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Sample records for extrachromosomal circular dna

  1. Genome-wide Purification of Extrachromosomal Circular DNA from Eukaryotic Cells

    DEFF Research Database (Denmark)

    Møller, Henrik D.; Bojsen, Rasmus Kenneth; Tachibana, Chris

    2016-01-01

    Extrachromosomal circular DNAs (eccDNAs) are common genetic elements in Saccharomyces cerevisiae and are reported in other eukaryotes as well. EccDNAs contribute to genetic variation among somatic cells in multicellular organisms and to evolution of unicellular eukaryotes. Sensitive methods for d...

  2. Genome-wide Purification of Extrachromosomal Circular DNA from Eukaryotic Cells

    DEFF Research Database (Denmark)

    Møller, Henrik D.; Bojsen, Rasmus Kenneth; Tachibana, Chris

    2016-01-01

    Extrachromosomal circular DNAs (eccDNAs) are common genetic elements in Saccharomyces cerevisiae and are reported in other eukaryotes as well. EccDNAs contribute to genetic variation among somatic cells in multicellular organisms and to evolution of unicellular eukaryotes. Sensitive methods...

  3. Sequencing the extrachromosomal circular mobilome reveals retrotransposon activity in plants

    OpenAIRE

    Lanciano, Sophie; Carpentier, M. C.; Llauro, C.; Jobet, E.; Robakowska-Hyzorek, D.; Lasserre, E.; Ghesquière, Alain; Panaud, O.; Mirouze, Marie

    2017-01-01

    Retrotransposons are mobile genetic elements abundant in plant and animal genomes. While efficiently silenced by the epigenetic machinery, they can be reactivated upon stress or during development. Their level of transcription not reflecting their transposition ability, it is thus difficult to evaluate their contribution to the active mobilome. Here we applied a simple methodology based on the high throughput sequencing of extrachromosomal circular DNA (eccDNA) forms of active retrotransposon...

  4. Sequencing the extrachromosomal circular mobilome reveals retrotransposon activity in plants.

    Directory of Open Access Journals (Sweden)

    Sophie Lanciano

    2017-02-01

    Full Text Available Retrotransposons are mobile genetic elements abundant in plant and animal genomes. While efficiently silenced by the epigenetic machinery, they can be reactivated upon stress or during development. Their level of transcription not reflecting their transposition ability, it is thus difficult to evaluate their contribution to the active mobilome. Here we applied a simple methodology based on the high throughput sequencing of extrachromosomal circular DNA (eccDNA forms of active retrotransposons to characterize the repertoire of mobile retrotransposons in plants. This method successfully identified known active retrotransposons in both Arabidopsis and rice material where the epigenome is destabilized. When applying mobilome-seq to developmental stages in wild type rice, we identified PopRice as a highly active retrotransposon producing eccDNA forms in the wild type endosperm. The mobilome-seq strategy opens new routes for the characterization of a yet unexplored fraction of plant genomes.

  5. Sequencing the extrachromosomal circular mobilome reveals retrotransposon activity in plants.

    Science.gov (United States)

    Lanciano, Sophie; Carpentier, Marie-Christine; Llauro, Christel; Jobet, Edouard; Robakowska-Hyzorek, Dagmara; Lasserre, Eric; Ghesquière, Alain; Panaud, Olivier; Mirouze, Marie

    2017-02-01

    Retrotransposons are mobile genetic elements abundant in plant and animal genomes. While efficiently silenced by the epigenetic machinery, they can be reactivated upon stress or during development. Their level of transcription not reflecting their transposition ability, it is thus difficult to evaluate their contribution to the active mobilome. Here we applied a simple methodology based on the high throughput sequencing of extrachromosomal circular DNA (eccDNA) forms of active retrotransposons to characterize the repertoire of mobile retrotransposons in plants. This method successfully identified known active retrotransposons in both Arabidopsis and rice material where the epigenome is destabilized. When applying mobilome-seq to developmental stages in wild type rice, we identified PopRice as a highly active retrotransposon producing eccDNA forms in the wild type endosperm. The mobilome-seq strategy opens new routes for the characterization of a yet unexplored fraction of plant genomes.

  6. Phytoplasma PMU1 exists as linear chromosomal and circular extrachromosomal elements and has enhanced expression in insect vectors compared with plant hosts.

    Science.gov (United States)

    Toruño, Tania Y; Musić, Martina Seruga; Simi, Silvia; Nicolaisen, Mogens; Hogenhout, Saskia A

    2010-09-01

    Phytoplasmas replicate intracellularly in plants and insects and are dependent on both hosts for dissemination in nature. Phytoplasmas have small genomes lacking genes for major metabolic pathways. Nevertheless, their genomes harbour multicopy gene clusters that were named potential mobile units (PMUs). PMU1 is the largest most complete repeat among the PMUs in the genome of Aster Yellows phytoplasma strain Witches' Broom (AY-WB). PMU1 is c. 20 kb in size and contains 21 genes encoding DNA replication and predicted membrane-targeted proteins. Here we show that AY-WB has a chromosomal linear PMU1 (L-PMU1) and an extrachromosomal circular PMU1 (C-PMU1). The C-PMU1 copy number was consistently higher by in average approximately fivefold in insects compared with plants and PMU1 gene expression levels were also considerably higher in insects indicating that C-PMU1 synthesis and expression are regulated. We found that the majority of AY-WB virulence genes lie on chromosomal PMU regions that have similar gene content and organization as PMU1 providing evidence that PMUs contribute to phytoplasma host adaptation and have integrated into the AY-WB chromosome. © 2010 Blackwell Publishing Ltd.

  7. Extrachromosomal circles of satellite repeats and 5S ribosomal DNA in human cells

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    Cohen Sarit

    2010-03-01

    Full Text Available Abstract Background Extrachomosomal circular DNA (eccDNA is ubiquitous in eukaryotic organisms and was detected in every organism tested, including in humans. A two-dimensional gel electrophoresis facilitates the detection of eccDNA in preparations of genomic DNA. Using this technique we have previously demonstrated that most of eccDNA consists of exact multiples of chromosomal tandemly repeated DNA, including both coding genes and satellite DNA. Results Here we report the occurrence of eccDNA in every tested human cell line. It has heterogeneous mass ranging from less than 2 kb to over 20 kb. We describe eccDNA homologous to human alpha satellite and the SstI mega satellite. Moreover, we show, for the first time, circular multimers of the human 5S ribosomal DNA (rDNA, similar to previous findings in Drosophila and plants. We further demonstrate structures that correspond to intermediates of rolling circle replication, which emerge from the circular multimers of 5S rDNA and SstI satellite. Conclusions These findings, and previous reports, support the general notion that every chromosomal tandem repeat is prone to generate eccDNA in eukryoric organisms including humans. They suggest the possible involvement of eccDNA in the length variability observed in arrays of tandem repeats. The implications of eccDNA on genome biology may include mechanisms of centromere evolution, concerted evolution and homogenization of tandem repeats and genomic plasticity.

  8. Detection of circular telomeric DNA without 2D gel electrophoresis.

    Science.gov (United States)

    Dlaska, Margit; Anderl, Conrad; Eisterer, Wolfgang; Bechter, Oliver E

    2008-09-01

    The end of linear chromosomes forms a lasso-like structure called the t-loop. Such t-loops resemble a DNA recombination intermediate, where the single-stranded 3' overhang is arrested in a stretch of duplex DNA. Presumably, such a t-loop can also be deleted via a recombination process. This would result in the occurrence of circular extrachromosomal telomeric DNA (t-circles), which are known to be abundantly present in immortal cells engaging the recombination-based alternative lengthening of telomeres pathway (ALT pathway). Little is known about the basic mechanism of telomeric recombination in these cells and what ultimately causes the generation of such t-circles. Current standard procedures for detecting these molecules involve 2D gel electrophoresis or electron microscopy. However, both methods are labor intense and sophisticated to perform. Here, we present a simpler, faster, and equally sensitive method for detecting t-circles. Our approach is a telomere restriction fragment assay that involves the enzymatic preservation of circular DNA with Klenow enzyme followed by Bal31 degradation of the remaining linear DNA molecules. We show that with this approach t-circles can be detected in ALT cell lines, whereas no t-circles are present in telomerase-positive cell lines. We consider our approach a valid method in which t-circle generation is the experimental readout.

  9. The fosfomycin resistance gene fosB3 is located on a transferable, extrachromosomal circular intermediate in clinical Enterococcus faecium isolates.

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    Xiaogang Xu

    Full Text Available Some VanM-type vancomycin-resistant Enterococcus faecium isolates from China are also resistant to fosfomycin. To investigate the mechanism of fosfomycin resistance in these clinical isolates, antimicrobial susceptibility testing, filter-mating, Illumina/Solexa sequencing, inverse PCR and fosfomycin resistance gene cloning were performed. Three E. faecium clinical isolates were highly resistant to fosfomycin and vancomycin with minimal inhibitory concentrations (MICs >1024 µg/ml and >256 µg/ml, respectively. The fosfomycin and vancomycin resistance of these strains could be co-transferred by conjugation. They carried a fosfomycin resistance gene fosB encoding a protein differing by one or two amino acids from FosB, which is encoded on staphylococcal plasmids. Accordingly, the gene was designated fosB3. The fosB3 gene was cloned into pMD19-T, and transformed into E. coli DH5α. The fosfomycin MIC for transformants with fosB3 was 750-fold higher than transformants without fosB3. The fosB3 gene could be transferred by an extrachromosomal circular intermediate. The results indicate that the fosB3 gene is transferable, can mediate high level fosfomycin resistance in both Gram-positive and Gram-negative bacteria, and can be located on a circular intermediate.

  10. Extrachromosomal genetic elements in Micrococcus.

    Science.gov (United States)

    Dib, Julián Rafael; Liebl, Wolfgang; Wagenknecht, Martin; Farías, María Eugenia; Meinhardt, Friedhelm

    2013-01-01

    Micrococci are Gram-positive G + C-rich, nonmotile, nonspore-forming actinomycetous bacteria. Micrococcus comprises ten members, with Micrococcus luteus being the type species. Representatives of the genus play important roles in the biodegradation of xenobiotics, bioremediation processes, production of biotechnologically important enzymes or bioactive compounds, as test strains in biological assays for lysozyme and antibiotics, and as infective agents in immunocompromised humans. The first description of plasmids dates back approximately 28 years, when several extrachromosomal elements ranging in size from 1.5 to 30.2 kb were found in Micrococcus luteus. Up to the present, a number of circular plasmids conferring antibiotic resistance, the ability to degrade aromatic compounds, and osmotolerance are known, as well as cryptic elements with unidentified functions. Here, we review the Micrococcus extrachromosomal traits reported thus far including phages and the only quite recently described large linear extrachromosomal genetic elements, termed linear plasmids, which range in size from 75 kb (pJD12) to 110 kb (pLMA1) and which confer putative advantageous capabilities, such as antibiotic or heavy metal resistances (inferred from sequence analyses and curing experiments). The role of the extrachromosomal elements for the frequently proven ecological and biotechnological versatility of the genus will be addressed as well as their potential for the development and use as genetic tools.

  11. Small RNA-based feedforward loop with AND-gate logic regulates extrachromosomal DNA transfer in Salmonella.

    Science.gov (United States)

    Papenfort, Kai; Espinosa, Elena; Casadesús, Josep; Vogel, Jörg

    2015-08-25

    Horizontal gene transfer via plasmid conjugation is a major driving force in microbial evolution but constitutes a complex process that requires synchronization with the physiological state of the host bacteria. Although several host transcription factors are known to regulate plasmid-borne transfer genes, RNA-based regulatory circuits for host-plasmid communication remain unknown. We describe a posttranscriptional mechanism whereby the Hfq-dependent small RNA, RprA, inhibits transfer of pSLT, the virulence plasmid of Salmonella enterica. RprA employs two separate seed-pairing domains to activate the mRNAs of both the sigma-factor σ(S) and the RicI protein, a previously uncharacterized membrane protein here shown to inhibit conjugation. Transcription of ricI requires σ(S) and, together, RprA and σ(S) orchestrate a coherent feedforward loop with AND-gate logic to tightly control the activation of RicI synthesis. RicI interacts with the conjugation apparatus protein TraV and limits plasmid transfer under membrane-damaging conditions. To our knowledge, this study reports the first small RNA-controlled feedforward loop relying on posttranscriptional activation of two independent targets and an unexpected role of the conserved RprA small RNA in controlling extrachromosomal DNA transfer.

  12. Adaptation to diverse nitrogen-limited environments by deletion or extrachromosomal element formation of the GAP1 locus

    DEFF Research Database (Denmark)

    Gresham, D.; Usaite, Renata; Germann, S.M.

    2010-01-01

    and deletions at the GAP1 locus. GAP1 encodes the general amino acid permease, which transports amino acids across the plasma membrane. We identified a self-propagating extrachromosomal circular DNA molecule that results from intrachromosomal recombination between long terminal repeats (LTRs) flanking GAP1....... Extrachromosomal DNA circles (GAP1(circle)) contain GAP1, the replication origin ARS1116, and a single hybrid LTR derived from recombination between the two flanking LTRs. Formation of the GAP1(circle) is associated with deletion of chromosomal GAP1 (gap1 Delta) and production of a single hybrid LTR at the GAP1...

