imaged ex vivo, and we demonstrate that the addition of SI achieves higher image contrast, enabling visualization of nuclear morphology.

  2. Pinning efficiency of splayed columnar defects in Bi-2212 single crystal: Evidence of a cage pinning effect

    Science.gov (United States)

    Shaidiuk, V. A.; Ruyter, A.; Plessis, D.; Simon, Ch.; Maignan, A.; Wahl, A.; de Brion, S.; Ammor, L.

    2011-05-01

    A three-directional configuration of columnar defects has been induced in a Bi2Sr2CaCu2O8 single crystal by irradiation with heavy ions of high energy. Persistent current densities have been extracted, using the Bean model, from hysteresis loops recorded in the orientation H||c. We have shown that improvements in pinning properties are larger in this three-directional splayed configuration than in the one obtained with columnar defects parallel to the c-axis. This effect exists only for H larger than HΦ, where HΦ is the matching field, and disappears as temperature is increased and vortices become less stiff. This is the first time that such a beneficial effect is reported for a compound of such a high electronic anisotropy.

  3. Contribution of proton NMR relaxation to the investigation of molecular dynamics in columnar mesophases of discotic and polycatenar molecules

    Indian Academy of Sciences (India)

    A C Ribeiro; P J Sebastiao; C Cruz

    2003-08-01

    We present in this work a review concerning wide frequency range 1 proton NMR relaxation studies performed in compounds exhibiting columnar mesophases, namely the Colho mesophase in the case of a liquid crystal of discotic molecules and the h mesophase in the case of a liquid crystal of biforked molecules. These NMR relaxation studies were performed combining conventional and fast field cycling NMR techniques in a frequency range between 100 Hz and 300 MHz. The possibility of probing such a large frequency range has provided a way to effectively distinguish the influence, on the 1 relaxation profiles, of the different molecular movements observed in this type of mesophases. In addition, we present a comparison between the molecular dynamics in columnar (h) and lamellar (SmC) mesophases exhibited by the same biforked compound.

  4. Micro-physics simulations of columnar recombination along nuclear recoil tracks in high-pressure Xe gas for directional dark matter searches

    CERN Document Server

    Nakajima, Y; Long, M; Nygren, D; Oliveira, C; Renner, J

    2015-01-01

    Directional sensitivity is one of the most important aspects of WIMP dark matter searches. Yet, making the direction of nuclear recoil visible with large target masses is a challenge. To achieve this, we are exploring a new method of detecting directions of short nuclear recoil tracks in high-pressure Xe gas, down to a few micron long, by utilizing columnar recombination. Columnar recombination changes the scintillation and ionization yields depending on the angle between a track and the electric field direction. In order to realize this, efficient cooling of electrons is essential. Trimethylamine(TMA) is one of the candidate additives to gaseous Xe in order to enhance the effect, not only by efficiently cooling the electrons, but also by increasing the amount of columnar recombination by Penning transfer. We performed a detailed simulation of ionization electrons transport created by nuclear recoils in a Xe + TMA gas mixture, and evaluated the size of the columnar recombination signal. The results show that ...

  5. Nanostructure and crystallography of aberrant columnar vaterite in Corbicula fluminea (Mollusca).

    Science.gov (United States)

    Frenzel, Max; Harrison, Richard J; Harper, Elizabeth M

    2012-04-01

    Both the crystallographic and nanostructural organisation of aberrant columnar vaterite occurring in Corbicula fluminea were characterised in detail for the first time using electron microscopic and X-ray powder diffraction techniques. At the millimetre scale, only a confinement of the otherwise randomly oriented c-axis to the growth surface is observed. Domains of 100 or more individual vaterite columns with common c-axis orientation exist within this disordered material. Each column behaves as a single crystal on the scale of EBSD measurements, but is internally composed of smaller irregularly shaped and slightly misaligned crystalline units (0.3-1.3μm in dimension). These are in turn partitioned by porous boundaries into rounded nanodomains, up to 600nm in size. The geometry of the nanodomains and their respective boundaries might suggest formation by the accretion of vesicles. In addition to crystallographic textures, this observation indicates formation under significant biological control with wider implications for possible causes of the condition.

  6. Adhesive hydrophobicity of Cu2O nano-columnar arrays induced by nitrogen ion irradiation.

    Science.gov (United States)

    Dhal, Satyanarayan; Chatterjee, Sriparna; Manju, Unnikrishnan; Tribedi, Lokesh C; Thulasiram, K V; Fernandez, W A; Chatterjee, Shyamal

    2015-12-21

    Low energy nitrogen ions are used in this work to manipulate wetting properties of the surface of the array of Cu2O nano-columns, which yields remarkable results. The nano-columnar thin films were grown on a highly conductive silicon surface by a sputter deposition technique. The films were irradiated at two different fluences of 5 × 10(15) and 1 × 10(16) ions per cm(2), respectively. With increasing fluence the shape of column tip changes, columns are bent and porous channels between columns are clogged up. While the surface of the pristine sample is hydrophilic, the irradiated surface turns into hydrophobic but having adhesion properties. We have analysed the structural and chemical properties of the surface in detail to understand the initial and modified wetting properties. Furthermore, the temporal evolutions of different droplet parameters are investigated to realize the interactions between the water droplet, the sample surface and the atmosphere. We envisage that such modified surfaces can be beneficial for transport of a small volume of liquids with minimum loss and spectroscopic studies, where a small amount of water droplet is available for measurements.

  7. In Situ Observation of Crystal Rain and Its Effect on Columnar to Equiaxed Transition

    Directory of Open Access Journals (Sweden)

    Honggang Zhong

    2016-11-01

    Full Text Available The investigation of a columnar to equiaxed transition (CET and grain refinement is of high commercial importance for the improvement of the solidification structure of metal castings. The crystal rain from the free surface is frequently generated to produce grain refinement and promote a CET in alloys under the application of electromagnetic fields. However, the mechanism underlying the CET influenced by the generated crystal rain is not clear because the employed metallic alloys are opaque. In the present paper, the crystal rain in a transparent NH4Cl–H2O solution is produced by blowing a cooled nitrogen gas on the free surface to observe in situ its impact on the occurrence of a CET. The results show that the crystal rain can significantly promote a CET even in a high temperature gradient and that a CET only can occur when the temperature gradient is almost close to zero in the reference experiment. Finally, the most likely mechanism is discussed and clarified.

  8. Comparison of Columnar Water Vapor Measurements During The Fall 1997 ARM Intensive Observation Period: Optical Methods

    Science.gov (United States)

    Schmid, Beat; Michalsky, J.; Slater, D.; Barnard, J.; Halthore, R.; Liljegren, J.; Holben, B.; Eck, T.; Livingston, J.; Russell, P.; Hipskind, R. Stephen (Technical Monitor)

    2000-01-01

    In the fall of 1997 the Atmospheric Radiation Measurement (ARM program conducted an intensive Observation Period (IOP) to study water vapor at its Southern Great Plains (SGP) site. Among the large number of instruments, four sun-tracking radiometers were present to measure the columnar water vapor (CWV). All four solar radiometers retrieve CWV by measuring solar transmittance in the 0.94-micrometer water vapor absorption band. As one of the steps in the CWV retrievals the aerosol component is subtracted from the total transmittance, in the 0.94-micrometer band. The aerosol optical depth comparisons among the same four radiometers are presented elsewhere. We have used three different methods to retrieve CWV. Without attempting to standardize on the same radiative transfer model and its underlying water vapor spectroscopy we found the CWV to agree within 0.13 cm (rms) for CWV values ranging from 1 to 5 cm. Preliminary results obtained when using the same updated radiative transfer model with updated spectroscopy for all instruments will also be shown. Comparisons to the microwave radiometer results will be included in the comparisons.

  9. Out-of-plane magnetic anisotropy in columnar grown Fe-Ni films

    Science.gov (United States)

    Pires, M. J. M.; Araújo Filho, M. S.; Tedesco, J. C. G.; Ardisson, J. D.; Macedo, W. A. A.

    2014-10-01

    Polycrystalline thin films usually present magnetic anisotropy resulting from a conjunction of textures, residual stresses, surface effects, and magnetic dipole distribution. The shape anisotropy, which is caused by the magnetic dipole distribution, is dominant in most of the cases, and it forces the occurrence of in-plane easy axes for the magnetization. Contrary to this common expectation, we have found predominant out-of-plane easy axes in a series of Fe-Ni thin films produced by DC sputtering. Films with different thicknesses, from 40 to 1000 nm, and different deposition temperatures have been tested and show similar results. These unusual characteristics are results of a particular columnar structure formed during the films growth. The magnetic characterization of the samples has been done by Mössbauer spectroscopy, magnetometry, and ferromagnetic resonance. The unusual anisotropy observed is not believed to be uniform along the film thickness. This interpretation comes from the comparison of the experimental results with hysteresis obtained by micromagnetic simulations. Five distinct configurations for the anisotropies have been simulated for this comparison.

  10. Solute Distribution in Columnar Crystal Zone and Influences of Correlative Factors for Continuous Casting Slabs

    Institute of Scientific and Technical Information of China (English)

    CHEN Shu-ying; CHANG Guo-wei; YUE Xu-dong; WU Chun-jing

    2008-01-01

    The expression of the solute distribution in columnar crystal zone was deduced when the solid-liquid interface bended periodically,and the quantitative calculations of macrosegregation were also made in the process of the continuous casting.The solute distribution along the thickness direction of the slabs was obtained,which verified the theoretical calculation.The effect of the bulge size,solidification speed,and solidification shrinkage speed on macrosegregation of the slabs was calculated.It can be concluded that normal segregation and negative segregation alternatively appear as a result of the bulge.The normal segregation exponentially depends on the bulge size,and the negative segregation linearly depends on the bulge size.The extent of the normal segregation is greater than that of the negative segregation when the bulge size is the same.The macrosegregation of the same position along the thickness direction of the slabs changes in a sine wave with increasing the solidification rate,and the amplitude is larger at the casting blank center.The normal segregation linearly decreases with increasing the solidification shrinkage speed,and when the solidification shrinkage speed exceeds a critical value,the segregation appears negatively and increases linearly.

  11. Measurements and estimation of the columnar optical depth of tropospheric aerosols in the UV spectral region

    Directory of Open Access Journals (Sweden)

    V. E. Cachorro

    Full Text Available We report values of the columnar tropospheric aerosol optical depth at UV wavelengths based on experimental measurements of the direct spectral irradiances carried out by a commercial spectroradiometer (Li1800 of Licor company covering the range from 300–1100 nm at two stations with different climate characteristics in Spain. The first station is located in a rural site in north central Spain with continental climate. The data extend from March to the end of October of 1995. The other station is a coastal site in the Gulf of Cádiz (southwest Spain of maritime climate type. This study is mainly focused on the capability of estimating aerosol optical depth values in the UV region based on the extracted information in the visible and near infrared ranges. A first method has been used based on the Ångström turbidity parameters. However, since this method requires detailed spectral information, a second method has also been used, based on the correlation between wavelengths. A correlation has been established between the experimental aerosol optical depth values at 350 nm and 500 nm wavelengths. Although the type of aerosol seems to be the key factor that determines the quality of these estimations, the evaluation of the associated error is necessary to know the behaviour of these estimations in each area of study.

    Key words. Atmospheric composition and structure (aerosols and particles; transmission and scattering of radiation; troposphere – composition and chemistry

  12. Measurements and estimation of the columnar optical depth of tropospheric aerosols in the UV spectral region

    Energy Technology Data Exchange (ETDEWEB)

    Cachorro, V.E.; Vergaz, R.; Martin, M.J.; Frutos, A.M. de [Grupo de Optica Atmosferica, Univ. de Valladolid (GOA-UVA), Valladolid (Spain); Vilaplana, J.M.; Morena, B. de la [Estacion de Sondeos Atmosfericos ESAT ' ' El Arenosillo' ' , INTA, Huelva (Spain)

    2002-04-01

    We report values of the columnar tropospheric aerosol optical depth at UV wavelengths based on experimental measurements of the direct spectral irradiances carried out by a commercial spectroradiometer (Li1800 of Licor company) covering the range from 300-1100 nm at two stations with different climate characteristics in Spain. The first station is located in a rural site in north central Spain with continental climate. The data extend from March to the end of October of 1995. The other station is a coastal site in the Gulf of Cadiz (southwest Spain) of maritime climate type. This study is mainly focused on the capability of estimating aerosol optical depth values in the UV region based on the extracted information in the visible and near infrared ranges. A first method has been used based on the Aangstroem turbidity parameters. However, since this method requires detailed spectral information, a second method has also been used, based on the correlation between wavelengths. A correlation has been established between the experimental aerosol optical depth values at 350 nm and 500 nm wavelengths. Although the type of aerosol seems to be the key factor that determines the quality of these estimations, the evaluation of the associated error is necessary to know the behavior of these estimations in each area of study. (orig.)

  13. Secondary recrystallization behavior in the rolled columnar-grained Fe–Ga alloys

    Energy Technology Data Exchange (ETDEWEB)

    Yuan, Chao; Li, Jiheng; Zhang, Wenlan; Bao, Xiaoqian; Gao, Xuexu, E-mail: gaox@skl.ustb.edu.cn

    2015-10-01

    The secondary recrystallization behavior with temperature increasing from 900 to 1080 °C was investigated in the rolled columnar-grained magnetostrictive Fe–Ga alloy sheets. The abnormal Goss grain growth occurred due to the inhibitory action of NbC in the Fe–Ga–0.1 at%NbC sheets. With the temperature increasing at a rate of 0.25 °C/min, the secondary recrystallization started below 950 °C. In addition to the S-induced surface energy effect, sulfur annealing also introduced a large number of S-rich and Nb-rich precipitates, which retarded the grain boundary migration on the surface. The abnormal grain growth was found to be restricted inside the sheet during the sulfur annealing process when the temperature was below 1000 °C, and a large amount of small island-like grains was remained on S-annealed sheets. After final Ar/H{sub 2} annealing processes, the S-rich precipitates and small island-like grains were eliminated, and sharp Goss orientation and high magnetostriction of 245 ppm were obtained in the final S-annealed sheets. - Highlights: • Secondary recrystallization started below 1000 °C in rolled Fe–Ga sheets. • Inhibition effect was introduced on the surfaces by sulfur annealing. • Abnormal Goss grains develop inside the sheets during sulfur annealing.

  14. Retrieval of columnar water vapor using multispectral radiometer measurements over northern China

    Science.gov (United States)

    Liu, Chaoshun; Li, Yun; Gao, Wei; Shi, Runhe; Bai, Kaixu

    2011-01-01

    Water vapor is an important component in hydrological processes that basically involve all types of seasons, including dry (e.g., drought) or wet (e.g., hurricane or monsoon). This study retrieved columnar water vapor (CWV) with the 939.3 nm band of a multifilter rotating shadowband radiometer (MFRSR) using the modified Langley technique. Such an investigation was in concert with the use of the atmospheric transmission model MODTRAN for determining the instrument coefficients required for CWV estimation. Results of the retrieval of CWV by MFRSR from September 23, 2004 to June 20, 2005 at the XiangHe site are presented and analyzed in this paper. To improve the credibility, the MFRSR results were compared with those obtained from the AErosol RObotic NETwork CIMEL sun-photometer measurements, co-located at the XiangHe site, and the moderate resolution imaging spectroradiometer (MODIS) near-infrared total precipitable water product (MOD05), respectively. These comparisons show good agreement in terms of correlation coefficients, slopes, and offsets, revealing that the accuracy of CWV estimation using the MFRSR instrument is reliable and suitable for extended studies in northern China.

  15. On the variation of aerosol properties over Finland based on the optical columnar measurements

    Science.gov (United States)

    Aaltonen, V.; Rodriguez, E.; Kazadzis, S.; Arola, A.; Amiridis, V.; Lihavainen, H.; de Leeuw, G.

    2012-10-01

    Long-range aerosol transport over Finland has been studied using ground-based sunphotometer measurements of aerosol optical properties. Cimel sunphotometers were used at an urban site (Helsinki), a rural site (Hyytiälä) and a semiurban site (Kuopio) and PFR sunphotometer measurements were made at two rural sites, Jokioinen and Sodankylä. The CIMEL measurements are part of the AERONET (Aerosol robotic network) network and Jokioinen and Sodankylä are GAW-PFR (Global Atmosphere Watch-Precision Filter Radiometer) Associate Stations. Sunphotometers provide information on local columnar aerosol properties such as aerosol optical depth (AOD) and Ångström exponent (ÅE) that were used to investigate the aerosol content and aerosol type in this region. A set of representative event days, i.e. days with high turbidity, covering the time period between March 2006 and June 2010 has been selected for further analysis. For these days the AOD results were combined with air mass back trajectories to provide information about the air mass origin, especially for cases with moderate turbidity produced by long-range transported aerosols from mid latitudes to Finland. As expected, episodes with high AOD are connected with the transport of polluted air masses originating from the east or southeast or from industrial areas in Central Europe. We distinguished events with long range transported air pollution from cases where pollution was accumulated in the area due to the local meteorological factors.

  16. Novel Prospects for Plasma Spray-Physical Vapor Deposition of Columnar Thermal Barrier Coatings

    Science.gov (United States)

    Anwaar, Aleem; Wei, Lianglinag; Guo, Qian; Zhang, Baopeng; Guo, Hongbo

    2017-09-01

    Plasma spray-physical vapor deposition (PS-PVD) is an emerging coating technique that can produce columnar thermal barrier coatings from vapor phase. Feedstock treatment at the start of its trajectory in the plasma torch nozzle is important for such vapor-phase deposition. This study describes the effects of the plasma composition (Ar/He) on the plasma characteristics, plasma-particle interaction, and particle dynamics at different points spatially distributed inside the plasma torch nozzle. The results of calculations show that increasing the fraction of argon in the plasma gas mixture enhances the momentum and heat flow between the plasma and injected feedstock. For the plasma gas combination of 45Ar/45He, the total enthalpy transferred to a representative powder particle inside the plasma torch nozzle is highest ( 9828 kJ/kg). Moreover, due to the properties of the plasma, the contribution of the cylindrical throat, i.e., from the feed injection point (FIP) to the start of divergence (SOD), to the total transferred energy is 69%. The carrier gas flow for different plasma gas mixtures was also investigated by optical emission spectroscopy (OES) measurements of zirconium emissions. Yttria-stabilized zirconia (YSZ) coating microstructures were produced when using selected plasma gas compositions and corresponding carrier gas flows; structural morphologies were found to be in good agreement with OES and theoretical predictions. Quasicolumnar microstructure was obtained with porosity of 15% when applying the plasma composition of 45Ar/45He.

  17. Columnar-to-Equiaxed Transition in Metal-Matrix Composites Reinforced with Silicon Carbide Particles

    Directory of Open Access Journals (Sweden)

    Alicia E. Ares

    2013-01-01

    Full Text Available The present work is focused on the study of the effect of directional heat extraction on the silicon-carbide (SiC distribution in zinc-aluminum matrix composites (MMCs and on the columnar-to-equiaxed (CET position in directionally solidified samples. To this end, a ZA-27 alloy matrix was reinforced with ceramic particles of SiC and vertically directionally solidified. The cooling rates, temperature gradients, and interphase velocities were then measured, and their influence on the solidification microstructure of the MMCs was analyzed. The recalescence detected and measured during the equiaxed transition was of the order of 3.5°C to 1.1°C. The values of the temperature gradients reached a minimum during the CET and were even negative in most cases (between −3.89 K and 0.06 K. The interphase velocities varied between 0.07 mm/s and 0.44 mm/s at the transition. Also, the presence of ceramic particles in ZA-27 alloys affected the thermodynamic local conditions and the kinetics of nucleation, producing a finer microstructure.

  18. High flux pinning efficiency by columnar defects dispersed in three directions in YBCO thin films

    Science.gov (United States)

    Sueyoshi, Tetsuro; Nishimura, Takahiro; Fujiyoshi, Takanori; Mitsugi, Fumiaki; Ikegami, Tomoaki; Ishikawa, Norito

    2016-10-01

    A systematic investigation of flux pinning by widely direction-dispersed columnar defects (CDs) in YBa2Cu3O y thin films was carried out by using heavy-ion irradiation: a parallel configuration of CDs aligned along the c-axis, and two trimodal splay configurations composed of CDs crossing at 0° and ± 45° relative to the c-axis, where the splay plane defined by the three irradiation angles is perpendicular (trimodal-A) or parallel (trimodal-B) to the transport current direction. The trimodal configurations show high pinning efficiency over a wide range of magnetic field orientations compared to the parallel one at low magnetic field. In particular, trimodal-B shows the higher critical current density of the two trimodal configurations. The crossed CDs at ± 45° in the trimodal configurations provide uncorrelated flux pinning at B || c due to the large tilting angle off the c-axis, which effectively reinforce the flux pinning of CDs parallel to the c-axis. This assist effect is more remarkable for trimodal-B: a kink sliding motion of flux lines along the CDs is more effectively reduced by the splay plane, not only at B || c but also at inclined magnetic fields off the c-axis.

  19. A study of the endocervical columnar cells I - morphology and frequency

    Directory of Open Access Journals (Sweden)

    Eitel Duarte

    1966-01-01

    Full Text Available After the observation of many thousands of histological sections of the endocervical mucosa it became evident that its columnar cells present a great variety of aspects not only those of the surface of the canal but also those of the glands. A classification of these cells was made taking into account the staining affinity, the intensity staining of the cytoplasm, the presence or absence of cilia, the shape and location of the nucleus. The various combinations of these different data made possible the characterization of 26 types of cells which we labelled by the alphabetical letters. Two hundred and fifty cervices obtained by cervical amputation and by hysterectomy were studied. The uteri presented lesions in the course of routine laboratory examination. In each of the 250 histological sections there were specifically counted 2,000 columnar cells which cover the cervical canal and 2,000columnar cells which form the glands. A graphic representation of the frequency of both the superficial and glandular columnar cells was presented; this was given the name EPITHELIOGRAM. The variation of the cellular "composition" of each epithelium is discussed and the frequency of the various cellular types after the count of one million of cells is presented.O estudo minucioso do epitélio da mucosa endocervical possibilitou o reconhecimento de vinte e seis tipos de células cilíndricas, tanto na superfície de revestimento do canal, como nas chamadas glândulas endocervicais. Para a classificação destas 26 células, que tomaram, cada uma, uma letra do alfabeto, foram levados em consideração a intensidade de coloração, a apresença ou não de cílios, a forma e dimensões dos núcleos e sua posição na célula. Foram analisados inicialmente 250 cortes histológicos, sendo contadas especìficamente, em cada corte, 2000 células cilíndricas de revestimento e 2000 células cilíndricas das glândulas. Em cada caso foram anotados, nas tabelas, além dos

  20. Population Genetic Structure of a Widespread Bat-Pollinated Columnar Cactus.

    Science.gov (United States)

    Bustamante, Enriquena; Búrquez, Alberto; Scheinvar, Enrique; Eguiarte, Luis Enrique

    2016-01-01

    Bats are the main pollinators and seed dispersers of Stenocereus thurberi, a xenogamous columnar cactus of northwestern Mexico and a good model to illustrate spatial dynamics of gene flow in long-lived species. Previous studies in this cactus showed differences among populations in the type and abundance of pollinators, and in the timing of flowering and fruiting. In this study we analyzed genetic variability and population differentiation among populations. We used three primers of ISSR to analyze within and among populations genetic variation from eight widely separated populations of S. thurberi in Sonora, Mexico. Sixty-six out of 99 of the ISSR bands (P = 66.7%) were polymorphic. Total heterozygosity for all populations sampled revealed high genetic diversity (Hsp = 0.207, HBT = 0.224). The AMOVA showed that most of the genetic variation was within populations (80.5%). At the species level, estimates of population differentiation, θ = 0.175 and θB = 0.194, indicated moderate gene flow among populations. The absence of a significant correlation between genetic and geographic distances indicated little isolation by geographic distance. The large genetic variation and diversity found in S. thurberi is consistent with its open reproductive system and the high mobility of bats, a major pollinator. However, small changes in number or kind of pollinators and seed dispersal agents, in the directionality of migratory routes, and/or in the timing of flowering and fruiting among populations, can critically affect gene flow dynamics.

  1. Selection of optimal conditions for anti-corrosive microbial biopolymer production by the Flavobacterium strain using response surface methodology (RSM

    Directory of Open Access Journals (Sweden)

    mojtaba khani

    2016-09-01

    Full Text Available Introduction: Various methods have been proposed to deal with corrosion. One of these methods is using of paints and coatings. In formulation of paints and coatings several anti-corrosion compounds are applied that slow down the corrosion process. In this respect, using microbial biopolymers can improve this problem in the industry with lower costs because of biopolymer production not required to factory and advanced industry. in this study, the effects of temperature, pH and agitation on the biopolymer production using response surface methodology (RSM were evaluated. Materials and methods: To produce biopolymer, the culture medium (300 ml were added in the 500 ml erlenmeyer flasks. Then, the bacterial preculture medium (6% V/V were inoculated in the flasks and incubated for 96hr in different conditions (agitation speed, tempreture and pH. Afterwards, the medium was centrifuged at 9000 rpm for 10 min and the supernatant was mixed with triple volume of chilled absolute ethanol and stored at 4°C for 24hr to precipitate. Results: Analysis of the results of design experiments indicate that the biopolymer production­ was strongly governed by the temperature, pH and agitation. The biopolymer production increased steadily up to pH 8 and decreased in the higher pH values. Also, for cell growth suitable temperature was 33°C and maximum concentration of the biopolymer production was agitation of 210 rpm. Finally, maximum concentration of the biopolymer production (14.3g/l was determined to be in pH of 8, temperature of 33°C and agitation of 210­rpm. Discussion and conclusion: Anti-corrosive biopolymer production by Flavobacterium sp. affected significantly by physical parameters. The results of the biopolymer production by investigating the conditions of temperature, pH and agitation after optimization, indicates the importance of this parameter for economic production of biopolymer.

  2. Effect of strontium on columnar growth of dendritic α phase in near-eutectic Al-11.6%Si alloys

    Institute of Scientific and Technical Information of China (English)

    廖恒成; 丁毅; 孙国雄

    2004-01-01

    For Al-11.6 % Si alloy, the influence of the addition of Sr on the morphology of the dendrite α phase was investigated, and the characteristic parameters of the dendrite α phase, the primary dendrite spacing and the secondary dendrite arm spacing, were also measured. The addition of strontium promotes the columnar dendrite growth and leads to a decrease of both the primary dendrite spacing and secondary dendrite arm spacing with the increase of the content of strontium in the modified near-eutectic Al-Si alloys. It is thought that the addition of Sr leads to a reduction of the solid-liquid interfacial energy of the dendrite α phase, consequently resulting in a decrease of the growth undercooling of dendrite tips. And hence, the nucleation of the equiaxed grains in the liquid in front of the columnar dendrite tips is restrained, thus the addition of strontium in Al-Si alloys promotes the growth of the columnar dendrites. The reduction of the solid-liquid interfacial energy also leads to the decreases in the primary dendrite spacing and the secondary dendrite arm spacing.

  3. Explorations of a series of second order nonlinear optical materials based on monovalent metal gold(III) iodates.

    Science.gov (United States)

    Huang, Chao; Hu, Chun-Li; Xu, Xiang; Yang, Bing-Ping; Mao, Jiang-Gao

    2013-10-07

    The syntheses, crystal structures, and characterizations of a series of monovalent metal gold(III) iodates, namely, α-NaAu(IO3)4, β-NaAu(IO3)4, RbAu(IO3)4, α-CsAu(IO3)4, β-CsAu(IO3)4, and AgAu(IO3)4 are reported. Their structures feature Au(IO3)4(-) anions that are separated by alkali metal ions or silver(I) ions. The Au(IO3)4(-) anions in the polar α-NaAu(IO3)4, RbAu(IO3)4, and α-CsAu(IO3)4 are polar with all four iodate groups being located only above (or below) the AuO4 square plane (cis- configuration). α-NaAu(IO3)4, RbAu(IO3)4, and α-CsAu(IO3)4 display moderate strong Second-Hamonic Generation (SHG) responses of 1.17 ×, 1.33 ×, and 1.17 × KTP (KTiOPO4), respectively, and all three materials are type-I phase-matchable. The Au(IO3)4(-) anions in centrysymmetric β-NaAu(IO3)4, β-CsAu(IO3)4, and AgAu(IO3)4 are nonpolar with the four iodate groups of the Au(IO3)4(-) anion being located both above and below the AuO4 square plane (trans- configuration). IR and UV spectra, luminescent and ferroelectric properties have also been measured. Theoretical calculations of their optical properties based on density functional theory (DFT) methods were performed by using the CASTEP total-energy code.

  4. Neutralizing antibody responses in macaques induced by human immunodeficiency virus type 1 monovalent or trivalent envelope glycoproteins.

    Directory of Open Access Journals (Sweden)

    Gerald V Quinnan

    Full Text Available A major goal of efforts to develop a vaccine to prevent HIV-1 infection is induction of broadly cross-reactive neutralizing antibodies (bcnAb. In previous studies we have demonstrated induction of neutralizing antibodies that did cross-react among multiple primary and laboratory strains of HIV-1, but neutralized with limited potency. In the present study we tested the hypothesis that immunization with multiple HIV-1 envelope glycoproteins (Envs would result in a more potent and cross-reactive neutralizing response. One Env, CM243(N610Q, was selected on the basis of studies of the effects of single and multiple mutations of the four gp41 glycosylation sites. The other two Envs included R2 (subtype B and 14/00/4 (subtype F, both of which were obtained from donors with bcnAb. Rhesus monkeys were immunized using a prime boost regimen as in previous studies. Individual groups of monkeys were immunized with either one of the three Envs or all three. The single N610Q and N615Q mutations of CM243 Env did not disrupt protein secretion, processing into, or reactivity with mAbs, unlike other single or multiple deglycosylation mutations. In rabbit studies the N610Q mutation alone or in combination was associated with an enhanced neutralizing response against homologous and heterologous subtype E viruses. In the subsequent monkey study the response induced by the R2 Env regimen was equivalent to the trivalent regimen and superior to the other monovalent regimens against the virus panel used for testing. The 14/00/4 Env induced responses superior to CM243(N610Q. The results indicate that elimination of the glycosylation site near the gp41 loop results in enhanced immunogenicity, but that immunization of monkeys with these three distinct Envs was not more immunogenic than with one.

  5. Group a rotavirus and norovirus genotypes circulating in the northeastern Brazil in the post-monovalent vaccination era.

    Science.gov (United States)

    Sá, Ana Caroline C; Gómez, Mariela M; Lima, Ila Fernanda N; Quetz, Josiane S; Havt, Alexandre; Oriá, Reinaldo B; Lima, Aldo A; Leite, José Paulo G

    2015-09-01

    Group A rotaviruses (RVA) and noroviruses (NoV) are the leading cause of acute gastroenteritis (AGE) worldwide. Childhood diarrhea deaths and hospital admissions have declined since the introduction of the monovalent (G1P[8]) vaccine (Rotarix(®) [RV1]) in the National Immunization Program in Brazil in 2006. This study aims to investigate the epidemiological profile of NoV and RVA infections from children with AGE in the Northeastern region of Brazil in the post vaccine season. Two-hundred fecal samples collected from children up to 10 years old in Fortaleza, Ceará between 2008-2009 were screened for the presence of RVA and NoV. Positive samples were genotyped and sequenced. The RVA screening revealed 12% prevalence and all RVA strains belonged to G2P[4] genotype. Phylogenetic analysis based on the 11 RVA genome segments sequenced from eight samples revealed a DS-1-like genotype constellation: I2-R2-C2-M2-A2-N2-T2-E2-H2. For NoV screening, the prevalence observed was 17% and the following genotypes were detected: GII.4 (59%), GII.12 (17%), GII.6 (9%), GII.3 (6%), and GII.? (9%). At least four different NoVs genotypes and two RVA G2P[4] variants were identified circulating in the Northeastern region of Brazil. RVA phylogenetic analysis suggests that the RVA G2P[4] strains might have originated from intragenogroup reassortment events. Whether the genetic modifications observed in these contemporary G2P[4] RVA strains may impact the long-term effectiveness of the current vaccination programs remains to be explored. These data reinforce the importance of surveillance for monitoring the emergence of new strains of RVA and NoV and their impact on cases of acute gastroenteritis.

  6. Policy statement—Prevention of varicella: update of recommendations for use of quadrivalent and monovalent varicella vaccines in children.

    Science.gov (United States)

    2011-09-01

    Two varicella-containing vaccines are licensed for use in the United States: monovalent varicella vaccine (Varivax [Merck & Co, Inc, West Point, PA]) and quadrivalent measles-mumps-rubella-varicella vaccine (MMRV) (ProQuad [Merck & Co, Inc]). It is estimated from postlicensure data that after vaccination at 12 through 23 months of age, 7 to 9 febrile seizures occur per 10,000 children who receive the MMRV, and 3 to 4 febrile seizures occur per 10,000 children who receive the measles-mumps-rubella (MMR) and varicella vaccines administered concurrently but at separate sites. Thus, 1 additional febrile seizure is expected to occur per approximately 2300 to 2600 children 12 to 23 months old vaccinated with the MMRV, when compared with separate MMR and varicella vaccine administration. The period of risk for febrile seizures is from 5 through 12 days after receipt of the vaccine(s). No increased risk of febrile seizures is seen among patients 4 to 6 years of age receiving MMRV. Febrile seizures do not predispose to epilepsy or neurodevelopmental delays later in life and are not associated with long-term health impairment. The American Academy of Pediatrics recommends that either MMR and varicella vaccines separately or the MMRV be used for the first dose of measles, mumps, rubella, and varicella vaccines administered at 12 through 47 months of age. For the first dose of measles, mumps, rubella, and varicella vaccines administered at ages 48 months and older, and for dose 2 at any age (15 months to 12 years), use of MMRV generally is preferred over separate injections of MMR and varicella vaccines.

  7. Anogenital Mammary-Like Glands: A Study of Their Normal Histology With Emphasis on Glandular Depth, Presence of Columnar Epithelial Cells, and Distribution of Elastic Fibers.

    Science.gov (United States)

    Konstantinova, Anastasia M; Kyrpychova, Liubov; Belousova, Irena E; Spagnolo, Dominic V; Kacerovska, Denisa; Michal, Michal; Kerl, Katrin; Kazakov, Dmitry V

    2016-10-18

    The normal histology of anogenital mammary-like glands (AGMLG) has been studied previously, but some aspects, including glandular depth, presence of columnar epithelium resembling columnar cell change/hyperplasia as defined in mammary pathology, and distribution of elastic fibers, have not been previously investigated. To address these issues, we studied 148 AGMLG identified in 133 paraffin blocks sampled from 64 vulvar wide excision or vulvectomy specimens (64 patients, various indications for surgery). The depth of AGMLG ranged from 0.64 to 3.9 mm. Epithelial columnar cell change was noted in 33.1% of all AGMLG, whereas columnar cell hyperplasia was detected in 10.1%. Occasionally, combinations of cuboidal epithelium and columnar cell change were seen within 1 histological section. Of 22 specimens stained for elastic fibers, in only 6 (27.3%) cases were elastic fibers found around glands. Periductal elastic fibers were demonstrated around 3 of the only 5 ducts, which were available for analysis in slides stained for elastic fibers. The depth of AGMLG should be taken into account when planning topical and surgical therapies for lesions derived or evolving from AGMLG. Alterations identical to columnar cell change may represent a normal variation of AGMLG.

  8. Texture evolution and flow stress of columnar-grained polycrystalline copper during intense plastic deformation process at room temperature

    Energy Technology Data Exchange (ETDEWEB)

    Wang Yu; Huang Haiyou [Key Laboratory for Advanced Materials Processing (MOE), University of Science and Technology Beijing, Beijing 100083 (China); Xie Jianxin, E-mail: jxxie@mater.ustb.edu.cn [Key Laboratory for Advanced Materials Processing (MOE), University of Science and Technology Beijing, Beijing 100083 (China)

    2011-12-15

    Highlights: Black-Right-Pointing-Pointer Continuous columnar-grained (CCG) copper exhibits excellent plastic extensibility with a true strain of 13.5. Black-Right-Pointing-Pointer It was explained from the view of texture evolution and the flow stress calculation based on texture constitution. Black-Right-Pointing-Pointer The relatively low content of Left-Pointing-Angle-Bracket 1 1 1 Right-Pointing-Angle-Bracket fiber texture accounts for the excellent extensibility of CCG copper. - Abstract: The texture evolution and microstructure in continuous columnar-grained (CCG) polycrystalline copper during wire drawing at room temperature were investigated quantitatively using the electron backscatter diffraction (EBSD) technique, and the stored energy and flow stress were calculated based on the texture constitution and structural parameters of different texture components measured by high resolution EBSD. The results indicate that the development of Left-Pointing-Angle-Bracket 1 1 1 Right-Pointing-Angle-Bracket texture within original Left-Pointing-Angle-Bracket 1 0 0 Right-Pointing-Angle-Bracket columnar grains was significantly slower compared with that in equiaxed polycrystalline copper, e.g. the volumetric ratio of the Left-Pointing-Angle-Bracket 1 1 1 Right-Pointing-Angle-Bracket to Left-Pointing-Angle-Bracket 1 0 0 Right-Pointing-Angle-Bracket component in columnar-grain copper was 0.82 at the strain of 2.98, while it was 2.96 in equiaxed polycrystalline copper at the same strain. The relatively low content of Left-Pointing-Angle-Bracket 1 1 1 Right-Pointing-Angle-Bracket fiber texture accounted for the low flow stress, low work hardening rate and excellent cold plastic extensibility of the columnar-grained polycrystalline copper. The average size of the dislocation cells developed within the Left-Pointing-Angle-Bracket 1 1 1 Right-Pointing-Angle-Bracket fiber was the minimum among all the deformation texture components, and decreased rapidly with the increase of

  9. How important are columnar cacti as sources of water and nutrients for desert consumers? A review.

    Science.gov (United States)

    Wolf, B O; del Rio, C Martínez

    2003-03-01

    Succulent CAM plants, such as columnar cacti, are important physiognomic elements of many arid lands. Although, these plans are often ecologically important because they provide abundant resources in the form of nectar and fruit, their contribution to the energy, nutrient and water budgets of consumes has not been quantified. We describe an isotopic approach that allows quantifying the ecological importance of CAM succulents. We first briefly review our work on the interaction between saguaros, an archetypical CAM succulent, and the desert doves that feed on its fruit. We then describe the potential importance of saguaro fruit as a function of its abundance, macronutrient composition, and seasonal availability. We argue that the resources provided by saguaros do much to satisfy the energy and water requirements of the birds that reside in hot subtropical deserts during the summer. We then describe the carbon isotope composition of saguaros and of the plant community in which they are imbedded and use two species of desert doves to illustrate how stable isotopes can reveal the importance of a single plant as a source of carbon and water for consumers. The second section of this review presents new data on the importance of saguaros for the entire community of birds that inhabit the Sonoran Desert during the summer. We show how the resources of saguaro reach across dietary guilds and account for a large proportion of the diet of many insectivorous species as well as that of granivorous and frugivorous species. We demonstrate that many of these species probably obtain significant water as well as nutrients from saguaro fruit. Finally, we point out the current limitations of using deuterium as a water tracer in animal systems.

  10. Unidirectional Flux Balance of Monovalent Ions in Cells with Na/Na and Li/Na Exchange: Experimental and Computational Studies on Lymphoid U937 Cells.

    Directory of Open Access Journals (Sweden)

    Igor A Vereninov

    Full Text Available Monovalent ion traffic across the cell membrane occurs via various pathways. Evaluation of individual fluxes in whole cell is hampered by their strong interdependence. This difficulty can be overcome by computational analysis of the whole cell flux balance. However, the previous computational studies disregarded ion movement of the self-exchange type. We have taken this exchange into account. The developed software allows determination of unidirectional fluxes of all monovalent ions via the major pathways both under the balanced state and during transient processes. We show how the problem of finding the rate coefficients can be solved by measurement of monovalent ion concentrations and some of the fluxes. Interdependence of fluxes due to the mandatory conditions of electroneutrality and osmotic balance and due to specific effects can be discriminated, enabling one to identify specific changes in ion transfer machinery under varied conditions. To test the effectiveness of the developed approach we made use of the fact that Li/Na exchange is known to be an analogue of the coupled Na/Na exchange. Thus, we compared the predicted and experimental data obtained on U937 cells under varied Li+ concentrations and following inhibition of the sodium pump with ouabain. We found that the coupled Na/Na exchange in U937 cells comprises a significant portion of the entire Na+ turnover. The data showed that the loading of the sodium pump by Li/Na exchange involved in the secondary active Li+ transport at 1-10 mM external Li+ is small. This result may be extrapolated to similar Li+ and Na+ flux relationships in erythrocytes and other cells in patients treated with Li+ in therapeutic doses. The developed computational approach is applicable for studying various cells and can be useful in education for demonstrating the effects of individual transporters and channels on ion gradients, cell water content and membrane potential.

  11. Unidirectional Flux Balance of Monovalent Ions in Cells with Na/Na and Li/Na Exchange: Experimental and Computational Studies on Lymphoid U937 Cells.

    Science.gov (United States)

    Vereninov, Igor A; Yurinskaya, Valentina E; Model, Michael A; Vereninov, Alexey A

    2016-01-01

    Monovalent ion traffic across the cell membrane occurs via various pathways. Evaluation of individual fluxes in whole cell is hampered by their strong interdependence. This difficulty can be overcome by computational analysis of the whole cell flux balance. However, the previous computational studies disregarded ion movement of the self-exchange type. We have taken this exchange into account. The developed software allows determination of unidirectional fluxes of all monovalent ions via the major pathways both under the balanced state and during transient processes. We show how the problem of finding the rate coefficients can be solved by measurement of monovalent ion concentrations and some of the fluxes. Interdependence of fluxes due to the mandatory conditions of electroneutrality and osmotic balance and due to specific effects can be discriminated, enabling one to identify specific changes in ion transfer machinery under varied conditions. To test the effectiveness of the developed approach we made use of the fact that Li/Na exchange is known to be an analogue of the coupled Na/Na exchange. Thus, we compared the predicted and experimental data obtained on U937 cells under varied Li+ concentrations and following inhibition of the sodium pump with ouabain. We found that the coupled Na/Na exchange in U937 cells comprises a significant portion of the entire Na+ turnover. The data showed that the loading of the sodium pump by Li/Na exchange involved in the secondary active Li+ transport at 1-10 mM external Li+ is small. This result may be extrapolated to similar Li+ and Na+ flux relationships in erythrocytes and other cells in patients treated with Li+ in therapeutic doses. The developed computational approach is applicable for studying various cells and can be useful in education for demonstrating the effects of individual transporters and channels on ion gradients, cell water content and membrane potential.

  12. Assessment of epicutaneous testing of a monovalent Influenza A (H1N1 2009 vaccine in egg allergic patients

    Directory of Open Access Journals (Sweden)

    Pitt Tracy

    2011-02-01

    Full Text Available Abstract Background H1N1 is responsible for the first influenza pandemic in 41 years. In the fall of 2009, an H1N1 vaccine became available in Canada with the hopes of reducing the overall effect of the pandemic. The purpose of this study was to assess the safety of administering 2 different doses of a monovalent split virus 2009 H1N1 vaccine in egg allergic patients. Methods Patients were skin tested to the H1N1 vaccine in the outpatient paediatric and adult allergy and immunology clinics of the Health Sciences Centre and Children's Hospital of Winnipeg, Manitoba Canada. Individuals Results A total of 61 patients with egg allergy (history of an allergic reaction to egg with either positive skin test &/or specific IgE to egg >0.35 Ku/L were referred to our allergy clinics for skin testing to the H1N1 vaccine. 2 patients were excluded, one did not have a skin prick test to the H1N1 vaccine (only vaccine administration and the other passed an egg challenge during the study period. Ages ranged from 1 to 27 years (mean 5.6 years. There were 41(69.5% males and 18(30.5% females. All but one patient with a history of egg allergy, positive skin test to egg and/or elevated specific IgE level to egg had negative skin tests to the H1N1 vaccine. The 58 patients with negative skin testing to the H1N1 vaccine were administered the vaccine and observed for 30 minutes post vaccination with no adverse results. The patient with the positive skin test to the H1N1 vaccine was also administered the vaccine intramuscularly with no adverse results. Conclusions Despite concern regarding possible anaphylaxis to the H1N1 vaccine in egg allergic patients, in our case series 1/59(1.7% patients with sensitization to egg were also sensitized to the H1N1 vaccine. Administration of the H1N1 vaccine in egg allergic patients with negative H1N1 skin tests and observation is safe. Administering the vaccine in a 1 or 2 dose protocol without skin testing is a reasonable alternative

  13. Different Phenotypes of Mature Biofilm in Flavobacterium psychrophilum Share a Potential for Virulence That Differs from Planktonic State

    Science.gov (United States)

    Levipan, Héctor A.; Avendaño-Herrera, Ruben

    2017-01-01

    Flavobacterium psychrophilum is the etiological agent of bacterial coldwater disease and the rainbow trout fry syndrome in salmonid aquaculture worldwide. However, there have been few studies into the capacity of F. psychrophilum to form biofilms and how these cellular accretions differ from planktonic cells or how they affect potential virulence. We evaluated the biofilm formation by three Chilean isolates of F. psychrophilum (LM-02-Fp, LM-06-Fp, and LM-13-Fp) and two non-Chilean strains (JIP02/86 and NCMB1947T), and compared biofilm and planktonic states to obtain insights into expression differences of virulence- and biofilm-related genes (VBRGs). Our findings are based on scanning confocal laser microscopy (SCLM) and LIVE/DEAD staining, enzymatic reactions, reverse transcription-quantitative PCR (RT-qPCR) of genes encoding putative virulence factors, and transcriptomes (RNA-Seq). The LM-02-Fp and NCMB1947T strains were the strongest and weakest biofilm producers, respectively. The strong-biofilm producer showed different physiological cell states distributed in different layers of mature biofilms, whereas the NCMB1947T biofilms consisted of cells arranged in a monolayer. WGA-binding exopolysaccharides would be the main components of their corresponding extracellular matrices. Transcriptomes of F. psychrophilum NCMB1947T and LM-02-Fp were clustered by state (biofilm vs. planktonic) rather than by strain, indicating important state-dependent differences in gene expression. Analysis of differentially expressed genes between states identified putative VBRGs involved in polysaccharide biosynthesis, lateral gene transfer, membrane transport (e.g., for drugs and Fe3+), sensory mechanisms, and adhesion, and indicated that about 60–100% of VBRGs involved in these processes was significantly upregulated in the biofilm state. Conversely, upregulated motility-related genes in the biofilm state were not identified, whereas a lower fraction of proteolysis-related genes (33

  14. Sox9 drives columnar differentiation of esophageal squamous epithelium: a possible role in the pathogenesis of Barrett's esophagus.

    Science.gov (United States)

    Clemons, Nicholas J; Wang, David H; Croagh, Daniel; Tikoo, Anjali; Fennell, Christina M; Murone, Carmel; Scott, Andrew M; Watkins, D Neil; Phillips, Wayne A

    2012-12-15

    The molecular mechanism underlying the development of Barrett's esophagus (BE), the precursor to esophageal adenocarcinoma, remains unknown. Our previous work implicated sonic hedgehog (Shh) signaling as a possible driver of BE and suggested that bone morphogenetic protein 4 (Bmp4) and Sox9 were downstream mediators. We have utilized a novel in vivo tissue reconstitution model to investigate the relative roles of Bmp4 and Sox9 in driving metaplasia. Epithelia reconstituted from squamous epithelial cells or empty vector-transduced cells had a stratified squamous phenotype, reminiscent of normal esophagus. Expression of Bmp4 in the stromal compartment activated signaling in the epithelium but did not alter the squamous phenotype. In contrast, expression of Sox9 in squamous epithelial cells induced formation of columnar-like epithelium with expression of the columnar differentiation marker cytokeratin 8 and the intestinal-specific glycoprotein A33. In patient tissue, A33 protein was expressed specifically in BE, but not in normal esophagus. Expression of Cdx2, another putative driver of BE, alone had no effect on reconstitution of a squamous epithelium. Furthermore, epithelium coexpressing Cdx2 and Sox9 had a phenotype similar to epithelium expressing Sox9 alone. Our results demonstrate that Sox9 is sufficient to drive columnar differentiation of squamous epithelium and expression of an intestinal differentiation marker, reminiscent of BE. These data suggest that Shh-mediated expression of Sox9 may be an important early event in the development of BE and that the potential for inhibitors of the hedgehog pathway to be used in the treatment of BE and/or esophageal adenocarcinoma could be tested in the near future.

  15. Design of columnar quantum dots for polarization-independent emission using 8-band k{center_dot}p method

    Energy Technology Data Exchange (ETDEWEB)

    Andrzejewski, J; Sek, G; Misiewicz, J [Institute of Physics, Wroclaw University of Technology, Wybrze z-dot e Wyspianskiego 27, 50-370 Wroclaw (Poland); O' Reilly, E [Department of Physics, University College Cork and Tyndall National Institute, Lee Maltings, Cork (Ireland); Fiore, A, E-mail: janusz.andrzejewski@pwr.wroc.p [CORBA Research Institute, Eindhoven University of Technology, PO Box 513, 5600 MB Eindhoven (Netherlands)

    2010-09-01

    Control of the polarization of the emitted light can be highly beneficial for certain optoelectronic applications such as optical amplifiers. It has been recently demonstrated experimentally that semiconductor quantum dots with large height to base length aspect ratio are able to emit polarization-independent light from the edge of the wafer. However, analysis of the physics responsible for the observed polarization properties of such nano-objects (like columnar quantum dots or quantum rods) is still rather limited. In particular, the role of the material surrounding the columnar QD on the strain and thus on the polarization properties has not been considered previously. We report here, based on original software, the results of eight-band k{center_dot}p calculations of the electronic and polarization properties of columnar In{sub y}Ga{sub 1-y}As quantum dots (CQD) with high aspect ratio (up to 6) embedded in an In{sub x}Ga{sub 1-x}As/GaAs quantum well. We calculate the relative intensities of transverse-magnetic (TM) and transverse-electric (TE) linear polarized light emitted from the edge of the semiconductor wafer as a function of the two main factors affecting the heavy hole - light hole valence band mixing and hence the polarization dependent selection rules for the optical transitions, namely i) the composition contrast y/x between the dot material and the surrounding well, and ii) the dot aspect ratio. Our numerical results show, in contrast to the previously reported expectations, that the former is the main driving parameter for tuning the polarization properties. This is explained analyzing the biaxial strain in the CQD, based on which it is possible to predict on the TM to TE intensity ratio.

  16. Sub- and Super-Synchronous Self-Excited Vibrations of a Columnar Rotor Due to Axial Clearance Flow

    Science.gov (United States)

    Nishimura, H.; Horiguchi, H.; Suzuki, T.; Sugiyama, K.; Tsujimoto, Y.

    2016-11-01

    Sub- and super-synchronous self-excited vibrations due to axial clearance flows were observed in a columnar rotor with an upstream seal in experiments. A smaller clearance on the downstream seal had a larger effect of stabilizing the rotor. In computations, it was found that the rotordynamic fluid force tangential to the whirling orbit, which is caused as a response to the vibrations (whirling motions), destabilizes the rotor in the case of the upstream seal and stabilizes the rotor in the case of the downstream seal. It was clarified in the 1-D flow model that the tangential rotordynamic fluid force is mainly caused by an inertia of the clearance flow.

  17. Long-term comparative study of columnar and surface mass concentration aerosol properties in a background environment

    Science.gov (United States)

    Bennouna, Y. S.; Cachorro, V. E.; Mateos, D.; Burgos, M. A.; Toledano, C.; Torres, B.; de Frutos, A. M.

    2016-09-01

    The relationship between columnar and surface aerosol properties is not a straightforward problem. The Aerosol Optical Depth (AOD), Ångström exponent (AE), and ground-level Particulate Matter (PMX, x = 10 or 2.5 μm) data have been studied from a climatological point of view. Despite the different meanings of AOD and PMx both are key and complementary quantities that quantify aerosol load in the atmosphere and many studies intend to find specific relationships between them. Related parameters such as AE and PM ratio (PR = PM2.5/PM10), giving information about the predominant particle size, are included in this study on the relationships between columnar and surface aerosol parameters. This study is based on long measurement records (2003-2014) obtained at two nearby background sites from the AERONET and EMEP networks in the north-central area of Spain. The climatological annual cycle of PMx shows two maxima along the year (one in late-winter/early-spring and another in summer), but this cycle is not followed by the AOD which shows only a summer maximum and a nearly bell shape. However, the annual means of both data sets show strong correlation (R = 0.89) and similar decreasing trends of 40% (PM10) and 38% (AOD) for the 12-year record. PM10 and AOD daily data are moderately correlated (R = 0.58), whereas correlation increases for monthly (R = 0.74) and yearly (R = 0.89) means. Scatter plots of AE vs. AOD and PR vs. PM10 have been used to characterize aerosols over the region. The PR vs. AE scatterplot of daily data shows no correlation due to the prevalence of intermediate-sized particles. As day-to-day correlation is low (especially for high turbidity events), a binned analysis was also carried out to establish consistent relationships between columnar and surface quantities, which is considered to be an appropriate approach for environmental and climate studies. In this way the link between surface concentrations and columnar remote sensing data is shown to

  18. A technique for evaluating the influence of spatial sampling on the determination of global mean total columnar ozone

    Science.gov (United States)

    Tolson, R. H.

    1981-01-01

    A technique is described for providing a means of evaluating the influence of spatial sampling on the determination of global mean total columnar ozone. A finite number of coefficients in the expansion are determined, and the truncated part of the expansion is shown to contribute an error to the estimate, which depends strongly on the spatial sampling and is relatively insensitive to data noise. First and second order statistics are derived for each term in a spherical harmonic expansion which represents the ozone field, and the statistics are used to estimate systematic and random errors in the estimates of total ozone.

  19. An Efficient 3D Stochastic Model for Predicting the Columnar-to-Equiaxed Transition in Alloy 718

    Science.gov (United States)

    Nastac, L.

    2015-06-01

    A three-dimensional (3D) stochastic model for simulating the evolution of dendritic crystals during the solidification of alloys was developed. The model includes time-dependent computations for temperature distribution, solute redistribution in the liquid and solid phases, curvature, and growth anisotropy. The 3D model can run on PCs with reasonable amount of RAM and CPU time. 3D stochastic mesoscopic simulations at the dendrite tip length scale were performed to simulate the evolution of the columnar-to-equiaxed transition in alloy 718. Comparisons between simulated microstructures and segregation patterns obtained with 2D and 3D stochastic models are also presented.

  20. CAFE simulation of columnar-to-equiaxed transition in Al-7wt%Si alloys directionally solidified under microgravity

    Science.gov (United States)

    Liu, D. R.; Mangelinck-Noël, N.; Gandin, Ch-A.; Zimmermann, G.; Sturz, L.; Nguyen Thi, H.; Billia, B.

    2016-03-01

    A two-dimensional multi-scale cellular automaton - finite element (CAFE) model is used to simulate grain structure evolution and microsegregation formation during solidification of refined Al-7wt%Si alloys under microgravity. The CAFE simulations are first qualitatively compared with the benchmark experimental data under microgravity. Qualitative agreement is obtained for the position of columnar to equiaxed transition (CET) and the CET transition mode (sharp or progressive). Further comparisons of the distributions of grain elongation factor and equivalent diameter are conducted and reveal a fair quantitative agreement.

  1. Columnar-lined oesophagus without intestinal metaplasia: results from a cohort with a mean follow-up of 7 years.

    Science.gov (United States)

    Dias Pereira, A; Chaves, P

    2012-08-01

    The definition of Barrett's oesophagus lacks consensus, particularly the requirement of intestinal metaplasia for diagnosis. Scarce information exists on the prevalence and natural history of columnar-lined oesophagus without intestinal metaplasia. To evaluate the demographics and natural history of columnar-lined oesophagus without intestinal metaplasia ≥ 2 cm in length. Patients with columnar-lined oesophagus ≥ 2 cm in length and no intestinal metaplasia in biopsy specimens from two consecutive endoscopies with at least a 1-year interval were prospectively followed. A cohort of Barrett's oesophagus patients was used as a control. Columnar-lined oesophagus without intestinal metaplasia (n = 15) had a similar gender distribution, reflux symptoms prevalence and length as those of Barrett's oesophagus (n = 205). Patients were significantly younger (28.6 vs. 60 years, P 40 years (P 50 years) was significantly different, except for patients aged 40-49 years. Intestinal metaplasia was documented in 60% of the cohort after a mean follow-up of 7.1 years. Columnar-lined oesophagus without intestinal metaplasia ≥ 2 cm is infrequent in the setting of a systematic biopsy protocol, is associated with a younger age in comparison with Barrett's oesophagus, and appears to be an intermediate step between squamous and intestinal lining of the oesophagus. © 2012 Blackwell Publishing Ltd.

  2. Simulation of macrosegregation in a 2.45-ton steel ingot using a three-phase mixed columnar-equiaxed model.

    Science.gov (United States)

    Li, Jun; Wu, Menghuai; Ludwig, Andreas; Kharicha, Abdellah

    2014-05-01

    A three-phase mixed columnar-equiaxed solidification model is used to calculate the macrosegregation in a 2.45 ton steel ingot. The main features of mixed columnar-equiaxed solidification in such an ingot can be quantitatively modelled: growth of columnar dendrite trunks; nucleation, growth and sedimentation of equiaxed crystals; thermosolutal convection of the melt; solute transport by both convection and crystal sedimentation; and the columnar-to-equiaxed transition (CET). The predicted as-cast macrostructure and the segregation pattern are in qualitative agreement with the reported experimental results. Parameter study on the numerical grid size and the nucleation of the equiaxed crystals are performed, and some segregation mechanisms are numerically analyzed. Discontinued positive-negative segregation just below the hot top is predicted because of the formation of a local mini-ingot and the subsequent sedimentation of equiaxed grains within the mini-ingot. Quasi A-segregates in the middle radius region between the casting outer surface and the centreline are also found. The quasi A-segregates originate from the flow instability, but both the appearance of equiaxed crystals and their interaction with the growing columnar dendrite tips significantly strengthen the segregates. The appearance of equiaxed phase is not a necessary condition for the formation of quasi A-segregates. The quantitative discrepancy between the predicted and experimental results is also discussed.

  3. Simultaneous Analysis of Monovalent Anions and Cations with a Sub-Microliter Dead-Volume Flow-Through Potentiometric Detector for Ion Chromatography.

    Science.gov (United States)

    Dumanli, Rukiye; Attar, Azade; Erci, Vildan; Isildak, Ibrahim

    2016-04-01

    A microliter dead-volume flow-through cell as a potentiometric detector is described in this article for sensitive, selective and simultaneous detection of common monovalent anions and cations in single column ion chromatography for the first time. The detection cell consisted of less selective anion- and cation-selective composite membrane electrodes together with a solid-state composite matrix reference electrode. The simultaneous separation and sensitive detection of sodium (Na(+)), potassium (K(+)), ammonium (NH4 (+)), chloride (Cl(-)) and nitrate (NO3 (-)) in a single run was achieved by using 98% 1.5 mM MgSO4 and 2% acetonitrile eluent with a mixed-bed ion-exchange separation column without suppressor column system. The separation and simultaneous detection of the anions and cations were completed in 6 min at the eluent flow-rate of 0.8 mL/min. Detection limits, at S/N = 3, were ranged from 0.2 to 1.0 µM for the anions and 0.3 to 3.0 µM for the cations, respectively. The developed method was successfully applied to the simultaneous determination of monovalent anions and cations in several environmental and biological samples.

  4. Effect of initial ion positions on the interactions of monovalent and divalent ions with a DNA duplex as revealed with atomistic molecular dynamics simulations.

    Science.gov (United States)

    Robbins, Timothy J; Wang, Yongmei

    2013-01-01

    Monovalent (Na(+)) and divalent (Mg(2+)) ion distributions around the Dickerson-Drew dodecamer were studied by atomistic molecular dynamics (MD) simulations with AMBER molecular modeling software. Different initial placements of ions were tried and the resulting effects on the ion distributions around DNA were investigated. For monovalent ions, results were found to be nearly independent of initial cation coordinates. However, Mg(2+) ions demonstrated a strong initial coordinate dependent behavior. While some divalent ions initially placed near the DNA formed essentially permanent direct coordination complexes with electronegative DNA atoms, Mg(2+) ions initially placed further away from the duplex formed a full, nonexchanging, octahedral first solvation shell. These fully solvated cations were still capable of binding with DNA with events lasting up to 20 ns, and in comparison were bound much longer than Na(+) ions. Force field parameters were also investigated with modest and little differences arising from ion (ions94 and ions08) and nucleic acid description (ff99, ff99bsc0, and ff10), respectively. Based on known Mg(2+) ion solvation structure, we conclude that in most cases Mg(2+) ions retain their first solvation shell, making only solvent-mediated contacts with DNA duplex. The proper way to simulate Mg(2+) ions around DNA duplex, therefore, should begin with ions placed in the bulk water.

  5. 机械通气致下呼吸道黄杆菌属感染的临床研究%A clinical study on lower respiratory tract infections caused by Flavobacterium after mechanical ventilation

    Institute of Scientific and Technical Information of China (English)

    孙健龙; 张素梅; 管晓芸; 张仁仙; 宋秀琴

    2012-01-01

    目的 研究机械通气导致下呼吸道黄杆菌属感染的临床特点、黄杆菌属对抗菌药的敏感性,探讨预防措施.方法 对医院加强医疗室2001-2010年30例行机械通气发生下呼吸道黄杆菌属感染的临床资料进行回顾性调查.结果 30例机械通气发生下呼吸道黄杆菌属感染的病例均有基础疾病、长期应用多种抗菌药史;共分离出30株黄杆菌属,主要为脑膜脓毒金黄杆菌,占33.33%;黄杆菌属对红霉素、环丙沙星、磺胺甲噁唑/甲氧苄啶、克林霉素、万古霉素、利福平较敏感;30例患者死亡2例,死亡率为6.7%.结论 黄杆菌属引起的下呼吸道感染多发生在老年、有基础疾病、应用广谱抗菌药、进行机械通气治疗的患者,黄杆菌属耐药率较高;严格落实清洁、消毒、隔离措施、无菌操作规程,可以预防黄杆菌属的感染.%OBJECTIVE To explore the clinical characteristics of lower respiratory tract infections caused by Flavobacterium after mechanical ventilation, the susceptibility of Flavobacterium to antimicrobial agents so as to propose preventive measures. METHODS A total of 30 medical records of patients with lower respiratory tract infection caused by Flavobacterium after mechanical ventilation in ICU during 2001-2010 were investigated retrospectively. RESULTS All of 30 patients with Flavobacterium infections who underwent mechanical ventilation were complicated with underlying diseases and were with long-term use of antibiotics; of 30 strains of Flavobacterium isolated, Staphylococcus bacteria meningeal sepsis was the major species, accounting for 33.33%; Flavobacterium were susceptible to erythromycin, ciprofloxacin, trimethoprim/sulfamethoxazole, clindamycin, vancomycin, and rifampicins2 of 30 patients were dead with the mortality of 6. 1%. CONCLUSION Lower respiratory tract infections caused by Flavobacterium mainly occur in patients who are elderly, suffered from underlying

  6. Crystallization and preliminary X-ray diffraction studies of tetrameric malate dehydrogenase from the novel Antarctic psychrophile Flavobacterium frigidimaris KUC-1

    Energy Technology Data Exchange (ETDEWEB)

    Fujii, Tomomi [Institute for Chemical Research, Kyoto University, Uji, Kyoto 611-0011 (Japan); Oikawa, Tadao; Muraoka, Ikuo [Department of Life Science and Biotechnology, Faculty of Chemistry, Materials and Bioengineering, Kansai University, Suita, Osaka 564-8680 (Japan); Soda, Kenji [Institute for Chemical Research, Kyoto University, Uji, Kyoto 611-0011 (Japan); Department of Life Science and Biotechnology, Faculty of Chemistry, Materials and Bioengineering, Kansai University, Suita, Osaka 564-8680 (Japan); Hata, Yasuo, E-mail: hata@scl.kyoto-u.ac.jp [Institute for Chemical Research, Kyoto University, Uji, Kyoto 611-0011 (Japan)

    2007-11-01

    A psychrophilic malate dehydrogenase from the novel Antarctic bacterium F. frigidimaris KUC-1 was crystallized using the hanging-drop vapour-diffusion method. The crystals contained one tetrameric molecule per asymmetric unit. The best crystal diffracted to 1.8 Å resolution. Flavobacterium frigidimaris KUC-1 is a novel psychrotolerant bacterium isolated from Antarctic seawater. Malate dehydrogenase (MDH) is an essential metabolic enzyme in the citric acid cycle and has been cloned, overexpressed and purified from F. frigidimaris KUC-1. In contrast to the already known dimeric form of MDH from the psychrophile Aquaspirillium arcticum, F. frigidimaris MDH exists as a tetramer. It was crystallized at 288 K by the hanging-drop vapour-diffusion method using ammonium sulfate as the precipitating agent. The crystal diffracted to a maximum resolution of 1.80 Å. It contains one tetrameric molecule in the asymmetric unit.

  7. Simultaneous demonstration of infectious pancreatic necrosis virus (IPNV) and Flavobacterium psychrophilum in paraffin-embedded specimens of rainbow trout Oncorhynchus mykiss fry by use of paired immunohistochemistry

    DEFF Research Database (Denmark)

    Evensen, Ø.; Lorenzen, Ellen

    1997-01-01

    be considered the primary cause of the mortality observed. Further, it may be difficult to cultivate the bacterium in later stages of the disease or from dead fish that have been transported without cooling. In the case of (suspected) double infections it is therefore suggested that immunohistochemistry......The Gram-negative bacterium Flavobacterium psychrophilum, which is the causative agent of rainbow trout fry syndrome (RTFS), and infectious pancreatic necrosis virus (IPNV), the causative agent of infectious pancreatic necrosis (IPN), are both highly pathogenic for rainbow trout fry. Several...... 'persistent' cases of RTFS have been observed concomitant with IPNV. Cultivation alone might not be sufficient for evaluation of the disease situation as both pathogens can be cultivated from fish that do not show any clinical signs of disease. In such cases it may be difficult to decide which pathogen should...

  8. Dispersal and Survival of Flavobacterium psychrophilum Phages In Vivo in Rainbow Trout and In Vitro under Laboratory Conditions: Implications for Their Use in Phage Therapy

    DEFF Research Database (Denmark)

    Madsen, Lone; Bertelsen, Sif K.; Dalsgaard, Inger

    2013-01-01

    Attention has been drawn to phage therapy as an alternative approach for controlling pathogenic bacteria such as Flavobacterium psychrophilum in salmonid aquaculture, which can give rise to high mortalities, especially in rainbow trout fry. Recently, phages have been isolated with a broad host...... range and a strong lytic potential against pathogenic F. psychrophilum under experimental conditions. However, little is known about the fate of phages at environmental conditions. Here, we quantified the dispersal and fate of F. psychrophilum phages and hosts in rainbow trout fry after intraperitoneal...... injection. Both phages and bacteria were isolated from the fish organs for up to 10 days after injection, and coinjection with both bacteria and phages resulted in a longer persistence of the phage in the fish organs, than when the fish had been injected with the phages only. The occurrence of both phage...

  9. Wong-Type Dermatomyositis Showing Porokeratosis-Like Changes (Columnar Dyskeratosis: A Case Report and Review of the Literature

    Directory of Open Access Journals (Sweden)

    Nicole Umanoff

    2015-01-01

    Full Text Available Background: Wong-type dermatomyositis (DM exhibits simultaneous pityriasis rubra pilaris (PRP features. Case Report: A 50-year-old woman presented with a heliotrope rash, Gottron's papules, and a poikilodermic, erythematous rash in shawl distribution without evidence of muscle weakness. Despite topical corticosteroids, the eruption progressed 9 months later to include generalized hyperkeratotic follicular papules, islands of sparing, and atrophic macules with a collarette of scale suggestive of porokeratosis. Mild dysphonia was the only sign of muscle weakness. Serology showed positive ANA. Histopathology revealed interface dermatitis with dermal mucin and melanophages, irregular psoriasiform hyperplasia, alternating mounds of para- and orthokeratosis, and tiers of dyskeratotic cells (columnar dyskeratosis. Systemic corticosteroid therapy was not tolerated; acitretin diminished the hyperkeratosis. While hyperpigmentation persisted, no progression of cutaneous or muscular symptoms has occurred after 22 months of follow-up and cessation of the therapy. Overall, her course did not differ from the natural history documented in the literature review of Wong-type DM. The most similar case also exhibited pseudocornoid lamella changes. Conclusion: Wong-type DM is a clinicopathologic DM-PRP hybrid that can also exhibit porokeratosis-like features best described as columnar dyskeratosis. Recognizing these types of lesions in DM is warranted in order to make an accurate assessment of their prognostic significance.

  10. Modeling of columnar and equiaxed solidification of binary mixtures; Modelisation de la solidification colonnaire et equiaxe de melanges binaires

    Energy Technology Data Exchange (ETDEWEB)

    Roux, P

    2005-12-15

    This work deals with the modelling of dendritic solidification in binary mixtures. Large scale phenomena are represented by volume averaging of the local conservation equations. This method allows to rigorously derive the partial differential equations of averaged fields and the closure problems associated to the deviations. Such problems can be resolved numerically on periodic cells, representative of dendritic structures, in order to give a precise evaluation of macroscopic transfer coefficients (Drag coefficients, exchange coefficients, diffusion-dispersion tensors...). The method had already been applied for a model of columnar dendritic mushy zone and it is extended to the case of equiaxed dendritic solidification, where solid grains can move. The two-phase flow is modelled with an Eulerian-Eulerian approach and the novelty is to account for the dispersion of solid velocity through the kinetic agitation of the particles. A coupling of the two models is proposed thanks to an original adaptation of the columnar model, allowing for undercooling calculation: a solid-liquid interfacial area density is introduced and calculated. At last, direct numerical simulations of crystal growth are proposed with a diffuse interface method for a representation of local phenomena. (author)

  11. Monte Carlo simulation of the crossover from Bose glass to Bragg glass phase in layered BSCCO with columnar defects

    Science.gov (United States)

    Queiroz, L. M.; Coutinho-Filho, M. D.

    2017-01-01

    Monte Carlo simulations of layered BSCCO samples are used to investigate the behavior of vortex matter at low fields, particularly in connection with the possible occurrence of a Bragg glass (BrG) phase at low density of columnar defects, a phenomenon characterized by the prevalence of short-range over long-range order. In this dislocation-free topological phase the translational order correlation function displays a power law decay. For magnetic induction B  =  0.1 kG the analysis of the data for the first Bragg peak of the planar structure factor, the hexatic order parameter, and the Delaunay triangulation shows that, as the density of columnar defects is lowered, a crossover (or transition) from Bose glass to BrG phase takes place in this highly anisotropic high-T{{}\\text{c}} superconductor. Most importantly, an analysis of the low-temperature 3D vortex–vortex correlation function in terms of the structure factor, calculated via a saddle point approach and the use of the numerical data as input, provides clear-cut evidence of the power law decay of the divergent Bragg peaks in the BrG phase, a fundamental feature that was inequivocally verified only in isotropic compounds.

  12. Deformation behavior of Cu-12wt%AI alloy wires with continuous columnar crystals in dieless drawing process

    Institute of Scientific and Technical Information of China (English)

    LIU XueFeng; WU YuHui; XIE JianXin

    2009-01-01

    The microstructure and mechanical properties of Cu-12wt%AI alloy wires which are composed of continuous columnar crystals after dieless drawing forming at drawing speed of 1.0-1.4 mm/s and deformation temperature of 600-900℃ were analyzed,and deformation behavior of the alloy during dieless drawing forming was experimentally investigated.The results showed that in the above-mentioned conditions,recrystallization phenomenon was not found during dieless drawing forming.When a drawing speed of 1.0 mm/s was used,the grain boundaries were out of straight gradually with increasing deformation temperature from 600℃ to 900℃,and tensile strength of the dieless drawn Cu-12wt%AI alloy wires increased while elongations decreased with increasing deformation temperature.At drawing speed of 1.1-1.2 mm/s and deformation temperature of 600℃,the effect of dieless drawing forming process on the microstructure of the alloy was inconspicuous,and when drawing speed was up to 1.3-1.4 mm/s,the grain boundaries of continuous columnar crystals became zigzag while there was little effect of drawing speed of 1.1-1.4 mm/s on the elongation and tensile strength of the alloy wires.

  13. Deformation behavior of Cu-12wt%Al alloy wires with continuous columnar crystals in dieless drawing process

    Institute of Scientific and Technical Information of China (English)

    2009-01-01

    The microstructure and mechanical properties of Cu-12wt%Al alloy wires which are composed of continuous columnar crystals after dieless drawing forming at drawing speed of 1.0―1.4 mm/s and deformation temperature of 600―900℃ were analyzed, and deformation behavior of the alloy during dieless drawing forming was experimentally investigated. The results showed that in the abovemen-tioned conditions, recrystallization phenomenon was not found during dieless drawing forming. When a drawing speed of 1.0 mm/s was used, the grain boundaries were out of straight gradually with increasing deformation temperature from 600℃ to 900℃, and tensile strength of the dieless drawn Cu-12wt%Al alloy wires increased while elongations decreased with increasing deformation temperature. At drawing speed of 1.1―1.2 mm/s and deformation temperature of 600℃, the effect of dieless drawing forming process on the microstructure of the alloy was inconspicuous, and when drawing speed was up to 1.3―1.4 mm/s, the grain boundaries of continuous columnar crystals became zigzag while there was little effect of drawing speed of 1.1―1.4 mm/s on the elongation and tensile strength of the alloy wires.

  14. Comparative pollination biology of Venezuelan columnar cacti and the role of nectar-feeding bats in their sexual reproduction.

    Science.gov (United States)

    Nassar, J; Ramirez, N; Linares, O

    1997-07-01

    The floral biology, reproductive system, and visitation behavior of pollinators of four species of columnar cacti, Stenocereus griseus, Pilosocereus moritzianus, Subpilocereus repandus, and Subpilocereus horrispinus, were studied in two arid zones in the north of Venezuela. Our results support the hypothesis that Venezuelan species of columnar cacti have evolved toward specialization on bat pollination. Additional information on the floral biology of a fifth species, Pilosocereus lanuginosus, was also included. All species showed the typical traits that characterize the pollination syndrome of chiropterophily. All species but Pilosocereus moritzianus were obligate outcrossers. Nectar and pollen were restricted to nocturnal floral visitors. Two species of nectar-feeding bats, Leptonycteris curasoae Miller and Glossophaga longirostris Miller, were responsible for practically all the fruit set in these cacti. Frequency of bat visitation per flower per night was highly variable within and between species of cactus, with average frequencies varying between 27 and 78 visits/flower/night. In general terms, the pattern of floral visitation through the night was significantly correlated with the pattern of nectar production and nectar sugar concentration for all species of cactus. Under natural pollination, fruit:flower ratios varied from 0.46 in Subpilocereus repandus to 0.76 in Stenocereus griseus. The efficiency of bat pollination in terms of seed:ovule ratio was high in all species, varying between 0.70 and 0.94.