  13. TRE5-A retrotransposition profiling reveals putative RNA polymerase III transcription complex binding sites on the Dictyostelium extrachromosomal rDNA element.

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    Thomas Spaller

    Full Text Available The amoeba Dictyostelium discoideum has a haploid genome in which two thirds of the DNA encodes proteins. Consequently, the space available for selfish mobile elements to expand without excess damage to the host genome is limited. The non-long terminal repeat retrotransposon TRE5-A maintains an active population in the D. discoideum genome and apparently adapted to this gene-dense environment by targeting positions ~47 bp upstream of tRNA genes that are devoid of protein-coding regions. Because only ~24% of tRNA genes are associated with a TRE5-A element in the reference genome, we evaluated whether TRE5-A retrotransposition is limited to this subset of tRNA genes. We determined that a tagged TRE5-A element (TRE5-Absr integrated at 384 of 405 tRNA genes, suggesting that expansion of the current natural TRE5-A population is not limited by the availability of targets. We further observed that TRE5-Absr targets the ribosomal 5S gene on the multicopy extrachromosomal DNA element that carries the ribosomal RNA genes, indicating that TRE5-A integration may extend to the entire RNA polymerase III (Pol III transcriptome. We determined that both natural TRE5-A and cloned TRE5-Absr retrotranspose to locations on the extrachromosomal rDNA element that contain tRNA gene-typical A/B box promoter motifs without displaying any other tRNA gene context. Based on previous data suggesting that TRE5-A targets tRNA genes by locating Pol III transcription complexes, we propose that A/B box loci reflect Pol III transcription complex assembly sites that possess a function in the biology of the extrachromosomal rDNA element.

  14. Intricate and Cell Type-Specific Populations of Endogenous Circular DNA (eccDNA) in Caenorhabditis elegans and Homo sapiens.

    Science.gov (United States)

    Shoura, Massa J; Gabdank, Idan; Hansen, Loren; Merker, Jason; Gotlib, Jason; Levene, Stephen D; Fire, Andrew Z

    2017-10-05

    Investigations aimed at defining the 3D configuration of eukaryotic chromosomes have consistently encountered an endogenous population of chromosome-derived circular genomic DNA, referred to as extrachromosomal circular DNA (eccDNA). While the production, distribution, and activities of eccDNAs remain understudied, eccDNA formation from specific regions of the linear genome has profound consequences on the regulatory and coding capabilities for these regions. Here, we define eccDNA distributions in Caenorhabditis elegans and in three human cell types, utilizing a set of DNA topology-dependent approaches for enrichment and characterization. The use of parallel biophysical, enzymatic, and informatic approaches provides a comprehensive profiling of eccDNA robust to isolation and analysis methodology. Results in human and nematode systems provide quantitative analysis of the eccDNA loci at both unique and repetitive regions. Our studies converge on and support a consistent picture, in which endogenous genomic DNA circles are present in normal physiological states, and in which the circles come from both coding and noncoding genomic regions. Prominent among the coding regions generating DNA circles are several genes known to produce a diversity of protein isoforms, with mucin proteins and titin as specific examples. Copyright © 2017 Shoura et al.

  15. Extra-chromosomal DNA maintenance in Bacillus subtilis, dependence on flagellation factor FliF and moonlighting mediator EdmS.

    Science.gov (United States)

    Hakumai, Yuichi; Shimomoto, Kouko; Ashiuchi, Makoto

    2015-05-15

    Extra-chromosomal DNA maintenance (EDM) as an important process in the propagation and genetic engineering of microbes. Bacillus subtilis EdmS (formerly PgsE), a protein comprising 55 amino acids, is a mediator of the EDM process. In this study, the effect of mutation of global regulators on B. subtilis EDM was examined. Mutation of the swrA gene abolished EdmS-mediated EDM. It is known that swrA predominantly regulates expression of the fla/che operon in B. subtilis. We therefore performed EDM analysis using fla/che-deletion mutants and identified an EDM-mediated EDM cooperator in the flgB-fliL region. Further genetic investigation identified the flagellation factor FliF is a crucial EDM cooperator. To our knowledge, this is the first observation of the moonlighting function of FliF in DNA maintenance. Copyright © 2015 Elsevier Inc. All rights reserved.

  16. Transposable elements and circular DNAs

    KAUST Repository

    Mourier, Tobias

    2016-09-26

    Circular DNAs are extra-chromosomal fragments that become circularized by genomic recombination events. We have recently shown that yeast LTR elements generate circular DNAs through recombination events between their flanking long terminal repeats (LTRs). Similarly, circular DNAs can be generated by recombination between LTRs residing at different genomic loci, in which case the circular DNA will contain the intervening sequence. In yeast, this can result in gene copy number variations when circles contain genes and origins of replication. Here, I speculate on the potential and implications of circular DNAs generated through recombination between human transposable elements.

  17. Transposable elements and circular DNAs

    KAUST Repository

    Mourier, Tobias

    2016-01-01

    Circular DNAs are extra-chromosomal fragments that become circularized by genomic recombination events. We have recently shown that yeast LTR elements generate circular DNAs through recombination events between their flanking long terminal repeats (LTRs). Similarly, circular DNAs can be generated by recombination between LTRs residing at different genomic loci, in which case the circular DNA will contain the intervening sequence. In yeast, this can result in gene copy number variations when circles contain genes and origins of replication. Here, I speculate on the potential and implications of circular DNAs generated through recombination between human transposable elements.

  18. Beyond the chromosome: the prevalence of unique extra-chromosomal bacteriophages with integrated virulence genes in pathogenic Staphylococcus aureus.

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    Bryan Utter

    Full Text Available In Staphylococcus aureus, the disease impact of chromosomally integrated prophages on virulence is well described. However, the existence of extra-chromosomal prophages, both plasmidial and episomal, remains obscure. Despite the recent explosion in bacterial and bacteriophage genomic sequencing, studies have failed to specifically focus on extra-chromosomal elements. We selectively enriched and sequenced extra-chromosomal DNA from S. aureus isolates using Roche-454 technology and uncovered evidence for the widespread distribution of multiple extra-chromosomal prophages (ExPΦs throughout both antibiotic-sensitive and -resistant strains. We completely sequenced one such element comprised of a 43.8 kbp, circular ExPΦ (designated ФBU01 from a vancomycin-intermediate S. aureus (VISA strain. Assembly and annotation of ФBU01 revealed a number of putative virulence determinants encoded within a bacteriophage immune evasion cluster (IEC. Our identification of several potential ExPΦs and mobile genetic elements (MGEs also revealed numerous putative virulence factors and antibiotic resistance genes. We describe here a previously unidentified level of genetic diversity of stealth extra-chromosomal elements in S. aureus, including phages with a larger presence outside the chromosome that likely play a prominent role in pathogenesis and strain diversity driven by horizontal gene transfer (HGT.

  19. A Real Time PCR Platform for the Simultaneous Quantification of Total and Extrachromosomal HIV DNA Forms in Blood of HIV-1 Infected Patients

    Science.gov (United States)

    Canovari, Benedetta; Scotti, Maddalena; Acetoso, Marcello; Valentini, Massimo; Petrelli, Enzo; Magnani, Mauro

    2014-01-01

    Background The quantitative measurement of various HIV-1 DNA forms including total, unintegrated and integrated provirus play an increasingly important role in HIV-1 infection monitoring and treatment-related research. We report the development and validation of a SYBR Green real time PCR (TotUFsys platform) for the simultaneous quantification of total and extrachromosomal HIV-1 DNA forms in patients. This innovative technique makes it possible to obtain both measurements in a single PCR run starting from frozen blood employing the same primers and standard curve. Moreover, due to identical amplification efficiency, it allows indirect estimation of integrated level. To specifically detect 2-LTR a qPCR method was also developed. Methodology/Findings Primers used for total HIV-1 DNA quantification spanning a highly conserved region were selected and found to detect all HIV-1 clades of group M and the unintegrated forms of the same. A total of 195 samples from HIV-1 patients in a wide range of clinical conditions were analyzed with a 100% success rate, even in patients with suppressed plasma viremia, regardless of CD4+ or therapy. No significant correlation was observed between the two current prognostic markers, CD4+ and plasma viremia, while a moderate or high inverse correlation was found between CD4+ and total HIV DNA, with strong values for unintegrated HIV DNA. Conclusions/Significance Taken together, the results support the use of HIV DNA as another tool, in addition to traditional assays, which can be used to estimate the state of viral infection, the risk of disease progression and to monitor the effects of ART. The TotUFsys platform allowed us to obtain a final result, expressed as the total and unintegrated HIV DNA copy number per microgram of DNA or 104 CD4+, for 12 patients within two working days. PMID:25364909

  20. Detection of HBV Covalently Closed Circular DNA

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    Xiaoling Li

    2017-06-01

    Full Text Available Chronic hepatitis B virus (HBV infection affects approximately 240 million people worldwide and remains a serious public health concern because its complete cure is impossible with current treatments. Covalently closed circular DNA (cccDNA in the nucleus of infected cells cannot be eliminated by present therapeutics and may result in persistence and relapse. Drug development targeting cccDNA formation and maintenance is hindered by the lack of efficient cccDNA models and reliable cccDNA detection methods. Southern blotting is regarded as the gold standard for quantitative cccDNA detection, but it is complicated and not suitable for high-throughput drug screening, so more sensitive and simple methods, including polymerase chain reaction (PCR-based methods, Invader assays, in situ hybridization and surrogates, have been developed for cccDNA detection. However, most methods are not reliable enough, and there are no unified standards for these approaches. This review will summarize available methods for cccDNA detection. It is hoped that more robust methods for cccDNA monitoring will be developed and that standard operation procedures for routine cccDNA detection in scientific research and clinical monitoring will be established.

  1. Extrachromosomal deoxyribonucleic acid in R factor-harboring Enterobacteriaceae

    DEFF Research Database (Denmark)

    Møller, JK; Bak, AL; Christiansen, C

    1976-01-01

    Extrachromosomal deoxyribonucleic acid (DNA) from 24 different R factor-harboring Enterobacteriaceae was isolated and characterized by analytical ultracentrifugation and electron microscopy. The R factors represented 15 different patterns of transferable drug resistance found in enterobacteria from...

  2. Archaeal extrachromosomal genetic elements

    DEFF Research Database (Denmark)

    Wang, Haina; Peng, Nan; Shah, Shiraz Ali

    2015-01-01

    SUMMARY: Research on archaeal extrachromosomal genetic elements (ECEs) has progressed rapidly in the past decade. To date, over 60 archaeal viruses and 60 plasmids have been isolated. These archaeal viruses exhibit an exceptional diversity in morphology, with a wide array of shapes, such as spind......SUMMARY: Research on archaeal extrachromosomal genetic elements (ECEs) has progressed rapidly in the past decade. To date, over 60 archaeal viruses and 60 plasmids have been isolated. These archaeal viruses exhibit an exceptional diversity in morphology, with a wide array of shapes...... on archaeal ECEs has just started to unravel the molecular biology of these genetic entities and their interactions with archaeal hosts, it is expected to accelerate in the next decade....

  3. Isolation of bacterial extrachromosomal DNA from human dental plaque associated with periodontal disease, using transposon-aided capture (TRACA).

    Science.gov (United States)

    Warburton, Philip J; Allan, Elaine; Hunter, Stephanie; Ward, John; Booth, Veronica; Wade, William G; Mullany, Peter

    2011-11-01

    The human oral cavity is host to a complex microbial community estimated to comprise >700 bacterial species, of which at least half are thought to be not yet cultivable in vitro. To investigate the plasmids present in this community, we used a transposon-aided capture system, which allowed the isolation of plasmids from human oral supra- and subgingival plaque samples. Thirty-two novel plasmids and a circular molecule that could be an integrase-generated circular intermediate were isolated. © 2011 Federation of European Microbiological Societies. Published by Blackwell Publishing Ltd. All rights reserved.

  4. Preferential inclusion of extrachromosomal genetic elements in yeast meiotic spores.

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    Brewer, B J; Fangman, W L

    1980-09-01

    During meiosis and sporulation in the yeast Saccharomyces cerevisiae, extrachromosomal traits are efficiently transmitted to haploid spores. Although the pattern of inheritance of chromosomal traits reflects the mechanism of regular chromosomal segregation in meiosis, it is not known what processes are reflected by the efficient inheritance of extrachromosomal traits. Because extrachromosomal genetic elements in yeast are present in multiple copies, perpetuation of an extrachromosomal trait could occur by the passive envelopment of a subset of copies or by an active sequestering of all or a subset of copies within the four spores. We show that only subsets of the four extrachromosomal nucleic acids commonly found in yeast are transmitted through meiosis--55% of mitochondrial DNA copies, 82% of the 2-micron DNA plasmids, and about 70% of the L and M double-stranded RNAs. However, electron micrographs of serial sections through yeast asci indicate that the four spore enclose only 30% of the total ascus material. Thus these extrachromosomal elements are preferentially included within the spores, indicating that their inheritance is not a random process. Transmission of mitochondrial DNA can be accounted for by the observed enclosure of 52% of the mitochondrial volume within the spores. The high transmission frequencies of the double-stranded RNAs (which exist as virus-like particles in the cytoplasm) and 2-micron DNA must indicate that either these nucleic acids are actively recruited from the cytoplasm by some mechanism or they are associated in some way with the nucleus during meiosis.