  15. Population genetics and phylogenetic relationships of beetles (Coleoptera: Histeridae and Staphylinidae) from the Sonoran Desert associated with rotting columnar cacti.

    Science.gov (United States)

    Pfeiler, Edward; Johnson, Sarah; Richmond, Maxi Polihronakis; Markow, Therese A

    2013-12-01

    Dozens of arthropod species are known to feed and breed in the necrotic tissues (rots) of columnar cacti in the Sonoran Desert. Because the necrotic patches are ephemeral, the associated arthropods must continually disperse to new cacti and therefore the populations of any given species are expected to show very little local genetic differentiation. While this has been found to be true for the cactophilic Drosophila, the evolutionary histories and characteristics of other arthropods inhabiting the same necrotic patches, especially the beetles, have yet to be examined. Here we used nucleotide sequence data from segments of the mitochondrial 16S rRNA and cytochrome c oxidase subunit I (COI) genes to examine population structure and demographic history of three sympatric beetle species (Coleoptera: Histeridae and Staphylinidae) collected on senita cactus (Lophocereus schottii) from six widely-separated localities on the Baja California peninsula of northwestern Mexico. Two histerids, Iliotona beyeri and Carcinops gilensis, and an unidentified staphylinid, Belonuchus sp., showed little or no population structure over a broad geographic area on the peninsula, consistent with the prediction that these beetles should show high dispersal ability. Demographic tests revealed varying levels of historical population expansion among the beetle species analyzed, which are discussed in light of their ecologies and concurrent biogeographic events. Additionally, phylogenetic analyses of COI sequences in Carcinops collected on a variety of columnar cacti from both peninsular and mainland Mexico localities revealed several species-level partitions, including a putative undescribed peninsular species that occurred sympatrically with C. gilensis on senita.

  16. The collapse of the columnar spatial topology of pseudogap excitations in the underdoped-overdoped transition of cuprate superconductors

    Energy Technology Data Exchange (ETDEWEB)

    Roehler, Juergen [Universitaet zu Koeln, 50937 Koeln (Germany)

    2016-07-01

    The intensity I{sub Q{sub 0}} of the Q=0 nematic pseudogap excitations in Bi{sub 2}Sr{sub 2}CaCu{sub 2}O{sub 8+x} was found to increase between p ≥ 0.06 and 0.14 and to collapse at p{sub opt}=0.16, reaching zero at p=0.2. Evidentially it maps the growth and the collapse of the bulge in the doping dependence of the basal-plane area (ab) of p-type cuprates. The nematic topology of the pseudogap excitations results from the non-occupancy constraint for nn ZR-holes excluding 1a dimerization, but favoring 3a pair states with inequivalent O{sub x,y} sites. 3a pair states have hard core properties, yield d-type CDW excitations, and inflate the basal-plane area by a columnar topology against covalency-driven contraction. We show that optimal delocalization of ZR-holes at p{sub opt}=1/6 ≅ 0.17, tantamount to maximal connectedness of 3a pair states, will transform the columnar nematic pattern into isotropic tweedy striations, hence collapses I{sub Q{sub 0}}, and the bulge.

  17. Monte Carlo Simulation of the Crossover from Bose Glass to Bragg Glass Phase in Layered BSCCO with Columnar Defects

    CERN Document Server

    Queiroz, L M

    2016-01-01

    Monte Carlo simulations of layered BSCCO samples are used to investigate the behavior of vortex matter at low fields, particularly in connection with the possible occurrence of a Bragg glass (BrG) phase at low density of columnar defects, a phenomenon characterized by the prevalence of short-range over long-range order. In this dislocation-free topological phase the translational order correlation function displays a power law decay. For magnetic induction $B=0.1$ kG the analysis of the data for the first Bragg peak of the planar structure factor, the hexatic order parameter, and the Delaunay triangulation shows that, as the density of columnar defects is lowered, a \\textit{crossover} (or transition) from Bose glass to BrG phase takes place in this \\textit{highly anisotropic} high-T${}_c$ superconductor. Most importantly, an analysis of the 3D vortex-vortex correlation function in terms of the structure factor, calculated via a saddle point approach and the use of the numerical data as input, provides clear-c...

  18. Cu2+ removal and recovery by Spi SORB: batch stirred and up-flow packed bed columnar reactor systems.

    Science.gov (United States)

    Vannela, Raveender; Verma, Sanjay Kumar

    2006-06-01

    The biosorption of Cu(2+) by free and poly acrylamide gel (PAG) immobilized Spirulina platensis (SpiSORB) was characterized under batch and continuous packed bed columnar reaction systems. The biosorption of Cu(2+) was shown to be highest at pH of 6.0 for both types of biomass. The PAG immobilization process did not interfere with the Cu(2+) binding sites present on biomass leading to cent percent (ca. 250 mg g(-1) of dry biomass) retention of biosorption as compared to free cells. Transmission electron microscopy on Cu(2+) localization revealed that majority of metal is being sequestered by the cell wall only. The infrared spectrum of metal treated S. platensis biomass indicated the possible involvement of amide, amino, and carboxyl groups in metal binding. Up-flow packed bed columnar reactor containing 2.0 g of PAG immobilized S. platensis shown a maximum of 143-fold volume reduction factor at the residence time of 4.6 min for Cu(2+) alone and found to decrease dramatically when Zn(2+ )is present in a bimetallic solution.

  19. Low-dose aspirin use does not diminish the immune response to monovalent H1N1 influenza vaccine in older adults.

    Science.gov (United States)

    Jackson, M L; Bellamy, A; Wolff, M; Hill, H; Jackson, L A

    2016-03-01

    Non-steroidal anti-inflammatory drugs (NSAIDs) may inhibit antibody production by peripheral blood mononuclear cells; one consequence of this could be decreased effectiveness of vaccines in NSAID users. Because many older adults use low-dose aspirin for primary or secondary prevention of coronary events, any inhibitory effect of aspirin on vaccine immune response could reduce the benefits of vaccination programmes in older adults. We tested whether immune response to vaccination differed between users vs. non-users of low-dose aspirin, using data from four randomized trials of monovalent 2009 pandemic influenza A(H1N1) vaccine. Geometric mean haemagglutination inhibition antibody titres were not significantly lower in low-dose aspirin users compared to non-users. Our results provide reassurance that influenza vaccination effectiveness is probably not reduced in older adults taking chronic low-dose aspirin.

  20. The effect of primycin on the intracellular monovalent ion and water contents of rat hepatocytes as revealed by energy dispersive X-ray microanalysis and interference microscopy.

    Science.gov (United States)

    Horváth, I; Nagy, I; Lustyik, G; Váradi, G

    1983-01-01

    Using energy-dispersive X-ray microanalytic and interference microscopic techniques, the intracellular concentration of the monovalent ions (Na+, K+, Cl+) as well as the intracytoplasmic and intracellular water contents were studied in normal and adrenalectomized rat hepatocytes with and without primycin treatment. Although primycin influenced significantly only the intracellular potassium content of the adrenalectomized group, it exerted a marked influence on the intranuclear water content in both the normal and adrenalectomized rats. The intranuclear water content increased significantly in the primycin-treated animals. The conclusion is drawn that the increased level of hydration of the nuclear substances reflects a 'decondensation' of the chromatin which on the other hand, may represent the basis for the various effects of primycin on the induction of certain hepatic enzymes.

  1. Electrical transport and EPR investigations: A comparative study for d.c. conduction mechanism in monovalent and multivalent ions doped polyaniline

    Indian Academy of Sciences (India)

    Suresh Kumar Gupta; Vandna Luthra; Ramadhar Singh

    2012-10-01

    A detailed comparative study of electron paramagnetic resonance (EPR) in conjunction with d.c. electrical conductivity has been undertaken to know about the charge transport mechanism in polyaniline (PANI) doped with monovalent and multivalent protonic acids. This work is in continuation of our previous work for further understanding the conduction mechanism in conducting polymers. The results reveal that the polarons and bipolarons are the main charge carriers formed during doping process and these cause increase in electrical conductivity not only by increase in their concentration but also because of their enhanced mobility due to increased inter-chain transport in polyaniline at high doping levels. EPR line asymmetry having Dysonian line shape for highly doped samples shows a marked deviation of amplitudes / ratio from values close to one to much high values as usually observed in metals, thereby support the idea of high conductivity at higher doping levels. The nature of dopant ions and their doping levels control the charge carriers concentration as well as electrical conductivity of polyaniline. The electrical conductivity has also been studied as a function of temperature to know the thermally assisted transport process of these charge carriers at different doping levels which has been found to follow the Mott’s variable range hopping (VRH) conduction model for all the three dopants used. The charge carriers show a change over from 3D VRH to quasi 1D VRH hopping process for multivalent ions at higher doping levels whereas 1D VRH has been followed by monovalent ion for full doping range. These studies collectively give evidence of inter-chain percolation at higher doping levels causing increase in effective mobility of the charge carriers which mainly seems to govern the electrical conduction behaviour in this system.

  2. Regulation of formyl peptide receptor binding to rabbit neutrophil plasma membranes. Use of monovalent cations, guanine nucleotides, and bacterial toxins to discriminate among different states of the receptor

    Energy Technology Data Exchange (ETDEWEB)

    Feltner, D.E.; Marasco, W.A.

    1989-06-01

    The regulation by monovalent cations, guanine nucleotides, and bacterial toxins of (3H)FMLP binding to rabbit neutrophil plasma membranes was studied by using dissociation techniques to identify regulatory effects on separate receptor states. Under conditions of low receptor occupancy (1 nM (3H)FMLP) and in both Na+ and K+ buffers, dissociation is heterogenous, displaying two distinct, statistically significant off rates. (3H)FMLP binding was enhanced by substituting other monovalent cations for Na+. In particular, enhanced binding in the presence of K+ relative to Na+ was caused by additional binding to both rapidly and slowly dissociating receptors. Three receptor dissociation rates, two of which appear to correspond to the two affinity states detected in equilibrium binding studies, were defined by specific GTP and pertussis toxin (PT) treatments. Neither GTP, nor PT or cholera toxins (CT) had an effect on the rate of dissociation of (3H)FMLP from the rapidly dissociating form of the receptor. Both 100 microM GTP and PT treatments increased the percentage of rapidly dissociating receptors, correspondingly decreasing the percentage of slowly dissociating receptors. The observed changes in the rapidly and slowly dissociating receptors after GTP, PT, and CT treatments were caused by an absolute decrease in the amount of binding to the slowly dissociating receptors. However, complete inhibition of slowly dissociating receptor binding by GTP, PT, or both was never observed. Both GTP and PT treatments, but not CT treatment, increased by two-fold the rate of dissociation of 1 nM (3H)FMLP from the slowly dissociating form of the receptor, resulting in a third dissociation rate. Thus, slowly dissociating receptors comprise two different receptor states, a G protein-associated guanine nucleotide and PT-sensitive state and a guanine nucleotide-insensitive state.

  3. Modification of leaf morphology and anatomy as a consequence of columnar architecture in domestic apple (Malus x domestica Borkh.) trees

    DEFF Research Database (Denmark)

    Talwara, Susheela; Grout, Brian William Wilson; Toldam-Andersen, Torben Bo

    2013-01-01

    size and density and leaf chlorophyll content were recorded. Scanning electron microscopy revealed that columnar cultivars develop an additional layer of well-developed palisade mesophyll and a greater depth of spongy mesophyll when compared to their standard counterparts. This large-scale modification...

  4. On columnar thin films as platforms for surface-plasmonic-polaritonic optical sensing: higher-order considerations

    CERN Document Server

    Jamaian, Siti S

    2011-01-01

    The ability to tailor the porosity and optical properties of columnar thin films (CTFs) renders them promising platforms for optical sensing. In particular, surface-plasmon-polariton (SPP) waves, guided by the planar interface of an infiltrated CTF and a thin layer of metal, may be harnessed to detect substances that penetrate the void regions in between the columns of a CTF. This scenario was investigated theoretically using a higher-order homogenization technique, based on an extended version of the second-order strong-permittivity-fluctuation theory, which takes into account the size of the component particles which make up the infiltrated CTF and the statistical distribution of these particles. Our numerical studies revealed that as the size of the component particles increases and as the correlation length that characterizes their distribution increases: (i) the phase speed of the SPP wave decreases and the SPP wave's attenuation increases; (ii) the SPP wave's penetration into the CTF decreases; (iii) th...

  5. Experimental Investigation of the Anisotropic Mechanical Properties of a Columnar Jointed Rock Mass: Observations from Laboratory-Based Physical Modelling

    Science.gov (United States)

    Ji, H.; Zhang, J. C.; Xu, W. Y.; Wang, R. B.; Wang, H. L.; Yan, L.; Lin, Z. N.

    2017-07-01

    Because of the complex geological structure, determination of the field mechanical parameters of the columnar jointed rock mass (CJRM) was a challenging task in the design and construction of the Baihetan hydropower plant. To model the mechanical behaviour of the CJRM, uniaxial compression tests were conducted on artificial CJRM specimens with geological structure similar to that found in the actual CJRM. Based on the test results, the anisotropic deformation and strength were mainly analysed. The empirical correlations of evaluating the field mechanical parameters were derived based on the joint factor approach and the modulus reduction factor method. The findings of the physical model tests were then used to estimate the field moduli and unconfined compressive strengths of the Baihetan CJRM. The results predicted by physical model tests were compared with those obtained from the field tests and the RMR classification system. It is concluded that physical model tests were capable of providing valuable estimations on the field mechanical parameters of the CJRM.

  6. High Temperature Thermal Properties of Columnar Yttria Stabilized Zirconia Thermal Barrier Coating Performed by Suspension Plasma Spraying

    Science.gov (United States)

    Bernard, B.; Schick, V.; Remy, B.; Quet, A.; Bianchi, L.

    2016-09-01

    Performance enhancement of gas turbines is a main issue for the aircraft industry. Over many years, a large part of the effort has been focused on the development of more insulating Thermal Barrier Coatings (TBCs). In this study, Yttria Stabilized Zirconia (YSZ) columnar structures are processed by Suspension Plasma Spraying (SPS). These structures have already demonstrated abilities to get improved thermal lifetime, similarly to standard YSZ TBCs performed by EB-PVD. Thermal diffusivity measurements coupled with differential scanning calorimetry analysis are performed from room temperature up to 1100 °C, first, on HastelloyX substrates and then, on bilayers including a SPS YSZ coating. Results show an effective thermal conductivity for YSZ performed by SPS lower than 1 W.m-1K-1 whereas EB- PVD YSZ coatings exhibit a value of 1.5 W.m-1K-1.

  7. A new ground-based differential absorption sunphotometer for measuring atmospheric columnar CO2 and preliminary applications

    Science.gov (United States)

    Xie, Yisong; Li, Zhengqiang; Zhang, Xingying; Xu, Hua; Li, Donghui; Li, Kaitao

    2015-10-01

    Carbon dioxide is commonly considered as the most important greenhouse gas. Ground-based remote sensing technology of acquiring CO2 columnar concentration is needed to provide validation for spaceborne CO2 products. A new groundbased sunphotometer prototype for remotely measuring atmospheric CO2 is introduced in this paper, which is designed to be robust, portable, automatic and suitable for field observation. A simple quantity, Differential Absorption Index (DAI) related to CO2 optical depth, is proposed to derive the columnar CO2 information based on the differential absorption principle around 1.57 micron. Another sun/sky radiometer CE318, is used to provide correction parameters of aerosol extinction and water vapor absorption. A cloud screening method based on the measurement stability is developed. A systematic error assessment of the prototype and DAI is also performed. We collect two-year DAI observation from 2010 to 2012 in Beijing, analyze the DAI seasonal variation and find that the daily average DAI decreases in growing season and reaches to a minimum on August, while increases after that until January of the next year, when DAI reaches its highest peak, showing generally the seasonal cycle of CO2. We also investigate the seasonal differences of DAI variation and attribute the tendencies of high in the morning and evening while low in the noon to photosynthesis efficiency variation of vegetation and anthropogenic emissions. Preliminary comparison between DAI and model simulated XCO2 (Carbon Tracker 2011) is conducted, showing that DAI roughly reveals some temporal characteristics of CO2 when using the average of multiple measurements.

  8. hybridMANTIS: a CPU-GPU Monte Carlo method for modeling indirect x-ray detectors with columnar scintillators.

    Science.gov (United States)

    Sharma, Diksha; Badal, Andreu; Badano, Aldo

    2012-04-21

    The computational modeling of medical imaging systems often requires obtaining a large number of simulated images with low statistical uncertainty which translates into prohibitive computing times. We describe a novel hybrid approach for Monte Carlo simulations that maximizes utilization of CPUs and GPUs in modern workstations. We apply the method to the modeling of indirect x-ray detectors using a new and improved version of the code MANTIS, an open source software tool used for the Monte Carlo simulations of indirect x-ray imagers. We first describe a GPU implementation of the physics and geometry models in fastDETECT2 (the optical transport model) and a serial CPU version of the same code. We discuss its new features like on-the-fly column geometry and columnar crosstalk in relation to the MANTIS code, and point out areas where our model provides more flexibility for the modeling of realistic columnar structures in large area detectors. Second, we modify PENELOPE (the open source software package that handles the x-ray and electron transport in MANTIS) to allow direct output of location and energy deposited during x-ray and electron interactions occurring within the scintillator. This information is then handled by optical transport routines in fastDETECT2. A load balancer dynamically allocates optical transport showers to the GPU and CPU computing cores. Our hybridMANTIS approach achieves a significant speed-up factor of 627 when compared to MANTIS and of 35 when compared to the same code running only in a CPU instead of a GPU. Using hybridMANTIS, we successfully hide hours of optical transport time by running it in parallel with the x-ray and electron transport, thus shifting the computational bottleneck from optical tox-ray transport. The new code requires much less memory than MANTIS and, asa result, allows us to efficiently simulate large area detectors.

  9. Report on Breeding Columnar Apple Varieties%柱型苹果品种选育研究

    Institute of Scientific and Technical Information of China (English)

    戴洪义; 王彩虹; 迟斌; 祝军; 王然; 李贵学; 庄丽丽

    2003-01-01

    An apple breeding program started at Laiyang Agricultural College in 1994, aiming at combining columnar growthhabit and other desirable characteristics in a new variety. Preliminary observation on the performance of the crossed progeniesshowed that the growth vigor; precocity; resistances to mildew,ring spot and woolly aphid varied greatly. The fruit size andshape, flesh firmness,eating quality, flowering date and fruit ripening date were apparently polygenic characters. An AFLPmarker of Co gene was selected and converted into SCAR marker, which could be employed to detect columnar genotype withhigher efficiency. Further trials of several promising selections are under way.%柱型苹果品种选育项目始于1994年,旨在将苹果柱型生长习性与其它优良性状结合起来.结果表明:杂种后代的生长势、早实性,对白粉病、轮纹病和绵蚜的抗性等与杂交组合有关.果实大小、果形、果肉硬度、风味品质、花期和果实成熟期为多基因控制的性状.筛选出了一个柱型基因(Co)的AFLP标记并成功地将其转为SCAR标记,其可以用于柱型苹果杂种的早期选择.几个优系的田间实验正在进一步进行中.

  10. A case study of columnar marine and dust particle ratios calculated with photometric and lidar measurements during the CHARADMEXP campaign

    Science.gov (United States)

    Panagiotis Raptis, Ioannis; Kokkalis, Panagiotis; Amiridis, Vassilis; Taylor, Michael; Kazadzis, Stelios

    2015-04-01

    The CHARADMEXP campaign took place at the Finokalia meteorological station on the island of Crete, Greece from the 20th of June to 10th July 2014 deploying various instruments to monitor aerosol mixtures of dust and marine origin (more info at http://charadmexp.gr). In this study we focus on data recorded on 1st July. This day gain our interest because we had two distinguished layer of particles at different heights, sea salt near the ground and dust at planetary boundary layer height. A raman/depolarization lidar (EMORAL) and a CIMEL photometer were simultaneously operating during the time of interest in the area. Multimodal analysis of retrieved AERONET volume size distributions on that day was used to distinguish between dominant aerosol types and to calculate the percentage contribution of each mode to the columnar volume concentration. Selection of the method was based on previous work which showed that in cases of mixtures that contain sea salt, bi-lognormals fail to recover key features of the average size distribution. Linear particle depolarization ratio profiles were used to discriminate spherical from non-spherical particles and to validate the columnar volume percentage contribution of different types provided by multimodal analysis. We found that the column was dominated mainly by coarse mode aerosol of marine and dust origin in equal volume proportion in the morning hours. As the day progressed, dust concentrations declined and marine particles became dominant . Lidar profiles confirmed dual layering of particles. The aerosol load was found to be low (AOD≈0.1-0.2) and allowed for a test of the sensitivity of the multimodal method at small concentrations.

  11. Columnar jointing in vapor-phase-altered, non-welded Cerro Galán Ignimbrite, Paycuqui, Argentina

    Science.gov (United States)

    Wright, Heather M.; Lesti, Chiara; Cas, Ray A.F.; Porreca, Massimiliano; Viramonte, Jose G.; Folkes, Christopher B.; Giordano, Guido

    2011-01-01

    Columnar jointing is thought to occur primarily in lavas and welded pyroclastic flow deposits. However, the non-welded Cerro Galán Ignimbrite at Paycuqui, Argentina, contains well-developed columnar joints that are instead due to high-temperature vapor-phase alteration of the deposit, where devitrification and vapor-phase crystallization have increased the density and cohesion of the upper half of the section. Thermal remanent magnetization analyses of entrained lithic clasts indicate high emplacement temperatures, above 630°C, but the lack of welding textures indicates temperatures below the glass transition temperature. In order to remain below the glass transition at 630°C, the minimum cooling rate prior to deposition was 3.0 × 10−3–8.5 × 10−2°C/min (depending on the experimental data used for comparison). Alternatively, if the deposit was emplaced above the glass transition temperature, conductive cooling alone was insufficient to prevent welding. Crack patterns (average, 4.5 sides to each polygon) and column diameters (average, 75 cm) are consistent with relatively rapid cooling, where advective heat loss due to vapor fluxing increases cooling over simple conductive heat transfer. The presence of regularly spaced, complex radiating joint patterns is consistent with fumarolic gas rise, where volatiles originated in the valley-confined drainage system below. Joint spacing is a proxy for cooling rates and is controlled by depositional thickness/valley width. We suggest that the formation of joints in high-temperature, non-welded deposits is aided by the presence of underlying external water, where vapor transfer causes crystallization in pore spaces, densifies the deposit, and helps prevent welding.

  12. Identification of a 4-Deoxy-l-erythro-5-hexoseulose Uronic Acid Reductase, FlRed, in an Alginolytic Bacterium Flavobacterium sp. Strain UMI-01

    Directory of Open Access Journals (Sweden)

    Akira Inoue

    2015-01-01

    Full Text Available In alginate-assimilating bacteria, alginate is depolymerized to unsaturated monosaccharide by the actions of endolytic and exolytic alginate lyases (EC 4.2.2.3 and EC 4.2.2.11. The monosaccharide is non-enzymatically converted to 4-deoxy-l-ery thro-5-hexoseulose uronic acid (DEH, then reduced to 2-keto-3-deoxy-d-gluconate (KDG by a specific reductase, and metabolized through the Entner–Doudoroff pathway. Recently, the NADPH-dependent reductase A1-R that belongs to short-chain dehydrogenases/reductases (SDR superfamily was identified as the DEH-reductase in Sphingomonas sp. A1. We have subsequently noticed that an SDR-like enzyme gene, flred, occurred in the genome of an alginolytic bacterium Flavobacterium sp. strain UMI-01. In the present study, we report on the deduced amino-acid sequence of flred and DEH-reducing activity of recombinant FlRed. The deduced amino-acid sequence of flred comprised 254 residues and showed 34% amino-acid identities to that of A1-R from Sphingomonas sp. A1 and 80%–88% to those of SDR-like enzymes from several alginolytic bacteria. Common sequence motifs of SDR-superfamily enzymes, e.g., the catalytic tetrad Asn-Lys-Tyr-Ser and the cofactor-binding sequence Thr-Gly-x-x-x-Gly-x-Gly in Rossmann fold, were completely conserved in FlRed. On the other hand, an Arg residue that determined the NADPH-specificity of Sphingomonas A1-R was replaced by Glu in FlRed. Thus, we investigated cofactor-preference of FlRed using a recombinant enzyme. As a result, the recombinant FlRed (recFlRed was found to show high specificity to NADH. recFlRed exhibited practically no activity toward variety of aldehyde, ketone, keto ester, keto acid and aldose substrates except for DEH. On the basis of these results, we conclude that FlRed is the NADH-dependent DEH-specific SDR of Flavobacterium sp. strain UMI-01.

  13. Flavobacterium psychrophilum y su patología en alevines de Onchorhynchus mykiss del centro piscícola El Ingenio, Huancayo

    Directory of Open Access Journals (Sweden)

    Jorge León

    2008-12-01

    Full Text Available En el presente trabajo se reporta la presencia de Flavobacterium psychrophilum, como agente causante de la patología “enfermedad bacteriana del agua fría” en alevines de Onchorhynchus mykiss “trucha arco iris” del Centro Piscícola El Ingenio, Junín (3250 m de altitud. La lesión macroscópica externa más frecuente fue la ulceración profunda de la región dorsal del pez acompañado de un ennegrecimiento localizado de la piel. Internamente se observó una marcada esplenomegalia, palidez del hígado, riñón y branquias, inflamación del intestino y acumulación de líquido ascítico en el peritoneo. No se detectó hemorragia interna. En Agar Cytophaga Modificado (ACM según Anaker & Ordal (1959 fueron aisladas inicialmente 29 Gram negativas, de las cuales según la caracterización fenotípica y pruebas bioquímicas 9 fueron consideradas como F. psychrophilum. Pruebas de susceptibilidad antibiótica mostraron alta sensibilidad de las cepas a Gentamicina, Ceftazidina, oxitetraciclina, Norfloxacina, furazolidona, Ciprofloxacina y Cefoxitina.

  14. Hemolytic activity in Flavobacterium psychrophilum is a contact-dependent, two-step mechanism and differently expressed in smooth and rough phenotypes.

    Science.gov (United States)

    Högfors-Rönnholm, Eva; Wiklund, Tom

    2010-12-01

    The hemolytic activity of cells of smooth and rough phenotypic variants of the Gram-negative fish pathogen Flavobacterium psychrophilum was investigated in two different assays, a microplate and an agarose hemolysis assay, using rainbow trout erythrocytes. The smooth cells showed a high and the rough cells a negligible, concentration dependent, hemolytic activity in the microplate assay. Both smooth and rough cells showed a rather weak hemolytic activity, with two distinct hemolytic patterns, in the agarose assay. The hemolytic activity of the cells was not regulated by iron availability and cell-free extracellular products did not show any hemolytic activity. The smooth cells, in contrast to the rough cells, showed a high ability to agglutinate erythrocytes and both hemagglutination and hemolytic activity was impaired by treatment of the cells with sialic acid. The hemolytic activity was furthermore reduced after proteolytic and heat treatment of the cells. The results from the present study suggest that the hemolytic activity in F. psychrophilum is highly expressed in the smooth phenotype, and that it is a contact-dependent and two-step mechanism that is initiated by the binding of the bacterial cells to the erythrocytes through sialic acid-binding lectins and then executed by thermolabile proteinaceous hemolysins.

  15. Materials Science Laboratory - Columnar-to-Equiaxed Transition in Solidification Processing and Microstructure Formation in Casting of Technical Alloys under Diffusive and Magnetically Controlled Convective Conditions

    Science.gov (United States)

    Gandin, Charles-Andre; Ratke, Lorenz

    2008-01-01

    The Materials Science Laboratory - Columnar-to-Equiaxed Transition in Solidification Processing and Microstructure Formation in Casting of Technical Alloys under Diffusive and Magnetically Controlled Convective Conditions (MSL-CETSOL and MICAST) are two investigations which supports research into metallurgical solidification, semiconductor crystal growth (Bridgman and zone melting), and measurement of thermo-physical properties of materials. This is a cooperative investigation with the European Space Agency (ESA) and National Aeronautics and Space Administration (NASA) for accommodation and operation aboard the International Space Station (ISS). Research Summary: Materials Science Laboratory - Columnar-to-Equiaxed Transition in Solidification Processing (CETSOL) and Microstructure Formation in Casting of Technical Alloys under Diffusive and Magnetically Controlled Convective Conditions (MICAST) are two complementary investigations which will examine different growth patterns and evolution of microstructures during crystallization of metallic alloys in microgravity. The aim of these experiments is to deepen the quantitative understanding of the physical principles that govern solidification processes in cast alloys by directional solidification.

  16. Giant elastocaloric effect covering wide temperature range in columnar-grained Cu71.5Al17.5Mn11 shape memory alloy

    Science.gov (United States)

    Xu, Sheng; Huang, Hai-You; Xie, Jianxin; Takekawa, Shouhei; Xu, Xiao; Omori, Toshihiro; Kainuma, Ryosuke

    2016-10-01

    The elastocaloric effect in a columnar-grained Cu71.5Al17.5Mn11 shape memory alloy fabricated by directional solidification was investigated. A large entropy change of 25.0 J/kg K generated by the reversible martensitic transformation was demonstrated. The adiabatic temperature change of 12-13 K was directly measured, covering a wide temperature range of more than 100 K. The low applied stress with a specific elastocaloric ability of 100.8 K/GPa was identified and the potentially attainable operational temperature window as wide as more than 215 K was also discussed. The outstanding elastocaloric refrigeration capability, together with the low applying stress and uniform phase transformation, makes the columnar-grained Cu-Al-Mn shape memory alloy a promising material for solid-state refrigeration.

  17. Giant elastocaloric effect covering wide temperature range in columnar-grained Cu71.5Al17.5Mn11 shape memory alloy

    Directory of Open Access Journals (Sweden)

    Sheng Xu

    2016-10-01

    Full Text Available The elastocaloric effect in a columnar-grained Cu71.5Al17.5Mn11 shape memory alloy fabricated by directional solidification was investigated. A large entropy change of 25.0 J/kg K generated by the reversible martensitic transformation was demonstrated. The adiabatic temperature change of 12-13 K was directly measured, covering a wide temperature range of more than 100 K. The low applied stress with a specific elastocaloric ability of 100.8 K/GPa was identified and the potentially attainable operational temperature window as wide as more than 215 K was also discussed. The outstanding elastocaloric refrigeration capability, together with the low applying stress and uniform phase transformation, makes the columnar-grained Cu–Al–Mn shape memory alloy a promising material for solid-state refrigeration.

  18. Photoinduced Processes of Supramolecular Nanoarrays Composed of Porphyrin and Benzo[ghi]perylenetriimide Units through Triple Hydrogen Bonds with One-Dimensional Columnar Phases.

    Science.gov (United States)

    Sakai, Hayato; Ohkubo, Kei; Fukuzumi, Shunichi; Hasobe, Taku

    2016-02-18

    One-dimensional supramolecular columnar phases composed of porphyrins (electron donor: D) and benzo[ghi]perylenetriimides (electron acceptor: A) through triple hydrogen bonds have been successfully constructed to perform sequential light-harvesting and electron-transfer processes. A series of benzo[ghi]peryleneimide derivatives have been synthesized to examine the substituent effects such as imide and nitrile groups on the spectroscopic and electrochemical properties. Then, formation of the 1:1 supramolecular complex between zinc porphyrin and benzo[ghi]perylenetriimide derivatives through triple hydrogen bonds was confirmed by Job's plot of (1) H NMR titration. Next, the one-dimensional supramolecular nanoarrays were successfully prepared in a mixed solvent. X-ray diffraction (XRD) measurement suggested that these nanoarrays contained one-dimensional columnar phases composed of stacked donor and acceptor layers. Finally, femtosecond transient absorption and electron spin resonance (ESR) measurements clearly indicated that photoinduced electron transfer occurred via the singlet excited states in the supramolecular columns.

  19. Yeast Kch1 and Kch2 membrane proteins play a pleiotropic role in membrane potential establishment and monovalent cation homeostasis regulation.

    Science.gov (United States)

    Felcmanova, Kristina; Neveceralova, Petra; Sychrova, Hana; Zimmermannova, Olga

    2017-08-01

    The Kch1 and Kch2 plasma-membrane proteins were identified in Saccharomyces cerevisiae as being essential for the activation of a high-affinity Ca2+ influx system. We searched for Kch proteins roles in the maintenance of cation homeostasis and tested the effect of kch1 and/or kch2 deletions on various physiological parameters. Compared to wild-type, kch1 kch2 mutant cells were smaller, relatively hyperpolarised, grew better under limited K+ conditions and exhibited altered growth in the presence of monovalent cations. The absence of Kch1 and Kch2 did not change the intracellular pH in cells growing at low potassium or the tolerance of cells to divalent cations, high concentration of sorbitol or extreme external pH. The overexpression of KCH1 only increased the intracellular pH in the presence of elevated K+ in media. None of the phenotypes associated with the deletion of KCH1 and KCH2 in wild type were observed in a strain lacking KCH genes and main K+ uptake systems Trk1 and Trk2. The role of the Kch homologue in cation homeostasis was also tested in Candida albicans cells. Our data demonstrate that Kch proteins significantly contribute to the maintenance of optimal cation homeostasis and membrane potential in S. cerevisiae but not in C. albicans. © FEMS 2017. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

  20. Response to tilted magnetic fields in Bi(2)Sr(2)CaCu(2)O(8) with columnar defects: evidence for transverse Meissner effect.

    Science.gov (United States)

    Ta Phuoc, V; Olive, E; De Sousa, R; Ruyter, A; Ammor, L; Soret, J C

    2002-05-06

    The transverse Meissner effect (TME) in the highly layered superconductor Bi(2)Sr(2)CaCu(2)O(8+y) with columnar defects is investigated by transport measurements. We present evidence for the persistence of the Bose glass phase for H(perpendicular)H(+)(perpendicular c), moving kink chains consistent with a commensurate-incommensurate transition scenario are observed. These results show the existence of the TME for H(perpendicular)

  1. α-Spectrin and integrins act together to regulate actomyosin and columnarization, and to maintain a monolayered follicular epithelium.

    Science.gov (United States)

    Ng, Bing Fu; Selvaraj, Gokul Kannan; Santa-Cruz Mateos, Carmen; Grosheva, Inna; Alvarez-Garcia, Ines; Martín-Bermudo, María Dolores; Palacios, Isabel M

    2016-04-15

    The spectrin cytoskeleton crosslinks actin to the membrane, and although it has been greatly studied in erythrocytes, much is unknown about its function in epithelia. We have studied the role of spectrins during epithelia morphogenesis using the Drosophila follicular epithelium (FE). As previously described, we show that α-Spectrin and β-Spectrin are essential to maintain a monolayered FE, but, contrary to previous work, spectrins are not required to control proliferation. Furthermore, spectrin mutant cells show differentiation and polarity defects only in the ectopic layers of stratified epithelia, similar to integrin mutants. Our results identify α-Spectrin and integrins as novel regulators of apical constriction-independent cell elongation, as α-Spectrin and integrin mutant cells fail to columnarize. Finally, we show that increasing and reducing the activity of the Rho1-Myosin II pathway enhances and decreases multilayering of α-Spectrin cells, respectively. Similarly, higher Myosin II activity enhances the integrin multilayering phenotype. This work identifies a primary role for α-Spectrin in controlling cell shape, perhaps by modulating actomyosin. In summary, we suggest that a functional spectrin-integrin complex is essential to balance adequate forces, in order to maintain a monolayered epithelium.

  2. Comparison of Columnar Water Vapor Measurements During The Fall 1997 ARM Intensive Observation Period: Solar Transmittance Methods

    Science.gov (United States)

    Schmid, B.; Michalsky, J. J.; Slater, D. W.; Barnard, J. C.; Halthore, R. N.; Liljegren, J. C.; Holben, B. N.; Eck, T. F.; Livingston, J. M.; Russell, P. B.

    2000-01-01

    In the fall of 1997, during an Intensive Observation Period (IOP), the Atmospheric Radiation Measurement (ARM) program conducted a study of water vapor abundance measurement at its Southern Great Plains (SGP) site. Among a large number of instruments, four sun-tracking radiometers were present to measure the columnar water vapor (CWV). All four solar radiometers retrieve CWV by measuring total solar transmittance in the 0.94-gm water vapor absorption band and subtracting contributions due to Rayleigh, ozone and aerosol transmittances. The aerosol optical depth comparisons among the same four radiometers has been presented elsewhere (Geophys. Res. Lett., 26, 17, 2725-2728, 1999). We have used three different methods to retrieve CWV. In a first round of comparison no attempt was made to standardize on the same radiative transfer model and its underlying water vapor spectroscopy. In the second round of comparison we used the same line-by-line code (which includes recently corrected H2O spectroscopy) to retrieve CAN from all four suntracking radiometers. This decreased the mean CWV by 8% or 13%. The spread of 8% in the solar radiometer results found when using the same model is an indication of the other-than-model uncertainties involved in determining CWV from solar transmittance measurements with current instrumentation.

  3. Analysis on the Deflection Angle of Columnar Dendrites of Continuous Casting Steel Billets Under the Influence of Mold Electromagnetic Stirring

    Science.gov (United States)

    Wang, Xincheng; Wang, Shengqian; Zhang, Lifeng; Sridhar, Seetharaman; Conejo, Alberto; Liu, Xuefeng

    2016-11-01

    In the current study, the deflection angle of columnar dendrites on the cross section of steel billets under mold electromagnetic stirring (M-EMS) was observed. A mathematical model was developed to define the effect of M-EMS on fluid flow and then to analyze the relationship between flow velocities and deflection angle. The model was validated using experimental data that was measured with a Tesla meter on magnetic intensity. By coupling the numerical results with the experimental data, it was possible to define a relationship between the velocities of the fluid with the deflection angle of high-carbon steel. The deflection angle of high-carbon steel reached maximum values from 18 to 23 deg for a velocity from 0.35 to 0.40 m/s. The deflection angles of low-carbon steel under different EM parameters were discussed. The deflection angle of low-carbon steel was increased as the magnetic intensity, EM force, and velocity of molten steel increased.