  5. Extrachromosomal deoxyribonucleic acid in R factor-harboring Enterobacteriaceae

    DEFF Research Database (Denmark)

    Møller, JK; Bak, AL; Christiansen, C

    1976-01-01

    Extrachromosomal deoxyribonucleic acid (DNA) from 24 different R factor-harboring Enterobacteriaceae was isolated and characterized by analytical ultracentrifugation and electron microscopy. The R factors represented 15 different patterns of transferable drug resistance found in enterobacteria from...... from 1.700 to 1.720 g/cm3. The majority of the bacteria contained extrachromosomal DNAs of various densities. Three-fourths of the R factors were classified as fi+. The investigation illustrates the extensive variability in the physical characteristics of plasmid DNA from R factor-harboring strains....

  6. Effect of Temperature on Topological States of Circular DNA

    Science.gov (United States)

    Fan, Yang-Tao; Li, Xiu-Yan; Liu, Yan-Hui; Chen, Hu

    2017-07-01

    The different topological states of circular double-stranded DNA can be defined by their linking number. The equilibrium distribution of linking number can be obtained by circularizing a linear DNA into a circle by ligase. Based on the recent experimental results that the DNA bending rigidity and twist rigidity strongly depend on temperature, the reduced bending rigidity can be approximated by g=(3.19× {10}-19-T\\cdot 4.14× {10}-22) {erg}\\cdot {cm} over the temperature interval (5 ∼ 53) °C, and the temperature dependence of twist rigidity can be fitted by C(T)=(4588.89{exp} (-T/117.04)-251.33) nm. The temperature dependence of the linking number distribution of circular DNAs can be predicted by using Monte Carlo simulation. The variance of linking number distribution on temperature is in accordance with the previous experimental results. Compared with the temperature dependence of bending rigidity, the temperature dependence of twist rigidity causes a noticeable fluctuation in linking number distribution and mainly contribute towards the variance change of linking number distribution of circular DNA. The variance of the writhe number and twist number in the equation = + depends on the length of circular DNA. When the length of circular DNA is less than 230 nm, the variance of twist number is dominant over the variance of writhe number ( ), whereas for the condition that the length of the circular DNA is larger than 370 nm. Supported by the National Natural Science Foundation of China under Grant Nos. 11047022, 11204045, and 11464004, Guizhou Provincial Tracking Key Program of Social Development (SY20123089, SZ20113069), the General Financial Grant from the China Postdoctoral Science Foundation (2014M562341), the Research Foundation for Young University Teachers from Guizhou University (201311), and College Innovation Talent Team of Guizhou Province (2014)32

  7. CSA: An efficient algorithm to improve circular DNA multiple alignment

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    Pereira Luísa

    2009-07-01

    Full Text Available Abstract Background The comparison of homologous sequences from different species is an essential approach to reconstruct the evolutionary history of species and of the genes they harbour in their genomes. Several complete mitochondrial and nuclear genomes are now available, increasing the importance of using multiple sequence alignment algorithms in comparative genomics. MtDNA has long been used in phylogenetic analysis and errors in the alignments can lead to errors in the interpretation of evolutionary information. Although a large number of multiple sequence alignment algorithms have been proposed to date, they all deal with linear DNA and cannot handle directly circular DNA. Researchers interested in aligning circular DNA sequences must first rotate them to the "right" place using an essentially manual process, before they can use multiple sequence alignment tools. Results In this paper we propose an efficient algorithm that identifies the most interesting region to cut circular genomes in order to improve phylogenetic analysis when using standard multiple sequence alignment algorithms. This algorithm identifies the largest chain of non-repeated longest subsequences common to a set of circular mitochondrial DNA sequences. All the sequences are then rotated and made linear for multiple alignment purposes. To evaluate the effectiveness of this new tool, three different sets of mitochondrial DNA sequences were considered. Other tests considering randomly rotated sequences were also performed. The software package Arlequin was used to evaluate the standard genetic measures of the alignments obtained with and without the use of the CSA algorithm with two well known multiple alignment algorithms, the CLUSTALW and the MAVID tools, and also the visualization tool SinicView. Conclusion The results show that a circularization and rotation pre-processing step significantly improves the efficiency of public available multiple sequence alignment

  8. Supercoiled circular DNA of an insect granulosis virus.

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    Tweeten, K A; Bulla, L A; Consigli, R A

    1977-08-01

    The DNA of the granulosis virus of the Indian meal moth, Plodia interpunctella, was characterized by physical chemical and electron microscopic techniques. Twenty-five percent of the DNA extracted from purified virus was isolated as supercoiled circular molecules. The remaining 75% consisted of relaxed circular molecules. These molecular forms were indicated by the production of two radioactive bands during sedimentation of (3)H-labeled granulosis virus DNA in alkaline sucrose gradients or in equilibrium density gradients of neutral cesium chloride/propidium iodide. Electron microscopic visualization of the DNA that banded at the higher density in the latter gradients revealed supercoiled structures whereas that of DNA that banded at the lower density demonstrated relaxed circular molecules. The superhelical molecules were converted to relaxed circles by treatment with pancreatic DNase. The molecular weight of the viral DNA was calculated to be 81 x 10(6) by sedimentation in neutral sucrose and 78 x 10(6) by sedimentation in alkaline sucrose. The molecular weight estimated from length measurements in electron micrographs was 76 x 10(6). The buoyant density of the granulosis virus DNA was 1.703 g/cm(3) and that of its insect host DNA was 1.697 g/cm(3). Equilibrium sedimentation in cesium chloride and thermal denaturation indicated G + C contents of 44% and 39% for the viral and host DNA, respectively.

  9. Somatic DNA recombination yielding circular DNA and deletion of a genomic region in embryonic brain

    International Nuclear Information System (INIS)

    Maeda, Toyoki; Chijiiwa, Yoshiharu; Tsuji, Hideo; Sakoda, Saburo; Tani, Kenzaburo; Suzuki, Tomokazu

    2004-01-01

    In this study, a mouse genomic region is identified that undergoes DNA rearrangement and yields circular DNA in brain during embryogenesis. External region-directed inverse polymerase chain reaction on circular DNA extracted from late embryonic brain tissue repeatedly detected DNA of this region containing recombination joints. Wide-range genomic PCR and digestion-circularization PCR analysis showed this region underwent recombination accompanied with deletion of intervening sequences, including the circularized regions. This region was mapped by fluorescence in situ hybridization to C1 on mouse chromosome 16, where no gene and no physiological DNA rearrangement had been identified. DNA sequence in the region has segmental homology to an orthologous region on human chromosome 3q.13. These observations demonstrated somatic DNA recombination yielding genomic deletions in brain during embryogenesis

  10. Quantitative analysis of the flexibility effect of cisplatin on circular DNA

    Science.gov (United States)

    Ji, Chao; Zhang, Lingyun; Wang, Peng-Ye

    2013-10-01

    We study the effects of cisplatin on the circular configuration of DNA using atomic force microscopy (AFM) and observe that the DNA gradually transforms to a complex configuration with an intersection and interwound structures from a circlelike structure. An algorithm is developed to extract the configuration profiles of circular DNA from AFM images and the radius of gyration is used to describe the flexibility of circular DNA. The quantitative analysis of the circular DNA demonstrates that the radius of gyration gradually decreases and two processes on the change of flexibility of circular DNA are found as the cisplatin concentration increases. Furthermore, a model is proposed and discussed to explain the mechanism for understanding the complicated interaction between DNA and cisplatin.

  11. Antiviral strategies to eliminate hepatitis B virus covalently closed circular DNA (cccDNA).

    Science.gov (United States)

    Revill, Peter; Locarnini, Stephen

    2016-10-01

    It has been over 50 years since the discovery of hepatitis B virus (HBV), yet 240 million people worldwide live with chronic HBV, resulting in up to 800000 deaths per year. A cure is yet to be achieved, due largely to a viral nuclear reservoir of transcriptionally active covalently closed circular DNA (cccDNA). While current antiviral therapies are effective at reducing viral replication, they have no impact on the existing cccDNA reservoir. Identifying mechanisms to either eliminate (complete cure) or inactivate (functional cure) HBV cccDNA are a major focus of HBV research worldwide. This review discusses recent advances in efforts to eliminate and/or regulate cccDNA, as well as future directions that may be considered in efforts to cure chronic HBV. Crown Copyright © 2016. Published by Elsevier Ltd. All rights reserved.

  12. Validation of DNA probes for molecular cytogenetics by mapping onto immobilized circular DNA

    Energy Technology Data Exchange (ETDEWEB)

    Greulich-Bode, Karin; Wang, Mei; Rhein, Andreas; Weier, Jingly; Weier, Heinz-Ulli

    2008-12-16

    Fluorescence in situ hybridization (FISH) is a sensitive and rapid procedure to detect gene rearrangements in tumor cells using non-isotopically labeled DNA probes. Large insert recombinant DNA clones such as bacterial artificial chromosome (BAC) or P1/PAC clones have established themselves in recent years as preferred starting material for probe preparations due to their low rates of chimerism and ease of use. However, when developing probes for the quantitative analysis of rearrangements involving genomic intervals of less than 100kb, careful probe selection and characterization are of paramount importance. We describe a sensitive approach to quality control probe clones suspected of carrying deletions or for measuring clone overlap with near kilobase resolution. The method takes advantage of the fact that P1/PAC/BAC's can be isolated as circular DNA molecules, stretched out on glass slides and fine-mapped by multicolor hybridization with smaller probe molecules. Two examples demonstrate the application of this technique: mapping of a gene-specific {approx}6kb plasmid onto an unusually small, {approx}55kb circular P1 molecule and the determination of the extent of overlap between P1 molecules homologous to the human NF-?B2 locus. The relatively simple method presented here does not require specialized equipment and may thus find widespread applications in DNA probe preparation and characterization, the assembly of physical maps for model organisms or in studies on gene rearrangements.

  13. Validation of DNA probes for molecular cytogenetics by mapping onto immobilized circular DNA

    Energy Technology Data Exchange (ETDEWEB)

    Greulich-Bode, Karin M.; Wang, Mei; Rhein, Andreas P.; Weier, Jingly F.; Weier, Heinz-Ulli G.

    2008-12-04

    Fluorescence in situ hybridization (FISH) is a sensitive and rapid procedure to detect gene rearrangements in tumor cells using non-isotopically labeled DNA probes. Large insert recombinant DNA clones such as bacterial artificial chromosome (BAC) or P1/PAC clones have established themselves in recent years as preferred starting material for probe preparations due to their low rates of chimerism and ease of use. However, when developing probes for the quantitative analysis of rearrangements involving genomic intervals of less than 100kb, careful probe selection and characterization are of paramount importance. We describe a sensitive approach to quality control probe clones suspected of carrying deletions or for measuring clone overlap with near kilobase resolution. The method takes advantage of the fact that P1/PAC/BAC's can be isolated as circular DNA molecules, stretched out on glass slides and fine-mapped by multicolor hybridization with smaller probe molecules. Two examples demonstrate the application of this technique: mapping of a gene-specific {approx}6kb plasmid onto an unusually small, {approx}55kb circular P1 molecule and the determination of the extent of overlap between P1 molecules homologous to the human NF-{kappa}B2 locus. The relatively simple method presented here does not require specialized equipment and may thus find widespread applications in DNA probe preparation and characterization, the assembly of physical maps for model organisms or in studies on gene rearrangements.

  14. Circular viral DNA detection and junction sequence analysis from PBMC of SHIV-infected cynomolgus monkeys with undetectable virus plasma RNA

    International Nuclear Information System (INIS)

    Cara, Andrea; Maggiorella, Maria Teresa; Bona, Roberta; Sernicola, Leonardo; Baroncelli, Silvia; Negri, Donatella R.M.; Leone, Pasqualina; Fagrouch, Zahra; Heeney, Jonathan; Titti, Fausto; Cafaro, Aurelio; Ensoli, Barbara

    2004-01-01

    Extrachromosomal forms of human immunodeficiency virus (HIV)-1 can be detected in peripheral blood mononuclear cell (PBMC) from HIV-infected patients in the absence of detectable viral replication and are thought to be a sign of active but cryptic virus replication. No information, however, are available on whether these forms are also present in animal models for acquired immunodeficiency syndrome (AIDS) and on their relation with other methods of detection of virus replication. To this aim, a polymerase chain reaction (PCR) approach was used to detect and analyze unintegrated circular 2-LTR-containing forms in PBMC of simian human immunodeficiency virus (SHIV)89.6P infected cynomolgus monkeys with RNA levels ranging between 1.8x10 6 and less than 50 copies/ml of plasma. 2-LTR forms were detected in 96.5% of monkeys' samples above 50 copies/ml of plasma, whereas they were present in 75.8% of monkeys' samples below 50 copies/ml of plasma. Persistence of unintegrated viral DNA in monkeys with undetectable plasma RNA could indicate either stability in non-dividing cells or ongoing low levels of viral replication in dividing cells

  15. DNA electronic circular dichroism on the inter-base pair scale

    DEFF Research Database (Denmark)

    Di Meo, Florent; Nørby, Morten Steen; Rubio-Magnieto, Jenifer

    2015-01-01

    A successful elucidation of the near-ultraviolet electronic circular dichroism spectrum of a short double-stranded DNA is reported. Time-dependent density functional theory methods are shown to accurately predict spectra and assign bands on the microscopic base-pair scale, a finding that opens...... the field for using circular dichroism spectroscopy as a sensitive nanoscale probe of DNA to reveal its complex interactions with the environment. (Chemical Equation Presented)....