  4. Ephrin-B1 controls the columnar distribution of cortical pyramidal neurons by restricting their tangential migration.

    Science.gov (United States)

    Dimidschstein, Jordane; Passante, Lara; Dufour, Audrey; van den Ameele, Jelle; Tiberi, Luca; Hrechdakian, Tatyana; Adams, Ralf; Klein, Rüdiger; Lie, Dieter Chichung; Jossin, Yves; Vanderhaeghen, Pierre

    2013-09-18

    Neurons of the cerebral cortex are organized in layers and columns. Unlike laminar patterning, the mechanisms underlying columnar organization remain largely unexplored. Here, we show that ephrin-B1 plays a key role in this process through the control of nonradial steps of migration of pyramidal neurons. In vivo gain of function of ephrin-B1 resulted in a reduction of tangential motility of pyramidal neurons, leading to abnormal neuronal clustering. Conversely, following genetic disruption of ephrin-B1, cortical neurons displayed a wider lateral dispersion, resulting in enlarged ontogenic columns. Dynamic analyses revealed that ephrin-B1 controls the lateral spread of pyramidal neurons by limiting neurite extension and tangential migration during the multipolar phase. Furthermore, we identified P-Rex1, a guanine-exchange factor for Rac3, as a downstream ephrin-B1 effector required to control migration during the multipolar phase. Our results demonstrate that ephrin-B1 inhibits nonradial migration of pyramidal neurons, thereby controlling the pattern of cortical columns.

  5. Effects of aging treatment on the microstructure and superelasticity of columnar-grained Cu71Al18Mn11 shape memory alloy

    Science.gov (United States)

    Liu, Ji-li; Huang, Hai-you; Xie, Jian-xin

    2016-10-01

    The effect of aging treatment on the superelasticity and martensitic transformation critical stress in columnar-grained Cu71Al18Mn11 shape memory alloy (SMA) at the temperature ranging from 250°C to 400°C was investigated. The microstructure evolution during the aging treatment was characterized by optical microscopy, scanning electron microscopy, transmission electron microscopy, and X-ray diffraction. The results show that the plate-like bainite precipitates distribute homogeneously within austenitic grains and at grain boundaries. The volume fraction of bainite increases with the increase in aging temperature and aging time, which substantially improves the martensitic transformation critical stress of the alloy, whereas the bainite only slightly affects the superelasticity. This behavior is attributed to a coherent relationship between the bainite and the austenite, as well as to the bainite and the martensite exhibiting the same crystal structure. The variations of the martensitic transformation critical stress and the superelasticity of columnar-grained Cu71Al18Mn11 SMA with aging temperature and aging time are described by the Austin-Rickett equation, where the activation energy of bainite precipitation is 77.2 kJ·mol-1. Finally, a columnar-grained Cu71Al18Mn11 SMA with both excellent superelasticity (5%-9%) and high martensitic transformation critical stress (443-677 MPa) is obtained through the application of the appropriate aging treatments.

  6. Columnar modelling of nucleation burst evolution in the convective boundary layer – first results from a feasibility study Part IV: A compilation of previous observations for valuation of simulation results from a columnar modelling study

    Directory of Open Access Journals (Sweden)

    O. Hellmuth

    2006-01-01

    Full Text Available In the preceding Papers I, II and III a revised columnar high-order modelling approach to model gas-aerosol-turbulence interactions in the convective boundary layer (CBL was proposed, and simulation results of two synthetic nucleation scenarios (binary vs. ternary on new particle formation (NPF in the anthropogenically influenced CBL were presented and discussed. The purpose of the present finishing Paper IV is twofold: Firstly, an attempt is made to compile previous observational findings on NPF bursts in the CBL, obtained from a number of field experiments. Secondly, the scenario simulations discussed in Paper III will be evaluated with respect to the role of CBL turbulence in NPF burst evolution. It was demonstrated, that completely different nucleation mechanisms can lead to the occurrence of NPF bursts in the surface layer, but the corresponding evolution patterns strongly differ with respect to the origin, amplitude and phase of the NPF burst as well as with respect to the time-height evolution of turbulent vertical fluxes and double correlation terms of physicochemical and aerosoldynamical variables. The large differences between the binary and ternary case scenario indicate, that ammonia (NH3 can not be considered as a time-independent tuning parameter in nucleation modelling. Its contribution to the evolution of the NPF burst pattern is much more complicated and reflects the influence of CBL turbulence as well as the strong non-linearity of the ternary nucleation rate. The impact of water (H2O vapour on the nucleation rate is quite varying depending on the considered nucleation mechanism. According to the classical theory of binary nucleation involving H2O and sulphuric acid (H2SO4, H2O vapour favours NPF, according to the classical theory of ternary nuncleation involving H2O, H2SO4 and NH3 and according to organic nucleation via chemical reactions involving stabilised Criegee intermediates (SCIs, H2O vapour disfavours nucleation, and

  7. SU-E-I-11: Cascaded Linear System Model for Columnar CsI Flat Panel Imagers with Depth Dependent Gain and Blur

    Energy Technology Data Exchange (ETDEWEB)

    Peng, B; Lubinsky, A; Zheng, H; Zhao, W [Stony Brook University, Stony Brook, NY (United States); Teymurazyan, A [Lakehead University, Thunder Bay, Ontario (Canada)

    2014-06-01

    Purpose: To implement a depth dependent gain and blur cascaded linear system model (CLSM) for optimizing columnar structured CsI indirect conversion flat panel imager (FPI) for advanced imaging applications. Methods: For experimental validation, depth dependent escape efficiency, e(z), was extracted from PHS measurement of different CsI scintillators (thickness, substrate and light output). The inherent MTF and DQE of CsI was measured using high resolution CMOS sensor. For CLSM, e(z) and the depth dependent MTF(f,z), were estimated using Monte Carlo simulation (Geant4) of optical photon transport through columnar CsI. Previous work showed that Monte Carlo simulation for CsI was hindered by the non-ideality of its columnar structure. In the present work we allowed variation in columnar width with depth, and assumed diffusive reflective backing and columns. Monte Carlo simulation was performed using an optical point source placed at different depth of the CsI layer, from which MTF(z,f) and e(z) were computed. The resulting e(z) with excellent matching with experimental measurements were then applied to the CLSM, Monte Carlo simulation was repeated until the modeled MTF, DQE(f) also match experimental measurement. Results: For a 150 micron FOS HL type CsI, e(z) varies between 0.56 to 0.45, and the MTF at 14 cycles/mm varies between 62.1% to 3.9%, from the front to the back of the scintillator. The overall MTF and DQE(f) at all frequencies are in excellent agreement with experimental measurements at all frequencies. Conclusion: We have developed a CLSM for columnar CsI scintillators with depth dependent gain and MTF, which were estimated from Monte Carlo simulation with novel optical simulation settings. Preliminary results showed excellent agreement between simulation results and experimental measurements. Future work is aimed at extending this approach to optimize CsI screen optic design and sensor structure for achieving higher DQE(f) in cone-beam CT, which uses

  8. Digestibilidad del polen de cactáceas columnares en los murciélagos glosofaginos Glossophaga longirostris y Leptonycteris curasoae (Chiroptera:Phyllostomidae

    Directory of Open Access Journals (Sweden)

    Mariana Muñoz-Romo

    2005-06-01

    Full Text Available Para estudiar la asimilación protoplasmática de los granos de polen de cactáceas columnares en dos especies de murciélagos glosofaginos, determinamos el porcentaje de granos de polen vacíos (digeridos en muestras fecales de Glossophaga longirostris y Leptonycteris curasoae , capturados en una zona árida de Venezuela. Para determinar el porcentaje de granos de polen digeridos por los murciélagos, aplicamos un colorante sobre las muestras fecales que permite diferenciar sin dificultad el polen vacio del polen lleno. Después de cuantificar los granos de polen de ambas categorías en las muestras fecales, los valores fueron corregidos tomando en cuenta el porcentaje de polen vacío (previo a la antesis en las flores maduras de las especies de cactáceas columnares (Subpilocereus repandus, Stenocereus griseus y Pilosocereus tillianus . G. longirostris asimila el 64.2% de los granos de polen que ingiere y L. curasoae asimila el 71.3%. Estos elevados porcentajes confirman la importancia del polen en la dieta de estos murciélagos, dado su alto contenido de nitrógenoDigestibility of columnar cacti pollen grains in the glosophagine bats Glossophaga longirostris and Leptonycteris curasoae (Chiroptera: Phyllostomidae. We examined the protoplasmic assimilation of columnar cacti pollen grains in two species of Venezuelan desert glosophagine bats, Glossophaga longirostris and Leptonycteris curasoae, by determining the amount of empty (digested pollen grains found in their fecal samples. To determine the amount of empty pollen grains, the fecal samples were stained to differ between empty and full (non-digested pollen grains. The number of empty and full pollen grains observed in the fecal samples were corrected using the amount of aborted pollens present (before anthesis in flowers of the columnar cacti species (Subpilocereus repandus, Stenocereus griseus and Pilosocereus tillianus used by bats as food in the study site; G. longirostris and L

  9. Diversity and geographical distribution of Flavobacterium psychrophilum isolates and their phages: patterns of susceptibility to phage infection and phage host range.

    Science.gov (United States)

    Castillo, Daniel; Christiansen, Rói Hammershaimb; Espejo, Romilio; Middelboe, Mathias

    2014-05-01

    Flavobacterium psychrophilum is an important fish pathogen worldwide that causes cold water disease (CWD) or rainbow trout fry syndrome (RTFS). Phage therapy has been suggested as an alternative method for the control of this pathogen in aquaculture. However, effective use of bacteriophages in disease control requires detailed knowledge about the diversity and dynamics of host susceptibility to phage infection. For this reason, we examined the genetic diversity of 49 F. psychrophilum strains isolated in three different areas (Chile, Denmark, and USA) through direct genome restriction enzyme analysis (DGREA) and their susceptibility to 33 bacteriophages isolated in Chile and Denmark, thus covering large geographical (>12,000 km) and temporal (>60 years) scales of isolation. An additional 40 phage-resistant isolates obtained from culture experiments after exposure to specific phages were examined for changes in phage susceptibility against the 33 phages. The F. psychrophilum and phage populations isolated from Chile and Denmark clustered into geographically distinct groups with respect to DGREA profile and host range, respectively. However, cross infection between Chilean phage isolates and Danish host isolates and vice versa was observed. Development of resistance to certain bacteriophages led to susceptibility to other phages suggesting that "enhanced infection" is potentially an important cost of resistance in F. psychrophilum, possibly contributing to the observed co-existence of phage-sensitive F. psychrophilum strains and lytic phages across local and global scales. Overall, our results showed that despite the identification of local communities of phages and hosts, some key properties determining phage infection patterns seem to be globally distributed.

  10. Characterization of an Alginate Lyase, FlAlyA, from Flavobacterium sp. Strain UMI-01 and Its Expression in Escherichia coli

    Science.gov (United States)

    Inoue, Akira; Takadono, Kohei; Nishiyama, Ryuji; Tajima, Kenji; Kobayashi, Takanori; Ojima, Takao

    2014-01-01

    A major alginate lyase, FlAlyA, was purified from the periplasmic fraction of an alginate-assimilating bacterium, Flavobacterium sp. strain UMI-01. FlAlyA showed a single band of ~30 kDa on SDS-PAGE and exhibited the optimal temperature and pH at 55 °C and pH 7.7, respectively. Analyses for substrate preference and reaction products indicated that FlAlyA was an endolytic poly(mannuronate) lyase (EC 4.2.2.3). A gene fragment encoding the amino-acid sequence of 288 residues for FlAlyA was amplified by inverse PCR. The N-terminal region of 21 residues except for the initiation Met in the deduced sequence was predicted as the signal peptide and the following region of six residues was regarded as propeptide, while the C-terminal region of 260 residues was regarded as the polysaccharide-lyase-family-7-type catalytic domain. The entire coding region for FlAlyA was subjected to the pCold I—Escherichia coli BL21(DE3) expression system and ~eight times higher yield of recombinant FlAlyA (recFlAlyA) than that of native FlAlyA was achieved. The recFlAlyA recovered in the periplasmic fraction of E. coli had lost the signal peptide region along with the N-terminal 3 residues of propeptide region. This suggested that the signal peptide of FlAlyA could function in part in E. coli. PMID:25153766

  11. Characterization of an Alginate Lyase, FlAlyA, from Flavobacterium sp. Strain UMI-01 and Its Expression in Escherichia coli

    Directory of Open Access Journals (Sweden)

    Akira Inoue

    2014-08-01

    Full Text Available A major alginate lyase, FlAlyA, was purified from the periplasmic fraction of an alginate-assimilating bacterium, Flavobacterium sp. strain UMI-01. FlAlyA showed a single band of ~30 kDa on SDS-PAGE and exhibited the optimal temperature and pH at 55 °C and pH 7.7, respectively. Analyses for substrate preference and reaction products indicated that FlAlyA was an endolytic poly(mannuronate lyase (EC 4.2.2.3. A gene fragment encoding the amino-acid sequence of 288 residues for FlAlyA was amplified by inverse PCR. The N-terminal region of 21 residues except for the initiation Met in the deduced sequence was predicted as the signal peptide and the following region of six residues was regarded as propeptide, while the C-terminal region of 260 residues was regarded as the polysaccharide-lyase-family-7-type catalytic domain. The entire coding region for FlAlyA was subjected to the pCold I—Escherichia coli BL21(DE3 expression system and ~eight times higher yield of recombinant FlAlyA (recFlAlyA than that of native FlAlyA was achieved. The recFlAlyA recovered in the periplasmic fraction of E. coli had lost the signal peptide region along with the N-terminal 3 residues of propeptide region. This suggested that the signal peptide of FlAlyA could function in part in E. coli.

  12. Structure and magnetic properties of columnar Fe-N thin films deposited by direct current magnetron sputtering

    Institute of Scientific and Technical Information of China (English)

    JIA Hui; WANG Xin; PANG Shao-ping; ZHENG Wei-tao; LONG Bei-hong; LI Bo

    2009-01-01

    Columnar Fe-N thin films with thickness ranging from 30 to 150 nm were deposited by direct current magnetron sputtering using an Ar/N2 gas mixture (V(N2)/V(N2+Ar)=5%) on corning glass substrates. The structure, surface morphology and magnetic properties were investigated using X-ray diffractometry(XRD), scanning electron microscopy, atomic force microscopy, transmission electron microscopy(TEM) and superconducting quantum interference magnetometry. XRD investigation shows that Fe-N films exhibit amorphous-like structures; however, TEM measurements indicate the synthesis of mixture phases of α-Fe+ζ-Fe2N+ε-Fe3N in these films. The magnetic anisotropy and coercivity of Fe-N thin films exhibit strong dependence on the film growth behavior and surface morphology. With increasing the height of Fe-N films with column structures, the coercivity increases from 7.96 kA/m to 22.28 kA/m in the direction parallel to the film surface. In perpendicular direction the coercivity only increases slightly from 39.79 kA/m to 43.77 kA/m. However, the values of anisotropy field increase from 0.79×106 to 1.44×106 A/m, which is mainly attributed to the shape anisotropy of elongated columns due to the fact that the difference of magneto-crystalline anisotropy among these Fe-N films is small. The saturation magnetizations of Fe-N films vary with increasing film thickness from 23.5 to 85.1 A-m2/kg.

  13. Study of the correlation between columnar aerosol burden, suspended matter at ground and chemical components in a background European environment

    Science.gov (United States)

    EstelléS, VíCtor; MartíNez-Lozano, José A.; Pey, Jorge; Sicard, MichaëL.; Querol, Xavier; Esteve, Anna R.; Utrillas, MaríA. P.; Sorribas, Mar; Gangoiti, Gotzon; Alastuey, AndréS.; Rocadenbosch, Francesc

    2012-02-01

    Although routinely monitored by ground based air quality networks, the particulate matter distribution could be eventually better described with remote sensing techniques. However, valid relationships between ground level and columnar ground based quantities should be known beforehand. In this study we have performed a comparison between particulate matter measurements at ground level at different cut sizes (10, 2.5 and 1.0 μm), and the aerosol optical depth obtained by means of a ground based sunphotometer during a multiinstrumental field campaign held in El Arenosillo (Huelva, Spain) from 28 June to 4 July 2006. All the PM fractions were very well correlated with AOD with correlation coefficients that ranged from 0.71 to 0.81 for PM10, PM2.5 and PM1. Furthermore, the influence of the mixing layer height in the correlations was explored. The improvement in the correlation when the vertical distribution is taken into account was significant for days with a homogeneous mixing layer. Moreover, the chemical analysis of the individual size fractions allowed us to study the origin of the particulate matter. Secondary components were the most abundant and also well correlated in the three size fractions; but for PM10 fraction, chemical species related to marine origin were best correlated. Finally, we obtained a relationship between MODIS L3 AOD from collection 5.1 and the three PM cut sizes. In spite of being a relatively clean environment, all the techniques were able to capture similar day to day variations during this field campaign.

  14. Daily to decadal patterns of precipitation, humidity, and photosynthetic physiology recorded in the spines of the columnar cactus, Carnegiea gigantea

    Science.gov (United States)

    English, Nathan B.; Dettman, David L.; Sandquist, Darren R.; Williams, David G.

    2010-06-01

    Isotopic analyses of cactus spines grown serially from the apex of long-lived columnar cactuses may be useful for climatological and ecological studies if time series can be reliably determined from spines. To characterize the timescales over which spines may record this information, we measured spine growth in saguaro cactus over days, months, and years with time-lapse photography, periodic marking, and postbomb radiocarbon dating and then analyzed isotopic variability over these same timescales and compared these measurements to local climate. We used daily increments of growth, visible as transverse bands of light and dark tissue in spines, as chronometers to develop diurnally resolved δ13C and δ18O records from three spines grown in series over a 70 day period. We also constructed a 22 year record of δ13C variations from spine tips arranged in chronological sequence along the side of a 4 m tall, single-stemmed saguaro. We evaluated two mechanisms potentially responsible for daily, weekly, and annual variability in δ13C values of spines; both related to vapor pressure deficit (VPD). Our data suggest that stomatal conductance is unlikely to be the determinant of δ13C variation in spines. We suggest that either VPD-induced changes in the balance of nighttime- and daytime-assimilated CO2 or mesophyll-limited diffusion of CO2 at night are the most likely determinant of δ13C variation in spines. Intra-annual and interannual variability of δ18O in spine tissue appears to be controlled by the mass balance of 18O-depleted water taken up after rain events and evaporative enrichment of 18O in tissue water between rains. We were able to estimate the annual growth and areole generation rate of a saguaro cactus from its 22 yearlong isotopic record because VPD, rainfall, and evaporation exhibit strong annual cycles in the Sonoran Desert and these variations are recorded in the oxygen and carbon isotope ratios of spines.

  15. Improved Aerosol Optical Thickness, Columnar Water Vapor, and Surface Reflectance Retrieval from Combined CASI and SASI Airborne Hyperspectral Sensors

    Directory of Open Access Journals (Sweden)

    Hang Yang

    2017-02-01

    Full Text Available An increasingly common requirement in remote sensing is the integration of hyperspectral data collected simultaneously from different sensors (and fore-optics operating across different wavelength ranges. Data from one module are often relied on to correct information in the other, such as aerosol optical thickness (AOT and columnar water vapor (CWV. This paper describes problems associated with this process and recommends an improved strategy for processing remote sensing data, collected from both visible to near-infrared and shortwave infrared modules, to retrieve accurate AOT, CWV, and surface reflectance values. This strategy includes a workflow for radiometric and spatial cross-calibration and a method to retrieve atmospheric parameters and surface reflectance based on a radiative transfer function. This method was tested using data collected with the Compact Airborne Spectrographic Imager (CASI and SWIR Airborne Spectrographic Imager (SASI from a site in Huailai County, Hebei Province, China. Various methods for retrieving AOT and CWV specific to this region were assessed. The results showed that retrieving AOT from the remote sensing data required establishing empirical relationships between 465.6 nm/659 nm and 2105 nm, augmented by ground-based reflectance validation data, and minimizing the merit function based on AOT@550 nm optimization. The paper also extends the second-order difference algorithm (SODA method using Powell’s methods to optimize CWV retrieval. The resulting CWV image has fewer residual surface features compared with the standard methods. The derived remote sensing surface reflectance correlated significantly with the ground spectra of comparable vegetation, cement road and soil targets. Therefore, the method proposed in this paper is reliable enough for integrated atmospheric correction and surface reflectance retrieval from hyperspectral remote sensing data. This study provides a good reference for surface

  16. Effect of habitat disturbance on pollination biology of the columnar cactus Stenocereus quevedonis at landscape-level in central Mexico.

    Science.gov (United States)

    Rodríguez-Oseguera, A G; Casas, A; Herrerías-Diego, Y; Pérez-Negrón, E

    2013-05-01

    Stenocereus quevedonis ('pitire') is a columnar cactus endemic to central Mexico, grown for its edible fruit. Phenology, pollination biology and behaviour of flower visitors of this species were compared in six conserved and disturbed sites, hypothesising that: (i) pitire pollination is self-incompatible, requiring animal vectors; (ii) higher incidence of radiation on plants in cleared forest may lead to a higher number of flowers per pitire plant and longer blooming season, and disturbing and differential spatial availability of flower resources may determine differential attraction of pollinators to conserved and disturbed areas; (iii) if pitire pollination system is specialised, reproductive success would decrease with pollinator scarcity, or other species may substitute for main pollinators. In all sites, pitire reproduction started in January, flowering peak occurring in April, anthesis duration was 15 h and predominantly nocturnal (9 h), pollen was released at 23:00 h, nectar was produced throughout anthesis, and breeding system was self-incompatible. Flower production per plant was similar in disturbed and conserved sites, but flower availability was higher (because of higher tree density) and longer in disturbed sites. Pollination is nocturnal, the most frequent legitimate pollinator being the bat Leptonycteris yerbabuenae; diurnal pollination is rare but possible, carried out by bee species. Fruit and seed set in control and nocturnal pollination treatments at disturbed sites were higher than in conserved sites. Frequency of L. yerbabuenae visits was similar among site types, but more visits of complementary nocturnal and diurnal pollinators were recorded in disturbed sites, which could explain differences in reproductive success.

  17. Effects of monovalent cation doping on the structure, microstructure, lattice distortion and magnetic behavior of single crystalline NdMnO3 compounds.

    Science.gov (United States)

    Nandy, Anshuman; Pradhan, S K

    2015-10-21

    Pure and 15 mol% Na, K-doped NdMnO3 compounds with perovskite structures are prepared by sol-gel method. Tiny single crystals are formed after sintering the compounds at 1000 °C. The effect of Na and K doping as well as the effect of sintering temperature on the formation and microstructure of NdMnO3 are studied in detail by the Rietveld refinement technique using X-ray powder diffraction data. Single phase formation and single crystalline growth are also confirmed by high resolution transmission electron microscopy (HRTEM). Bond angles and bond lengths are calculated and shown by 3D diagrams. Monovalent doping induces noticeable changes in the microstructure and yields better structural stability in these compounds. Doping results in the change of Mn-O, Nd-O and Mn-O-Mn bond lengths which in turn reduces the lattice and octahedral distortion in the system along with an increase in the tolerance factor. The magnetic properties of these compounds are also modified as a result of doping. The temperature dependent magnetization results show that the Neel temperature of antiferromagnetic NdMnO3 compound is 67.2 K and the Curie temperatures of ferromagnetic Nd0.85Na0.15MnO3 and Nd0.85K0.15MnO3 compounds are 99.1 K and 98.6 K respectively. Both 15% Na and K doping results in a similar TC in doped NdMnO3 compounds.

  18. Adverse events following pandemic A (H1N1 2009 monovalent vaccines in pregnant women--Taiwan, November 2009-August 2010.

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    Wan-Ting Huang

    Full Text Available BACKGROUND: During the 2009 H1N1 pandemic, pregnant women were prioritized to receive the unadjuvanted or MF59®-adjuvanted pandemic A (H1N1 2009 monovalent vaccines ("2009 H1N1 vaccines" in Taiwan regardless of stage of pregnancy. Monitoring adverse events following 2009 H1N1 vaccination in pregnant women was a priority for the mass immunization campaign beginning November 2009. METHODS/FINDINGS: We characterized reports to the national passive surveillance from November 2009 through August 2010 involving adverse events following 2009 H1N1 vaccines among pregnant women. Reports from the passive surveillance were matched to a large-linked database on a unique identifier, date of vaccination, and date of diagnosis in a capture-recapture analysis to estimate the true number of spontaneous abortion after 2009 H1N1 vaccination. We verified 16 spontaneous abortions, 11 stillbirths, 4 neonatal deaths, 4 nonpregnancy-specific adverse events, and 2 inadvertent immunizations in recipients who were unaware of pregnancy at time of vaccination. The Chapman capture-recapture estimator of true number of spontaneous abortion after 2009 H1N1 vaccination was 329 (95% confidence interval [CI] 196-553. Of the 14,474 pregnant women who received the 2009 H1N1 vaccines, the estimated risk of spontaneous abortion was 2.3 (95% CI, 1.4-3.8 per 100 pregnancies, compared with a local background rate of 12.8 (95% CI, 12.8-12.9 per 100 pregnancies. CONCLUSIONS: The passive surveillance provided rapid initial assessment of adverse events after 2009 H1N1 vaccination among pregnant women. Its findings were reassuring for the safety of 2009 H1N1 vaccines in pregnancy.

  19. Cloning and identification of Group 1 mrp operon encoding a novel monovalent cation/proton antiporter system from the moderate halophile Halomonas zhaodongensis.

    Science.gov (United States)

    Meng, Lin; Hong, Shan; Liu, Henan; Huang, Haipeng; Sun, Hao; Xu, Tong; Jiang, Juquan

    2014-11-01

    The novel species Halomonas zhaodongensis NEAU-ST10-25(T) recently identified by our group is a moderate halophile which can grow at the range of 0-2.5 M NaCl (optimum 0.5 M) and pH 6-12 (optimum pH 9). To explore its halo-alkaline tolerant mechanism, genomic DNA was screened from NEAU-ST10-25(T) in this study for Na(+)(Li(+))/H(+) antiporter genes by selection in Escherichia coli KNabc lacking three major Na(+)(Li(+))/H(+) antiporters. One mrp operon could confer tolerance of E. coli KNabc to 0.8 M NaCl and 100 mM LiCl, and an alkaline pH. This operon was previously mainly designated mrp (also mnh, pha or sha) due to its multiple resistance and pH-related activity. Here, we will also use mrp to designate the homolog from H. zhaodongensis (Hz_mrp). Sequence analysis and protein alignment showed that Hz_mrp should belong to Group 1 mrp operons. Further phylogenetic analysis reveals that Hz_Mrp system should represent a novel sub-class of Group 1 Mrp systems. This was confirmed by a significant difference in pH-dependent activity profile or the specificity and affinity for the transported monovalent cations between Hz_Mrp system and all the known Mrp systems. Therefore, we propose that Hz_Mrp should be categorized as a novel Group 1 Mrp system.

  20. Comparison of accelerated and rapid schedules for monovalent hepatitis B and combined hepatitis A/B vaccines in children with cancer.

    Science.gov (United States)

    Köksal, Yavuz; Varan, Ali; Aydin, G Burca; Sari, Neriman; Yazici, Nalan; Yalcin, Bilgehan; Kutluk, Tezer; Akyuz, Canan; Büyükpamukçu, Münevver

    2007-12-01

    The aim of this study was to determine the efficacy of immunization against hepatitis A and B infections with "rapid" or "accelerated" schedules in children with cancer receiving chemotherapy. Fifty-one children were recruited to receive either vaccination schedule, in the "rapid vaccination schedule"; hepatitis B (group I) or combined hepatitis A/B vaccines (group III) were administered at months 0, 1, 2, and 12; in the "accelerated vaccination schedule," hepatitis B (group II) or combined hepatitis A/B (group IV) vaccines were administered on days 0, 7, 21, and 365 intramuscularly. The seroconversion rates at months 1 and 3 were 35.7 and 57.1% in group I and 25 and 18.8% in group II, respectively. Group I developed higher seroconversion rates at month 3. In group III the seroconversion rates for hepatitis B at months 1 and 3 were 54.5 and 60% and in group IV 50 and 70%, respectively. For hepatitis A, the seroconversion rates at months 1 and 3 were 81.8 and 90% in group III and 80 and 88.9% in group IV, respectively. The accelerated vaccination schedule seems to have no advantage in children receiving cancer chemotherapy except for high antibody levels at month 1. In conclusion, the accelerated vaccination schedules are not good choices for cancer patients. The combined hepatitis A/B vaccine is more effective than monovalent vaccine in cancer patients, which probably can be explained by an adjuvant effect of the antigens. The seroconversion of hepatitis A by the combined hepatitis A/B vaccination is very good in cancer patients.

  1. Growing large columnar grains of CH3NH3PbI3 using the solid-state reaction method enhanced by less-crystallized nanoporous PbI2 films

    Science.gov (United States)

    Zheng, Huifeng; Wang, Weiqi; Liu, Yangqiao; Sun, Jing

    2017-03-01

    Compact, pinhole-free and PbI2-free perovskite films, are desirable for high-performance perovskite solar cells (PSCs), especially if large columnar grains are obtained in which the adverse effects of grain boundaries will be minimized. However, the conventional solid-state reaction methods, originated from the two-step method, failed to grow columnar grains of CH3NH3PbI3 in a facile way. Here, we demonstrate a strategy for growing large columnar grains of CH3NH3PbI3, by less-crystallized nanoporous PbI2 (ln-PbI2) film enhanced solid-state reaction method. We demonstrated columnar grains were obtainable only when ln-PbI2 films were applied. Therefore, the replacement of compact PbI2 by ln-PbI2 in the solid-sate reaction, leads to higher power conversion efficiency, better reproducibility, better stability and less hysteresis. Furthermore, by systematically investigating the effects of annealing temperature and duration, we found that an annealing temperature ≥120 °C was also critical for growing columnar grains. With the optimal process, a champion efficiency of 16.4% was obtained and the average efficiency reached 14.2%. Finally, the mechanism of growing columnar grains was investigated, in which a VPb″ -assisted hooping model was proposed. This work reveals the origins of grain growth in the solid-state reaction method, which will contribute to preparing high quality perovskite films with much larger columnar grains.

  2. Some features of columnar aerosol optical depth, ozone and precipitable water content observed over land during the INDOEX-IFP99

    Directory of Open Access Journals (Sweden)

    Panuganti China Sattilingam Devara

    2001-04-01

    Full Text Available Columnar aerosol optical depth (AOD, ozone and precipitable water content measurements have been made under different atmospheric conditions on a total of 46 days at the Indian Institute of Tropical Meteorology (IITM, Pune during the Intensive Field Phase (IFP of the Indian Ocean Experiment INDOEX (January-March 1999. These observations have been obtained using two compact, on-line, multi-band solar radiometers (MICROTOPS-II simultaneously. The results indicate higher aerosol optical depth (more than double on hazy days as compared to clear stable days. Further increase in aerosol optical depth and markable changes in the size spectrum are also noticed during the occasions of smoke particles' emission from combustion processes in proximity to the experimental site and high water content in the atmosphere. Size spectra of aerosols exhibit characteristic bimodal distribution with mode radii between 0.1 and 1.0 μm on the days associated with hazy-sky conditions and combustion activity. However, the mean aerosol optical depth over the entire IFP shows almost exponential decrease with increase in wavelength, and corresponding size spectrum portrays power law distribution, which may be due to the averaging effect of time variations such as forenoon, afternoon and day-to-day. Moreover, the daily values of columnar aerosol optical depth and water content show almost similar variations. Besides an increasing trend in the total column ozone variations throughout the period of study, it shows opposite variation with those observed in AOD and water content. These interesting features reveal the influence of water content on the growth processes of aerosol particles, and relationship between the increase in aerosol extinction and reduction in ozone amount and vice versa. The columnar aerosol optical depth or content or loading during the IFP99 exhibit higher values as compared to those during the First Field Phase (FFP98.

  3. Analysis of the columnar radiative properties retrieved during African desert dust events over Granada (2005-2010) using principal plane sky radiances and spheroids retrieval procedure

    Science.gov (United States)

    Valenzuela, A.; Olmo, F. J.; Lyamani, H.; Antón, M.; Quirantes, A.; Alados-Arboledas, L.

    2012-02-01

    The southern Iberian Peninsula is an important area for studying the columnar radiative properties of African desert dust air masses reaching Europe. The Aerosol Optical Depth (AOD) and Angström coefficient, α (440-1020 nm), have been retrieved during the dust events reached at surface from 2005 to 2010 at Granada (37.18°N, 3.58°W, 680 m a.m.s.l), using extinction measurements by means of a CIMEL CE 318-1 sun-photometer. In addition, sky radiance measurements performed in principal plane in conjunction with solar irradiance measurements were used to retrieve columnar aerosol size distributions, single scattering albedo and asymmetry parameter. During these desert dust intrusions, high values of AOD at 440 nm (0.27 ± 0.17) and low values of α (0.4 ± 0.2) were found. These values indicate both high aerosol load and predominance of coarse particles during these events. The aerosol volume size distributions were bimodal, with the fine and coarse radius mode centered at 0.20 μm and 2.41 μm, respectively. The mean coarse to fine volume concentration ratio value was 11 ± 6, showing a predominance of coarse particles in good agreement with α analysis. During these events, columnar aerosol single scattering albedo (ω0) increased with wavelength in accordance with previous works. However, the obtained values of ω0 in all wavelengths were lower than those reported by other authors during desert dust intrusions. The mixing of desert dust with absorbing particles from anthropogenic origin could explain the low ω0 values measured in the study area.

  4. Ultrasonic Characterization of Cast Austenitic Stainless Steel Microstructure: Discrimination between Equiaxed- and Columnar-Grain Material – An Interim Study

    Energy Technology Data Exchange (ETDEWEB)

    Ramuhalli, Pradeep; Good, Morris S.; Diaz, Aaron A.; Anderson, Michael T.; Watson, Bruce E.; Peters, Timothy J.; Dixit, Mukul; Bond, Leonard J.

    2009-10-27

    Ultrasonic nondestructive evaluation (NDE) and inspection of cast austenitic stainless steel (CASS) components used in the nuclear power industry is neither as effective nor reliable as is needed due to detrimental effects upon the interrogating ultrasonic beam and interference from ultrasonic backscatter. The root cause is the coarse-grain microstructure inherent to this class of materials. Some ultrasonic techniques perform better for particular microstructural classifications and this has led to the hypothesis that an ultrasonic inspection can be optimized for a particular microstructural class, if a technique exists to reliably classify the microstructure for feedback to the inspection. This document summarizes scoping experiments of in-situ ultrasonic methods for classification and/or characterization of the material microstructures in CASS components from the outside surface of a pipe. The focus of this study was to evaluate ultrasonic methods and provide an interim report that documents results and technical progress. An initial set of experiments were performed to test the hypothesis that in-service characterization of cast austenitic stainless steel (CASS) is feasible, and that, if reliably performed, such data would provide real-time feedback to optimize in-service inspections in the field. With this objective in mind, measurements for the experiment were restricted to techniques that should be robust if carried forward to eventual field implementation. Two parameters were investigated for their ability to discriminate between different microstructures in CASS components. The first parameter was a time-of-flight ratio of a normal incidence shear wave to that of a normal incidence longitudinal wave (TOFRSL). The ratio removed dependency on component thickness which may not be accurately reported in the field. The second parameter was longitudinal wave attenuation. The selected CASS specimens provided five equiaxed-grain material samples and five columnar

  5. Detection and Quantification of Flavobacterium psychrophilum-Specific Bacteriophages In Vivo in Rainbow Trout upon Oral Administration: Implications for Disease Control in Aquaculture

    Science.gov (United States)

    Christiansen, Rói Hammershaimb; Dalsgaard, Inger; Middelboe, Mathias; Lauritsen, Anne H.

    2014-01-01

    The use of bacteriophages in the treatment and prevention of infections by the fish pathogen Flavobacterium psychrophilum has attracted increased attention in recent years. It has been shown recently that phage delivery via the parenteral route resulted in immediate distribution of phages to the circulatory system and the different organs. However, little is known about phage dispersal and survival in vivo in rainbow trout after delivery via the oral route. Here we examined the dispersal and survival of F. psychrophilum phage FpV-9 in vivo in juvenile rainbow trout after administration by three different methods—bath, oral intubation into the stomach, and phage-coated feed—with special emphasis on the oral route of delivery. Phages could be detected in all the organs investigated (intestine, spleen, brain, and kidney) 0.5 h postadministration, reaching concentrations as high as ∼105 PFU mg intestine−1 and ∼103 PFU mg spleen−1 within the first 24 h following the bath and ∼107 PFU mg intestine−1 and ∼104 PFU mg spleen−1 within the first 24 h following oral intubation. The phages were most persistent in the organs for the first 24 h and then decreased exponentially; no phages were detected after 83 h in the organs investigated. Phage administration via feed resulted in the detection of phages in the intestine, spleen, and kidney 1 h after feeding. Average concentrations of ∼104 PFU mg intestine−1 and ∼101 PFU mg spleen−1 were found throughout the experimental period (200 h) following continuous delivery of phages with feed. These experiments clearly demonstrate the ability of the phages to survive passage through the fish stomach and to penetrate the intestinal barrier and enter the circulatory system after oral delivery, although the quantity of phages found in the spleen was 100- to 1,000-fold lower than that in the intestine. It was also shown that phages could tolerate long periods of desiccation on the feed pellets, with 60% survival

  6. Detection and quantification of Flavobacterium psychrophilum-specific bacteriophages in vivo in rainbow trout upon oral administration: implications for disease control in aquaculture.