  16. The Infection Efficiency and Replication Ability of Circularized HBV DNA Optimized the Linear HBV DNA in Vitro and in Vivo

    Science.gov (United States)

    Li, Xiaosong; Zhu, Junke; Lai, Guoqi; Yan, Lei; Hu, Jieli; Chen, Juan; Tang, Ni; Huang, Ailong

    2015-01-01

    Studies on molecular mechanisms of the persist infection of hepatitis B virus have been hampered by a lack of a robust animal model. We successfully established a simple, versatile, and reproducible HBV persist infection model in vitro and in vivo with the circularized HBV DNA. The cells and mice were transfected or injected with circularized HBV DNA and pAAV/HBV1.2, respectively. At the indicated time, the cells, supernatants, serum samples, and liver tissues were collected for virological and serological detection. Both in vitro and in vivo, the circularized HBV DNA and pAAV/HBV1.2 could replicate and transcribe efficiently, but the infection effect of the former was superior to the latter (p HBV genome DNA into the mice robustly supported HBV infection and approximately 80% of HBV infected mice established persistent infection for at least 10 weeks. This study demonstrated that the infection efficiency and replication ability of the circularized structure of HBV DNA overmatched that of the expression plasmid containing the linear structure of HBV DNA in vitro and in vivo. Meanwhile, this research results could provide useful tools and methodology for further study of pathogenic mechanisms and potential antiviral treatments of human chronic HBV infection in vitro and in vivo. PMID:25751726

  17. Rapid purification of circular DNA by triplex-mediated affinity capture

    Science.gov (United States)

    Ji, H.; Smith, L.M.

    1997-01-07

    A single-step capture of a target supercoiled double-stranded DNA molecule is accomplished by forming a local triple-helix among two strands of the supercoiled circular DNA and an oligonucleotide probe. The oligonucleotide is bound to an immobilizing support which facilitates the immobilization and purification of target DNA molecules. Non-target DNA molecules and other contaminating cellular material are easily removed by washing. The triple-helical structure is destabilized by raising the pH, leaving purified target DNA in the supernatant and reusable affinity capture oligonucleotide secured to the immobilizing support. 3 figs.

  18. DNA Polymerase κ Is a Key Cellular Factor for the Formation of Covalently Closed Circular DNA of Hepatitis B Virus.

    Directory of Open Access Journals (Sweden)

    Yonghe Qi

    2016-10-01

    Full Text Available Hepatitis B virus (HBV infection of hepatocytes begins by binding to its cellular receptor sodium taurocholate cotransporting polypeptide (NTCP, followed by the internalization of viral nucleocapsid into the cytoplasm. The viral relaxed circular (rc DNA genome in nucleocapsid is transported into the nucleus and converted into covalently closed circular (ccc DNA to serve as a viral persistence reservoir that is refractory to current antiviral therapies. Host DNA repair enzymes have been speculated to catalyze the conversion of rcDNA to cccDNA, however, the DNA polymerase(s that fills the gap in the plus strand of rcDNA remains to be determined. Here we conducted targeted genetic screening in combination with chemical inhibition to identify the cellular DNA polymerase(s responsible for cccDNA formation, and exploited recombinant HBV with capsid coding deficiency which infects HepG2-NTCP cells with similar efficiency of wild-type HBV to assure cccDNA synthesis is exclusively from de novo HBV infection. We found that DNA polymerase κ (POLK, a Y-family DNA polymerase with maximum activity in non-dividing cells, substantially contributes to cccDNA formation during de novo HBV infection. Depleting gene expression of POLK in HepG2-NTCP cells by either siRNA knockdown or CRISPR/Cas9 knockout inhibited the conversion of rcDNA into cccDNA, while the diminished cccDNA formation in, and hence the viral infection of, the knockout cells could be effectively rescued by ectopic expression of POLK. These studies revealed that POLK is a crucial host factor required for cccDNA formation during a de novo HBV infection and suggest that POLK may be a potential target for developing antivirals against HBV.

  19. Circular dichroism as a means to follow DNA gymnastics: on the shoulders of giants

    Directory of Open Access Journals (Sweden)

    H.H. Klump

    2010-01-01

    Full Text Available This is the first report of DNA stem-loops self-assembled by ‘foot-loop’ interactions into either two-dimensional strings or three-dimensional spirals, distinguished by circular dichroism spectroscopy. All subunits are linked by cooperative Watson-Crick hydrogen bonds.

  20. Amplified DNAs in laboratory stocks of Leishmania tarentolae: extrachromosomal circles structurally and functionally similar to the inverted-H-region amplification of methotrexate-resistant Leishmania major

    International Nuclear Information System (INIS)

    Petrillo-Peixoto, M.L.; Beverley, S.M.

    1988-01-01

    We describe the structure of amplified DNA that was discovered in two laboratory stocks of the protozoan parasite Leishmania tarentolae. Restriction mapping and molecular cloning revealed that a region of 42 kilobases was amplified 8- to 30-fold in these lines. Southern blot analyses of digested DNAs or chromosomes separated by pulsed-field electrophoresis showed that the amplified DNA corresponded to the H region, a locus defined originally by its amplification in methotrexate-resistant Leishmania major. Similarities between the amplified DNA of the two species included (i) extensive cross-hybridization; (ii) approximate conservation of sequence order; (iii) extrachromosomal localization; (iv) an overall inverted, head-to-head configuration as a circular 140-kilobase tetrameric molecule; (v) two regions of DNA sequence rearrangement, each of which was closely associated with the two centers of the inverted repeats; (vi) association with methotrexate resistance; and (vii) phenotypically conservative amplification, in which the wild-type chromosomal arrangement was retained without apparent modification. Our data showed that amplified DNA mediating drug resistance arose in unselected L. tarentolae, although the pressures leading to apparently spontaneous amplification and maintenance of the H region are not known. The simple structure and limited extent of DNA amplified in these and other Leishmania lines suggests that the study of gene amplification in Leishmania spp. offers an attractive model system for the study of amplification in cultured mammalian cells and tumors. We also introduced a method for measuring the size of large circular DNAs, using gamma-irradiation to introduce limited double-strand breaks followed by sizing of the linear DNAs by pulsed-field electrophoresis

  1. Long Terminal Repeat Circular DNA as Markers of Active Viral Replication of Human T Lymphotropic Virus-1 in Vivo

    Directory of Open Access Journals (Sweden)

    James M Fox

    2016-03-01

    Full Text Available Clonal expansion of human T-lymphotropic virus type-1 (HTLV-1 infected cells in vivo is well documented. Unlike human immunodeficiency virus type 1 (HIV-1, HTLV-1 plasma RNA is sparse. The contribution of the “mitotic” spread of HTLV-1 compared with infectious spread of the virus to HTLV-1 viral burden in established infection is uncertain. Since extrachromosomal long terminal repeat (LTR DNA circles are indicators of viral replication in HIV-1 carriers with undetectable plasma HIV RNA, we hypothesised that HTLV-1 LTR circles could indicate reverse transcriptase (RT usage and infectious activity. 1LTR and 2LTR DNA circles were measured in HTLV-1 cell lines and peripheral blood mononuclear cells (PBMC of asymptomatic carriers (ACs and patients with HTLV-1-associated myelopathy/tropical spastic paraparesis (HAM/TSP or adult T cell leukaemia/lymphoma (ATLL. 1LTR DNA circles were detected in 14/20 patients at a mean of 1.38/100 PBMC but did not differentiate disease status nor correlate with HTLV-1 DNA copies. 2LTR DNA circles were detected in 30/31 patients and at higher concentrations in patients with HTLV-1-associated diseases, independent of HTLV-1 DNA load. In an incident case the 2LTR DNA circle concentration increased 2.1 fold at the onset of HAM/TSP compared to baseline. Detectable and fluctuating levels of HTLV-1 DNA circles in patients indicate viral RT usage and virus replication. Our results indicate HTLV-1 viral replication capacity is maintained in chronic infection and may be associated with disease onset.

  2. Production of highly knotted DNA by means of cosmid circularization inside phage capsids

    Directory of Open Access Journals (Sweden)

    Trigueros Sonia

    2007-12-01

    Full Text Available Abstract Background The formation of DNA knots is common during biological transactions. Yet, functional implications of knotted DNA are not fully understood. Moreover, potential applications of DNA molecules condensed by means of knotting remain to be explored. A convenient method to produce abundant highly knotted DNA would be highly valuable for these studies. Results We had previously shown that circularization of the 11.2 kb linear DNA of phage P4 inside its viral capsid generates complex knots by the effect of confinement. We demonstrate here that this mechanism is not restricted to the viral genome. We constructed DNA cosmids as small as 5 kb and introduced them inside P4 capsids. Such cosmids were then recovered as a complex mixture of highly knotted DNA circles. Over 250 μg of knotted cosmid were typically obtained from 1 liter of bacterial culture. Conclusion With this biological system, DNA molecules of varying length and sequence can be shaped into very complex and heterogeneous knotted forms. These molecules can be produced in preparative amounts suitable for systematic studies and applications.

  3. Duck hepatitis B virus covalently closed circular DNA appears to survive hepatocyte mitosis in the growing liver

    International Nuclear Information System (INIS)

    Reaiche-Miller, Georget Y.; Thorpe, Michael; Low, Huey Chi; Qiao, Qiao; Scougall, Catherine A.; Mason, William S.; Litwin, Samuel; Jilbert, Allison R.

    2013-01-01

    Nucleos(t)ide analogues that inhibit hepatitis B virus (HBV) DNA replication are typically used as monotherapy for chronically infected patients. Treatment with a nucleos(t)ide analogue eliminates most HBV DNA replication intermediates and produces a gradual decline in levels of covalently closed circular DNA (cccDNA), the template for viral RNA synthesis. It remains uncertain if levels of cccDNA decline primarily through hepatocyte death, or if loss also occurs during hepatocyte mitosis. To determine if cccDNA survives mitosis, growing ducklings infected with duck hepatitis B virus (DHBV) were treated with the nucleoside analogue, Entecavir. Viremia was suppressed at least 10 5 -fold, during a period when average liver mass increased 23-fold. Analysis of the data suggested that if cccDNA synthesis was completely inhibited, at least 49% of cccDNA survived hepatocyte mitosis. However, there was a large duck-to-duck variation in cccDNA levels, suggesting that low level cccDNA synthesis may contribute to this apparent survival through mitosis. - Highlights: • The hepatitis B virus nuclear template is covalently closed circular DNA (cccDNA). • cccDNA was studied during liver growth in duck hepatitis B virus infected ducks. • Virus DNA replication and new cccDNA synthesis were inhibited with Entecavir. • At least 49% of cccDNA appeared to survive hepatocyte mitosis. • Low level virus DNA synthesis may contribute to survival of cccDNA through mitosis

  4. Duck hepatitis B virus covalently closed circular DNA appears to survive hepatocyte mitosis in the growing liver

    Energy Technology Data Exchange (ETDEWEB)

    Reaiche-Miller, Georget Y.; Thorpe, Michael; Low, Huey Chi; Qiao, Qiao; Scougall, Catherine A. [School of Molecular and Biomedical Science, University of Adelaide, Adelaide, SA 5005 (Australia); Mason, William S.; Litwin, Samuel [Institute for Cancer Research, Fox Chase Cancer Center, Philadelphia, PA 19111 (United States); Jilbert, Allison R., E-mail: allison.jilbert@adelaide.edu.au [School of Molecular and Biomedical Science, University of Adelaide, Adelaide, SA 5005 (Australia)

    2013-11-15

    Nucleos(t)ide analogues that inhibit hepatitis B virus (HBV) DNA replication are typically used as monotherapy for chronically infected patients. Treatment with a nucleos(t)ide analogue eliminates most HBV DNA replication intermediates and produces a gradual decline in levels of covalently closed circular DNA (cccDNA), the template for viral RNA synthesis. It remains uncertain if levels of cccDNA decline primarily through hepatocyte death, or if loss also occurs during hepatocyte mitosis. To determine if cccDNA survives mitosis, growing ducklings infected with duck hepatitis B virus (DHBV) were treated with the nucleoside analogue, Entecavir. Viremia was suppressed at least 10{sup 5}-fold, during a period when average liver mass increased 23-fold. Analysis of the data suggested that if cccDNA synthesis was completely inhibited, at least 49% of cccDNA survived hepatocyte mitosis. However, there was a large duck-to-duck variation in cccDNA levels, suggesting that low level cccDNA synthesis may contribute to this apparent survival through mitosis. - Highlights: • The hepatitis B virus nuclear template is covalently closed circular DNA (cccDNA). • cccDNA was studied during liver growth in duck hepatitis B virus infected ducks. • Virus DNA replication and new cccDNA synthesis were inhibited with Entecavir. • At least 49% of cccDNA appeared to survive hepatocyte mitosis. • Low level virus DNA synthesis may contribute to survival of cccDNA through mitosis.

  5. Predicting near-UV electronic circular dichroism in nucleosomal DNA by means of DFT response theory.

    Science.gov (United States)

    Norman, Patrick; Parello, Joseph; Polavarapu, Prasad L; Linares, Mathieu

    2015-09-14

    It is demonstrated that time-dependent density functional theory (DFT) calculations can accurately predict changes in near-UV electronic circular dichroism (ECD) spectra of DNA as the structure is altered from the linear (free) B-DNA form to the supercoiled N-DNA form found in nucleosome core particles. At the DFT/B3LYP level of theory, the ECD signal response is reduced by a factor of 6.7 in going from the B-DNA to the N-DNA form, and it is illustrated how more than 90% of the individual base-pair dimers contribute to this strong hypochromic effect. Of the several inter-base pair parameters, an increase in twist angles is identified as to strongly contribute to a reduced ellipticity. The present work provides first evidence that first-principles calculations can elucidate changes in DNA dichroism due to the supramolecular organization of the nucleoprotein particle and associates these changes with the local structural features of nucleosomal DNA.

  6. Origin of DNA-Induced Circular Dichroism in a Minor-Groove Binder.

    Science.gov (United States)

    Holmgaard List, Nanna; Knoops, Jérémie; Rubio-Magnieto, Jenifer; Idé, Julien; Beljonne, David; Norman, Patrick; Surin, Mathieu; Linares, Mathieu

    2017-10-25

    Induced circular dichroism (ICD) of DNA-binding ligands is well known to be strongly influenced by the specific mode of binding, but the relative importance of the possible mechanisms has remained undetermined. With a combination of molecular dynamics simulations, CD response calculations, and experiments on an AT-sequence, we show that the ICD of minor-groove-bound 4',6-diamidino-2-phenylindole (DAPI) originates from an intricate interplay between the chiral imprint of DNA, off-resonant excitonic coupling to nucleobases, charge-transfer, and resonant excitonic coupling between DAPIs. The significant contributions from charge-transfer and the chiral imprint to the ICD demonstrate the inadequacy of a standard Frenkel exciton theory of the DAPI-DNA interactions.

  7. Tethered particle analysis of supercoiled circular DNA using peptide nucleic acid handles

    DEFF Research Database (Denmark)

    Norregaard, Kamilla; Andersson, Magnus; Nielsen, Peter Eigil

    2014-01-01

    This protocol describes how to monitor individual naturally supercoiled circular DNA plasmids bound via peptide nucleic acid (PNA) handles between a bead and a surface. The protocol was developed for single-molecule investigation of the dynamics of supercoiled DNA, and it allows the investigation...... of both the dynamics of the molecule itself and of its interactions with a regulatory protein. Two bis-PNA clamps designed to bind with extremely high affinity to predetermined homopurine sequence sites in supercoiled DNA are prepared: one conjugated with digoxigenin for attachment to an anti......-digoxigenin-coated glass cover slide, and one conjugated with biotin for attachment to a submicron-sized streptavidin-coated polystyrene bead. Plasmids are constructed, purified and incubated with the PNA handles. The dynamics of the construct is analyzed by tracking the tethered bead using video microscopy: less...

  8. Effects of Circular DNA Length on Transfection Efficiency by Electroporation into HeLa Cells.

    Science.gov (United States)

    Hornstein, Benjamin D; Roman, Dany; Arévalo-Soliz, Lirio M; Engevik, Melinda A; Zechiedrich, Lynn

    2016-01-01

    The ability to produce extremely small and circular supercoiled vectors has opened new territory for improving non-viral gene therapy vectors. In this work, we compared transfection of supercoiled DNA vectors ranging from 383 to 4,548 bp, each encoding shRNA against GFP under control of the H1 promoter. We assessed knockdown of GFP by electroporation into HeLa cells. All of our vectors entered cells in comparable numbers when electroporated with equal moles of DNA. Despite similar cell entry, we found length-dependent differences in how efficiently the vectors knocked down GFP. As vector length increased up to 1,869 bp, GFP knockdown efficiency per mole of transfected DNA increased. From 1,869 to 4,257 bp, GFP knockdown efficiency per mole was steady, then decreased with increasing vector length. In comparing GFP knockdown with equal masses of vectors, we found that the shorter vectors transfect more efficiently per nanogram of DNA transfected. Our results rule out cell entry and DNA mass as determining factors for gene knockdown efficiency via electroporation. The length-dependent effects we have uncovered are likely explained by differences in nuclear translocation or transcription. These data add an important step towards clinical applications of non-viral vector delivery.

  9. Tethered particle analysis of supercoiled circular DNA using peptide nucleic acid handles.

    Science.gov (United States)

    Norregaard, Kamilla; Andersson, Magnus; Nielsen, Peter Eigil; Brown, Stanley; Oddershede, Lene B

    2014-09-01

    This protocol describes how to monitor individual naturally supercoiled circular DNA plasmids bound via peptide nucleic acid (PNA) handles between a bead and a surface. The protocol was developed for single-molecule investigation of the dynamics of supercoiled DNA, and it allows the investigation of both the dynamics of the molecule itself and of its interactions with a regulatory protein. Two bis-PNA clamps designed to bind with extremely high affinity to predetermined homopurine sequence sites in supercoiled DNA are prepared: one conjugated with digoxigenin for attachment to an anti-digoxigenin-coated glass cover slide, and one conjugated with biotin for attachment to a submicron-sized streptavidin-coated polystyrene bead. Plasmids are constructed, purified and incubated with the PNA handles. The dynamics of the construct is analyzed by tracking the tethered bead using video microscopy: less supercoiling results in more movement, and more supercoiling results in less movement. In contrast to other single-molecule methodologies, the current methodology allows for studying DNA in its naturally supercoiled state with constant linking number and constant writhe. The protocol has potential for use in studying the influence of supercoils on the dynamics of DNA and its associated proteins, e.g., topoisomerase. The procedure takes ~4 weeks.

  10. Circularly polarized luminescence of helically assembled pyrene π-stacks on RNA and DNA duplexes.

    Science.gov (United States)

    Nakamura, Mitsunobu; Ota, Fuyuki; Takada, Tadao; Akagi, Kazuo; Yamana, Kazushige

    2018-05-01

    In this report, we describe the circularly polarized luminescence (CPL) of the RNA duplexes having one to four 2'-O-pyrene modified uridines (Upy) and the DNA duplexes having two, four, and six pyrene modified non-nucleosidic linkers (Py). Both the pyrene π-stack arrays formed on the RNA and DNA double helical structures exhibited pyrene excimer fluorescence. In the pyrene-modified RNA systems, the RNA duplex having four Upys gives CPL emission with g lum value of <0.01 at 480 nm. The structure of pyrene stacks on the RNA duplex may be rigidly regulated with increase in the Upy domains, which resulted in the CPL emission. In the DNA systems, the pyrene-modified duplexes containing two and four Pys exhibited CPL emission with g lum values of <0.001 at 505 nm. The pyrene π-stack arrays presented here show CPL emission. However, the g lum values are relatively small when compared with our previous system consisting of the pyrene-zipper arrays on RNA. © 2018 Wiley Periodicals, Inc.

  11. Circular DNA Intermediate in the Duplication of Nile Tilapia vasa Genes

    Science.gov (United States)

    Fujimura, Koji; Conte, Matthew A.; Kocher, Thomas D.

    2011-01-01

    vasa is a highly conserved RNA helicase involved in animal germ cell development. Among vertebrate species, it is typically present as a single copy per genome. Here we report the isolation and sequencing of BAC clones for Nile tilapia vasa genes. Contrary to a previous report that Nile tilapia have a single copy of the vasa gene, we find evidence for at least three vasa gene loci. The vasa gene locus was duplicated from the original site and integrated into two distant novel sites. For one of these insertions we find evidence that the duplication was mediated by a circular DNA intermediate. This mechanism of gene duplication may explain the origin of isolated gene duplicates during the evolution of fish genomes. These data provide a foundation for studying the role of multiple vasa genes in the development of tilapia gonads, and will contribute to investigations of the molecular mechanisms of sex determination and evolution in cichlid fishes. PMID:22216289

  12. HBV-Specific shRNA is Capable of Reducing the Formation of Hepatitis B Virus Covalently Closed Circular DNA, but has No Effect on Established Covalently Closed Circular DNA in vitro

    OpenAIRE

    Starkey, Jason L.; Chiari, Estelle F.; Isom, Harriet C.

    2009-01-01

    Hepatitis B virus (HBV) covalently closed circular DNA (CCC DNA) is the source of HBV transcripts and persistence in chronically infected patients. The novel aspect of this study was to determine the effect of RNA interference (RNAi) on HBV CCC DNA when administered prior to establishment of HBV replication or during chronic HBV infection. HBV replication was initiated in HepG2 cells by transduction with HBV baculovirus. Subculture of HBV expressing HepG2 cells at 10 days post-transduction ge...

  13. Molecular Characterization of Extrachromosomal DNA Accompanying Primula Red Phytoplasma

    Czech Academy of Sciences Publication Activity Database

    Sarkisova, Tatiana; Lenz, Ondřej; Petrzik, Karel

    2015-01-01

    Roč. 163, č. 3 (2015), s. 222-226 ISSN 0931-1785 R&D Projects: GA MŠk LD12074 Institutional support: RVO:60077344 Keywords : Phylogenetic analysis * phytoplasma * rep gene * plasmid Subject RIV: EE - Microbiology, Virology Impact factor: 0.945, year: 2015

  14. Transcription of hepatitis B virus covalently closed circular DNA is regulated by CpG methylation during chronic infection.

    Directory of Open Access Journals (Sweden)

    Yongmei Zhang

    Full Text Available The persistence of hepatitis B virus (HBV infection is maintained by the nuclear viral covalently closed circular DNA (cccDNA, which serves as transcription template for viral mRNAs. Previous studies suggested that cccDNA contains methylation-prone CpG islands, and that the minichromosome structure of cccDNA is epigenetically regulated by DNA methylation. However, the regulatory effect of each CpG island methylation on cccDNA activity remains elusive. In the present study, we analyzed the distribution of CpG methylation within cccDNA in patient samples and investigated the impact of CpG island methylation on cccDNA-driven virus replication. Our study revealed the following observations: 1 Bisulfite sequencing of cccDNA from chronic hepatitis B patients indicated that CpG island I was seldom methylated, 2 CpG island II methylation was correlated to the low level of serum HBV DNA in patients, and in vitro methylation studies confirmed that CpG island II methylation markedly reduced cccDNA transcription and subsequent viral core DNA replication, 3 CpG island III methylation was associated with low serum HBsAg titers, and 4 Furthermore, we found that HBV genotype, HBeAg positivity, and patient age and liver fibrosis stage were also relevant to cccDNA CpG methylation status. Therefore, we clearly demonstrated that the status of cccDNA methylation is connected to the biological behavior of HBV. Taken together, our study provides a complete profile of CpG island methylation within HBV cccDNA and new insights for the function of CpG methylation in regulating HBV cccDNA transcription.

  15. Generation of covalently closed circular DNA of hepatitis B viruses via intracellular recycling is regulated in a virus specific manner.

    Directory of Open Access Journals (Sweden)

    Josef Köck

    Full Text Available Persistence of hepatitis B virus (HBV infection requires covalently closed circular (cccDNA formation and amplification, which can occur via intracellular recycling of the viral polymerase-linked relaxed circular (rc DNA genomes present in virions. Here we reveal a fundamental difference between HBV and the related duck hepatitis B virus (DHBV in the recycling mechanism. Direct comparison of HBV and DHBV cccDNA amplification in cross-species transfection experiments showed that, in the same human cell background, DHBV but not HBV rcDNA converts efficiently into cccDNA. By characterizing the distinct forms of HBV and DHBV rcDNA accumulating in the cells we find that nuclear import, complete versus partial release from the capsid and complete versus partial removal of the covalently bound polymerase contribute to limiting HBV cccDNA formation; particularly, we identify genome region-selectively opened nuclear capsids as a putative novel HBV uncoating intermediate. However, the presence in the nucleus of around 40% of completely uncoated rcDNA that lacks most if not all of the covalently bound protein strongly suggests a major block further downstream that operates in the HBV but not DHBV recycling pathway. In summary, our results uncover an unexpected contribution of the virus to cccDNA formation that might help to better understand the persistence of HBV infection. Moreover, efficient DHBV cccDNA formation in human hepatoma cells should greatly facilitate experimental identification, and possibly inhibition, of the human cell factors involved in the process.