    Science.gov (United States)

    Christiansen, Rói Hammershaimb; Dalsgaard, Inger; Middelboe, Mathias; Lauritsen, Anne H; Madsen, Lone

    2014-12-01

    The use of bacteriophages in the treatment and prevention of infections by the fish pathogen Flavobacterium psychrophilum has attracted increased attention in recent years. It has been shown recently that phage delivery via the parenteral route resulted in immediate distribution of phages to the circulatory system and the different organs. However, little is known about phage dispersal and survival in vivo in rainbow trout after delivery via the oral route. Here we examined the dispersal and survival of F. psychrophilum phage FpV-9 in vivo in juvenile rainbow trout after administration by three different methods-bath, oral intubation into the stomach, and phage-coated feed-with special emphasis on the oral route of delivery. Phages could be detected in all the organs investigated (intestine, spleen, brain, and kidney) 0.5 h postadministration, reaching concentrations as high as ∼10(5) PFU mg intestine(-1) and ∼10(3) PFU mg spleen(-1) within the first 24 h following the bath and ∼10(7) PFU mg intestine(-1) and ∼10(4) PFU mg spleen(-1) within the first 24 h following oral intubation. The phages were most persistent in the organs for the first 24 h and then decreased exponentially; no phages were detected after 83 h in the organs investigated. Phage administration via feed resulted in the detection of phages in the intestine, spleen, and kidney 1 h after feeding. Average concentrations of ∼10(4) PFU mg intestine(-1) and ∼10(1) PFU mg spleen(-1) were found throughout the experimental period (200 h) following continuous delivery of phages with feed. These experiments clearly demonstrate the ability of the phages to survive passage through the fish stomach and to penetrate the intestinal barrier and enter the circulatory system after oral delivery, although the quantity of phages found in the spleen was 100- to 1,000-fold lower than that in the intestine. It was also shown that phages could tolerate long periods of desiccation on the feed pellets, with 60

  7. Antimicrobial Susceptibility of Flavobacterium psychrophilum from Chilean Salmon Farms and their Epidemiological Cut-off Values using Agar Dilution and Disk Diffusion Methods

    Directory of Open Access Journals (Sweden)

    Claudio D Miranda

    2016-11-01

    Full Text Available Flavobacterium psychrophilum is the most important bacterial pathogen for freshwater farmed salmonids in Chile. The aims of this study were to determine the susceptibility to antimicrobials used in fish farming of Chilean isolates and to calculate their epidemiological cut-off (COWT values. A number of 125 Chilean isolates of F. psychrophilum were isolated from reared salmonids presenting clinical symptoms indicative of flavobacteriosis and their identities were confirmed by 16S rRNA polymerase chain reaction. Susceptibility to antibacterials was tested on diluted Mueller-Hinton by using an agar dilution MIC method and a disk diffusion method. The COWT values calculated by Normalised Resistance Interpretation (NRI analysis allow isolates to be categorized either as wild-type fully susceptible (WT or as manifesting reduced susceptibility (NWT. When MIC data was used, NRI analysis calculated a COWT of ≤ 0.125 μg mL-1, ≤ 2 μg mL-1 and ≤ 0.5 μg mL-1 for amoxicillin, florfenicol and oxytetracycline, respectively. For the quinolones, the COWT were ≤1 μg mL-1, ≤ 0.5 μg mL-1 and ≤ 0.125 μg mL-1 for oxolinic acid, flumequine and enrofloxacin respectively. The disc diffusion data sets obtained in this work were extremely diverse and were spread over a wide range. For the quinolones there was a close agreement between the frequencies of NWT isolates calculated using MIC and disc data. For oxolinic acid, flumequine and enrofloxacin the frequencies were 45, 39 and 38% using MIC data, and 42, 41 and 44%, when disc data were used. There was less agreement with the other antimicrobials, because NWT frequencies obtained using MIC and disc data respectively, were 24% and 10% for amoxicillin, 8% and 2% for florfenicol and 70% and 64% for oxytetracycline. Considering that the MIC data was more precise than the disc diffusion data, MIC determination would be the preferred method for susceptibility testing for this species and the NWT frequencies

  8. Dispersal and survival of Flavobacterium psychrophilum phages in vivo in rainbow trout and in vitro under laboratory conditions: implications for their use in phage therapy.

    Science.gov (United States)

    Madsen, Lone; Bertelsen, Sif K; Dalsgaard, Inger; Middelboe, Mathias

    2013-08-01

    Attention has been drawn to phage therapy as an alternative approach for controlling pathogenic bacteria such as Flavobacterium psychrophilum in salmonid aquaculture, which can give rise to high mortalities, especially in rainbow trout fry. Recently, phages have been isolated with a broad host range and a strong lytic potential against pathogenic F. psychrophilum under experimental conditions. However, little is known about the fate of phages at environmental conditions. Here, we quantified the dispersal and fate of F. psychrophilum phages and hosts in rainbow trout fry after intraperitoneal injection. Both phages and bacteria were isolated from the fish organs for up to 10 days after injection, and coinjection with both bacteria and phages resulted in a longer persistence of the phage in the fish organs, than when the fish had been injected with the phages only. The occurrence of both phage and bacterium was most prevalent in the kidney and spleen, with only minor occurrence in the brain. The experiment showed that injected phages were rapidly spread in the internal organs of the fish, also in the absence of bacteria. Parallel examination of the regulation of bacteriophage infectivity in controlled laboratory experiments at various environmental conditions showed that pH had only minor effects on long-term (3 months) phage infectivity within a pH range of 4.5 to 7.5, whereas phage infectivity was immediately lost at pH 3. In the absence of host cells, phage infectivity decreased by a factor of 10,000 over 55 days in untreated pond water, while the sterilization and removal of particles caused a 100-fold increase in phage survival relative to the control. In addition, F. psychrophilum-specific phages maintained their infectivity for ∼2 months in glycerol at -80°C, whereas infectivity decreased by a factor 10 when kept in a buffer at 20°C. Only a very small degradation in infectivity was seen when bacteriophages were added and dried on fish feed pellets

  9. Proinflammatory cytokine and cytokine receptor gene expression kinetics following challenge with Flavobacterium psychrophilum in resistant and susceptible lines of rainbow trout (Oncorhynchus mykiss).

    Science.gov (United States)

    Kutyrev, Ivan; Cleveland, Beth; Leeds, Timothy; Wiens, Gregory D

    2016-11-01

    Flavobacterium psychrophilum (Fp) is the causative agent of bacterial cold water disease (BCWD) which causes appreciable economic losses in rainbow trout aquaculture. We previously reported development of a genetic line, designated ARS-Fp-R that exhibits higher survival relative to a susceptible line, designated ARS-Fp-S, following either laboratory or natural on-farm challenge. The objectives of this study were to determine the temporal kinetics of gene expression between experimentally-challenged ARS-Fp-R and ARS-Fp-S fish and the correlation between gene expression and pathogen load. We developed a GeXP multiplex RT-PCR assay to simultaneously examine expression of immune-relevant genes, concentrating on tumor necrosis factor and interleukin-1 ligand/receptor systems and acute phase response genes. Spleen tissue was sampled at 6 h, 24 h, 48 h and 144 h post-challenge and pathogen load quantified by qPCR. Transcript abundance of cytokine genes tnfa1, tnfa2, tnfa3, il1b1, il1b2, il11a; acute phase response genes saa and drtp1; and putative cytokine receptors il1r1-like-b, il1r2, tnfrsf1a, tnfrsf9, tnfrsf1a-like-b increased following challenge while the transcript abundance of il1r-like-1 and tnfrsf1a-like-a decreased compared to PBS-injected line-matched control fish. Principal component analysis identified transcript levels of genes il1r-like-1 and tnfrsf1a-like-a as exhibiting differential expression between genetic lines. In summary, Fp i.p. injection challenge elicited a proinflammatory cytokine gene expression response in the spleen, with ARS-Fp-R line fish exhibiting modestly higher basal expression levels of several putative cytokine receptors. This study furthers the understanding of the immune response following Fp challenge and differences in gene expression associated with selective breeding for disease resistance.

  10. Preliminary results: surveillance for Guillain-Barré syndrome after receipt of influenza A (H1N1) 2009 monovalent vaccine - United States, 2009-2010.

    Science.gov (United States)

    2010-06-01

    Guillain-Barré syndrome (GBS) is an uncommon peripheral neuropathy causing paralysis and in severe cases respiratory failure and death. GBS often follows an antecedent gastrointestinal or upper respiratory illness but, in rare cases, can follow vaccination. In 1976, vaccination against a novel swine-origin influenza A (H1N1) virus was associated with a statistically significant increased risk for GBS in the 42 days after vaccination (approximately 10 excess cases per 1 million vaccinations), a consideration in halting the vaccination program in the context of limited influenza virus transmission. To monitor influenza A (H1N1) 2009 monovalent vaccine safety, several federal surveillance systems, including CDC's Emerging Infections Program (EIP), are being used. In October 2009, EIP began active surveillance to assess the risk for GBS after 2009 H1N1 vaccination. Preliminary results from an analysis in EIP comparing GBS patients hospitalized through March 31, 2010, who did and did not receive 2009 H1N1 vaccination showed an estimated age-adjusted rate ratio of 1.77 (GBS incidence of 1.92 per 100,000 person-years among vaccinated persons and 1.21 per 100,000 person-years among unvaccinated persons). If end-of-surveillance analysis confirms this finding, this would correspond to 0.8 excess cases of GBS per 1 million vaccinations, similar to that found in seasonal influenza vaccines. No other federal system to date has detected a statistically significant association between GBS and 2009 H1N1 vaccination. Surveillance and further analyses are ongoing. The 2009 H1N1 vaccine safety profile is similar to that for seasonal influenza vaccines, which have an excellent safety record. Vaccination remains the most effective method to prevent serious illness and death from 2009 H1N1 influenza infection; illness from the 2009 H1N1 influenza virus has been associated with a hospitalization rate of 222 per 1 million and a death rate of 9.7 per 1 million population.

  11. Plant Natural Compounds with Antibacterial Activity Towards Common Pathogens of Pond-Cultured Channel Catfish (Ictalurus punctatus)

    Science.gov (United States)

    The bacteria Edwardsiella ictaluri and Flavobacterium columnare cause enteric septicemia and columnaris disease, respectively, in channel catfish (Ictalurus punctatus). Natural therapeutants may provide an alternative to current management approaches used by producers. In this study, a rapid bioas...

  12. Solid-state 13C NMR study of banana liquid crystals - 3: Alkyl-tail-group packing environments of an acute-angle bent-core molecule in the hexagonal columnar and cubic phases

    Science.gov (United States)

    Kurosu, Hiromichi; Endo, Yumi; Kimura, Saori; Hashimoto, Tomoko; Harada, Motoi; Lee, Eun-Woo; Sone, Masato; Watanabe, Junji; Kang, Sungmin

    2016-02-01

    Solid-state 13C nuclear magnetic resonance (NMR) measurements were performed on the hexagonal columnar and cubic phases of an acute-angle banana-shaped molecule, N(1,7)-S30. In the hexagonal columnar phase, three peaks appear at the NMR chemical shifts assigned to the internal methylene carbons of alkyl tails, indicating that the two alkyl tails have different packing structures, and one of the tails has two different conformations within a single molecule. Combined cross-polarization/magic-angle spinning and pulse saturation transfer/magic-angle spinning measurements show that one of the alkyl chains is located inside and the other is located outside the columnar structure. In the cubic phase, pulse saturation transfer/magic-angle spinning measurement shows that only one peak appears at the NMR chemical shifts assigned to the internal methylene carbons of alkyl tails, indicating that both of the alkyl chains are located outside the cubic structure.

  13. The schizophrenia- and autism-associated gene, transcription factor 4 regulates the columnar distribution of layer 2/3 prefrontal pyramidal neurons in an activity-dependent manner.

    Science.gov (United States)

    Page, S C; Hamersky, G R; Gallo, R A; Rannals, M D; Calcaterra, N E; Campbell, M N; Mayfield, B; Briley, A; Phan, B N; Jaffe, A E; Maher, B J

    2017-03-14

    Disruption of the laminar and columnar organization of the brain is implicated in several psychiatric disorders. Here, we show in utero gain-of-function of the psychiatric risk gene transcription factor 4 (TCF4) severely disrupts the columnar organization of medial prefrontal cortex (mPFC) in a transcription- and activity-dependent manner. This morphological phenotype was rescued by co-expression of TCF4 plus calmodulin in a calcium-dependent manner and by dampening neuronal excitability through co-expression of an inwardly rectifying potassium channel (Kir2.1). For we believe the first time, we show that N-methyl-d-aspartate (NMDA) receptor-dependent Ca(2+) transients are instructive to minicolumn organization because Crispr/Cas9-mediated mutation of NMDA receptors rescued TCF4-dependent morphological phenotypes. Furthermore, we demonstrate that the transcriptional regulation by the psychiatric risk gene TCF4 enhances NMDA receptor-dependent early network oscillations. Our novel findings indicate that TCF4-dependent transcription directs the proper formation of prefrontal cortical minicolumns by regulating the expression of genes involved in early spontaneous neuronal activity, and thus our results provides insights into potential pathophysiological mechanisms of TCF4-associated psychiatric disorders.Molecular Psychiatry advance online publication, 14 March 2017; doi:10.1038/mp.2017.37.

  14. An analytical approach to the light transport in columnar phosphors. Detector Optical Gain, angular distribution and the CsI:Tl paradigm.

    Science.gov (United States)

    Psichis, Konstantinos; Kalyvas, Nektarios; Kandarakis, Ioannis; Panayiotakis, George

    2017-03-01

    An analytical model has been developed for the light propagation in columnar phosphors, based on the optical photon propagation physical and geometrical principles. This model accounts for the multiple reflections on the sides of the crystal column, as well as for the infinite forward and backward reflections of the propagated optical photon beams created in the crystal bulk. Additionally it considers the lateral propagated optical photon beams after multiple refractions from the neighbor columns and the optical photon attenuation inside the scintillator. The model was used to predict the Detector Optical Gain (DOG), and the angular distribution, of the columnar CsI:Tl scintillators, used in medical imaging. The model was validated against CsI:Tl optical photon transmission published results and good agreement was observed. It was, also, found that the DOG is affected by the length of the columns, as well as the incident X-ray energy spectrum. The results of the angular distribution are in accordance with the theory that the longer crystal columns have more directional light distribution. The results of DOG are in accordance with the use of short crystal columns for lower energies (mammography) and the use of long crystal columns for higher energies (general radiology). Angular distribution was found more directive for long crystal columns. Copyright © 2017 Associazione Italiana di Fisica Medica. Published by Elsevier Ltd. All rights reserved.

  15. The importance of orientation in proton transport of a polymer film based on an oriented self-organized columnar liquid-crystalline polyether

    Energy Technology Data Exchange (ETDEWEB)

    Tylkowski, Bartosz; Castelao, Nuria [Departament d' Enginyeria Quimica, Universitat Rovira i Virgili, Av. Paiesos Catalans, 26, E-43007, Tarragona (Spain); Giamberini, Marta, E-mail: marta.giamberini@urv.net [Departament d' Enginyeria Quimica, Universitat Rovira i Virgili, Av. Paiesos Catalans, 26, E-43007, Tarragona (Spain); Garcia-Valls, Ricard [Departament d' Enginyeria Quimica, Universitat Rovira i Virgili, Av. Paiesos Catalans, 26, E-43007, Tarragona (Spain); Reina, Jose Antonio [Departament de Quimica Analitica i Quimica Organica, Universitat Rovira i Virgili, Carrer Marcel.li Domingo s/n, E-43007, Tarragona (Spain); Gumi, Tania [Departament d' Enginyeria Quimica, Universitat Rovira i Virgili, Av. Paiesos Catalans, 26, E-43007, Tarragona (Spain)

    2012-02-01

    We prepared membranes based on a liquid-crystalline side-chain polyether obtained by chemical modification of commercial poly(epichlorohydrin) (PECH) with dendrons. This polymer exhibited a columnar structure, which could form an ion channel in the inner part. The columns were successfully oriented by taking advantage of surface interactions between the polymer and hydrophilic substrates, as confirmed by X-ray diffraction analysis (XRD), environmental scanning electron microscopy (ESEM) and optical microscopy between crossed polars (POM). Column orientation was found to be crucial for effective transport: the oriented membranes exhibited proton transport comparable to that of Nafion Registered-Sign N117 and no water uptake. An increase in sodium ion concentration in the feed phase suggested a proton/cation antiport. On the contrary, no proton transport was detected on unoriented membranes based on the same liquid-crystalline side-chain polyether or on unmodified PECH. - Highlights: Black-Right-Pointing-Pointer We prepared oriented membranes based on a liquid crystalline columnar polyether. Black-Right-Pointing-Pointer In this structure, the inner polyether chain could work as an ion channel. Black-Right-Pointing-Pointer We obtained membranes by casting a chloroform solution in the presence of water. Black-Right-Pointing-Pointer Membranes showed good proton permeability due to the presence of oriented channels.

  16. Magnetic susceptibility and electron magnetic resonance study of monovalent potassium doped manganites Pr{sub 0.6}Sr{sub 0.4−x}K{sub x}MnO{sub 3}

    Energy Technology Data Exchange (ETDEWEB)

    Thaljaoui, R., E-mail: thaljaoui@gmail.com [Laboratoire de Physique des Matériaux, Faculté des Sciences de Sfax, Université de Sfax, B.P. 1171, 3000 Sfax (Tunisia); Faculty of Physics, Warsaw University of Technology, Koszykowa 75, 00-662 Warsaw (Poland); Department of Chemistry, University of Warsaw, Al. Żwirki i Wigury 101, 02-089 Warsaw (Poland); Pękała, K. [Faculty of Physics, Warsaw University of Technology, Koszykowa 75, 00-662 Warsaw (Poland); Pękała, M. [Department of Chemistry, University of Warsaw, Al. Żwirki i Wigury 101, 02-089 Warsaw (Poland); Boujelben, W. [Laboratoire de Physique des Matériaux, Faculté des Sciences de Sfax, Université de Sfax, B.P. 1171, 3000 Sfax (Tunisia); Szydłowska, J. [Department of Chemistry, University of Warsaw, Al. Żwirki i Wigury 101, 02-089 Warsaw (Poland); Fagnard, J.-F.; Vanderbemden, P. [SUPRATEC, Department of Electrical Engineering and Computer Science (B28), University of Liege (Belgium); Cheikhrouhou, A. [Laboratoire de Physique des Matériaux, Faculté des Sciences de Sfax, Université de Sfax, B.P. 1171, 3000 Sfax (Tunisia)

    2013-12-15

    Highlights: •Orthorhombic monovalent doped manganites Pr0.6Sr0.4-xKxMnO3 (x = 0.05 to 0.2). •Unit cell volume decreases with K content. •Curie temperature decreases with K content. •Electron magnetic resonance determines low temperature limit of paramagnetic phase. -- Abstract: The monovalent potassium doped manganites Pr{sub 0.6}Sr{sub 0.4−x}K{sub x}MnO{sub 3} (x = 0.05–0.2) are characterized using the complementary magnetic susceptibility and electron resonance methods. In paramagnetic phase the temperature variations of the inverse magnetic susceptibility and the inverse intensity of resonance signal obey the Curie–Weiss law. A similarity in temperature variation of resonance signal width and the adiabatic polaron conductivity points to the polaron mechanism controlling the resonance linewidth. The low temperature limit of the pure paramagnetic phase is determined from the electron resonance spectra revealing the mixed phase spread down to the Curie temperature.

  17. GCR Transport in the Brain: Assessment of Self-Shielding, Columnar Damage, and Nuclear Reactions on Cell Inactivation Rates

    Science.gov (United States)

    Shavers, M. R.; Atwell, W.; Cucinotta, F. A.; Badhwar, G. D. (Technical Monitor)

    1999-01-01

    Radiation shield design is driven by the need to limit radiation risks while optimizing risk reduction with launch mass/expense penalties. Both limitation and optimization objectives require the development of accurate and complete means for evaluating the effectiveness of various shield materials and body-self shielding. For galactic cosmic rays (GCR), biophysical response models indicate that track structure effects lead to substantially different assessments of shielding effectiveness relative to assessments based on LET-dependent quality factors. Methods for assessing risk to the central nervous system (CNS) from heavy ions are poorly understood at this time. High-energy and charge (HZE) ion can produce tissue events resulting in damage to clusters of cells in a columnar fashion, especially for stopping heavy ions. Grahn (1973) and Todd (1986) have discussed a microlesion concept or model of stochastic tissue events in analyzing damage from HZE's. Some tissues, including the CNS, maybe sensitive to microlesion's or stochastic tissue events in a manner not illuminated by either conventional dosimetry or fluence-based risk factors. HZE ions may also produce important lateral damage to adjacent cells. Fluences of high-energy proton and alpha particles in the GCR are many times higher than HZE ions. Behind spacecraft and body self-shielding the ratio of protons, alpha particles, and neutrons to HZE ions increases several-fold from free-space values. Models of GCR damage behind shielding have placed large concern on the role of target fragments produced from tissue atoms. The self-shielding of the brain reduces the number of heavy ions reaching the interior regions by a large amount and the remaining light particle environment (protons, neutrons, deuterons. and alpha particles) may be the greatest concern. Tracks of high-energy proton produce nuclear reactions in tissue, which can deposit doses of more than 1 Gv within 5 - 10 cell layers. Information on rates of

  18. Rainbow trout fed diets with varying content of marine and plant origin; how does that influence the outcome of experimental infections of the fry with Flavobacterium psychrophilum and Yersinia ruckeri?

    DEFF Research Database (Denmark)

    Madsen, Lone; Ingerslev, Hans-Christian; Boye, Mette

    2014-01-01

    Feed for rainbow trout aquaculture has traditionally been based on marine resources such as fish meal and fish oil. Because of a shortage of marine resources as well as the growing production of farmed fish, the feed industry has been forced to partially exchange fish meal protein with proteins...... derived from plants, like soy bean meal. This has been shown to affect the salmonid intestinal mucosa, and in addition, plant-based dietary proteins have been associated with changes in disease susceptibility in salmon and it has been suggested that these special diet types weakens the immune status...... of the fish. One major cause for losses in Danish freshwater fish farms is the fry disease rainbow trout fry syndrome (RTFS), caused by the bacterium Flavobacterium psychrophilum, and experiences of the fish farmers suggest that the diet type is an important factor for disease development. Enteric redmouth...

  19. Prevalence of intestinal metaplasia according to the length of the specialized columnar epithelium lining the distal esophagus in patients with gastroesophageal reflux.

    Science.gov (United States)

    Csendes, A; Smok, G; Burdiles, P; Korn, O; Gradiz, M; Rojas, J; Recio, M

    2003-01-01

    The diagnosis of Barrett's esophagus is based on the presence of intestinal metaplasia (IM) at the distal esophagus. The aim of this study was to determine the prevalence of IM in patients with symptoms of gastroesophageal reflux in whom endoscopically a segment of distal esophagus was covered by columnar epithelium (CE). In a prospective, descriptive and transversal study, 492 patients (33%) from 1480 patients with gastroesophageal reflux, in whom endoscopic evaluation demonstrated the presence of a short-segment CE measuring less than 3 cm or a long-segment CE measuring more than 3 cm, were evaluated. From each patient, several biopsy specimens were taken, which were stained with hematoxylin-eosin and Alcian blue pH 2.5. Out of 492 cases, 421 patients (86%) presented with a short-segment CE and 71 patients (14%) had a long-segment CE. Among these 71 cases, 38 had a 3-6 cm-length CE, 21 patients had a 6.1-10 cm-length CE and 12 patients had CE more than 10.1 cm in length. Endoscopic short-segment CE was six times more frequent than long-segment CE. The prevalence of IM was 35% among patients with short-segment CE and increased progressively according to the length of CE, being 100% in patients with > 10 cm in length. Therefore, true short-segment BE was three times more frequent during endoscopic studies than long-segment BE. Dysplasia in the metaplastic epithelium also increased parallel to the length of the CE. True BE (presence of IM at the columnar epithelium lining the distal esophagus), was present in 13.6% of all patients with symptoms of gastroesophageal reflux submitted to endoscopic evaluation. Short-segment BE is three times more frequent than long-segment BE, and endoscopic and bioptic evaluation is fundamental in all cases with gastroesophageal reflux who exhibit some segment of the distal esophagus lined by columnar epithelium, even if it is > or = 1 cm long.

  20. Growth of Hexagonal Columnar Nanograin Structured SiC Thin Films on Silicon Substrates with Graphene–Graphitic Carbon Nanoflakes Templates from Solid Carbon Sources

    Directory of Open Access Journals (Sweden)

    Wanshun Zhao

    2013-04-01

    Full Text Available We report a new method for growing hexagonal columnar nanograin structured silicon carbide (SiC thin films on silicon substrates by using graphene–graphitic carbon nanoflakes (GGNs templates from solid carbon sources. The growth was carried out in a conventional low pressure chemical vapor deposition system (LPCVD. The GGNs are small plates with lateral sizes of around 100 nm and overlap each other, and are made up of nanosized multilayer graphene and graphitic carbon matrix (GCM. Long and straight SiC nanograins with hexagonal shapes, and with lateral sizes of around 200–400 nm are synthesized on the GGNs, which form compact SiC thin films.

  1. Anisotropy, band-to-band transitions, phonon modes, and oxidation properties of cobalt-oxide core-shell slanted columnar thin films

    Energy Technology Data Exchange (ETDEWEB)

    Mock, Alyssa, E-mail: amock@huskers.unl.edu; Korlacki, Rafał; Briley, Chad; Sekora, Derek; Schubert, Eva; Schubert, Mathias [Department of Electrical and Computer Engineering and Center for Nanohybrid Functional Materials, University of Nebraska-Lincoln, Lincoln, Nebraska 68588 (United States); Hofmann, Tino [Department of Electrical and Computer Engineering and Center for Nanohybrid Functional Materials, University of Nebraska-Lincoln, Lincoln, Nebraska 68588 (United States); Department of Physics, Chemistry, and Biology, Linköping University, 58183 Linköping (Sweden); Wilson, Peter; Sinitskii, Alexander [Department of Chemistry and Center for Nanohybrid Functional Materials, University of Nebraska-Lincoln, Lincoln, Nebraska 68588 (United States)

    2016-02-01

    Highly ordered and spatially coherent cobalt slanted columnar thin films (SCTFs) were deposited by glancing angle deposition onto silicon substrates, and subsequently oxidized by annealing at 475 °C. Scanning electron microscopy, Raman scattering, generalized ellipsometry, and density functional theory investigations reveal shape-invariant transformation of the slanted nanocolumns from metallic to transparent metal-oxide core-shell structures with properties characteristic of spinel cobalt oxide. We find passivation of Co-SCTFs yielding Co-Al{sub 2}O{sub 3} core-shell structures produced by conformal deposition of a few nanometers of alumina using atomic layer deposition fully prevents cobalt oxidation in ambient and from annealing up to 475 °C.

  2. Climatology of columnar aerosol properties and the influence of synoptic conditions: First-time results from the northeastern region of India

    Science.gov (United States)

    Gogoi, Mukunda M.; Krishna Moorthy, K.; Babu, S. Suresh; Bhuyan, Pradip K.

    2009-04-01

    Six years of spectral aerosol optical depths (AODs), from the northeastern part of India (Dibrugarh), are used to evolve a climatology for this region. The results indicate that the seasonal mean AODs at 500 nm go as high as 0.45 ± 0.05 during premonsoon season (March to May), decrease gradually through the monsoon (June to September) to reach the lowest value of 0.19 ± 0.06 during the retreating-monsoon season (October and November), and increase to 0.31 ± 0.04 in winter (December to February). The AOD spectra are generally flatter than those seen typically over continental sites of India (and elsewhere in the neighboring regions) with Ångström exponent α remaining below 1.0 during February through August, indicating a relatively low abundance of fine and accumulation mode aerosols. The columnar size distributions (CSD) retrieved from spectral AODs are, in general, bimodal with primary mode at ˜ 0.1 μm and secondary mode at ˜ 1.0 μm. High mass loading (˜309.5 ± 65.9 mg m-2) and effective radius (˜0.40 ± 0.09 μm) occur during premonsoon and are attributed to significant abundance of coarse (natural) aerosols. Cluster analysis of air mass back trajectories indicate significant transport of mineral dust from the arid regions of west Asia and northwest India across the Indo-Gangetic plains and marine aerosols advected from the Bay of Bengal contributing largely to the coarse mode aerosols during this season. On the other hand, the peculiar topography combined with the local conditions and the widespread rainfall lead to a more pristine environment during retreating-monsoon season with quite low AODs and columnar loading.

  3. Immunogenicity, safety and tolerability of monovalent 2009 pandemic influenza A/H1N1 MF59-adjuvanted vaccine in children and adolescents with Williams or Cornelia De Lange syndrome.

    Science.gov (United States)

    Esposito, Susanna; Selicorni, Angelo; Daleno, Cristina; Valzano, Antonia; Cerutti, Marta; Galeone, Carlotta; Consolo, Silvia; Menni, Francesca; Principi, Nicola

    2011-06-01

    In some subjects with severe neurological diseases, a reduced immune response to seasonal influenza vaccine has been demonstrated. Patients with Williams or Cornelia de Lange syndrome frequently have abnormalities in neurodevelopment. This study has evaluated the immunogenicity, safety and tolerability of a monovalent 2009 pandemic influenza A/H1N1 MF59-adjuvanted vaccine in these subjects. Eighteen patients with Williams syndrome (ten males; mean age ± standard deviation [SD] 12.74 ± 4.49 years), 11 with Cornelia de Lange syndrome (six males; mean age 12.90 ± 4.85 years) and 30 age- and gender-matched healthy controls (16 males; mean age 12.49 ± 4.55 years), never vaccinated against influenza, received a dose of the vaccine between 1 and 30 November 2009. Four weeks later, the seroconversion rates in the three groups were between 72% and 80% and the seroprotection rates were 100%, with a similar increase in antibody levels. Two months later, most of the subjects remained seroconverted with no statistically significant difference between the groups, and about 94% of the patients with Williams syndrome, all of those with Cornelia de Lange syndrome and all of the healthy controls were still seroprotected. Safety and tolerability were very good, with no difference between the groups. None of the patients developed documented influenza during the study period. These results show that the immunogenicity, safety, and tolerability of a single dose of the monovalent 2009 pandemic influenza A/H1N1 MF59-adjuvanted vaccine in children and adolescents with Williams or Cornelia de Lange syndrome and moderate to severe mental disabilities is very good, and similar to that of healthy subjects.

  4. HIV-1特异性单抗2G12单价抗体的构建及活性分析%Construction and activity analysis of HIV specific monovalent mAb 2G12

    Institute of Scientific and Technical Information of China (English)

    冯一帆; 刘雪; 徐柯; 冯霞; 曾毅; 余双庆

    2015-01-01

    Objective To construct monovalent form IgG antibodies and compare their binding and neutralizing activity with parent antibody.Methods To obtain the monovalent form HIV-1 specific antibody 2G12 with 1 Fab and 1 Fc (2G12-tH),an expression vector containing DNA encoding the IgG1 hinge,CH2 and CH3 domain exons was constructed and co-transfected with the plasmids expressing 2G12 heavy and light chains.To obtain the half molecule form 2G12 (2G12-HM),the disulfide bond at hinge region and the stable non-covalent bonds in CH2,CH3 regions were removed by site-directed mutation on 2G12 heavy chain gene.The mutated heavy chain gene was co-transfected with light chain expressing plasmid.Purified 2G12-tH and 2G12-HM were analyzed by non-reducing SDS-PAGE.The antigen specific binding and neutralizing activity against HIV-1 was compared with parent IgG by ELISA and micro-neutralizing assay.Results Two forms of monovalent 2G12 antibody,2G12-tH and 2G12-HM,were constructed and expressed correctly.Both 2G12-tH and 2G12-HM effectively combined with HIV-1 Env.The results of neutralizing assay based on six pseudoviruses of HIV-1 subtype B indicated that monovalent form antibodies had similar neutralizing activity with IgG.Conclusions Two forms of monovalent antibody were successfully constructed.The binding and neutralizing activity of monovalent form antibodies were similar to that of parent IgG antibody.%目的 构建单价抗体并与IgG比较结合活性及中和活性的差异.方法 对IgG1抗体重链恒定区基因进行改造,分别构建N端截短型的IgG1重链恒定区基因IgG1-tH和去除绞链区二硫键及CH2、CH3区的稳定非共价键的2G12重链基因2G12-HM.将IgG1-tH与2G12抗体重链和轻链基因表达质粒共转染293T细胞,表达含有完整Fc的单价抗体;将2G12-HM和轻链基因表达质粒共转染293T细胞,表达半分子型的单价抗体.通过非还原SDS-PAGE对表达抗体的大小进行鉴定,并用ELISA和微量中和实验比较原型2

  5. Efecto de la densidad de semillas en la germinación de Isolatocereus dumortieri y Myrtillocactus geometrizans, cactáceas columnares endémicas de México Effect of seed density on germination of Isolatocereus dumortieri and Myrtillocactus geometrizans, endemic columnar cacti species from Mexico

    Directory of Open Access Journals (Sweden)

    Joel Flores

    2009-04-01

    Full Text Available Se evaluó el efecto de la densidad de semillas en la germinación de 2 cactáceas columnares: Isolatocereus dumortieri y Myrtillocactus geometrizans. Se utilizaron 5 tratamientos de densidad de semillas (1, 5, 10, 20 y 50 semillas. Isolatocereus dumortieri mostró menor porcentaje de germinación con el aumento de la densidad, mientras que la germinación de M. geometrizans no fue afectada por la densidad de semillas. Estos resultados sugieren que las plántulas de I. dumortieri podrían competir por recursos.The effect of seed density on the germination of 2 columnar cactus species (Isolatocereus dumortieri and Myrtillocactus geometrizans was evaluated using 5 seed density treatments (1, 5, 10, 20 and 50 seeds. Isolatocereus dumortieri had a lower germination percentage with increasing seed density; germination of M. geometrizans was not affected by seed density. These results suggest that I. dumortieri seedlings might compete for resources with siblings.

  6. Impacts of parasite infection on columnaris disease of tilapia

    Science.gov (United States)

    There is no information available on whether parasite infection will increase the susceptibility of tilapia to Flavobacterium columnare and whether parasite treatment could improve fish survival after F. columnare exposure. Two trials were conducted to evaluate 1) the susceptibility of hybrid tilapi...

  7. A mutant in one of two exbD loci of a TonB system in Flavobacterium psychrophilum shows attenuated virulence and confers protection against cold water disease.

    Science.gov (United States)

    Alvarez, Beatriz; Alvarez, Javier; Menéndez, Aurora; Guijarro, José A

    2008-04-01

    Flavobacterium psychrophilum is a psychrotrophic fish-pathogenic bacterium that causes cold water disease (CWD) in salmonids. By means of Tn4351 mutagenesis a mutant named FP1033, deficient in growth on iron-depleted medium, was previously isolated. FP1033 recovered the parental phenotype in the presence of iron. The gene disrupted by the transposon in this mutant encoded a protein with similarity to ExbD proteins, which are members of the TonB complex system involved in iron uptake mediated by siderophores. Analysis of the DNA surrounding the transposon insertion showed the presence of a tonB cluster of genes composed of exbB, two exbD (exbD1 and exbD2) and tonB loci. RT-PCR analysis and complementation studies indicated that these genes are transcribed as an operon and that the exbD2 : : Tn4351 phenotype was caused by the lack of ExbD2. FP1033 showed decreased virulence and conferred a high level of protection in rainbow trout fry after vaccination. This is believed to be the first report of a F. psychrophilum attenuated strain that induces a protective immune response in rainbow trout against CWD. These results suggest that the exbD2 locus from this particular TonB system is a suitable target to generate a live attenuated vaccine.

  8. Comparative study of hydrothermal treatment and thermal annealing effects on the properties of electrodeposited micro-columnar ZnO thin films

    Energy Technology Data Exchange (ETDEWEB)

    Lupan, O., E-mail: oleg-lupan@chimie-paristech.fr [Laboratoire d' Electrochimie, Chimie des Interfaces et Modelisation pour l' Energie (LECIME), UMR 7575 CNRS, Chimie ParisTech-ENSCP, 11 rue P. et M. Curie, 75231 Paris cedex 05 (France); Department of Microelectronics and Semiconductor Devices, Technical University of Moldova, 168 Stefan cel Mare Blvd., Chisinau, MD-2004, Republic of Moldova (Moldova, Republic of); Pauporte, T., E-mail: thierry-pauporte@chimie-paristech.fr [Laboratoire d' Electrochimie, Chimie des Interfaces et Modelisation pour l' Energie (LECIME), UMR 7575 CNRS, Chimie ParisTech-ENSCP, 11 rue P. et M. Curie, 75231 Paris cedex 05 (France); Tiginyanu, I.M.; Ursaki, V.V. [Institute of Electronic Engineering and Industrial Technologies, Institute of Applied Physics, Academy of Sciences of Moldova, 5, Academiei str, MD-2028, Chisinau, Republic of Moldova (Moldova, Republic of); Sontea, V. [Department of Microelectronics and Semiconductor Devices, Technical University of Moldova, 168 Stefan cel Mare Blvd., Chisinau, MD-2004, Republic of Moldova (Moldova, Republic of); Ono, L.K.; Cuenya, B. Roldan; Chow, L. [Department of Physics, University of Central Florida, 4000 Central Florida Blvd., Orlando, FL 32816 (United States)

    2011-09-01

    We report a comparison of the role played by different sample treatments, namely, a low-temperature hydrothermal treatment by hot H{sub 2}O vapor in an autoclave versus thermal annealing in air on the properties of ZnO films grown by electrochemical deposition (ECD). Scanning electron microscopy studies reveal a homogeneous micro-columnar morphology and changes in the film surface for the two different treatments. It is found that post-growth hydrothermal treatments of ECD ZnO films at 150 deg. C under an aqueous environment enhance their structural and optical properties (photoluminescence, transmission, Raman spectra, etc.) similar to thermal annealing in air at higher temperatures (> 200 deg. C). The modifications of the structural and optical properties of ZnO samples after thermal annealing in air in the temperature range of 150-600 deg. C are discussed. The removal of chlorine from the films by the hydrothermal treatment was evidenced which could be the main reason for the improvement of the film quality. The observation of the enhanced photoluminescence peak at 380 nm demonstrates the superior properties of the hydrothermally treated ZnO films as compared to the films annealed in air ambient at the same or higher temperature. This post-growth hydrothermal treatment would be useful for the realization of high performance optoelectronic devices on flexible supports which might not withstand at high temperature annealing treatments.