  16. Isothermal circular-strand-displacement polymerization of DNA and microRNA in digital microfluidic devices.

    Science.gov (United States)

    Giuffrida, Maria Chiara; Zanoli, Laura Maria; D'Agata, Roberta; Finotti, Alessia; Gambari, Roberto; Spoto, Giuseppe

    2015-02-01

    Nucleic-acid amplification is a crucial step in nucleic-acid-sequence-detection assays. The use of digital microfluidic devices to miniaturize amplification techniques reduces the required sample volume and the analysis time and offers new possibilities for process automation and integration in a single device. The recently introduced droplet polymerase-chain-reaction (PCR) amplification methods require repeated cycles of two or three temperature-dependent steps during the amplification of the nucleic-acid target sequence. In contrast, low-temperature isothermal-amplification methods have no need for thermal cycling, thus requiring simplified microfluidic-device features. Here, the combined use of digital microfluidics and molecular-beacon (MB)-assisted isothermal circular-strand-displacement polymerization (ICSDP) to detect microRNA-210 sequences is described. MicroRNA-210 has been described as the most consistently and predominantly upregulated hypoxia-inducible factor. The nmol L(-1)-pmol L(-1) detection capabilities of the method were first tested by targeting single-stranded DNA sequences from the genetically modified Roundup Ready soybean. The ability of the droplet-ICSDP method to discriminate between full-matched, single-mismatched, and unrelated sequences was also investigated. The detection of a range of nmol L(-1)-pmol L(-1) microRNA-210 solutions compartmentalized in nanoliter-sized droplets was performed, establishing the ability of the method to detect as little as 10(-18) mol of microRNA target sequences compartmentalized in 20 nL droplets. The suitability of the method for biological samples was tested by detecting microRNA-210 from transfected K562 cells.

  17. Topological and metric properties of linear and circular DNA chains in nano-slits and nano-channels

    Science.gov (United States)

    Orlandini, Enzo; Micheletti, Cristian

    2014-03-01

    Motivated by recent advancements in single DNA molecule experiments, based on nanofluidic devices, we investigate numerically the metric and topological properties of a modelof open and circular DNA chains confined inside nano-slits and nano-channles. The results reveal an interesting characterization of the metric crossover behaviour in terms of the abundance, type and length of occuring knots. In particular we find that the knotting probability is nonmonotonic for increasing confinement and can be largely enhanced or suppressed, compared to the bulk case, by simply varying the slit or channel trasversal dimension. The observed knot population consists of knots that are far simpler than for DNA chains in spherical (i.e. cavities or capsids) confinement. These results suggest that nanoslits and nanochannels can be properly designed to produce open DNA chains hosting simple knots or to sieve DNA rings according to their knotted state. Finally we discuss the implications that the presence of knots may have on the dynamical properties of confined DNA chains such as chain elongation, injection/ejection processes and entanglement relaxation. We acknowledge financial support from the Italian ministry of education, grant PRIN 2010HXAW77.

  18. Construction of a Holliday Junction in Small Circular DNA Molecules for Stable Motifs and Two-Dimensional Lattices.

    Science.gov (United States)

    Guo, Xin; Wang, Xue-Mei; Wei, Shuai; Xiao, Shou-Jun

    2018-04-12

    Design rules for DNA nanotechnology have been mostly learnt from using linear single-stranded (ss) DNA as the source material. For example, the core structure of a typical DAO (double crossover, antiparallel, odd half-turns) tile for assembling 2D lattices is constructed from only two linear ss-oligonucleotide scaffold strands, similar to two ropes making a square knot. Herein, a new type of coupled DAO (cDAO) tile and 2D lattices of small circular ss-oligonucleotides as scaffold strands and linear ss-oligonucleotides as staple strands are reported. A cDAO tile of cDAO-c64nt (c64nt: circular 64 nucleotides), shaped as a solid parallelogram, is constructed with a Holliday junction (HJ) at the center and two HJs at both poles of a c64nt; similarly, cDAO-c84nt, shaped as a crossed quadrilateral composed of two congruent triangles, is formed with a HJ at the center and four three-way junctions at the corners of a c84nt. Perfect 2D lattices were assembled from cDAO tiles: infinite nanostructures of nanoribbons, nanotubes, and nanorings, and finite nanostructures. The structural relationship between the visible lattices imaged by AFM and the corresponding invisible secondary and tertiary molecular structures of HJs, inclination angle of hydrogen bonds against the double-helix axis, and the chirality of the tile can be interpreted very well. This work could shed new light on DNA nanotechnology with unique circular tiles. © 2018 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

  19. Uracil DNA glycosylase counteracts APOBEC3G-induced hypermutation of hepatitis B viral genomes: excision repair of covalently closed circular DNA.

    Directory of Open Access Journals (Sweden)

    Kouichi Kitamura

    Full Text Available The covalently closed circular DNA (cccDNA of the hepatitis B virus (HBV plays an essential role in chronic hepatitis. The cellular repair system is proposed to convert cytoplasmic nucleocapsid (NC DNA (partially double-stranded DNA into cccDNA in the nucleus. Recently, antiviral cytidine deaminases, AID/APOBEC proteins, were shown to generate uracil residues in the NC-DNA through deamination, resulting in cytidine-to-uracil (C-to-U hypermutation of the viral genome. We investigated whether uracil residues in hepadnavirus DNA were excised by uracil-DNA glycosylase (UNG, a host factor for base excision repair (BER. When UNG activity was inhibited by the expression of the UNG inhibitory protein (UGI, hypermutation of NC-DNA induced by either APOBEC3G or interferon treatment was enhanced in a human hepatocyte cell line. To assess the effect of UNG on the cccDNA viral intermediate, we used the duck HBV (DHBV replication model. Sequence analyses of DHBV DNAs showed that cccDNA accumulated G-to-A or C-to-T mutations in APOBEC3G-expressing cells, and this was extensively enhanced by UNG inhibition. The cccDNA hypermutation generated many premature stop codons in the P gene. UNG inhibition also enhanced the APOBEC3G-mediated suppression of viral replication, including reduction of NC-DNA, pre-C mRNA, and secreted viral particle-associated DNA in prolonged culture. Enhancement of APOBEC3G-mediated suppression by UNG inhibition was not observed when the catalytic site of APOBEC3G was mutated. Transfection experiments of recloned cccDNAs revealed that the combination of UNG inhibition and APOBEC3G expression reduced the replication ability of cccDNA. Taken together, these data indicate that UNG excises uracil residues from the viral genome during or after cccDNA formation in the nucleus and imply that BER pathway activities decrease the antiviral effect of APOBEC3-mediated hypermutation.

  20. Circular RNA (circRNA) was an important bridge in the switch from the RNA world to the DNA world.

    Science.gov (United States)

    Soslau, Gerald

    2018-06-14

    osmolarity. Circular RNA, circRNA, is proposed as a critical stable RNA molecule that served as the genetic precursor for the switch to DNA and the replication of circRNA by a rolling circle mechanism gave rise to the RNA complexity required for the genetic functions of the cell. The replicating ribocyte would have required protein synthesis as well as RNA replication and a model for non-coded and primordial coded protein synthesis is proposed. Finally, the switch from the RNA to the DNA world would have involved the synthesis of an RNA:DNA hybrid prior to the formation of dsDNA. If the hybrid was a circular molecule that ultimately yielded a circular dsDNA molecule, it could predict that the primordial DNA cell would evolve into a bacterial cell with a single circular chromosome. One would hope that continued speculation of the origin of life will spur new directions of research that may never fully answer the questions of the past but add to our ability to regulate potentially harmful biological events in the present and in the future. Copyright © 2018 Elsevier Ltd. All rights reserved.

  1. A new model mimicking persistent HBV e antigen-negative infection using covalently closed circular DNA in immunocompetent mice.

    Directory of Open Access Journals (Sweden)

    Lei Wang

    Full Text Available Despite the availability of an effective vaccine, hepatitis B virus (HBV infection remains a major health problem. HBV e antigen (HBeAg-negative strains have become prevalent. Previously, no animal model mimicked the clinical course of HBeAg-negative HBV infection. To establish an HBeAg-negative HBV infection model, the 3.2-kb full-length genome of HBeAg-negative HBV was cloned from a clinical sample and then circularized to form covalently closed circular (cccDNA. The resulting cccDNA was introduced into the liver of C57BL/6J mice through hydrodynamic injection. Persistence of the HBeAg-negative infection was monitored at predetermined time points using HBV-specific markers including HBV surface antigen (HBsAg, HBeAg, and HBV core antigen (HBcAg as well as DNA copies. Throughout the study, pAAV-HBV1.2 was used as a control. In mice injected with HBeAg-negative cccDNA, the HBV infection rate was 100% at the initial stage. HBsAg levels increased up to 1 week, at which point levels peaked and dropped quickly thereafter. In 60% of injected mice, HBsAg and HBcAg persisted for more than 10 weeks. High numbers of HBV DNA copies were detected in the serum and liver. Moreover, cccDNA persisted in the liver tissue of HBeAg-negative mice. In contrast to the pAAV-HBV 1.2 injected mice, no HBeAg was found in mice injected with HBeAg-negative HBV throughout the study period. These results demonstrate the first successful establishment of a model of HBeAg-negative HBV-persistent infection in immunocompetent mice. Compared to pAAV-HBV1.2-injected mice, the infection persistence and levels of serum virological and biochemical markers were approximately equal in the model mice. This model will be useful for mechanistic studies on HBeAg-negative HBV infection and will facilitate the evaluation of new antiviral drugs.

  2. Production of DNA minicircles less than 250 base pairs through a novel concentrated DNA circularization assay enabling minicircle design with NF-κB inhibition activity

    Science.gov (United States)

    Thibault, Thomas; Degrouard, Jeril; Baril, Patrick; Pichon, Chantal; Midoux, Patrick

    2017-01-01

    Abstract Double-stranded DNA minicircles of less than 1000 bp in length have great interest in both fundamental research and therapeutic applications. Although minicircles have shown promising activity in gene therapy thanks to their good biostability and better intracellular trafficking, minicircles down to 250 bp in size have not yet been investigated from the test tube to the cell for lack of an efficient production method. Herein, we report a novel versatile plasmid-free method for the production of DNA minicircles comprising fewer than 250 bp. We designed a linear nicked DNA double-stranded oligonucleotide blunt-ended substrate for efficient minicircle production in a ligase-mediated and bending protein-assisted circularization reaction at high DNA concentration of 2 μM. This one pot multi-step reaction based-method yields hundreds of micrograms of minicircle with sequences of any base composition and position and containing or not a variety of site-specifically chemical modifications or physiological supercoiling. Biochemical and cellular studies were then conducted to design a 95 bp minicircle capable of binding in vitro two NF-κB transcription factors per minicircle and to efficiently inhibiting NF-κB-dependent transcriptional activity in human cells. Therefore, our production method could pave the way for the design of minicircles as new decoy nucleic acids. PMID:27899652

  3. Production of DNA minicircles less than 250 base pairs through a novel concentrated DNA circularization assay enabling minicircle design with NF-κB inhibition activity.

    Science.gov (United States)

    Thibault, Thomas; Degrouard, Jeril; Baril, Patrick; Pichon, Chantal; Midoux, Patrick; Malinge, Jean-Marc

    2017-03-17

    Double-stranded DNA minicircles of less than 1000 bp in length have great interest in both fundamental research and therapeutic applications. Although minicircles have shown promising activity in gene therapy thanks to their good biostability and better intracellular trafficking, minicircles down to 250 bp in size have not yet been investigated from the test tube to the cell for lack of an efficient production method. Herein, we report a novel versatile plasmid-free method for the production of DNA minicircles comprising fewer than 250 bp. We designed a linear nicked DNA double-stranded oligonucleotide blunt-ended substrate for efficient minicircle production in a ligase-mediated and bending protein-assisted circularization reaction at high DNA concentration of 2 μM. This one pot multi-step reaction based-method yields hundreds of micrograms of minicircle with sequences of any base composition and position and containing or not a variety of site-specifically chemical modifications or physiological supercoiling. Biochemical and cellular studies were then conducted to design a 95 bp minicircle capable of binding in vitro two NF-κB transcription factors per minicircle and to efficiently inhibiting NF-κB-dependent transcriptional activity in human cells. Therefore, our production method could pave the way for the design of minicircles as new decoy nucleic acids. © The Author(s) 2016. Published by Oxford University Press on behalf of Nucleic Acids Research.

  4. Acinetobacter phage genome is similar to Sphinx 2.36, the circular DNA copurified with TSE infected particles.

    Science.gov (United States)

    Longkumer, Toshisangba; Kamireddy, Swetha; Muthyala, Venkateswar Reddy; Akbarpasha, Shaikh; Pitchika, Gopi Krishna; Kodetham, Gopinath; Ayaluru, Murali; Siddavattam, Dayananda

    2013-01-01

    While analyzing plasmids of Acinetobacter sp. DS002 we have detected a circular DNA molecule pTS236, which upon further investigation is identified as the genome of a phage. The phage genome has shown sequence similarity to the recently discovered Sphinx 2.36 DNA sequence co-purified with the Transmissible Spongiform Encephalopathy (TSE) particles isolated from infected brain samples collected from diverse geographical regions. As in Sphinx 2.36, the phage genome also codes for three proteins. One of them codes for RepA and is shown to be involved in replication of pTS236 through rolling circle (RC) mode. The other two translationally coupled ORFs, orf106 and orf96, code for coat proteins of the phage. Although an orf96 homologue was not previously reported in Sphinx 2.36, a closer examination of DNA sequence of Sphinx 2.36 revealed its presence downstream of orf106 homologue. TEM images and infection assays revealed existence of phage AbDs1 in Acinetobacter sp. DS002.