  9. SIMULACIÓN DE FORMACIÓN DE ESTRUCTURAS DE GRANO PERIMETRAL, COLUMNAR Y EQUIAXIAL EN SECCIONES DE ACERO INCLUYENDO RUTINAS DE PRE-SOLIDIFICACIÓN

    Directory of Open Access Journals (Sweden)

    Adán Ramírez-López

    2010-01-01

    Full Text Available Este trabajo muestra el desarrollo y la implementación de algoritmos computacionales basados en teoría del caos y autómatas celulares para la simulación del crecimiento de granos en secciones cuadradas de acero producidas por colada continua. Se desarrollaron tres algoritmos para la simulación de las estructuras de grano en las zonas perimetral, columnar y equiaxial; incluyen rutinas para estimular la nucleación y crecimiento del grano. Estas fueron compiladas separadamente al algoritmo principal con el objeto de hacer más eficiente el sistema de simulación. Los algoritmos analizan todos los nodos a cada paso, durante la simulación de cálculo y una interfase de despliegue gráfico muestra en la pantalla el proceso de solidificación. La teoría del caos fue empleada integrando un proceso aleatorio de selección. El resultado de este análisis es una imagen digital de celdas que representan a los granos (autómata celular y es desplegada en la pantalla en función a un código numérico asignado a las posiciones nodales.

  10. Synthesis of Mixed Tail Triphenylene Discotic Liquid Crystals:Molecular Symmetry and Oxygen-Atom Effect on the Stabilization of Columnar Mesophases

    Institute of Scientific and Technical Information of China (English)

    ZHAO Ke-Qing; HU Ping; WANG Bi-Qin; YU Wen-Hao; CHEN Hong-Mei; WANG Xin-Ling; SHIMIZU Yo

    2007-01-01

    Small change in chemical structure of discotic liquid crystals can cause big difference in their mesomorphism.Replacing of the alkoxy peripheral chains of triphenylene by oxygen-atom containing ester chains would result in novel mesomorphism. A series of mixed tail triphenylenes containing propoxyacetyloxy and alkoxy, abbreviated as C18H6(OCnH2n+1)3(OCOCH2OC3H7)3, n=4-8, and hexa(propyloxyacetyloxy)triphenylene, C18H6(OCOCH2OC3H7)6 were synthesized. Thermal gravimetry analysis (TGA) of three discogens showed that they had good thermal stability till 350℃. The mesomorphism was investigated through differential scanning calorimetry (DSC)and polarized optical microscopy (POM). The preliminary X-ray diffraction (XRD) results of one compound showed that it exhibited ordered hexagonal columnar (Colho) mesophase. These mixed tail triphenylene derivatives possessed much stable Colho mesophase and wider mesophase ranges than their hexaalkoxytriphenylene C18H6(OR)6 and hexaalkanoyloxytriphenylene C18H6(OCOR')6 analogues. The asymmetrical compounds 2,6,11-trialkoxy-3,7,10-tri(2-propyloxyacetyloxy)triphenylenes with n=5-8 displayed higher clearing points and wider temperature ranges than their symmetrical isomers 2,6,10-trialkoxy-3,7,11-tri(2-propyloxyacetyloxy)triphenylenes, while C18H6(OCOCH2OC3H7)6 had the highest clearing point due to the β-oxygen-atom effect.

  11. Columnar-to-Equiaxed Transition and Equiaxed Grain Alignment in Directionally Solidified Ni3Al Alloy Under an Axial Magnetic Field

    Science.gov (United States)

    Liu, Huan; Xuan, Weidong; Xie, Xinliang; Li, Chuanjun; Wang, Jiang; Yu, Jianbo; Li, Xi; Zhong, Yunbo; Ren, Zhongming

    2017-09-01

    The effect of an axial magnetic field on the solidification structure in directionally solidified Ni-21.5Al-0.4Zr-0.1B (at. pct) alloy was investigated. The experimental results indicated that the application of a high magnetic field caused the deformation of dendrites and the occurrence of columnar-to-equiaxed transition (CET). The magnetic field tended to orient the 〈001〉 crystal direction of the equiaxed grains along the magnetic field direction. The bulk solidification experiment under a high magnetic field showed that the crystal exhibited magnetic crystalline anisotropy. Further, the thermoelectric (TE) magnetic force and TE magnetic convention were analyzed by three-dimensional (3-D) numerical simulations. The results showed that the maximum value of TE magnetic force localized in the vicinity of the secondary dendrite arm root, which should be responsible for the dendrite break and CET. Based on the high-temperature creep mechanism, a simple model was proposed to describe the magnetic field intensity needed for CET: B \\ge kG^{ - 1.5} R^{1.25} . The model is in good agreement with the experiment results. The experimental results should be attributed to the combined action of TE magnetic effects and the magnetic moment.

  12. Creation of Superheterojunction Polymers via Direct Polycondensation: Segregated and Bicontinuous Donor-Acceptor π-Columnar Arrays in Covalent Organic Frameworks for Long-Lived Charge Separation.

    Science.gov (United States)

    Jin, Shangbin; Supur, Mustafa; Addicoat, Matthew; Furukawa, Ko; Chen, Long; Nakamura, Toshikazu; Fukuzumi, Shunichi; Irle, Stephan; Jiang, Donglin

    2015-06-24

    By developing metallophthalocyanines and diimides as electron-donating and -accepting building blocks, herein, we report the construction of new electron donor-acceptor covalent organic frameworks (COFs) with periodically ordered electron donor and acceptor π-columnar arrays via direct polycondensation reactions. X-ray diffraction measurements in conjunction with structural simulations resolved that the resulting frameworks consist of metallophthalocyanine and diimide columns, which are ordered in a segregated yet bicontinuous manner to form built-in periodic π-arrays. In the frameworks, each metallophthalocyanine donor and diimide acceptor units are exactly linked and interfaced, leading to the generation of superheterojunctions-a new type of heterojunction machinery, for photoinduced electron transfer and charge separation. We show that this polycondensation method is widely applicable to various metallophthalocyanines and diimides as demonstrated by the combination of copper, nickel, and zinc phthalocyanine donors with pyrommellitic diimide, naphthalene diimide, and perylene diimide acceptors. By using time-resolved transient absorption spectroscopy and electron spin resonance, we demonstrated that the COFs enable long-lived charge separation, whereas the metal species, the class of acceptors, and the local geometry between donor and acceptor units play roles in determining the photochemical dynamics. The results provide insights into photoelectric COFs and demonstrate their enormous potential for charge separation and photoenergy conversions.

  13. Alpha-catenin-Dependent Recruitment of the Centrosomal Protein CAP350 to Adherens Junctions Allows Epithelial Cells to Acquire a Columnar Shape

    Science.gov (United States)

    Zurbano, Angel; Formstecher, Etienne; Martinez-Morales, Juan R.; Bornens, Michel; Rios, Rosa M.

    2015-01-01

    Epithelial morphogenesis involves a dramatic reorganisation of the microtubule cytoskeleton. How this complex process is controlled at the molecular level is still largely unknown. Here, we report that the centrosomal microtubule (MT)-binding protein CAP350 localises at adherens junctions in epithelial cells. By two-hybrid screening, we identified a direct interaction of CAP350 with the adhesion protein α-catenin that was further confirmed by co-immunoprecipitation experiments. Block of epithelial cadherin (E-cadherin)-mediated cell-cell adhesion or α-catenin depletion prevented CAP350 localisation at cell-cell junctions. Knocking down junction-located CAP350 inhibited the establishment of an apico-basal array of microtubules and impaired the acquisition of columnar shape in Madin-Darby canine kidney II (MDCKII) cells grown as polarised epithelia. Furthermore, MDCKII cystogenesis was also defective in junctional CAP350-depleted cells. CAP350-depleted MDCKII cysts were smaller and contained either multiple lumens or no lumen. Membrane polarity was not affected, but cortical microtubule bundles did not properly form. Our results indicate that CAP350 may act as an adaptor between adherens junctions and microtubules, thus regulating epithelial differentiation and contributing to the definition of cell architecture. We also uncover a central role of α-catenin in global cytoskeleton remodelling, in which it acts not only on actin but also on MT reorganisation during epithelial morphogenesis. PMID:25764135

  14. Growth and reproductive characteristics of the columnar cactus Stenocereus queretaroensis and their relationships with environmental factors and colonization by arbuscular mycorrhizae.

    Science.gov (United States)

    Pimienta-Barrios, Eulogio; Pimienta-Barrios, Enrique; Salas-Galván, Mariá Eugenia; Zañudo-Hernandez, Julia; Nobel, Park S

    2002-06-01

    Three natural populations of pitayo (Stenocereus queretaroensis (Weber) Buxbaum), a columnar arborescent cactus, were studied in their subtropical environments in western Mexico. All of the sites were characterized by shallow, nutrient-poor soils. Percentage of colonization by arbuscular mycorrhizae (AM) fungi, stem growth, fruit mass, and percentage germination were greater in S. queretaroensis at Autlan, Jalisco (AJ) than at Zacoalco de Torres, Jalisco (ZTJ) or Santa Rosa, Zacatecas (SRZ). The onset of root colonization by arbuscular mycorrhizae during the middle of the summer wet period preceded increases in stem extension rate and stem phosphorus concentration. Based on previous studies of effects of environmental factors on photosynthesis, climatic conditions were more favorable for photosynthesis at AJ than at SRZ and ZTJ, as indicated by the amount of summer rainfall, the amount of light, and the moderate air temperatures that prevailed during the fall and winter seasons. There was a significant positive correlation between stem growth and percentage of total root length colonized by arbuscules of AM fungi for S. queretaroensis at SRZ and AJ, but not at ZTJ. A negative significant correlation was observed between stem growth and maximal and minimal air temperatures at the three study sites. Stem growth was positively related to rainfall only at SRZ, and light was statistically related to stem growth only at ZTJ. Among sites, S. queretaroensis at AJ had the highest carbon gain and greatest AM colonization, creating physiological conditions that led to the highest stem growth, fruit mass and percentage of seed germination.

  15. Direct and indirect estimates of gene flow among wild and managed populations of Polaskia chichipe, an endemic columnar cactus in Central Mexico.

    Science.gov (United States)

    Otero-Arnaiz, Adriana; Casas, Alejandro; Hamrick, James L

    2005-12-01

    Microsatellite markers were used to obtain direct and indirect estimates of gene flow in populations of Polaskia chichipe under different management regimes, in order to understand the genetic consequences of gene flow in the evolutionary process of domestication. P. chichipe is a columnar cactus endemic to the Tehuacan Valley, Central Mexico, and has come under domestication for its edible fruit. Morphological, phenological, physiological, and reproductive differences, apparently attributable to artificial selection, exist between wild and managed populations, which grow sympatrically. However, strong gene flow may counteract the effects of this selection. In this study, we used paternity analysis to demonstrate that although most of the pollinations occur among individuals within the same population at distances < 40 m, pollen flow from other populations is considerable (27 +/- 5%). Heterogeneity in pollen clouds sampled by mother plants (FST = 0.12) indicated nonrandom mating, which is probably due to temporal heterogeneity in pollen movement. Spatial structure on local and regional scales is consistent with an isolation-by-distance model. The similarity of indirect, direct and demographic estimates of neighbourhood size (74-250 individuals) suggests that this genetic structure is representative of an equilibrium state. These results suggest that traditional management practices have conserved the genetic resources of this species in situ, but also that gene flow is counteracting the effect of domestication to some degree. We discuss our results in the general context of genetic exchange between cultivated and wild populations during the domestication process.

  16. A clinical trial to assess the immunogenicity and safety of Inactivated Influenza Vaccine (Whole Virion IP (Pandemic Influenza (H1N1 2009 Monovalent Vaccine; VaxiFlu-S ™ in healthy Indian adult population

    Directory of Open Access Journals (Sweden)

    A H Kubavat

    2011-01-01

    Full Text Available Background : The pandemic of H1N1 2009 influenza has spread world over and low degree of virus transmission has continued in several regions of India. Aims : To assess the immunogenicity and safety of Pandemic Influenza (H1N1 2009 Monovalent Vaccine in healthy adult Indian population. Settings and Design : Prospective, open label, multicentric, phase 2/3 clinical trial. Materials and Methods : Healthy adult Indian subjects belonging to either 18-59 years or ≥60 years age groups were enrolled and administered a single 0.5 ml (≥15 mcg of hemagglutinin antigen dose of vaccine in the deltoid muscle. Anti-hemagglutinin antibody titer was assessed at baseline and 21 (±2 days after vaccination by Hemagglutination Inhibition (HI test. Safety assessments were done for a period of 42 days. Statistical Analysis Used : Percentages of appropriate population with 95% confidence intervals calculated, log transformation of the data to calculate Geometric Mean Titers (GMTs and chi-square test and student′s t-test applied for significance testing. Results : 182/198 and 53/63 volunteers in age groups of 18-59 years and ≥60 years, respectively, achieved an HI titer ≥1 : 40 at Day 21 (91.9% [95% confidence interval: 88.1-95.7%] and 84.1% [75.1-93.2%]; P=0.072. Further, 171/198 and 50/63 volunteers in the respective age groups achieved seroconversion/four-fold increase in titer at Day 21 (86.4% [81.6-91.1%] and 79.4% [69.4-89.4%]; P=0.179. A significant rise of 22.6-fold [18.0-28.4] and 10.5-fold [7.4-15.0] was noted in GMT in the respective age groups (P<0.001 for both groups as compared to baseline. Nine vaccine-related adverse events were reported (3.4% incidence [1.2-5.6%], which were of low severity only. Conclusions : Pandemic Influenza (H1N1 2009 Monovalent Vaccine produces excellent immunogenic response with a good tolerability profile in adult Indian population.

  17. Solid state 13C-NMR, infrared, X-ray powder diffraction and differential thermal studies of the homologous series of some mono-valent metal (Li, Na, K, Ag) n-alkanoates: A comparative study

    Science.gov (United States)

    Nelson, Peter N.; Ellis, Henry A.; White, Nicole A. S.

    2015-06-01

    A comparative study of the molecular packing, lattice structures and phase behaviors of the homologous series of some mono-valent metal carboxylates (Li, Na, K and Ag) is carried out via solid state FT-infrared and 13C-NMR spectroscopes, X-rays powder diffraction, density measurements, differential scanning calorimetry, polarizing light microscopy and variable temperature infrared spectroscopy. It is proposed that, for lithium, sodium and potassium carboxylates, metal-carboxyl coordination is via asymmetric chelating bidentate bonding with extensive intermolecular interactions to form tetrahedral metal centers, irrespective of chain length. However, for silver n-alkanoates, carboxyl moieties are bound to silver ions via syn-syn type bridging bidentate coordination to form dimeric units held together by extensive head group inter-molecular interactions. Furthermore, the fully extended hydrocarbon chains which are crystallized in the all-trans conformation are tilted at ca. 30°, 27°, 15° and 31° with respect to a normal to the metal plane, for lithium, sodium, silver and potassium carboxylates, respectively. All compounds are packed as lamellar bilayer structures, however, lithium compounds are crystallized in a triclinic crystal system whilst silver, sodium and potassium n-alkanoates are all monoclinic with possible P1 bravais lattice. Odd-even alternation observed in various physical features is associated with different inter-planar spacing between closely packed layers in the bilayer which are not in the same plane; a phenomenon controlled by lattice packing symmetry requirements. All compounds, except silver carboxylates, show partially reversibly first order pre-melting transitions; the number of which increases with increasing chain length. These transitions are associated, for the most part, with lamellar collapse followed by increased gauche-trans isomerism in the methylene group assembly, irrespective of chain length. It is proposed that the absence of

  18. Inmunogenicidad y capacidad protectora en hamsters de vacunas antileptospirósicas monovalentes de células enteras del serogrupo Ballum Immunogenicity and protective capacity of leptospiral whole-cell monovalent serogroup Ballum vaccines in hamsters

    Directory of Open Access Journals (Sweden)

    A. González

    2005-12-01

    challenge with 100 and 10 000 LD50 of five virulent strains belonging to serogroups Ballum, Canicola, Icterohaemorrhagiae and Pomona. Both monovalent serogroup Ballum vaccines were immunogenic and induced complete homologous protection in the animal model. Cross-protection was only significant in one of the two vaccines against challenge with 100 LD50 of serogroup Canicola. The results of this study demonstrate the high immunogenicity and protective capacity in hamsters of whole-cell monovalent vaccines formulated with two vaccine candidate strains belonging to the most prevalent serogroup of Leptospira in Cuba.

  19. Molecular characterization of poliovirus isolates from children who contracted vaccine-associated paralytic poliomyelitis (VAPP) following administration of monovalent type 3 oral poliovirus vaccine in the 1960s in Hungary.

    Science.gov (United States)

    Kapusinszky, Beatrix; Molnár, Zsuzsanna; Szomor, Katalin N; Berencsi, György

    2010-03-01

    Hungarian children were immunized with monovalent oral poliovaccine (mOPV) delivered at 6-week intervals in the order Sabin 1, Sabin 3, Sabin 2, from 1959 until 1992. During that period, 90 cases of vaccine-associated paralytic poliomyelitis (VAPP) were reported, 52 of which were associated with Sabin 3-related virus (76% of VAPP cases with virologic data). Because of renewed interest in type 3 mOPV (mOPV3), molecular methods were used to reanalyze 18 of the Sabin 3-related isolates from 15 VAPP patients, confirming the original identification. All isolates had the U472C 5'-untranslated region (5'-UTR) substitution associated with reversion to neurovirulence, and from zero to seven nucleotide substitutions in the virus protein 1 (VP1) region. No evidence was found for prolonged mOPV3 replication in the VAPP patients or for spread of Sabin 3-related viruses beyond close vaccinee contacts. The VAPP diseases were prevented by a single dose of inactivated poliovirus vaccine from 1992 to 2006 in Hungary, as proved by continuous surveillance of acute flaccid paralysis.

  20. Association between monovalent influenza A (H1N1) pdm09 vaccine and pneumonia among the elderly in the 2009-2010 season in Japan: A case-control study.

    Science.gov (United States)

    Kondo, Kyoko; Suzuki, Kanzo; Washio, Masakazu; Ohfuji, Satoko; Fukushima, Wakaba; Maeda, Akiko; Hirota, Yoshio

    2015-01-01

    We investigated the association between monovalent influenza A (H1N1) pdm09 (H1N1pdm) vaccine and pneumonia in elderly people. Study design was a hospital-based, matched case-control study. Cases comprised patients ≥ 65 years old who had been newly diagnosed with pneumonia. For each case, 2 controls were defined as individuals with other diseases (not pneumonia) who were matched by sex, age, entry date, and the visited hospital. Study period was the interval from 1 September 2009 until 30 September 2010. Because a pandemic of influenza A (H1N1) occurred during study period, we analyzed selected subjects who had enrolled during the influenza A (H1N1) pandemic. We calculated the odds ratios (ORs) and 95% confidence intervals (CIs) for pneumonia in H1N1pdm-vaccinated subjects compared with unvaccinated subjects using a conditional logistic regression model to assess the association between H1N1pdm vaccine and pneumonia. The subjects during the period of the influenza A (H1N1) pandemic were 20 cases and 40 controls. Subjects who had received H1N1pdm vaccine showed a significantly decreased OR for pneumonia (OR = 0.10, 95% CI = 0.01-0.98) compared with unvaccinated subjects. In conclusion, H1N1pdm vaccination may have prevented pneumonia among the elderly during the 2009-2010 influenza A (H1N1) pandemic in Japan.

  1. Compliance with future emission standards of mobile machines by developing a monovalent natural gas combustion process; Einhaltung zukuenftiger Abgasnormen von mobilen Arbeitsmaschinen durch Entwicklung eines monovalenten Erdgas-Brennverfahrens

    Energy Technology Data Exchange (ETDEWEB)

    Prehn, Sascha [Rostock Univ. (Germany). Lehrstuhl fuer Kolbenmaschinen und Verbrennungsmotoren; Wichmann, Volker; Harndorf, Horst; Beberdick, Wolfgang

    2014-08-01

    Within the presented project a monovalent natural gas engine is being developed. Based on a serial diesel engine the operation mode of this prototype is changed to a spark ignition concept. The long term purpose of this new engine is an agricultural application. One major objective of the project is the investigation and evaluation of a combustion process, able to fulfil the performance requests as well as the European emission limits for nitrogen oxides NO{sub x}, and carbon monoxide CO of mobile machinery, which become into law in October 2014 (EU stage IV). At the time there are no legislative regulations existing regarding the methane emissions of the observed engines. To get a benefit in greenhouse gas emissions compared to diesel or gasoline engines the methane emissions have to be minimized while operating in natural gas mode. In the course of the current project an engine operation with a methane emission less than 0.5 g/kWh (representing the EURO VI limit for heavy duty vehicles) could be demonstrated. In contrast to diesel engines for agricultural applications it is possible to comply with the emission standards without using a high sophisticated after treatment system consisting of diesel oxidation catalyst (DOC), particulate filter (DPF) and SCR catalyst. The usage of a three way catalyst optimized for high methane conversions is sufficient for a stoichiometry gas operation with exhaust gas recirculation. Therefore a significant cost advantage is given.

  2. Growth and microstructure of columnar Y-doped SrZrO{sub 3} films deposited on Pt-coated MgO by pulsed laser deposition

    Energy Technology Data Exchange (ETDEWEB)

    Luo, Sijun, E-mail: sluo1@tulane.edu; Riggs, Brian C.; Shipman, Joshua T.; Adireddy, Shiva; Sklare, Samuel C.; Chrisey, Douglas B., E-mail: dchrisey@tulane.edu [Department of Physics and Engineering Physics, Tulane University, New Orleans, Louisiana 70118 (United States); Zhang, Xiaodong; Koplitz, Brent [Department of Chemistry, Tulane University, New Orleans, Louisiana 70118 (United States)

    2015-07-21

    Direct integration of proton conductor films on Pt-coated substrates opens the way to film-based proton transport devices. Columnar SrZr{sub 0.95}Y{sub 0.05}O{sub 3−δ} (SZY) films with dense microstructure were deposited on Pt-coated MgO(100) substrates at 830 °C by pulsed laser deposition. The optimal window of ambient O{sub 2} pressure for good crystallinity of SZY films is from 400 to 600 mTorr. The ambient O{sub 2} compresses the plasma plume of SZY and increases the deposition rate. The 10 nm thick Ti adhesion layer on MgO(100) greatly affects the orientation of the sputtered Pt layers. Pt deposited directly on MgO shows a highly (111)-preferred orientation and leads to preferentially oriented SZY films while the addition of a Ti adhesion layer makes Pt show a less preferential orientation that leads to randomly oriented SZY films. The RMS surface roughness of preferentially oriented SZY films is larger than that of randomly oriented SZY films deposited under the same ambient O{sub 2} pressure. As the O{sub 2} pressure increased, the RMS surface roughness of preferentially oriented SZY films increased, reaching 45.7 nm (2.61% of film thickness) at 600 mTorr. This study revealed the ambient O{sub 2} pressure and orientation dependent surface roughness of SZY films grown on Pt-coated MgO substrates, which provides the potential to control the surface microstructure of SZY films for electrochemical applications in film-based hydrogen devices.

  3. Comparison of Head Scatter Factor for 6MV and 10MV flattened (FB) and Unflattened (FFF) Photon Beam using indigenously Designed Columnar Mini Phantom.

    Science.gov (United States)

    Ashokkumar, Sigamani; Nambi Raj, N Arunai; Sinha, Sujit Nath; Yadav, Girigesh; Thiyagarajan, Rajesh; Raman, Kothanda; Mishra, Manindra Bhushan

    2014-07-01

    To measure and compare the head scatter factor for flattened (FB) and unflattened (FFF) of 6MV and 10MV photon beam using indigenously designed mini phantom. A columnar mini phantom was designed as recommended by AAPM Task Group 74 with low and high atomic number materials at 10 cm (mini phantom) and at approximately twice the depth of maximum dose water equivalent thickness (brass build-up cap). Scatter in the accelerator (Sc) values of 6MV-FFF photon beams are lesser than that of the 6MV-FB photon beams (0.66-2.8%; Clinac iX, 2300CD) and (0.47-1.74%; True beam) for field sizes ranging from 10 × 10 cm(2) to 40 × 40 cm(2). Sc values of 10MV-FFF photon beams are lesser (0.61-2.19%; True beam) than that of the 10MV-FB photons beams for field sizes ranging from 10 × 10 cm(2) to 40 × 40 cm(2). The SSD had no influence on head scatter for both flattened and unflattened beams and irrespective of head design of the different linear accelerators. The presence of field shaping device influences the Sc values. The collimator exchange effect reveals that the opening of the upper jaw increases Sc irrespective of FB or FFF photon beams and different linear accelerators, and it is less significant in FFF beams. Sc values of 6MV-FB square field were in good agreement with that of AAPM, TG-74 published data for Varian (Clinac iX, 2300CD) accelerator. Our results confirm that the removal of flattening filter decreases in the head scatter factor compared to flattened beam. This could reduce the out-of-field dose in advanced treatment delivery techniques.

  4. Effects of natural and artificial selection on survival of columnar cacti seedlings: the role of adaptation to xeric and mesic environments.

    Science.gov (United States)

    Guillén, Susana; Terrazas, Teresa; Casas, Alejandro

    2015-05-01

    Escontria chiotilla, Polaskia chichipe, and Stenocereus pruinosus are species of Mexican columnar cacti that are economically important because of their edible fruits. These species are managed by gathering fruits from the wild, silvicultural management in agroforestry systems, and cultivation in home gardens. Previous studies reported that artificial selection favored individuals that produced larger fruits, which indirectly led to the production of larger seeds and seedlings, with possible effects on survival. We hypothesized that seedlings from managed populations would be larger but more susceptible to xeric conditions than those from wild populations. We evaluated the effects of artificial and natural selection on seedling survival of the three species in wild and managed populations, which were managed with low and high intensity, respectively. We tested seedling performance in gradients of shade (0, 40, and 80%) and humidity (low and high). A GLM of seedling survival showed significant differences among species, shade, and humidity treatments, with each species having environmental requirements associated with their particular adaptations. High humidity decreased seedling survival of all species, and high solar radiation decreased survival of S. pruinosus and P. chichipe. The effect of management type was significant only in S. pruinosus. Significant differences in the initial growth of seedlings among species were detected with ANOVA. In optimal conditions, the hypocotyl and the cotyledons decreased in size and the epicotyl grew, whereas under stress, these structures remained unchanged. The optimum conditions of shade and humidity varied among species and management types. The seedlings of S. pruinosus were the largest and the most susceptible, but in all species, seedlings from managed populations were more susceptible to environmental conditions. Thus, artificial selection influenced the susceptibility of these cacti to xeric environments.

  5. Characterization of prototype full-field breast tomosynthesis by using a CMOS array coupled with a columnar CsI(Tl) scintillator

    Energy Technology Data Exchange (ETDEWEB)

    Choi, Jae-Gu; Choi, Young-Wook; Ham, Tae-Hee [Korea Electrotechnology Research Institute, Ansan (Korea, Republic of); Park, Hye-Suk; Kim, Ye-Seul; Kim, Hee-Joung [Yonsei University, Wonju (Korea, Republic of)

    2012-02-15

    We have developed a prototype full-field digital breast tomosynthesis (DBT) system by using a complementary-metal-oxide semiconductive (CMOS) array coupled with a columnar CsI(Tl) scintillator. The imaging system consists of a matrix with an active detector area of 3072 x 3888 pixels and a pixel pitch of 74.8 μm. For tomosynthesis imaging, the X-ray tube is automatically rotated in 3 .deg. increments in the shoot mode to acquire projection images at 15 different angles over a ±21 .deg. angular range in less than 10 s. The digital detector is stationary during image acquisition. In this research, we also carried out evaluation studies to characterize the performance of the system in different operational modes designed for the DBT system, e.g., binning mode and the range of view angles, in terms of the modulation transfer function (MTF), the normalized noise power spectra (NNPS), and the detective quantum efficiency (DQE): The MTF value measured at the Nyquist frequency was 18.49%, the NNPS value at zero frequency was about 1.93 x 10{sup -5} (mm{sup 2}), and the maximum value of DQE was about 47.09% for the full resolution. For the pixel binning mode, the MTF decreased more than it did for the full resolution mode due to the increased effective pixel size. However, the full resolution mode was more sensitive to noise than the pixel binning mode. For the scan angle of the DBT system, oblique incidence of X-rays on a detector caused blurring that reduced resolution. These results seem to be promising for the use of the DBT system in potential clinical applications and will provide important information when comparisons with other DBT systems are made.

  6. Magnetocaloric effect of monovalent K doped manganites Pr{sub 0.6}Sr{sub 0.4−x}K{sub x}MnO{sub 3} (x=0 to 0.2)

    Energy Technology Data Exchange (ETDEWEB)

    Thaljaoui, R., E-mail: thaljaoui@gmail.com [Laboratoire de Physique des Matériaux, Facuté des Sciences de Sfax, Université de Sfax, B. P. 1171, 3000 Sfax (Tunisia); Faculty of Physics, Warsaw University of Technology, Koszykowa 75, 00-662 Warsaw (Poland); Department of Chemistry, University of Warsaw, Al. Zwirki i Wigury 101, 02-089 Warsaw (Poland); Boujelben, W. [Laboratoire de Physique des Matériaux, Facuté des Sciences de Sfax, Université de Sfax, B. P. 1171, 3000 Sfax (Tunisia); Pękała, M. [Department of Chemistry, University of Warsaw, Al. Zwirki i Wigury 101, 02-089 Warsaw (Poland); Pękała, K. [Faculty of Physics, Warsaw University of Technology, Koszykowa 75, 00-662 Warsaw (Poland); Fagnard, J.-F.; Vanderbemden, P. [SUPRATEC, Department of Electrical Engineering and Computer Science (B28), University of Liege, Liege (Belgium); Donten, M. [Department of Chemistry, University of Warsaw, Al. Zwirki i Wigury 101, 02-089 Warsaw (Poland); Cheikhrouhou, A. [Laboratoire de Physique des Matériaux, Facuté des Sciences de Sfax, Université de Sfax, B. P. 1171, 3000 Sfax (Tunisia)

    2014-02-15

    Magnetic and magnetocaloric properties are reported for polycrystalline monovalent potassium doped manganites Pr{sub 0.6}Sr{sub 0.4−x}K{sub x}MnO{sub 3} (x=0, 0.05, 0.1, 0.15 and 0.2) crystallized in orthorhombic structure with Pnma space group. The increasing K content shifts the paramagnetic to ferromagnetic transition temperature from 310 K for x=0 to 269 K for x=0.2. The magnetic entropy change under magnetic field variation of 2 T is found to be 1.95, 3.09, 2.89, 3.05 and 3.2 J/kgK for x varying from 0 to 0.2, respectively. The highest relative cooling power of 102 J/kg is observed for the undoped sample. The sensitivity of magnetic entropy change to magnetic field is estimated by a local N(T) exponent exhibiting the characteristic temperature variation. Phenomenological universal curves of entropy change and Arrott plots confirm the second order phase transition. - Highlights: • Unit-cell volume and tolerance factor grow with increasing K content in doped Pr{sub 0.6}Sr{sub 0.4−x}K{sub x}MnO{sub 3} manganites. • Maximum magnetic entropy change of 3.2 J/kg/K appears for x=0.2. • Maximum RCP equal to 102 J/kg observed for undoped sample. • Second order phase transition is confirmed by universal curves of entropy change and Arrott plots. • Sensitivity of magnetic entropy change and the RCP to magnetic field is estimated by exponent.

  7. Structural, magnetic and magneto-transport properties of monovalent doped manganite Pr{sub 0.55}K{sub 0.05}Sr{sub 0.4}MnO{sub 3}

    Energy Technology Data Exchange (ETDEWEB)

    Thaljaoui, R., E-mail: thaljaoui@gmail.com [Laboratoire de Physique des Matériaux, Faculté des Sciences de Sfax, Université de Sfax, B.P. 1171, 3000 Sfax (Tunisia); Faculty of Physics, Warsaw University of Technology, Koszykowa 75, 00-662 Warsaw (Poland); Department of Chemistry, University of Warsaw, Al. Zwirki i Wigury 101, 02-089 Warsaw (Poland); Boujelben, W. [Laboratoire de Physique des Matériaux, Faculté des Sciences de Sfax, Université de Sfax, B.P. 1171, 3000 Sfax (Tunisia); Pękała, M. [Department of Chemistry, University of Warsaw, Al. Zwirki i Wigury 101, 02-089 Warsaw (Poland); Pękała, K.; Antonowicz, J. [Faculty of Physics, Warsaw University of Technology, Koszykowa 75, 00-662 Warsaw (Poland); Fagnard, J.-F.; Vanderbemden, Ph. [SUPRATECS, Department of Electrical Engineering and Computer Science (B28), University of Liege (Belgium); Dąbrowska, S. [Warsaw University of Technology, Faculty of Materials Science, ul. Wołoska 141, 02-507 Warsaw (Poland); Mucha, J. [Institute of Low Temperature Physics and Structural Research, 50-422 Wrocław (Poland)

    2014-10-25

    Highlights: • Investigation of a new monovalent doped manganite Pr{sub 0.55}K{sub 0.05}Sr{sub 0.4}MnO{sub 3}. • The stability of the sample has been carried by using the DTA analysis. • Magnetic entropy change around 2.26 J kg{sup −1} K{sup −1} resulting RCP value of 70 J/kg for an applied magnetic field of 2 T. • Second order phase transition is confirmed by Arrott plots: A and B Landau coefficients. • Thermal conductivity values are found to be higher for sample with the largest crystallite sizes. - Abstract: Pr{sub 0.55}K{sub 0.05}Sr{sub 0.4}MnO{sub 3} sample have been synthesized using the conventional solid state reaction. Rietveld refinements of the X-ray diffraction patterns at room temperature confirm that the sample is single phase and crystallizes in the orthorhombic structure with Pnma space group; the crystallite size is around 70 nm. The SEM images show that grain size spreads around 1000–1200 nm. DTA analysis does not reveal any clear transition in temperature range studied. The low-temperature DSC indicates that Curie temperature is around 297 K. Magnetization measurements in a magnetic applied field of 0.01 T exhibit a paramagnetic–ferromagnetic transition at the Curie temperature T{sub C} = 303 K. A magnetic entropy change under an applied magnetic field of 2 T is found to be 2.26 J kg{sup −1} K{sup −1}, resulting in a large relative cooling power around 70 J/kg. Electrical resistivity measurements reveal a transition from semiconductor to metallic phase. The thermal conductivity is found to be higher than that reported for undoped and Na doped manganites reported by Thaljaoui et al. (2013)

  8. Single dose vaccination of the ASO3-adjuvanted A(H1N1)pdm09 monovalent vaccine in health care workers elicits homologous and cross-reactive cellular and humoral responses to H1N1 strains.

    Science.gov (United States)

    Lartey, Sarah; Pathirana, Rishi D; Zhou, Fan; Jul-Larsen, Åsne; Montomoli, Emanuele; Wood, John; Cox, Rebecca Jane

    2015-01-01

    Healthcare workers (HCW) were prioritized for vaccination during the 2009 influenza A(H1N1)pdm09 pandemic. We conducted a clinical trial in October 2009 where 237 HCWs were immunized with a AS03-adjuvanted A(H1N1)pdm09 monovalent vaccine. In the current study, we analyzed the homologous and cross-reactive H1N1 humoral responses using prototype vaccine strains dating back to 1977 by the haemagglutinin inhibition (HI), single radial hemolysis SRH), antibody secreting cell (ASC) and memory B cell (MBC) assays. The cellular responses were assessed by interferon-γ (IFN-γ) ELISPOT and by intracellular staining (ICS) for the Th1 cytokines IFN-γ, interleukin-2 (IL-2) and tumor necrosis factor-α (TNF-α). All assays were performed using blood samples obtained prior to (day 0) and 7, 14 and 21 d post-pandemic vaccination, except for ASC (day 7) and ICS (days 0 and 21). Vaccination elicited rapid HI, SRH and ASC responses against A(H1N1)pdm09 which cross reacted with seasonal H1N1 strains. MBC responses were detected against the homologous and seasonal H1N1 strains before vaccination and were boosted 2 weeks post-vaccination. An increase in cellular responses as determined by IFN-γ ELISPOT and ICS were observed 1-3 weeks after vaccination. Collectively, our data show that the AS03-adjuvanted A(H1N1)pdm09 vaccine induced rapid cellular and humoral responses against the vaccine strain and the response cross-reacted against prototype H1N1 strains dating back to 1977.