  5. Diverse replication-associated protein encoding circular DNA viruses in guano samples of Central-Eastern European bats.

    Science.gov (United States)

    Kemenesi, Gábor; Kurucz, Kornélia; Zana, Brigitta; Földes, Fanni; Urbán, Péter; Vlaschenko, Anton; Kravchenko, Kseniia; Budinski, Ivana; Szodoray-Parádi, Farkas; Bücs, Szilárd; Jére, Csaba; Csősz, István; Szodoray-Parádi, Abigél; Estók, Péter; Görföl, Tamás; Boldogh, Sándor; Jakab, Ferenc

    2018-03-01

    Circular replication-associated protein encoding single-stranded DNA (CRESS DNA) viruses are increasingly recognized worldwide in a variety of samples. Representative members include well-described veterinary pathogens with worldwide distribution, such as porcine circoviruses or beak and feather disease virus. In addition, numerous novel viruses belonging to the family Circoviridae with unverified pathogenic roles have been discovered in different human samples. Viruses of the family Genomoviridae have also been described as being highly abundant in different faecal and environmental samples, with case reports showing them to be suspected pathogens in human infections. In order to investigate the genetic diversity of these viruses in European bat populations, we tested guano samples from Georgia, Hungary, Romania, Serbia and Ukraine. This resulted in the detection of six novel members of the family Circoviridae and two novel members of the family Genomoviridae. Interestingly, a gemini-like virus, namely niminivirus, which was originally found in raw sewage samples in Nigeria, was also detected in our samples. We analyzed the nucleotide composition of members of the family Circoviridae to determine the possible host origins of these viruses. This study provides the first dataset on CRESS DNA viruses of European bats, and members of several novel viral species were discovered.

  6. Genes encoded within 8q24 on the amplicon of a large extrachromosomal element are selectively repressed during the terminal differentiation of HL-60 cells

    OpenAIRE

    Hirano, Tetsuo; Ike, Fumio; Murata, Takehide; Obata, Yuichi; Utiyama, Hiroyasu; Yokoyama, Kazunari K.

    2008-01-01

    Human acute myeloblastic leukemia HL-60 cells become resistant to differentiation during long­term cultivation. After 150 passages, double minute chromosomes (dmins) found in early­-passaged cells are replaced by large extrachromosomal elements (LEEs). In a DNA library derived from a purified fraction of LEEs, 12.6% (23/183) of clones were assigned to 8q24 and 9.2% (17/183) were assigned to 14q11 in the human genome. Fluorescence in situ hybridization (FISH) revealed a small aberrant chromos...

  7. Nudiviruses and other large, double-stranded circular DNA viruses of invertebrates: new insights on an old topic.

    Science.gov (United States)

    Wang, Yongjie; Jehle, Johannes A

    2009-07-01

    Nudiviruses (NVs) are a highly diverse group of large, circular dsDNA viruses pathogenic for invertebrates. They have rod-shaped and enveloped nucleocapsids, replicate in the nucleus of infected host cells, and possess interesting biological and molecular properties. The unassigned viral genus Nudivirus has been proposed for classification of nudiviruses. Currently, the nudiviruses comprise five different viruses: the palm rhinoceros beetle virus (Oryctes rhinoceros NV, OrNV), the Hz-1 virus (Heliothis zea NV-1, HzNV-1), the cricket virus (Gryllus bimaculatus NV, GbNV), the corn earworm moth Hz-2 virus (HzNV-2), and the occluded shrimp Monodon Baculovirus reassigned as Penaeus monodon NV (PmNV). Thus far, the genomes of OrNV, GbNV, HzNV-1 and HzNV-2 have been completely sequenced. They vary between 97 and 230kbp in size and encode between 98 and 160 open reading frames (ORFs). All sequenced nudiviruses have 33 ORFs in common. Strikingly, 20 of them are homologous to baculovirus core genes involved in RNA transcription, DNA replication, virion structural components and other functions. Another nine conserved ORFs are likely associated with DNA replication, repair and recombination, and nucleotide metabolism; one is homologous to baculovirus iap-3 gene; two are nudivirus-specific ORFs of unknown function. Interestingly, one nudivirus ORF is similar to polh/gran gene, encoding occlusion body protein matrix and being conserved in Alpha- Beta- and Gammabaculoviruses. Members of nudiviruses are closely related and form a monophyletic group consisting of two sister clades of OrNV/GbNV and HzNVs/PmNV. It is proposed that nudiviruses and baculoviruses derived from a common ancestor and are evolutionarily related to other large DNA viruses such as the insect-specific salivary gland hypertrophy virus (SGHV) and the marine white spot syndrome virus (WSSV).

  8. Localization and dynamics of small circular DNA in live mammalian nuclei

    DEFF Research Database (Denmark)

    Mearini, Giulia; Nielsen, Peter E; Fackelmayer, Frank O

    2004-01-01

    with intranuclear structural sites that strongly reduce its mobility and restrict the DNA to regions excluding nucleoli and nuclear bodies such as PML bodies. The labeled plasmids partially co-localize with SAF-A, a well characterized marker protein for the nuclear 'scaffold' or 'matrix', and are resistant towards...

  9. Circular dichroism spectroscopy of conformers of (guanine + adenine) repeat strands of DNA

    Czech Academy of Sciences Publication Activity Database

    Kejnovská, Iva; Kypr, Jaroslav; Vorlíčková, Michaela

    2003-01-01

    Roč. 15, č. 7 (2003), s. 584-592 ISSN 0899-0042 R&D Projects: GA AV ČR IAA4004201; GA ČR GA204/01/0561 Institutional research plan: CEZ:AV0Z5004920 Keywords : DNA conformation * (guanine + adenine) repeats * homoduplexes Subject RIV: BO - Biophysics Impact factor: 1.793, year: 2003

  10. Administrative Circulars

    CERN Document Server

    Département des Ressources humaines

    2004-01-01

    Administrative Circular N° 2 (Rev. 2) - May 2004 Guidelines and procedures concerning recruitment and probation period of staff members This circular has been revised. It cancels and replaces Administrative Circular N° 2 (Rev. 1) - March 2000. Administrative Circular N° 9 (Rev. 3) - May 2004 Staff members contracts This circular has been revised. It cancels and replaces Administrative Circular N° 9 (Rev. 2) - March 2000. Administrative Circular N° 26 (Rev. 4) - May 2004 Procedure governing the career evolution of staff members This circular has also been revised. It Administrative Circulars Administrative Circular N° 26 (Rev. 3) - December 2001 and brings up to date the French version (Rev. 4) published on the HR Department Web site in January 2004. Operational Circular N° 7 - May 2004 Work from home This circular has been drawn up. Operational Circular N° 8 - May 2004 Dealing with alcohol-related problems...

  11. Serum hepatitis B core-related antigen is a satisfactory surrogate marker of intrahepatic covalently closed circular DNA in chronic hepatitis B.

    Science.gov (United States)

    Chen, En-Qiang; Feng, Shu; Wang, Meng-Lan; Liang, Ling-Bo; Zhou, Ling-Yun; Du, Ling-Yao; Yan, Li-Bo; Tao, Chuan-Min; Tang, Hong

    2017-03-14

    Recently, hepatitis B core-related antigen (HBcrAg) has been suggested as an additional marker of hepatitis B virus (HBV) infection. This study aimed to investigate whether serum quantitative HBcrAg (qHBcrAg) was a satisfactory surrogate marker of intrahepatic covalently closed circular DNA (cccDNA). A total of 139 patients with liver biopsy were enrolled, consisting of 59 patients in immune tolerance (IT) phase, 52 patients in immune clearance (IC) phase, 18 patients in low-replication (LR) phase, and 10 patients in reactivation phase. All patients in IC phase have received entecavir (ETV) therapy, and 32 of them undergone a second liver biopsy at 24 months. Among those patients, qHBcrAg was strongly correlated with intrahepatic cccDNA, which is superior to that of qHBsAg and HBV DNA. And similar findings were also observed in patients in IT, IC, LR and reactivation phases. Among the 32 ETV-treated patients with a second liver biopsy in IC phase, the decline of intrahepatic cccDNA was accompanied by changes in both qHBcrAg and qHBsAg. However, as compared to qHBsAg, the change of qHBcrAg was more strongly associated with intrahepatic cccDNA-decline. In summary, serum qHBcrAg should be a satisfactory surrogate of intrahepatic HBV cccDNA in CHB patients.

  12. Circular Coinduction

    Science.gov (United States)

    Rosu, Grigore; Goguen, Joseph; Norvig, Peter (Technical Monitor)

    2001-01-01

    Circular coinduction is a technique for behavioral reasoning that extends cobasis coinduction to specifications with circularities. Because behavioral satisfaction is not recursively enumerable, no algorithm can work for every behavioral statement. However. algorithms using circular coinduction can prove every practical behavioral result that we know. This paper proves the correctness of circular coinduction and some consequences.

  13. Normal-Mode Analysis of Circular DNA at the Base-Pair Level. 2. Large-Scale Configurational Transformation of a Naturally Curved Molecule.

    Science.gov (United States)

    Matsumoto, Atsushi; Tobias, Irwin; Olson, Wilma K

    2005-01-01

    Fine structural and energetic details embedded in the DNA base sequence, such as intrinsic curvature, are important to the packaging and processing of the genetic material. Here we investigate the internal dynamics of a 200 bp closed circular molecule with natural curvature using a newly developed normal-mode treatment of DNA in terms of neighboring base-pair "step" parameters. The intrinsic curvature of the DNA is described by a 10 bp repeating pattern of bending distortions at successive base-pair steps. We vary the degree of intrinsic curvature and the superhelical stress on the molecule and consider the normal-mode fluctuations of both the circle and the stable figure-8 configuration under conditions where the energies of the two states are similar. To extract the properties due solely to curvature, we ignore other important features of the double helix, such as the extensibility of the chain, the anisotropy of local bending, and the coupling of step parameters. We compare the computed normal modes of the curved DNA model with the corresponding dynamical features of a covalently closed duplex of the same chain length constructed from naturally straight DNA and with the theoretically predicted dynamical properties of a naturally circular, inextensible elastic rod, i.e., an O-ring. The cyclic molecules with intrinsic curvature are found to be more deformable under superhelical stress than rings formed from naturally straight DNA. As superhelical stress is accumulated in the DNA, the frequency, i.e., energy, of the dominant bending mode decreases in value, and if the imposed stress is sufficiently large, a global configurational rearrangement of the circle to the figure-8 form takes place. We combine energy minimization with normal-mode calculations of the two states to decipher the configurational pathway between the two states. We also describe and make use of a general analytical treatment of the thermal fluctuations of an elastic rod to characterize the

  14. Biomolecular and structural analyses of cauliflower-like DNAs by ultraviolet, circular dichroism, and fluorescence spectroscopies in comparison with natural DNA.

    Science.gov (United States)

    Gill, Pooria; Ranjbar, Bijan; Saber, Reza; Khajeh, Khosro; Mohammadian, Mehdi

    2011-07-01

    Cauliflower-like DNAs are stem-loop DNAs that are fabricated periodically in inverted repetitions from deoxyribonucleic acid phosphates (dNTPs) by loop-mediated isothermal amplification (LAMP). Cauliflower-like DNAs have ladder-shape behaviors on gel electrophoresis, and increasing the time of LAMP leads to multiplying the repetitions, stem-loops, and electrophoretic bands. Cauliflower-like DNAs were fabricated via LAMP using two loop primers, two bumper primers, dNTPs, a λ-phage DNA template, and a Bst DNA polymerase in 75- and 90-min periods. These times led to manufacturing two types of cauliflower-like DNAs with different contents of inverted repetitions and stem-loops, which were clearly indicated by two comparable electrophoresis patterns in agarose gel. LAMP-fabricated DNAs and natural dsB-DNA (salmon genomic DNA) were dialyzed in Gomori phosphate buffer (10 mM, pH 7.4) to be isolated from salts, nucleotides, and primers. Dialyzed DNAs were studied using UV spectroscopy, circular dichroism spectropolarimetry, and fluorescence spectrophotometry. Structural analyses indicated reduction of the molecular ellipticity and extinction coefficients in comparison with B-DNA. Also, cauliflower-like DNAs demonstrated less intrinsic and more extrinsic fluorescence in comparison with natural DNA. The overwinding and lengthening of the cauliflower-like configurations of LAMP DNAs led to changes in physical parameters of this type of DNA in comparison with natural DNA. The results obtained introduced new biomolecular characteristics of DNA macromolecules fabricated within a LAMP process and show the effects of more inverted repeats and stem-loops, which are manufactured by lengthening the process.