  9. Transversely isotropic constitutive properties of a columnar jointed rock mass%柱状节理岩体横观各向同性本构关系研究

    Institute of Scientific and Technical Information of China (English)

    狄圣杰; 徐卫亚; 王伟; 石安池

    2011-01-01

    A constitutive model of a transversely isotropic,columnar jointed rock mass is presented.The methods of composite material mechanics were used to consider staggered joints,inner disturbed belts,coordinate deflection,and other factors.Equivalent elastic parameters were calculated from the model.An in situ test at a dam for a hydro-power station showed the impact of the inner disturbed belts and of the joints of a columnar jointed rock mass.It appears that the inner disturbed belts have a large effect upon the elastic parameters of the columnar jointed basaltic mass located at the dam site.This impact reduces the elastic modulus more than 50% in the vertical direction.The effect of dip angle is obvious.In this case the dip angle is 15 degrees and so the equivalent vertical elastic modulus is reduced by about 19%.This approach allows an improved description of the anisotropic columnar jointed rock mass.The field application shows the horizontal elastic modulus is larger than the vertical elastic modulus.%采用复合材料力学方法,针对柱状节理岩体考虑节理交错、层内错动带及柱轴偏转等因素建立了横观各向同性本构模型,对其等效弹性参数进行了系统分析,并根据某拟建水电站坝址区玄武岩体原位试验资料,探讨了层内错动带和节理等因素对弹性参数的影响.研究表明:坝址区分布的层内错动带对柱状节理岩体弹性参数影响较大,在垂直于层内错动带方向上弹性模量减小了50%以上;柱状节理倾角影响也比较明显,在倾角为15°时,等效弹性模量下降低约19%.该方法可以完善描述柱状节理岩体各向异性变形特征和规律,揭示了原位测试水平向弹性模量大于铅直向的原因.

  10. Evaluation of MODIS columnar aerosol retrievals using AERONET in semi-arid Nevada and California, U.S.A., during the summer of 2012

    Science.gov (United States)

    Loría-Salazar, S. Marcela; Holmes, Heather A.; Patrick Arnott, W.; Barnard, James C.; Moosmüller, Hans

    2016-11-01

    Satellite characterization of local aerosol pollution is desirable because of the potential for broad spatial coverage, enabling transport studies of pollution from major sources, such as biomass burning events. However, retrieval of quantitative measures of air pollution such as Aerosol Optical Depth (AOD) from satellite measurements is challenging over land because the underlying surface albedo may be heterogeneous in space and time. Ground-based sunphotometer measurements of AOD are unaffected by surface albedo and are crucial in enabling evaluation, testing, and further development of satellite instruments and retrieval algorithms. Columnar aerosol optical properties from ground-based sunphotometers (Cimel CE-318) as part of AERONET and MODIS aerosol retrievals from Aqua and Terra satellites were compared over semi-arid California and Nevada during the summer season of 2012. Sunphotometer measurements were used as a 'ground truth' to evaluate the current state of satellite retrievals in this spatiotemporal domain. Satellite retrieved (MODIS Collection 6) AOD showed the presence of wildfires in northern California during August. During the study period, the dark-target (DT) retrieval algorithm appears to overestimate AERONET AOD by an average factor of 3.85 in the entire study domain. AOD from the deep-blue (DB) algorithm overestimates AERONET AOD by an average factor of 1.64. Low AOD correlation was also found between AERONET, DT, and DB retrievals. Smoke from fires strengthened the aerosol signal, but MODIS versus AERONET AOD correlation hardly increased during fire events (r2∼0.1-0.2 during non-fire periods and r2∼0-0.31 during fire periods). Furthermore, aerosol from fires increased the normalized mean bias (NMB) of MODIS retrievals of AOD (NMB∼23%-154% for non-fire periods and NMB∼77%-196% for fire periods). Ångström Extinction Exponent (AEE) from DB for both Terra and Aqua did not correlate with AERONET observations. High surface reflectance and

  11. Long term (2007-2013) observations of columnar aerosol optical properties and retrieved size distributions over Anantapur, India using multi wavelength solar radiometer

    Science.gov (United States)

    Raja Obul Reddy, K.; Balakrishnaiah, G.; Rama Gopal, K.; Siva Kumar Reddy, N.; Chakradhar Rao, T.; Lokeswara Reddy, T.; Nazeer Hussain, S.; Vasudeva Reddy, M.; Reddy, R. R.; Boreddy, S. K. R.; Suresh Babu, S.

    2016-10-01

    This paper presents the long - term observational studies on aerosol optical properties measured at Sri Krishnadevaraya University (SKU) campus (14° 62‧ N, 77° 65‧ E, 331m asl), Anantapur, in southern India during 2007-2013 using a ground based Multi - Wavelength solar Radiometer (MWR). Seasonal mean values of Aerosol Optical Depth (AOD) for the whole study period were observed to be 0.34 ± 0.03, 0.45 ± 0.04, 0.24 ± 0.04, and 0.31 ± 0.03 during the winter, summer, monsoon and post - monsoon, respectively. Annual mean values of Ångström exponent (α) (turbidity coefficient (β)) varied from 0.68 ± 0.25 (0.18 ± 0.03) to 1.1 ± 0.12 (0.32 ± 0.12) during 2007-2013. However, high values of α in the range of 0.8-1.1 were observed during the winter, while low values in the range 0.3-0.7 were noticed during the monsoon. The frequency distribution of AODs during winter in the range of 0.2-0.4 is about 78%, while summer these were shifted from 0.3 to 0.6 around ∼70%, which indicated the dust strongly affects this region. The accumulated frequencies of Ångström exponent (α) less than 1.0 and greater than 1.0 were about 69% and 31%, respectively, occurred in the summer months indicates the dominance of coarse particles. Columnar size distributions, retrieved from the spectral optical depths, in general, show a bimodal log normal distribution in the optically active size range. The seasonal mean effective radius (Reff) was found to be high in monsoon (∼0.61 μm) and low in winter (∼0.38 μm). The highest mean mass loading values are lies between 475 ± 36 to 769 ± 49 mg m-2 during the summer, whereas the lowest value in the range 204 ± 19 to 278 ± 23 mg m-2 during the monsoon. The difference between α and curvature effect have been studied as a function of AOD on seasonal basis. Finally, to understand the contribution of long range transported aerosols, we have investigated this analysis making use of back trajectories obtained from the HYSPLIT

  12. Comparison of in situ and columnar aerosol spectral measurements during TexAQS-GoMACCS 2006: testing parameterizations for estimating aerosol fine mode properties

    Directory of Open Access Journals (Sweden)

    D. B. Atkinson

    2010-01-01

    Full Text Available During the 2006 Texas Air Quality Study and Gulf of Mexico Atmospheric Composition and Climate Study (TexAQS-GoMACCS 2006, the optical, chemical and microphysical properties of atmospheric aerosols were measured on multiple mobile platforms and at ground based stations. In situ measurements of the aerosol light extinction coefficient (σep were performed by two multi-wavelength cavity ring-down (CRD instruments, one located on board the NOAA R/V Ronald H. Brown (RHB and the other located at the University of Houston, Moody Tower (UHMT. An AERONET sunphotometer was also located at the UHMT to measure the columnar aerosol optical depth (AOD. The σep data were used to extract the extinction Ångström exponent (åep, a measure of the wavelength dependence of σep. There was general agreement between the åep (and to a lesser degree σep measurements by the two spatially separated CRD instruments during multi-day periods, suggesting a regional scale consistency of the sampled aerosols. Two spectral models are applied to the σep and AOD data to extract the fine mode fraction of extinction (η and the fine mode effective radius (Reff,f. These two parameters are robust measures of the fine mode contribution to total extinction and the fine mode size distribution, respectively. The results of the analysis are compared to Reff,f values extracted using AERONET V2 retrievals and calculated from in situ particle size measurements on the RHB and at UHMT. During a time period when fine mode aerosols dominated the extinction over a large area extending from Houston/Galveston Bay and out into the Gulf of Mexico, the various methods for obtaining Reff,f agree qualitatively (showing the same temporal trend and quantitatively (pooled standard deviation = 28 nm.

  13. Comparison of in situ and columnar aerosol spectral measurements during TexAQS-GoMACCS 2006: testing parameterizations for estimating aerosol fine mode properties

    Directory of Open Access Journals (Sweden)

    D. B. Atkinson

    2009-08-01

    Full Text Available During the 2006 Texas Air Quality Study and Gulf of Mexico Atmospheric Composition and Climate Study (TexAQS-GoMACCS 2006, the optical, chemical and microphysical properties of atmospheric aerosols were measured on multiple mobile platforms and at ground based stations. In situ measurements of the aerosol light extinction coefficient (σep were performed by two multi-wavelength cavity ring-down (CRD instruments, one located on board the NOAA R/V Ronald H. Brown (RHB and the other located at the University of Houston, Moody Tower (UHMT. An AERONET sunphotometer was also located at the UHMT to measure the columnar aerosol optical depth (AOD. The σep data were used to extract the extinction Ångström exponent (åep, a measure of the wavelength dependence of σep. There was general agreement between the åep (and to a lesser degree σep measurements by the two spatially separated CRD instruments during multi-day periods, suggesting a regional scale consistency of the sampled aerosols. Two spectral models are applied to the σep and AOD data to extract the fine mode fraction of extinction (η and the fine mode effective radius (Reff f. These two parameters are robust measures of the fine mode contribution to total extinction and the fine mode size distribution respectively. The results of the analysis are compared to Reff f values extracted using AERONET V2 retrievals and calculated from in situ particle size measurements on the RHB and at UHMT. During a time period when fine mode aerosols dominated the extinction over a large area extending from Houston/Galveston Bay and out into the Gulf of Mexico, the various methods for obtaining Reff f agree qualitatively (showing the same temporal trend and quantitatively (pooled standard deviation

  14. Airborne Sunphotometer Measurements of Aerosol Optical Depth and Columnar Water Vapor During the Puerto Rico Dust Experiment, and Comparison with Land, Aircraft, and Satellite Measurements

    Science.gov (United States)

    Livingston, John M.; Russell, Philip B.; Reid, Jeffrey; Redemann, Jens; Schmid, Beat; Allen, Duane A.; Torres, Omar; Levy, Robert C.; Remer, Lorraine A.; Holben, Brent N.; Hipskind, R. Stephen (Technical Monitor)

    2002-01-01

    Analyses of aerosol optical depth (AOD) and columnar water vapor (CWV) measurements obtained with the six-channel NASA Ames Airborne Tracking Sunphotometer (AATS-6) mounted on a twin-engine aircraft during the summer 2000 Puerto Rico Dust Experiment are presented. In general, aerosol extinction values calculated from AATS-6 AOD measurements acquired during aircraft profiles up to 5 km ASL reproduce the vertical structure measured by coincident aircraft in-situ measurements of total aerosol number and surface area concentration. Calculations show that the spectral dependence of AOD was small (mean Angstrom wavelength exponents of approximately 0.20) within three atmospheric layers defined as the total column beneath the top of each aircraft profile, the region beneath the trade wind inversion, and the region within the Saharan Air Layer (SAL) above the trade inversion. This spectral behavior is consistent with attenuation of incoming solar radiation by large dust particles or by dust plus sea salt. Values of CWV calculated from profile measurements by AATS-6 at 941.9 nm and from aircraft in-situ measurements by a chilled mirror dewpoint hygrometer agree to within approximately 4% (0.13 g/sq cm). AATS-6 AOD values measured on the ground at Roosevelt Roads Naval Air Station and during low altitude aircraft runs over the adjacent Cabras Island aerosol/radiation ground site agree to within 0.004 to 0.030 with coincident data obtained with an AERONET Sun/sky Cimel radiometer located at Cabras Island. For the same observation times, AERONET retrievals of CWV exceed AATS-6 values by a mean of 0.74 g/sq cm (approximately 21 %) for the 2.9-3.9 g/sq cm measured by AATS-6. Comparison of AATS-6 aerosol extinction values obtained during four aircraft ascents over Cabras Island with corresponding values calculated from coincident aerosol backscatter measurements by a ground-based micro-pulse lidar (MPL-Net) located at Cabras yields a similar vertical structure above the trade

  15. Dating Cactus: Annual and Sub-annual Variations of Oxygen-18, Carbon-13 and Radiocarbon in Spines of a Columnar Cactus, Carnegiea gigantea.

    Science.gov (United States)

    Dettman, D. L.; English, N. B.; Sandquist, D. R.; Williams, D. G.

    2006-12-01

    We measured δ18O, δ13C and F14C of spines from a long-lived columnar cactus, Carnegiea gigantea (saguaro), to resolve a record of plant physiological responses to annual and sub-annual climate variation in the eastern Sonoran Desert. Spines grow from the apex of the cactus and are arranged serially along the side of the cactus oldest at the base, youngest at the apex. To establish the age of the spine series, we measured F14C of spines collected at 8 different heights from the apex (3.77 m) to the base of a naturally occurring saguaro. These spines yielded fractions of modern carbon (F14C) from 0.9679 and 1.5537, indicating the presence of carbon in spine tissue derived from atmospheric nuclear testing. We used the F14C of spine tissue to calculate the year of spine emergence for each of the 11 spines, assuming minimal re-allocation of stored carbon to growing spines. At the same 8 heights, we interpolated the date of spine emergence from observed height measurements made between 1964 and 2002. A very strong positive correlation (linear regression, r2 = 0.99, P spines and ages determined from direct height measurements was observed, with a two year offset suggesting incorporation of carbon from fossil fuel combustion sources in the Tucson basin. Additionally, spine tips from 97 spines collected serially from the top half of the same saguaro (between 1.77 and 3.50 m) and representing ~15 years of growth, yielded δ18O variations in spine bulk organic material from 38° to 50° (VSMOW) and in δ13C from ° to 11.5° (VPDB). The δ18O and δ13C values were positively correlated over the entire record (linear regression, r2 = 0.22, P spine organic material from the naturally occurring cactus were observed in spines grown shortly following the 1983 and 1993 strong El Niño winter precipitation events in Tucson, suggesting that isotopes in spine tissue are a good proxy of these climate anomalies. We found similar δ18O, δ13C and F14C variations and relationships in a

  16. Risk factors for ventilator-associated pneumonia caused by meningeal septic flavobacterium in cardiac ICU and analysis of drug resistance%心外科ICU脑膜败血性黄杆菌致呼吸机相关性肺炎危险因素及耐药性分析

    Institute of Scientific and Technical Information of China (English)

    王珂; 王伟

    2013-01-01

    目的 探讨ICU脑膜败血性黄杆菌所致呼吸机相关性肺炎(VAP)危险因素及耐药性.方法 采用回顾性调查方法,对2009-2011年心外科ICU42例脑膜败血性黄杆菌所致VAP患者临床资料进行统计分析.结果 0~3岁患儿占80.95%,≥60岁患者占19.05%;机械通气天数平均≥1周,患者合并有≥3种侵入性操作;所有患者均有较长时间使用广谱抗菌药物史;脑膜败血性黄杆菌对哌拉西林/他唑巴坦、头孢哌酮/舒巴坦、磺胺甲噁唑/甲氧苄啶耐药率<5.0%,对庆大霉素、妥布霉素、哌拉西林、头孢噻肟耐药率>90.0%;部分呼吸机外置管道及附件采样监测出脑膜败血性黄杆菌.结论 低龄、长时间入住ICU、机械通气时间较长、多种侵入性操作、广谱抗菌药物使用及呼吸机管道附件消毒是否彻底,是心外ICU患者发生脑膜败血性黄杆菌致VAP的危险因素;哌拉西林/他唑巴坦、头孢哌酮/舒巴坦是抗感染治疗的首选药.%OBJECTIVE To investigate the risk factors and etiology on ventilator-associated pneumonia caused by meningeal septic flavobacterium in cardiac ICU.METHODS By means of the retrospective review,the clinical data of 42 patients with ventilator-associated pneumonia caused by meningeal septic flavobacterium in cardiac ICU from 2009 to 2011 was statistically analyzed.RESULTS The children aged from 0 to 3 years old accounted for 80.95%,and the patients aged more than 60 years accounted for 19.05 %; the average duration of mechanical ventilation was no less than 1 week,and the patients underwent no less than three invasive operations; all of the patients had the long history of using broad-spectrum antimicrobial drugs; the drug resistance rates of Meningeal septic flavobacterium to piperacillin/tazobactam,cefoperazone sodium/sulbactam,and trimethoprim and sulphamethoxazole were under 5.0%,and the drug resistance rates to gentamicin

  17. 虹彩病毒和柱状黄杆菌混合感染大鲵的诊治%Diagnosis and Treatment on Andrias davidianuss Mixed Infected with Iridovirus and Flabobacterium columnare

    Institute of Scientific and Technical Information of China (English)

    王芳; 余波; 史开志; 杨莉; 徐景峨; 谭诗文

    2013-01-01

    In July 2012,a case of disease occurred with typical clinical signs including ulcers in the skin,swell in the limbs,internal organs hyperemia and hemorrhage at A ndrias davidianus farm in Guizhou.After the clinical symptoms observation,the pathological anatomy and laboratory diagnosis,this disease was diagnosed of mixed infection of Iridovirus and Flabobacterium columnare.Through taking the synthesis effective preventive measure,the epidemic situation of A.davidimus had been effectively controlled.%2012年7月,贵州省某大鲵养殖场发生了以大鲵体表和四肢多处溃烂、内脏器官出现充血、出血为特征的疾病,经过临床症状观察、病理剖检及实验室诊断,诊断为虹彩病毒(Iridovirus)和柱状黄杆菌(Flabobacterium columnare)的混合感染.通过采取综合有效的防治措施,大鲵疫情得到有效控制.

  18. Identification of 2-keto-3-deoxy-d-Gluconate Kinase and 2-keto-3-deoxy-d-Phosphogluconate Aldolase in an Alginate-Assimilating Bacterium, Flavobacterium sp. Strain UMI-01

    Science.gov (United States)

    Nishiyama, Ryuji; Inoue, Akira; Ojima, Takao

    2017-01-01

    Recently, we identified an alginate-assimilating gene cluster in the genome of Flavobacterium sp. strain UMI-01, a member of Bacteroidetes. Alginate lyase genes and a 4-deoxy-l-erythro-5-hexoseulose uronic acid (DEH) reductase gene in the cluster have already been characterized; however, 2-keto-3-deoxy-d-gluconate (KDG) kinase and 2-keto-3-deoxy-6-phosphogluconate (KDPG) aldolase genes, i.e., flkin and flald, still remained uncharacterized. The amino acid sequences deduced from flkin and flald showed low identities with those of corresponding enzymes of Saccharophagus degradans 2-40T, a member of Proteobacteria (Kim et al., Process Biochem., 2016). This led us to consider that the DEH-assimilating enzymes of Bacteroidetes species are somewhat deviated from those of Proteobacteria species. Thus, in the present study, we first assessed the characteristics in the primary structures of KDG kinase and KDG aldolase of the strain UMI-01, and then investigated the enzymatic properties of recombinant enzymes, recFlKin and recFlAld, expressed by an Escherichia coli expression system. Multiple-sequence alignment among KDG kinases and KDG aldolases from several Proteobacteria and Bacteroidetes species indicated that the strain UMI-01 enzymes showed considerably low sequence identities (15%–25%) with the Proteobacteria enzymes, while they showed relatively high identities (47%–68%) with the Bacteroidetes enzymes. Phylogenetic analyses for these enzymes indicated the distant relationship between the Proteobacteria enzymes and the Bacteroidetes enzymes, i.e., they formed distinct clusters in the phylogenetic tree. recFlKin and recFlAld produced with the genes flkin and flald, respectively, were confirmed to show KDG kinase and KDPG aldolase activities. Namely, recFlKin produced 1.7 mM KDPG in a reaction mixture containing 2.5 mM KDG and 2.5 mM ATP in a 90-min reaction, while recFlAld produced 1.2 mM pyruvate in the reaction mixture containing 5 mM KDPG at the equilibrium

  19. Identification of 2-keto-3-deoxy-d-Gluconate Kinase and 2-keto-3-deoxy-d-Phosphogluconate Aldolase in an Alginate-Assimilating Bacterium, Flavobacterium sp. Strain UMI-01.

    Science.gov (United States)

    Nishiyama, Ryuji; Inoue, Akira; Ojima, Takao

    2017-02-14

    Recently, we identified an alginate-assimilating gene cluster in the genome of Flavobacterium sp. strain UMI-01, a member of Bacteroidetes. Alginate lyase genes and a 4-deoxy-l-erythro-5-hexoseulose uronic acid (DEH) reductase gene in the cluster have already been characterized; however, 2-keto-3-deoxy-d-gluconate (KDG) kinase and 2-keto-3-deoxy-6-phosphogluconate (KDPG) aldolase genes, i.e., flkin and flald, still remained uncharacterized. The amino acid sequences deduced from flkin and flald showed low identities with those of corresponding enzymes of Saccharophagus degradans 2-40(T), a member of Proteobacteria (Kim et al., Process Biochem., 2016). This led us to consider that the DEH-assimilating enzymes of Bacteroidetes species are somewhat deviated from those of Proteobacteria species. Thus, in the present study, we first assessed the characteristics in the primary structures of KDG kinase and KDG aldolase of the strain UMI-01, and then investigated the enzymatic properties of recombinant enzymes, recFlKin and recFlAld, expressed by an Escherichia coli expression system. Multiple-sequence alignment among KDG kinases and KDG aldolases from several Proteobacteria and Bacteroidetes species indicated that the strain UMI-01 enzymes showed considerably low sequence identities (15%-25%) with the Proteobacteria enzymes, while they showed relatively high identities (47%-68%) with the Bacteroidetes enzymes. Phylogenetic analyses for these enzymes indicated the distant relationship between the Proteobacteria enzymes and the Bacteroidetes enzymes, i.e., they formed distinct clusters in the phylogenetic tree. recFlKin and recFlAld produced with the genes flkin and flald, respectively, were confirmed to show KDG kinase and KDPG aldolase activities. Namely, recFlKin produced 1.7 mM KDPG in a reaction mixture containing 2.5 mM KDG and 2.5 mM ATP in a 90-min reaction, while recFlAld produced 1.2 mM pyruvate in the reaction mixture containing 5 mM KDPG at the equilibrium state

  20. Impact of wet scavenging of natural and anthropogenic aerosol components on the columnar aerosol optical depth over a tropical rural atmosphere

    Science.gov (United States)

    Chatterjee, Abhijit; Jayaraman, Achuthan

    A typical feature of Indian monsoon is that, several dry days are observed even between the rain events. Atmospheric aerosol shows significant variations in their concentration between "before" and "after" the rain because of their efficient scavenging during the rain. The below cloud scavenging of several aerosol components during the rain has a direct impact on the columnar aerosol optical depth (AOD) between "before" and "after" the rain. In order to investigate the impact of the scavenging of several natural and anthropogenic aerosol components on spectral properties of aerosol, simultaneous studies on the characterization of aerosol, rainwater and AOD were done during July-December 2009 over a tropical rural atmosphere at Gadanki (13.5 0N, 79.2 0E) in southern peninsular India. Aerosols were collected and analyzed before, during and after the rain along with the collection and analysis of rainwater in several rain events during the entire study period. AOD data (at wavelengths of 400, 500, 675, 870, 1020 nm) was retrieved by processing the data obtained from an automatic sunphotomer (PREDE, PM 01) using the standard SKYRAD pack. Aerosols and rainwater samples were analyzed for water soluble ionic species using an Ion Chromatograph (Metrohm, 861). We observed that aerosols were highly loaded in the atmosphere just before the rain, efficiently scavenged during the rain and built-up slowly after the rain. Interestingly, the loading of sulphate aerosol after the rain was remarkably high whereas that of calcium and magnesium were remarkably low. The poor resuspension of soil dust from the wet soils after the rain could not allow calcium and magnesium to be loaded in the atmosphere whereas the high relative humidity favored the gas-to-particle conversion of SO2 to SO42-which allowed the high loading of sulphate aerosol in the atmosphere. Significant reductions in AOD both at lower (400 nm) and higher wavelength (1020 nm) were observed after the rain events. Two

  1. The Green Function and the Law of Volumetric Strain for Biot Consolidation of Columnar Soil-sample%圆柱土样Biot固结模型的Green函数及其土体体积应变规律

    Institute of Scientific and Technical Information of China (English)

    原新生; 吕金城; 肖建清

    2013-01-01

    通过建立横观各向同性圆柱土样轴对称Biot固结问题的Green·函数,得到了用Green函数表示的径向位移分布表达式和相应的空隙水压力的精确解析解.该方法不仅避免了将问题的解分解为弹性静力学解和渗流拟动态解的叠加的过程和复杂的积分变换,而且问题的级数解形式简洁,收敛速度较快,便于数值计算和圆柱土样的全场渗流固结规律的分析.最后以此结果具体分析了Mandel-Cryer效应在圆柱土样不同位置的强弱程度和土的泊松比对Mandel-Cryer效应的影响,表明本文方法的正确性.%The expression of radial displacement which expressed by Green function for Biot consolidation of columnar cross-isotropic soil-sample is obtained by building Green function.Correspondingly,exact analytical solutions for volumetric strain and pore water pressure are obtained also.This method not only avoid the process of decomposing solution of the Biot consolidation of columnar cross-isotropic soil-sample into the elasticity static's solution and quasi-dynamic solution of fluids,but also easy to numerical calculation and analyzing the full-court filtration concretion law for columnar cross-isotropic soil-sample.In the end of this paper,with this result,we particularly analyze the law of volumetric strain of soils and the degree of the Mandel-Cryer effect in different position of soil-sample and the influence of Poisson's ratio on the Mandel-Cryer effect.

  2. 柱状节理岩体原位变形试验力学浅析与模拟%Mechanical analysis and simulation of in-situ deformation test of columnar jointed rock mass

    Institute of Scientific and Technical Information of China (English)

    狄圣杰; 徐卫亚; 王伟; 吴关叶

    2012-01-01

    在白鹤滩坝址区柱状节理岩体原位变形试验成果的基础上,针对节理刚度的取值进行讨论,利用柔性中心孔试验值反算得到柱状节理岩体节理面刚度值.岩体变形是由岩块和节理两部分组成,分析含单节理岩体概念模型的单轴加、卸载规律性和其变形特性,发现其滞回特性是节理力学行为造成的;推导得到了岩体变形计算公式,可用于多组相交节理岩体等效弹性模量的计算,能够反映出节理岩体的各向异性特征;建立了柱状节理随机模型,采用离散元方法和反算的刚度值进行了仿真分析,得到等效变形参数在试验结果范围内.%The value of joint stiffness based on in-situ deformation experimental results of columnar jointed rock mass in Baihetan dam region was discussed. The value of columnar joint stiffness is obtained by using experimental data of flexible central hole deformation test. The regulation and deformation properties of rock single concept model are analyzed. Rock deformation is made up of two parts, one of rock and one of rock joint, and its hysteretic properties are determined by joints' mechanical behavior. Moreover, the formula of deformation deduced can calculate the equivalent elastic modulus of multi-set intersection joint rock and describe the anisotropic characteristics of jointed rock. A random model of columnar jointed rock mass is established. The rock mass is stimulated by using discrete element method and the stiffness of reverse calculation; and equivalent deformation parameters obtained are in the range of test results.

  3. Polaribacter gen. nov., with three new species, P. irgensii sp. nov., P. franzmannii sp. nov. and P. filamentus sp. nov., gas vacuolate polar marine bacteria of the Cytophaga-Flavobacterium-Bacteroides group and reclassification of 'Flectobacillus glomeratus' as Polaribacter glomeratus comb. nov

    Science.gov (United States)

    Gosink, J. J.; Woese, C. R.; Staley, J. T.

    1998-01-01

    Several psychrophilic, gas vacuolate strains of the Cytophage-Flavobacterium-Bacteroides (CFB) phylogenetic group were isolated from sea ice and water from the Arctic and the Antarctic. The closest taxonomically defined species by 16S rRNA sequence analysis is 'Flectobacillus glomeratus'. However, 'Flc. glomeratus' is phylogenetically distant from the Flectobacillus type species, Flc. major. On the basis of phenotypic, genotypic and 16S rRNA sequence analyses we propose a new genus, Polaribacter, with three new species, Polaribacter irgensii strain 23-P (ATCC 700398), Polaribacter franzmannii strain 301 (ATCC 700399) and Polaribacter filamentus strain 215 (ATCC 700397). P. filamentus is the type species of the genus. None of these species exhibits a cosmopolitan or bipolar distribution. This is the first taxonomic description of gas vacuolate bacteria in the CFB group. Additionally, we propose that 'Flc. glomeratus' be reclassified to the genus Polaribacter as P. glomeratus, comb. nov.

  4. Polaribacter gen. nov., with three new species, P. irgensii sp. nov., P. franzmannii sp. nov. and P. filamentus sp. nov., gas vacuolate polar marine bacteria of the Cytophaga-Flavobacterium-Bacteroides group and reclassification of 'Flectobacillus glomeratus' as Polaribacter glomeratus comb. nov

    Science.gov (United States)

    Gosink, J. J.; Woese, C. R.; Staley, J. T.

    1998-01-01

    Several psychrophilic, gas vacuolate strains of the Cytophage-Flavobacterium-Bacteroides (CFB) phylogenetic group were isolated from sea ice and water from the Arctic and the Antarctic. The closest taxonomically defined species by 16S rRNA sequence analysis is 'Flectobacillus glomeratus'. However, 'Flc. glomeratus' is phylogenetically distant from the Flectobacillus type species, Flc. major. On the basis of phenotypic, genotypic and 16S rRNA sequence analyses we propose a new genus, Polaribacter, with three new species, Polaribacter irgensii strain 23-P (ATCC 700398), Polaribacter franzmannii strain 301 (ATCC 700399) and Polaribacter filamentus strain 215 (ATCC 700397). P. filamentus is the type species of the genus. None of these species exhibits a cosmopolitan or bipolar distribution. This is the first taxonomic description of gas vacuolate bacteria in the CFB group. Additionally, we propose that 'Flc. glomeratus' be reclassified to the genus Polaribacter as P. glomeratus, comb. nov.

  5. Practice of Participation of Clinical Pharmacists in Adjustment of Anti-infection Therapeutic Scheme in One Case of Flavobacterium Breve Infection%临床药师参与短黄杆菌感染患者抗感染治疗的实践

    Institute of Scientific and Technical Information of China (English)

    鲁晓燕; 孟静

    2016-01-01

    OBJECTIVE:To probe into the pharmaceutical practice of participation of clinical pharmacists in adjustment of anti-infection therapeutic scheme in one case of flavobacterium breve infection.METHODS:The clinical pharmacists participated into the drug treatment process of one case of flavobacterium breve infection by consultation and continuous monitoring, analyzed the medication status, put forward suggestions for the clinicians to formulate rational therapeutic regimen and monitored the patient’s medication process.RESULTS: The clinical pharmacists assisted the clinicians to adjust therapeutic regimen and promoted the improvement of the disease condition.CONCLUSIONS: The clinical pharmacists participate into the individualized treatment process, bring their pharmaceutical speciality into full play and assist the clinicians with safety and effective medication, which fully reflect their own value.%目的:探讨临床药师参与短黄杆菌感染患者抗感染治疗的药学实践。方法:临床药师参加会诊并持续性监护1例短黄杆菌感染患者的药物治疗过程,分析用药情况,为医师制订合理的用药方案提出建议,并对药品不良反应进行监护。结果:临床药师协助医师调整用药方案,促进患者病情好转。结论:临床药师参与个体化治疗过程,发挥药学专长,协助医师安全、有效地用药,体现了自身的价值。

  6. High temporal resolution estimates of columnar aerosol microphysical parameters from spectrum of aerosol optical depth by linear estimation: application to long-term AERONET and star-photometry measurements

    Science.gov (United States)

    Perez-Ramirez, D.; Veselovskii, I.; Whiteman, D. N.; Suvorina, A.; Korenskiy, M.; Kolgotin, A.; Holben, B.; Dubovik, O.; Siniuk, A.; Alados-Arboledas, L.

    2015-08-01

    This work deals with the applicability of the linear estimation technique (LE) to invert spectral measurements of aerosol optical depth (AOD) provided by AERONET CIMEL sun photometers. The inversion of particle properties using only direct-sun AODs allows the evaluation of parameters such as effective radius (reff) and columnar volume aerosol content (V) with significantly better temporal resolution than the operational AERONET algorithm which requires both direct sun and sky radiance measurements. Sensitivity studies performed demonstrate that the constraints on the range of the inversion are very important to minimize the uncertainties, and therefore estimates of reff can be obtained with uncertainties less than 30 % and of V with uncertainties below 40 %. The LE technique is applied to data acquired at five AERONET sites influenced by different aerosol types and the retrievals are compared with the results of the operational AERONET code. Good agreement between the two techniques is obtained when the fine mode predominates, while for coarse mode cases the LE results systematically underestimate both reff and V. The highest differences are found for cases where no mode predominates. To minimize these biases, correction functions are developed using the multi-year database of observations at selected sites, where the AERONET retrieval is used as the reference. The derived corrections are tested using data from 18 other AERONET stations offering a range of aerosol types. After correction, the LE retrievals provide better agreement with AERONET for all the sites considered. Finally, the LE approach developed here is applied to AERONET and star-photometry measurements in the city of Granada (Spain) to obtain day-to-night time evolution of columnar aerosol microphysical properties.

  7. Iron acquisition mechanisms of Flavobacterium psychrophilum

    DEFF Research Database (Denmark)

    Møller, Jeannette Dan; Ellis, A.E.; Barnes, A.C.

    2005-01-01

    strains and was lacking from negative strains. While a weak catechol reaction was detectable in CAS+ culture supernatants, the CAS reaction was, to some extent, heat sensitive, questioning whether the positive reaction was caused only by siderophores. The ability to grow in vitro under iron......-restricted conditions did not correlate with the CAS reactivity, as growth of both CAS+ and CAS- strains was similarly impaired under iron restriction induced by 2,2 dipyridyl. Suppressed growth under these conditions was restored by addition of FeCl3, haemoglobin and transferrin for both CAS+ and CAS- strains...

  8. Flavobacterium psychrophilum - Experimental challenge and immune response

    DEFF Research Database (Denmark)

    Henriksen, Maya Maria Mihályi

    use of antibiotics, further knowledge of the disease is needed. Previous studies focusing on various types of aquacultures demonstrated the presence of F. psychrophilum in all examined farms. The bacterium was demonstrated in gills, skin, internal organs and wounds both during RTFS outbreaks......) Establish an experimental infection model imitating natural infection, 2) examine the immune response in blood and selected organs, and 3) examine potential portals of entry for the bacterium. Previous experimental immersion-challenges involving F. psychrophilum have resulted in none or low mortality...... in rainbow trout fry, unless the fish are stressed or have their surface compromised through e.g. injuries to the skin. The effect of a range of hydrogen peroxide (H2O2) concentrations was tested on fry in order to assess mortality. An appropriate dose was subsequently combined with immersion in a diluted...

  9. Lasting immune memory against hepatitis B following challenge 10-11 years after primary vaccination with either three doses of hexavalent DTPa-HBV-IPV/Hib or monovalent hepatitis B vaccine at 3, 5 and 11-12 months of age.

    Science.gov (United States)

    Avdicova, Mária; Crasta, Priya D; Hardt, Karin; Kovac, Martina

    2015-05-28

    The combined hexavalent diphtheria-tetanus-pertussis-hepatitis B-inactivated poliomyelitis - Haemophilus influenzae type b conjugate vaccine (Infanrix hexa™; DTPa-HBV-IPV/Hib: GlaxoSmithKline Vaccines) induces robust responses to the HBV component when administered at 3, 5 and 11-12 months of age. We assessed long term HBV antibody persistence 10-11 years after primary vaccination in infancy. Antibody persistence and immune memory were assessed post-primary vaccination at 3, 5, 11-12 months with DTPa-HBV-IPV/Hib, or monovalent HBV vaccine (Engerix™ B, GlaxoSmithKline Vaccines) co-administered with DTPa-IPV/Hib (Infanrix™-IPV/Hib, GlaxoSmithKline Vaccines) in 185 children aged 11-12 years. Blood samples were collected before and 1 month after a challenge dose of Engerix™ B (10μg dose). 10-11 years after primary vaccination the percentage of subjects with persisting anti-HBs antibody concentrations ≥10mIU/ml was 48.4% in the DTPa-HBV-IPV/Hib group and 58.4% in the DTPa-IPV/Hib+HBV group. After the HBV challenge dose, the percentage with anti-HBs ≥100mIU/ml increased from 14.7% to 93.6% in the DTPa-HBV-IPV/Hib group and 19.1% to 94.4% in the DTPa-IPV/Hib+HBV group. Anti-HBs GMCs increased by at least 187-fold in each group. An anamnestic response (≥4-fold increase in initially seropositive or anti-HBs concentration ≥10mIU/ml in initially seronegative subjects) was observed in 96.8% and 96.6% of subjects in the DTPa-HBV-IPV/Hib and DTPa-IPV/Hib+HBV groups, respectively. No serious adverse events occurred that were considered related to challenge vaccination. Administration of HBV as part of a combination vaccine or as a monovalent vaccine induced long lasting immune memory against HBV in children primed at 3, 5 and 11 months of age. Antibody persistence and immune memory were similar, suggesting that protection afforded by DTPa-HBV-IPV/Hib and monovalent HBV vaccines, is likely to be of similar duration. The administration of HBV challenge dose 10

  10. 桂林西瓜霜对宫颈糜烂组织细胞的影响研究%Study on the effect of Guilin watermelon frost on cervical columnar ectopy tissue and cells

    Institute of Scientific and Technical Information of China (English)

    董林红; 蒋秋燕; 宋金玲; 张琪; 李艳林; 莫海霞

    2012-01-01

    Objective: To explore the effect of Guilin watermelon frost on cervical columnar ectopy tissue and cells. Methods: One hundred and sixty patients with cervical columnar ectopy were randomly divided into observation group and control group; the patients in observation group were treated with sprayed coating of Guilin watermelon frost on the erosion surface; while the patients in control group were treated with external application of bFGF - collagen sponge. The hyperplasia of mucosal epithelial cells, inflammatory cell infiltration, and interstitial fibroblast proliferation in the two groups were observed under light microscope. Results: Guilin watermelon frost used in observation group had a promoting effect on hyperplasia of squamous epithelial cells, decrease of the inflammatory cells, formation of granulation tissue and fibroblast, and angiogenesis. The intact rate of covering epithelium of cervical tissue in observation group was significantly higher than that in control group (P0.05) . Conclusion; Guilin watermelon frost has anti - inflammatory effect and anti - bacterial effect, which can promote the healing of the erosion surface.%目的:探讨桂林西瓜霜对宫颈糜烂组织细胞的影响.方法:将160例宫颈糜烂患者随机分为观察组和对照组,观察组用桂林西瓜霜喷敷宫颈糜烂面;对照组采用bFGF -胶原蛋白海绵外敷.光学显微镜下观察两组治疗前后的黏膜上皮细胞增生、炎细胞浸润、间质成纤维细胞增生情况.结果:观察组采用的桂林西瓜霜对鳞状上皮细胞增生、炎性细胞减少、肉芽组织及成纤维细胞形成、血管新生等有促进作用.经组织细胞病理形态学积分差比较,观察组对宫颈组织被覆上皮完好率高于对照组,经积分差u检验(P<0.05)差异有统计学意义;成纤维细胞增生积分差经u检验(P>0.05)差异无统计学意义.结论:桂林西瓜霜具有消炎抗菌、促进糜烂面愈合的作用.

  11. РЕЗУЛЬТАТЫ ИЗУЧЕНИЯ БИОХИМИЧЕСКИХ СВОЙСТВ FLAVOBACTERIUM PSYCHROPHILUM

    Directory of Open Access Journals (Sweden)

    ВИКТОРОВ Д.А.

    2014-01-01

    Full Text Available В проделанной работе проведёно изучение основных биохимических свойств Flavobacterium psychrophilum, определены дифференциально-значимые признаки, выяснены температурные оптимумы культивирования названного микроорганизма. Полученные результаты позволяют сделать выводы о целесообразности введения определённых компонентов (лактозы, мочевины в состав селективных и дифференциально-диагностических питательных сред для выделения и культивирования Flavobacterium psychrophilum.

  12. Using kaolin clay to combat columnaris disease

    Science.gov (United States)

    Columnaris disease, caused by the bacterial pathogen Flavobacterium columnare, continues to be a major problem in cultured freshwater finfish. Despite the far-reaching negative impacts of columnaris disease, safe and effective preventatives and curatives for this disease remain limited. In the pre...

  13. Kaolin clay protects fish from columnaris disease

    Science.gov (United States)

    Columnaris disease, caused by the bacterial pathogen Flavobacterium columnare, continues to be a major problem worldwide in cultured freshwater finfish. Despite the far-reaching negative impacts of columnaris disease, safe and efficacious preventatives and curatives for this disease remain limited....

  14. Antibacterial activity of plant extracts from Brazil against fish pathogenic bacteria

    Science.gov (United States)

    Castro, S.B.R.; Leal, C.A.G.; Freire, F.R.; Carvalho, D.A.; Oliveira, D.F.; Figueiredo, H.C.P.

    2008-01-01

    The aim of this work was to evaluate the antibacterial activity of Brazilian plants extracts against fish pathogenic bacteria. Forty six methanolic extracts were screened to identify their antibacterial properties against Streptococcus agalactiae, Flavobacterium columnare and Aeromonas hydrophila. Thirty one extracts showed antibacterial activity. PMID:24031303

  15. Rapid detection and identification of viral and bacterial fish pathogens using a DNA array‐based multiplex assay

    DEFF Research Database (Denmark)

    Lievens, B.; Frans, I.; Heusdens, C.

    2011-01-01

    for the simultaneous detection and identification of all cyprinid herpesviruses (CyHV‐1, CyHV‐2 and CyHV‐3) and some of the most important fish pathogenic Flavobacterium species, including F. branchiophilum, F. columnare and F. psychrophilum. For virus identification, the DNA polymerase and helicase genes were...

  16. Ultra Encryption Standard Modified (UES Version-I: Symmetric Key Cryptosystem With Multiple Encryption and Randomized Vernam Key Using Generalized Modified Vernam Cipher Method, Permutation Method, and Columnar Transposition Method

    Directory of Open Access Journals (Sweden)

    Satyaki Roy

    2012-07-01

    Full Text Available In the present paper a new combined cryptographic method called Modified UES Version-I has been introduced. Nath et al. have already developed several symmetric key methods. It combines three different methods namely, Generalized Modified Vernam Cipher method, Permutation method and Columnar Transposition method. Nath et al recently developed few efficient combined encryption methods such as TTJSA, DJMNA where they have used generalized MSA method, NJJSAA method and DJSA methods. Each of the methods can be applied independently to encrypt any message. Nath et. al showed that TTJSA and DJMNA is most suitable methods to encrypt password or any small message. The name of this method is Ultra Encryption Standard modified (UES version-I since it is based on UES version-I developed by Roy et. al. In this method an encryption key pad in Vernam Cipher Method also the feedback has been used which is considered to make the encryption process stronger. Modified UES Version-I may be applied to encrypt data in any office, corporate sectors etc. The method is most suitable to encrypt any type of file such as text, audio, video, image and databases etc

  17. Validation of columnar CsI x-ray detector responses obtained with hybridMANTIS, a CPU-GPU Monte Carlo code for coupled x-ray, electron, and optical transport.

    Science.gov (United States)

    Sharma, Diksha; Badano, Aldo

    2013-03-01

    hybridMANTIS is a Monte Carlo package for modeling indirect x-ray imagers using columnar geometry based on a hybrid concept that maximizes the utilization of available CPU and graphics processing unit processors in a workstation. The authors compare hybridMANTIS x-ray response simulations to previously published MANTIS and experimental data for four cesium iodide scintillator screens. These screens have a variety of reflective and absorptive surfaces with different thicknesses. The authors analyze hybridMANTIS results in terms of modulation transfer function and calculate the root mean square difference and Swank factors from simulated and experimental results. The comparison suggests that hybridMANTIS better matches the experimental data as compared to MANTIS, especially at high spatial frequencies and for the thicker screens. hybridMANTIS simulations are much faster than MANTIS with speed-ups up to 5260. hybridMANTIS is a useful tool for improved description and optimization of image acquisition stages in medical imaging systems and for modeling the forward problem in iterative reconstruction algorithms.

  18. An immunohistochemical detection of actin and myosin in the indigenous bacteria-adhering sites of microvillous columnar epithelial cells in Peyer's patches and intestinal villi in the rat jejunoileum.

    Science.gov (United States)

    Inamoto, Tetsurou; Namba, Makiko; Qi, Wang-Mei; Yamamoto, Kenkichi; Yokoo, Yuh; Miyata, Hidenori; Kawano, Junichi; Yokoyama, Toshifumi; Hoshi, Nobuhiko; Kitagawa, Hiroshi

    2008-11-01

    The mechanism of physical elimination of indigenous bacteria was ultrastructurally and immunohistochemically investigated in microvillous columnar epithelial cells of Peyer's patches and intestinal villi of the rat jejunoileum. From ultrastructural observation, the microfilaments accumulated to form several electron-dense layers beneath the bacteria adhering to the cell membrane, which was slightly invaginated in the epithelial cells of Peyer's patches and intestinal villi. As the microfilamentous layers were forming, the end portions of invaginations were deformed into a cone-shape and were finally collapsed. At the same time, the end portions of the adhered bacteria were also deformed into cone-shapes. The bacterial cells were moved back toward the invagination orifices with no morphological change in their inner structure. From immunohistochemical observation, beta-actin and nonmuscle-type myosin were detected at the thin layer just beneath the invaginated cell membrane. These findings suggest that indigenous bacteria which adhere to epithelial cells are removed by only a physical action of actin and myosin filaments, but are not killed. This bacterial cell removal system might lead to the establishment of a settlement of indigenous bacteria on host cells.

  19. LANGEVIN DYNAMICS OF THE TWO STAGE MELTING TRANSITION OF VORTEX MATTER IN Bi{sub 2}Sr{sub 2}CaCu{sub 2}O{sub 8+{delta}} IN THE PRESENCE OF STRAIGHT AND OF TILTED COLUMNAR DEFECTS

    Energy Technology Data Exchange (ETDEWEB)

    GOLDSCHMIDT, YADIN Y.; LIU, Jin-Tao

    2007-08-07

    In this paper we use London Langevin molecular dynamics simulations to investigate the vortex matter melting transition in the highly anisotropic high-temperature superconductor material Bi{sub 2}Sr{sub 2}CaCu{sub 2}O{sub 8+{delta}} in the presence of low concentration of columnar defects (CDs). We reproduce with further details our previous results obtained by using Multilevel Monte Carlo simulations that showed that the melting of the nanocrystalline vortex matter occurs in two stages: a first stage melting into nanoliquid vortex matter and a second stage delocalization transition into a homogeneous liquid. Furthermore, we report on new dynamical measurements in the presence of a current that identifies clearly the irreversibility line and the second stage delocalization transition. In addition to CDs aligned along the c-axis we also simulate the case of tilted CDs which are aligned at an angle with respect to the applied magnetic field. Results for CDs tilted by 45{degree} with respect to c-axis show that the locations of the melting and delocalization transitions are not affected by the tilt when the ratio of flux lines to CDs remains constant. On the other hand we argue that some dynamical properties and in particular the position of the irreversibility line should be affected.

  20. 嗜冷黄杆菌酰基-Acp 去饱和酶(AAD)的序列分析和结构建模%Sequence analysis and structure modeling study of acyl-ACP desaturase from Flavobacterium psychrophilum

    Institute of Scientific and Technical Information of China (English)

    张远; 茆灿泉

    2014-01-01

    多不饱和脂肪酸是生物膜的重要组成成分,在维持细胞膜的流动性与低温适应性中起到重要作用。以低温微生物嗜冷黄杆菌为对象,主要采用多重序列比对、同源建模、模型评价等生物信息学技术与方法,分析与研究了多不饱和脂肪酸代谢重要相关蛋白酰基-Acp去饱和酶的序列组成与基序特征、系统进化与重要活性位点中心,模建并高评分地获得了其三维空间结构。系统发育分析表明,嗜冷黄杆菌等低温耐受菌与植物类物种的酰基-Acp去饱和酶的分子进化关系较近,而与其他细菌的分子进化关系较远。多序列基序分析显示,多数物种含有HxxxxH、HxxHH和HxxHH等3个组氨酸保守区,为二Fe离子结合区。 Swiss-model对嗜冷黄杆菌的酰基-Acp去饱和酶进行的同源建模及其模型分析发现,其也具备与Fe 离子相互作用的活性区,与 Fe离子直接作用的活性位点有His114、Glu111、Glu76、His200、Glu19和Glu164,嗜冷黄杆菌的酰基-Acp去饱和酶有异于其它细菌的特异性。这从某种程度上揭示,相对于常温菌而言,低温耐受菌可能存在着低温相关蛋白酶的序列乃至功效上的差异。对于深入了解细菌耐低温机制,低温相关蛋白差异性分析及改造与应用均有重要的意义与价值。%Polyunsaturated fatty acids are important components of biofilms , which plays an important role in maintaining of membrane fluidity.In this paper, multiple sequence alignment , homology modeling , model evaluation and other bioinformatics methods were used to analyze the sequence composition , motifs characteristic , system evolution and important center of the active sites , as well as model-ing and high score evaluation of the modelled three-dimensional structure of acyl-ACP desaturase in psychrophilic microorganism of Fla-vobacterium related to the metabolism of polyunsaturated fatty acids .Phylogenetic

  1. Discussion on geometric modeling and mechanical analysis of columnar-strand wire rope%圆股钢丝绳几何建模与力学分析的探讨

    Institute of Scientific and Technical Information of China (English)

    王晓宇; 王雷; 孟祥宝

    2013-01-01

    主要介绍了圆股钢丝绳几何建模与力学分析的理论研究进展.在总结描述钢丝绳几何与运动学参数的基础上,结合Love-Kirchhoff曲杆理论、赫兹理论、Winkler地基模型和Archard-Kragelsky磨损定律,分析了在拉压、剪切、弯曲、扭转和局部接触等载荷作用下钢丝绳螺旋分层结构的非线性力学现象,并将钢丝绳的几何建模、运动描述、整体变形、接触应力与磨损之间的关系加以综合考虑,加深对钢丝绳结构和相关力学分析的理解,为进一步研究此类问题拓宽思路.%Progress in theoretical study on geometric modeling and mechanical analysis of the columnar-strand wire rope was introduced in detail.After summarizing of geometric and dynamic parameters of the wire rope,in combination with Love-Kirchhoff theory of curved rods,Hertz theory,Winkler foundation model and ArchardKragelsky abrasion law,the paper analyzed nonlinear mechanical behavior of spiral delamination of the wire rope under the action of squeezing,shearing,bending,torsion and local contact.Moreover,the relationship among geometric modeling,kinematic expression,total elastic deformation,contact stress and abrasion were taken into comprehensive account,thus the understanding of wire rope structure and relative mechanical analysis was enhanced,so as to broaden the thinking of studying this kind of problem.

  2. Method to increase fatigue limits under high temperature stress of castings made of nickel-based super alloys from monocrystals or with columnar structure. Verfahren zur Erhoehung der Dauerfestigkeit bei Hochtemperaturbeanspruchung von als Einkristall oder mit saeulenfoermigem Gefuege hergestellten Gussteilen aus Superlegierungen auf Nickelbasis

    Energy Technology Data Exchange (ETDEWEB)

    Gell, M.L.; Leverant, G.R.

    1977-04-21

    Castings manufactured as monocrystals or of columnar structure exhibit increased endurance limits under high-temperature stress if the nickel super alloy with alternating amounts of Cr, Al, Ti, Nb, Co, Mo, Ta, W, B, Zr contains less than 0.01 wt.% C. This has the effect of suppressing the formation of a separate metal monocarbide phase. In conventional Ni-super alloys cracks are present in the monocarbide structure following annealing and these have been chown to extend further during fatigue tests.

  3. 矮化型、短枝型和柱型苹果苗枝芽特性和叶片特征比较%Comparison of Branch, Bud and Leaf Characteristics of the Dwarf-type, Spur-type and Columnar Young Apple Trees

    Institute of Scientific and Technical Information of China (English)

    侯玉珏; 张晓云; 赵彩平; 韩明玉; 刘小媛; 邢利博

    2012-01-01

    为加深对苹果各种生长型的认识,以矮化型(长富2号/M26)、短枝型(福岛短枝)和柱型(鲁加6号)3种苹果生长型嫁接苗为试材,对其枝、芽和叶片的特征进行比较研究.结果表明,三者在株高上有极显著差异,矮化型>短枝型>柱型,但在主干粗度方面差异不显著;主干节间的差异也很明显,3种类型之间差异均达到极显著水平,矮化型最高,而柱型最低;在萌芽率和成枝力方面,柱型萌芽率最高,成枝力最低,而矮化型的萌芽率最低,成枝力最高,差异均达极显著水平;在叶片特征上,柱型品种的叶面积及叶长、叶宽均显著大于其他两种,而短枝型叶片的单位面积干、鲜质量均极显著高于其他两种类型.%Three kinds of growth type of apple young trees, dwarf-type, spur-type and columnar were used as material to investigate the characteristics of branches, buds and leaves. The results indicated that the height of trees and internode length of branches had significant difference among the three types, showing dwarf-type> spur-type>columnar; but stem diameter of trunks did not show obvious differences among the three types. The germination rate of columnar type apple tree was significantly higher than those of other two types, while its branching rate was the lowest. The germination rate of dwarf-type apple tree was the lowest, but its branching rate was the highest. The characteristics of the leaves, leaf area, leaf length and width of columnar type apple tree were obviously larger than those of other two types; dry and fresh mass per unit area of spur-type leaf were higher than those of other two types.

  4. 柱型苹果GRAS基因家族MdSCR的克隆与生物信息学分析%Cloning and Bioinformatic Analysis of MdSCR Gene of GRAS Gene Family in Columnar Apple

    Institute of Scientific and Technical Information of China (English)

    韩菲; 戴洪义; 张玉刚

    2012-01-01

    以“富士×特拉蒙”杂交后代柱型株系新梢为试材,用同源克隆方法,得到了柱型苹果GRAS基因家族的MdSCR基因,开放阅读框(ORF)长度为1458bp,编码486个氨基酸,推测其蛋白质分子质量为54.894kD,等电点(pI)为5.96,具有GRAS基因家族典型结构域.MdSCR基因与毛果杨(Populus trichocarpa)GRAS转录因子的氨基酸序列具有67.8%的相似性,与江南卷柏(Selaginella moellendorffii)、葡萄(Vitis vinifera)、大豆(Glycine max)的SCARECROW-like氨基酸序列均有58.5%以上的相似性.氨基酸聚类分析表明,苹果和毛果杨、江南卷柏聚类关系最近,其次是葡萄,关系最远的是欧洲赤松;生物信息学分析表明,MdSCR的蛋白质二级结构有208个α一螺旋,54个延伸链和224个无规则折叠区.%The shoot tips of columnar apple progeny of ' Fuji x Telamon' were used as experimental materials for cloning MdSCR gene,which belonged to GRAS transcription factors gene family. The open reading flame (ORF) of MdSCR was 1464bp,encoding 486 amino acids,and the estimated molecular weight and isoelectric point (pI) of trfe putative protein were 54. 894 kD and 5. 96. The results indicated that MdSCR had highly conserved GRAS domain. MdSCR has 67. 8% amino acid sequence similarity with GRAS transcription factors of Populus trichocarpa, and has more than 58. 85% amino acid sequence similarity with GRAS transcription factors of Selaginella moellen-dorffii, grape and soybean. Amino acids cluster analysis showed that apple and Populus trichocarpa, Selaginella moellendorffii had the closest clustering relations, and followed by grape, the furthest was Pinus sylvestris. Bioinfor-matics analysis showed that the protein secondary structure of MdSCR has 208 alpha helix,54 extended strand,and 224 random coils.

  5. Influence of Isothermal Deformation Parameters on Recrystallization of Columnar Crystal CuAlBe Alloy%等温变形参数对柱状晶CuAlBe合金再结晶的影响

    Institute of Scientific and Technical Information of China (English)

    赵仙兰; 蔡莲淑; 余业球; 黎沃光

    2012-01-01

    The isothermal compression experiment of columnar crystal CuAlBe wires was carried out with a temperature controlled mould on the universal testing machine to study its dynamic recrystallization and precipitation of γ2 phase in the different temperature,deformation and strain rate. Static recrystallization temperature and precipitation of γ2 phase were investigated by reheating the alloy after deformation. The results indicate that the dynamic recrystallization occurs at 550 ℃ when the deformation forms reach more than 20%. Martensite and crack forms below 450 ℃, the dynamic recrystallization doesn't occur at this temperature. Dynamic recrystallization deformation gradually increases with the decrease of the temperature or the increase of the strain rate in the range of 4501 ~550 ℃. Static recrystallization occurs when temperature is 610 ℃. The content of γ2 phase gradually increases with the increase of the deformation temperature before recrystallization. The content of-γ2 phase decreases along with dynamic recrystallization.%在万能材料试验机上采用控温模具对柱状晶CuAlBe合金进行等温压缩变形试验,研究不同变形温度、变形量和变形速率下发生动态再结晶的行为和析出物含量;对变形后的合金重新加热,研究其发生静态再结晶的温度和析出物含量.结果表明:在550℃等温变形,变形量大于20%都发生动态再结晶,450℃以下变形都不发生动态再结晶,但此温度下易形成马氏体和裂纹;在此温度区间,随着变形温度的降低或变形速率的增加,发生动态再结晶所需的变形量逐渐增大.发生静态再结晶的临界温度为610℃,再结晶前的析出物随变形温度的升高而增加,析出物的含量随动态再结晶的进行而降低.

  6. 登革病毒1、2型单、双价病毒样颗粒的免疫原性研究%Immunogenicity research of monovalent and bivalent dengue 1 and dengue 2 virus-like particles

    Institute of Scientific and Technical Information of China (English)

    喻治准; 刘岩; 付春云; 方丹云; 江丽芳; 周俊梅

    2012-01-01

    目的 初步研究登革病毒1、2型单、双价病毒样颗粒(VLP)的免疫原性.方法 表达纯化各型VLP,用纯化好的VLP免疫BALB/c小鼠,将BALB/c小鼠随机分PBS组、灭活DENV1、灭活DENV2、纯化VLP1、纯化VLP2、纯化VLP1+2组,以灭活病毒为阳性对照,PBS为阴性对照.ELISA法检测小鼠血清抗VLP抗体效价以及血清IFN-γ、TNF-α细胞因子水平,流式细胞术检测小鼠脾细胞CD4+细胞和CD8+细胞数.结果 登革病毒1、2型单、双价VLP均能刺激免疫小鼠产生一定程度的抗血清效价,VLP1的抗体水平较VLP2的低,双价VLP组针对DENV2抗原的抗体水平上升明显,是单价VLP2的2~3倍;攻毒后,灭活DENV1和VLP2可以产生高水平的IFN-γ,分别为60和35 pg/ml,双价VLP组的较低;VLP2组的TNF-α一直保持较高水平,双价VLP组中攻DENV2组的TNF-α水平较DENV1组高;三次免疫后,各实验组较之PBS组CD4+细胞的比例都有下降,而CD8+细胞变化不大,除灭活DENV1组有增加,其余各组都有减少.结论 无论单、双价VLP均能刺激小鼠产生一定程度的体液免疫和细胞免疫反应,联合免疫有一定程度的协同性.%Objective To investigate the virus-like particles (VLP) immunogenicity of dengue 1 and 2 in monovalent or bivalent.Methods The dengue 1 and 2 VLPs were expressed and purified and used to inject BALB/c mice. Meanwhile inactivate dengue virus 1 and 2 were used as positive controls, and PBS as negative control. The anti-VLPs serum6 antibody tilers of mice were detected by ELISA. The levels of cytokines IFN-γ,TNF-α were measured by Quantikine ELISA kit. The amount of CD4+, CD8+ in mice splenocytes were measured by flow cytometric analysis. Results Both monovalent and bivalent VLP of dengue 1 and 2 could induce mice to produce certain levels of anli-VLPs serum antibody, but the antibody level of VLP1 group was lower than that of VLP2 group.The antibody level of valant VLP group with DENV2 challenge increase greatly

  7. Columnar modelling of nucleation burst evolution in the convective boundary layer – first results from a feasibility study Part III: Preliminary results on physicochemical model performance using two "clean air mass" reference scenarios

    Directory of Open Access Journals (Sweden)

    O. Hellmuth

    2006-01-01

    Full Text Available In Paper I of four papers, a revised columnar high-order model to investigate gas-aerosol-turbulence interactions in the convective boundary layer (CBL was proposed. In Paper II, the model capability to predict first-, second- and third-order moments of meteorological variables in the CBL was demonstrated using available observational data. In the present Paper III, the high-order modelling concept is extended to sulphur and ammonia chemistry as well as to aerosol dynamics. Based on the previous CBL simulation, a feasibility study is performed using two "clean air mass" scenarios with an emission source at the ground but low aerosol background concentration. Such scenarios synoptically correspond to the advection of fresh post-frontal air in an anthropogenically influenced region. The aim is to evaluate the time-height evolution of ultrafine condensation nuclei (UCNs and to elucidate the interactions between meteorological and physicochemical variables in a CBL column. The scenarios differ in the treatment of new particle formation (NPF, whereas homogeneous nucleation according to the classical nucleation theory (CNT is considered. The first scenario considers nucleation of a binary system consisting of water vapour and sulphuric acid (H2SO4 vapour, the second one nucleation of a ternary system additionally involving ammonia (NH3. Here, the two synthetic scenarios are discussed in detail, whereas special attention is payed to the role of turbulence in the formation of the typical UCN burst behaviour, that can often be observed in the surface layer. The intercomparison of the two scenarios reveals large differences in the evolution of the UCN number concentration in the surface layer as well as in the time-height cross-sections of first-order moments and double correlation terms. Although in both cases the occurrence of NPF bursts could be simulated, the burst characteristics and genesis of the bursts are completely different. It is demonstrated

  8. Monovalent ions control proliferation of Ehrlich Lettre ascites cells

    DEFF Research Database (Denmark)

    Klausen, Thomas Kjaer; Preisler, Sarah; Pedersen, Stine Helene Falsig

    2010-01-01

    of Ehrlich Lettre ascites (ELA) cells. We measured the intracellular concentration of each ion in G(0), G(1), and S phases of the cell cycle following synchronization by serum starvation and release. We show that intracellular concentrations and content of Na+ and Cl(-) were reduced in the G(0)-G(1) phase...

  9. Adsorption of monovalent metal atoms on graphene: a theoretical approach

    Energy Technology Data Exchange (ETDEWEB)

    Medeiros, Paulo V C; De Brito Mota, F; De Castilho, Caio M C [Grupo de Fisica de Superficies e Materiais, Instituto de Fisica, Universidade Federal da Bahia, Campus Universitario da Federacao/Ondina, 40170-115, Salvador, Bahia (Brazil); Mascarenhas, Artur J S, E-mail: caio@ufba.br [Instituto Nacional de Ciencia e Tecnologia em Energia e Ambiente-INCT-E and A-CIENAM, Universidade Federal da Bahia, Salvador, Bahia (Brazil)

    2010-03-19

    This work investigates, using first-principles calculations, electronic and structural properties of hydrogen, lithium, sodium, potassium and rubidium that are adsorbed, in a regular pattern, on a graphene surface. The results for H-graphene (graphane) and Li-graphene were compared with previous calculations. The present results do not support previous claims that the Li-C bond in such a layer would result in an sp{sup 2} to an sp{sup 3} transition of carbon orbitals, being more compatible with some ionic character for the covalent bond and with lithium acting as an electron acceptor in a bridging environment. Calculations were also performed for the Na, K, and Rb-graphene systems, resulting in a similar electronic behaviour but with a more pronounced ionic character than for Li-graphene. Energy calculations indicate the possible stability of such ad-graphene layers, with only the Li-graphene being possible to be spontaneously obtained.

  10. SELECTION OF NEW EPITOPES FROM MONOVALENT DISPLAYED PHAGE OCTAPEPTIDE LIBRARY

    Institute of Scientific and Technical Information of China (English)

    李全喜; 王琰; 李竞; 王雅明; 徐建军; 王力民; 董志伟

    1998-01-01

    A library of 2×l07 random oetspaptides was constructed by use of phegemid-based monovaient phage display system. The randomly synthesized degenerated oilgodeoxyribonucleotides (oligos) were fused to the truncated gⅢ (p210-p408). Sequeraze analysis of 11 randomly chosen clones suggested that the degenerated inserts and its deduced amino acid (an) sequences are randomly distributed. The library was used to select binding paptides to the morroeloncl antlhody (mAb) 9E10, which recognizes a continuous decapaptide epitope of denatured human c-myc protein. After four to five rounds of panning, most of the eluted clones could bind to 9E10. Sequerlce analysis of the selected positive clones indlcated that the binding sequences could fall into two chsses, one class (clone 1) shares a consensus motif, ISE x x L, with c-mire decapeprider and the sequences of the other class are entirely different. The binding of both classes to 9E10 could be specifically lnhlhited by froe c-myc deeapeptide. The immunogenlcitF cff the phage peptide was further investigsted h5, construction of multivalent displayed phage peptides and immunization of animals with or without adjuvant. ELISA and competitive ELISA showed that anti-serum from both mice and rabbit immunized with either done could bind to the original antigen, c-myc decapeptide. These results denote that in spite of the dissimilarity of the selected psptides with c-myc decapeptide, they are capable of inducing similar immune respones in vivo, thus actually mimicking the antigen epitope.

  11. Cold gelation of alginates induced by monovalent cations.

    Science.gov (United States)

    Karakasyan, C; Legros, M; Lack, S; Brunel, F; Maingault, P; Ducouret, G; Hourdet, D

    2010-11-08

    A new reversible gelation pathway is described for alginates in aqueous media. From various samples differing by their mannuronic/guluronic content (M/G), both enthalpic and viscoelastic experiments demonstrate that alginates having a high M content are able to form thermoreversible assemblies in the presence of potassium salts. The aggregation behavior is driven by the low solubility of M-blocks at low temperature and high ionic strength. In semidilute solutions, responsive assemblies induce a strong increase of the viscosity below a critical temperature. A true physical gel is obtained in the entangled regime, although the length scale of specific interactions between M-blocks decreases with increasing density of entanglements. Cold setting takes place at low temperatures, below 0 °C for potassium concentrations lower than 0.2 mol/kg, but the aggregation process can be easily shifted to higher temperatures by increasing the salt concentration. The self-assembling process of alginates in solution of potassium salts is characterized by a sharp gelation exotherm and a broad melting endotherm with a large hysteresis of 20-30 °C between the transition temperatures. The viscoelastic properties of alginate gels in potassium salts closely depend on thermal treatment (rate of cooling, time, and temperature of storage), polymer and salt concentrations, and monomer composition as well. In the case of alginates with a high G content, a similar aggregation behavior is also evidenced at higher salt concentrations, but the extent of the self-assembling process remains too weak to develop a true gelation behavior in solution.

  12. Incorporation of Monovalent Cations in Sulfate Green Rust

    DEFF Research Database (Denmark)

    Christiansen, B. C.; Dideriksen, K.; Katz, A.;

    2014-01-01

    Green rust is a naturally occurring layered mixed-valent ferrous-ferric hydroxide, which can react with a range of redox-active compounds. Sulfate-bearing green rust is generally thought to have interlayers composed of sulfate and water. Here, we provide evidence that the interlayers also contain...... with water showed that Na+ and K+ were structurally fixed in the interlayer, whereas Rb+ and Cs+ could be removed, resulting in a decrease in the basal layer spacing. The incorporation of cations in the interlayer opens up new possibilities for the use of sulfate green rust for exchange reactions with both...

  13. Mechanism of interaction of monovalent ions with phosphatidylcholine lipid membranes.

    Science.gov (United States)

    Vácha, Robert; Jurkiewicz, Piotr; Petrov, Michal; Berkowitz, Max L; Böckmann, Rainer A; Barucha-Kraszewska, Justyna; Hof, Martin; Jungwirth, Pavel

    2010-07-29

    Interactions of different anions with phospholipid membranes in aqueous salt solutions were investigated by molecular dynamics simulations and fluorescence solvent relaxation measurements. Both approaches indicate that the anion-membrane interaction increases with the size and softness of the anion. Calculations show that iodide exhibits a genuine affinity for the membrane, which is due to its pairing with the choline group and its propensity for the nonpolar region of the acyl chains, the latter being enhanced in polarizable calculations showing that the iodide number density profile is expanded toward the glycerol level. Solvent relaxation measurements using Laurdan confirm the influence of large soft ions on the membrane organization at the glycerol level. In contrast, chloride exhibits a peak at the membrane surface only in the presence of a surface-attracted cation, such as sodium but not potassium, suggesting that this behavior is merely a counterion effect.

  14. Neutralisation and binding of VHS virus by monovalent antibody fragments

    DEFF Research Database (Denmark)

    Cupit, P.M.; Lorenzen, Niels; Strachan, G.

    2001-01-01

    appeared to recognise a broader range of virus isolates. The variable domains of these two antibodies differ by only four residues (Lorenzen et al., 2000a. Fish Shellfish Immunol. 10, 129-142). To further study the mechanism of neutralisation, Fab fragments as well as a series of recombinant bacterial...... single chain antibody (scAb) fragments were generated from the three anti-VHSV Mabs and their variable domain genes, respectively. Fabs and scAbs derived from the neutralising Mabs were both able to neutralise the VHSV type 1 isolate DK-F1. In addition, a series of scAb fragments were produced using...... the 3F1H10 variable heavy (VH) chain and variable light (V kappa) chain domains but containing, either alone or in dual combination, each of the four different residues present in 3F1A2. The dissociation constants of Mabs 3F1H10 and 3F1A2 and their respective Fab and scAb fragments were measured...

  15. Extraction mechanism of monovalent ion-pairs by polyurethane foams.

    Science.gov (United States)

    Fong, P; Chow, A

    1992-07-01

    The extractability sequence of K(+) approximately Rb(+) > Cs(+) > Na(+) > Li(+) for the extraction with polyether foam suggests that the cation chelation mechanism might be operative. However, the same order was obtained for the extraction with 100% polypropylene oxide polyether foam which does not normally adopt a helical structure to form oxygen-rich cavities as easily or as effectively as polyethylene oxide to accommodate alkali metal ions. This result indicates that a hole-size/cation-diameter relationship may not be required for the high extraction of K(+). The extraction of alkali metal DPAs and hydroxides from methanol demonstrates the importance of the solvent effect. It indicates that the water-structure enforced ion-pairing (WSEIP) is the driving force for extraction of the ion-pairs. The extraction mechanism for ionic species can be described as an ion-pair extraction process. The overall effect of ion-pair formation in water and interaction of the extracted ions with foam appears to determine the extractability of the ions of the extractable ion-pair.

  16. 柱状晶组织HA177-2铝黄铜的力学性能与加工硬化行为%MECHANICAL PROPERTIES AND WORK HARDENING BEHAVIOR OF COLUMNAR-GRAINED HA177-2 BRASS

    Institute of Scientific and Technical Information of China (English)

    莫永达; 姜雁斌; 刘新华; 谢建新

    2014-01-01

    利用室温单向拉伸实验、EBSD和TEM等手段,研究了柱状晶组织HA177-2铝黄铜的力学性能与加工硬化行为,探讨了晶粒尺寸对拉伸变形加工硬化速率和塑性变形能力的影响及其机制.结果表明,柱状晶组织HA177-2铝黄铜加工硬化速率-真应变关系曲线第2阶段具有显著上升趋势,晶内形成平行分布的小角度亚晶界使位错滑移长度减小并阻碍位错运动是加工硬化速率上升的主要原因,不同于文献报道的等轴晶组织黄铜加工硬化第2阶段形成形变孪晶使滑移长度减小的机制.随着晶粒尺寸的增大,柱状晶组织HA177-2铝黄铜的屈服强度和抗拉强度降低,而断后伸长率显著增大,由晶粒尺寸为2.0 mm的70.4%增大到晶粒尺寸为6.0 mm的84.4%.较高的抗塑性失稳能力和较好的晶内变形均匀性是大晶粒柱状晶试样具有更优塑性变形能力的主要原因.%The mechanical properties and work hardening behavior of columnar-grained HA177-2 brass were investigated by means of room temperature tensile test,EBSD and TEM.The effects of grain size on the work hardening rate and tensile ductility of the alloy were discussed.Some references reported that deformation twinning developed in the equiaxed-grained brass led to a reduction in slip length of dislocation and an increase in the work hardening rate at the second stage in the curve of work-hardening vs strain.In this work,however,the results showed that the low-angle subgrain boundaries distributed parallelly were formed in the columnar grain and reduced the slip length of dislocation at the second stage,which was responsible for the rise of the work hardening rate.With increasing grain size,both the yield strength and ultimate tensile strength of the columnar-grained HA177-2 brass decreased,but its elongation to failure increased significantly from 70.4% for the grain size of 2.0 mm to 84.4% for the grain size of 6.0 mm.Higher performance to resist

  17. Cloning and Location of MdCPS and Analysis Its Expression Difference Between Columnar and Standard Tree Architecture in Apple%苹果MdCPS基因的克隆、定位及其在柱型/普通型间的表达差异分析

    Institute of Scientific and Technical Information of China (English)

    田义轲; 白牡丹; 王彩虹; 刘云龙; 陈宝印

    2014-01-01

    level of similarity ( 49%-67%) with CPS protein from other plant species. Using the primary apical shoots of the parents and F1 progenies of Fuji( stand-ard) × Telamon ( columnar ) as plant materials, quantitative real-time PCR ( qRT-PCR ) analyses showed that even though the transcription level of this gene in the columnar parent was lower than that in the standard parent,there was no significant difference was observed between the two populations of columnar and standard progenies. At the same time,qRT-PCR analysis in the columnar hybrids and their correspondent standard mutants indicated that the expression level of MdCPS was not relevant to the columnar growth habit. These results suggested that the lower con-tent of active gibberellins in columnar apple apical shoots was not distinctively influenced by MdCPS in the early stage of gibberellins synthesis.

  18. Monovalent and with activation of components. Administration building for a winery; Monovalent und mit Bauteilaktivierung. Verwaltungsgebaeude fuer eine Weinkellerei

    Energy Technology Data Exchange (ETDEWEB)

    Freytag, Michaela [Uponor GmbH, Hassfurt (Germany)

    2011-07-01

    The climate is the key aspect: That what is recommended crucial for a good wine, also is recommended for the employees of the winery Zimmermann-Graeff and Mueller GmbH and Co. KG (Zell/Mosel, Federal Republic of Germany): Creation of an all-season comfort climate in order to achieve best results in quality and work. This in particular is valid for the management of this company on an area of 2,200 square meters. The owner laid great emphasis on quality and contemporarily solutions.

  19. Occurrence of Flavobacterium psychrophilum in fish-farming environments

    DEFF Research Database (Denmark)

    Madetoja, J.; Dalsgaard, Inger; Wiklund, T.

    2002-01-01

    . Isolates were biochemically homogenous, excluding the capability to degrade elastin. Five different agglutination patterns with different antisera against F. psychrophilum were found among the isolates studied. Although several different ribopatterns were found (ClaI: 12 ribopatterns and HaeIII: 9...

  20. IDENTIFICATION OF A FLAVOBACTERIUM STRAIN VIRULENT AGAINT GIARDIA LAMBLIA CYSTS

    Science.gov (United States)

    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...