  15. A novel Sulfolobus non-conjugative extrachromosomal genetic element capable of integration into the host genome and spreading in the presence of a fusellovirus

    DEFF Research Database (Denmark)

    Wang, Ying; Duan, Zhenhong; Zhu, Haojun

    2007-01-01

    An integrative non-conjugative extrachromosomal genetic element, denoted as pSSVi, has been isolated from a Sulfolobus solfataricus P2 strain and was characterized. This genetic element is a double-stranded DNA of 5740 bp in size and contains eight open reading frames (ORFs). It resembles members....... Interestingly, pSSVi encodes an SSV-type integrase which probably catalyzes the integration of its genome into a specific site (a tRNA(Arg) gene) in the S. solfataricus P2 genome. Like pSSVx, pSSVi can be packaged into a spindle-like viral particle and spread with the help of SSV1 or SSV2. In addition, both SSV......1 and SSV2 appeared to replicate more efficiently in the presence of pSSVi. Given the versatile genetic abilities, pSSVi appears to be well suited for a role in horizontal gene transfer....

  16. Characterization of the microDNA through the response to chemotherapeutics in lymphoblastoid cell lines.

    Directory of Open Access Journals (Sweden)

    Pamela Mehanna

    Full Text Available Recently, a new class of extrachromosomal circular DNA, called microDNA, was identified. They are on average 100 to 400 bp long and are derived from unique non-repetitive genomic regions with high gene density. MicroDNAs are thought to arise from DNA breaks associated with RNA metabolism or replication slippage. Given the paucity of information on this entirely novel phenomenon, we aimed to get an additional insight into microDNA features by performing the microDNA analysis in 20 independent human lymphoblastoid cell lines (LCLs prior and after treatment with chemotherapeutic drugs. The results showed non-random genesis of microDNA clusters from the active regions of the genome. The size periodicity of 190 bp was observed, which matches DNA fragmentation typical for apoptotic cells. The chemotherapeutic drug-induced apoptosis of LCLs increased both number and size of clusters further suggesting that part of microDNAs could result from the programmed cell death. Interestingly, proportion of identified microDNA sequences has common loci of origin when compared between cell line experiments. While compatible with the original observation that microDNAs originate from a normal physiological process, obtained results imply complementary source of its production. Furthermore, non-random genesis of microDNAs depicted by redundancy between samples makes these entities possible candidates for new biomarker generation.

  17. Administrative circular

    CERN Multimedia

    2003-01-01

    • N° 21 - August 2003 Special leave This circular has been amended. Copies of this circular are available in the Divisional Secretariats. In addition, administrative and operational circulars, as well as the lists of those in force, are available for consultation on the Web at: http://cern.ch/hr-div/internal/admin_services/admincirc/listadmincirc.asp Human Resources Division Tel. 74128

  18. Circular Solutions

    NARCIS (Netherlands)

    Annevelink, E.; Bos, H.L.; Meesters, K.P.H.; Oever, van den M.J.A.; Haas, de W.; Kuikman, P.J.; Rietra, R.P.J.J.; Sikirica, N.

    2016-01-01

    The fifth part of this report on Circular Solutions is about the circular principle From Waste to Resource. The purpose of this study is to select promising options for the implementation of this circular principle and to elaborate these options further.

  19. PRMT5 restricts hepatitis B virus replication through epigenetic repression of covalently closed circular DNA transcription and interference with pregenomic RNA encapsidation.

    Science.gov (United States)

    Zhang, Wen; Chen, Jieliang; Wu, Min; Zhang, Xiaonan; Zhang, Min; Yue, Lei; Li, Yaming; Liu, Jiangxia; Li, Baocun; Shen, Fang; Wang, Yang; Bai, Lu; Protzer, Ulrike; Levrero, Massimo; Yuan, Zhenghong

    2017-08-01

    Chronic hepatitis B virus (HBV) infection remains a major health problem worldwide. The covalently closed circular DNA (cccDNA) minichromosome, which serves as the template for the transcription of viral RNAs, plays a key role in viral persistence. While accumulating evidence suggests that cccDNA transcription is regulated by epigenetic machinery, particularly the acetylation of cccDNA-bound histone 3 (H3) and H4, the potential contributions of histone methylation and related host factors remain obscure. Here, by screening a series of methyltransferases and demethylases, we identified protein arginine methyltransferase 5 (PRMT5) as an effective restrictor of HBV transcription and replication. In cell culture-based models for HBV infection and in liver tissues of patients with chronic HBV infection, we found that symmetric dimethylation of arginine 3 on H4 on cccDNA was a repressive marker of cccDNA transcription and was regulated by PRMT5 depending on its methyltransferase domain. Moreover, PRMT5-triggered symmetric dimethylation of arginine 3 on H4 on the cccDNA minichromosome involved an interaction with the HBV core protein and the Brg1-based human SWI/SNF chromatin remodeler, which resulted in down-regulation of the binding of RNA polymerase II to cccDNA. In addition to the inhibitory effect on cccDNA transcription, PRMT5 inhibited HBV core particle DNA production independently of its methyltransferase activity. Further study revealed that PRMT5 interfered with pregenomic RNA encapsidation by preventing its interaction with viral polymerase protein through binding to the reverse transcriptase-ribonuclease H region of polymerase, which is crucial for the polymerase-pregenomic RNA interaction. PRMT5 restricts HBV replication through a two-part mechanism including epigenetic suppression of cccDNA transcription and interference with pregenomic RNA encapsidation; these findings improve the understanding of epigenetic regulation of HBV transcription and host

  20. Establishment and mitotic stability of an extra-chromosomal mammalian replicon

    Directory of Open Access Journals (Sweden)

    Jackson Dean A

    2007-08-01

    Full Text Available Abstract Background Basic functions of the eukaryotic nucleus, like transcription and replication, are regulated in a hierarchic fashion. It is assumed that epigenetic factors influence the efficiency and precision of these processes. In order to uncouple local and long-range epigenetic features we used an extra-chromosomal replicon to study the requirements for replication and segregation and compared its behavior to that of its integrated counterpart. Results The autonomous replicon replicates in all eukaryotic cells and is stably maintained in the absence of selection but, as other extra-chromosomal replicons, its establishment is very inefficient. We now show that following establishment the vector is stably associated with nuclear compartments involved in gene expression and chromosomal domains that replicate at the onset of S-phase. While the vector stays autonomous, its association with these compartments ensures the efficiency of replication and mitotic segregation in proliferating cells. Conclusion Using this novel minimal model system we demonstrate that relevant functions of the eukaryotic nucleus are strongly influenced by higher nuclear architecture. Furthermore our findings have relevance for the rational design of episomal vectors to be used for genetic modification of cells: in order to improve such constructs with respect to efficiency elements have to be identified which ensure that such constructs reach regions of the nucleus favorable for replication and transcription.

  1. Information Circulars

    International Nuclear Information System (INIS)

    1969-01-01

    Information circulars are published from time to time under the symbol INFCIRC/. . . . for the purpose of bringing matters of general interest to the attention of all Members of the Agency. A list of the circulars which were of current interest on 15 January 1969 is given below, followed by an index to their subject matter. Other circulars can be traced by reference to earlier issues of the present document.

  2. Information Circulars

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1969-01-24

    Information circulars are published from time to time under the symbol INFCIRC/. . . . for the purpose of bringing matters of general interest to the attention of all Members of the Agency. A list of the circulars which were of current interest on 15 January 1969 is given below, followed by an index to their subject matter. Other circulars can be traced by reference to earlier issues of the present document.

  3. Gene expression of benthic amphipods (genus: Diporeia in relation to a circular ssDNA virus across two Laurentian Great Lakes

    Directory of Open Access Journals (Sweden)

    Kalia S.I. Bistolas

    2017-09-01

    Full Text Available Circular rep-encoding ssDNA (CRESS-DNA viruses are common constituents of invertebrate viral consortia. Despite their ubiquity and sequence diversity, the effects of CRESS-DNA viruses on invertebrate biology and ecology remain largely unknown. This study assessed the relationship between the transcriptional profile of benthic amphipods of genus Diporeia and the presence of the CRESS-DNA virus, LM29173, in the Laurentian Great Lakes to provide potential insight into the influence of these viruses on invertebrate gene expression. Twelve transcriptomes derived from Diporeia were compared, representing organisms from two amphipod haplotype clades (Great Lakes Michigan and Superior, defined by COI barcode sequencing with varying viral loads (up to 3 × 106 genome copies organism−1. Read recruitment to de novo assembled transcripts revealed 2,208 significantly over or underexpressed contigs in transcriptomes with above average LM29173 load. Of these contigs, 31.5% were assigned a putative function. The greatest proportion of annotated, differentially expressed transcripts were associated with functions including: (1 replication, recombination, and repair, (2 cell structure/biogenesis, and (3 post-translational modification, protein turnover, and chaperones. Contigs putatively associated with innate immunity displayed no consistent pattern of expression, though several transcripts were significantly overexpressed in amphipods with high viral load. Quantitation (RT-qPCR of target transcripts, non-muscular myosin heavy chain, β-actin, and ubiquitin-conjugating enzyme E2, corroborated transcriptome analysis and indicated that Lake Michigan and Lake Superior amphipods with high LM29173 load exhibit lake-specific trends in gene expression. While this investigation provides the first comparative survey of the transcriptional profile of invertebrates of variable CRESS-DNA viral load, additional inquiry is required to define the scope of host

  4. Engineering Circular Gliding of Actin Filaments Along Myosin-Patterned DNA Nanotube Rings To Study Long-Term Actin-Myosin Behaviors.

    Science.gov (United States)

    Hariadi, Rizal F; Appukutty, Abhinav J; Sivaramakrishnan, Sivaraj

    2016-09-27

    Nature has evolved molecular motors that are critical in cellular processes occurring over broad time scales, ranging from seconds to years. Despite the importance of the long-term behavior of molecular machines, topics such as enzymatic lifetime are underexplored due to the lack of a suitable approach for monitoring motor activity over long time periods. Here, we developed an "O"-shaped Myosin Empowered Gliding Assay (OMEGA) that utilizes engineered micron-scale DNA nanotube rings with precise arrangements of myosin VI to trap gliding actin filaments. This circular gliding assay platform allows the same individual actin filament to glide over the same myosin ensemble (50-1000 motors per ring) multiple times. First, we systematically characterized the formation of DNA nanotubes rings with 4, 6, 8, and 10 helix circumferences. Individual actin filaments glide along the nanotube rings with high processivity for up to 12.8 revolutions or 11 min in run time. We then show actin gliding speed is robust to variation in motor number and independent of ring curvature within our sample space (ring diameter of 0.5-4 μm). As a model application of OMEGA, we then analyze motor-based mechanical influence on "stop-and-go" gliding behavior of actin filaments, revealing that the stop-to-go transition probability is dependent on motor flexibility. Our circular gliding assay may provide a closed-loop platform for monitoring long-term behavior of broad classes of molecular motors and enable characterization of motor robustness and long time scale nanomechanical processes.

  5. Information circulars

    International Nuclear Information System (INIS)

    1997-02-01

    The document summarizes the Information Circulars published by the IAEA for the purpose of bringing matters of general interest to the attention of all Member States. This revision contains INFCIRCs published up to February 1997, grouped by field of activity. A complete list of information circulars in numerical order is given in an annex

  6. Information circulars

    International Nuclear Information System (INIS)

    2002-05-01

    Information circulars are published from time to time under the symbol INFCIRC/... for the purpose of bringing matters of general interest to the attention of all Members of the Agency. The present revision contains INFCIRCs published up to the end of April 2002. A complete numerical list of information circulars is reproduced with their titles in the Annex

  7. Information circulars

    International Nuclear Information System (INIS)

    1999-06-01

    The document summarizes the Information Circulars published by the IAEA for the purpose of bringing matters of general interest to the attention of all Member States. This revision contains INFCIRCs published up to the end of May 1999, grouped by field of activity. A complete list of information circulars in numerical order is given in an annex

  8. Information circulars

    International Nuclear Information System (INIS)

    1994-08-01

    Information circulars are published from time to time under the symbol INFCIRC/... for the purpose of bringing matters of general interest to the attention of all Members of the Agency. The present revision contains INFCIRCs published up to mid-August 1994. A complete numerical list of information circulars is reproduced with their titles in the Annex

  9. Information circulars

    International Nuclear Information System (INIS)

    1992-08-01

    The document summarizes the Information Circulars published by the IAEA for the purpose of bringing matters of general interest to the attention of all Members of the Agency. This revision contains INFCIRCs published up to mid-August 1992. A complete numerical lift of Information Circulars with their titles is reproduced in an Annex

  10. Information Circulars

    International Nuclear Information System (INIS)

    1966-01-01

    Information circulars are published from time to time under the symbol INFCIRC/. . . . for the purpose of bringing matters of general interest to the attention of all Members of the Agency. A list of the circulars that were current or on the press on 15 May 1966 is given, followed by an index to their subject matter.

  11. Information Circulars

    International Nuclear Information System (INIS)

    1965-01-01

    Information circulars are published from time to time under the symbol INFCIRC/. for the purpose of bringing matters of general interest to the attention of all Members of the Agency. A list of the circulars that were current on 31 December 1964 is given, followed by an index to their subject matter.

  12. Information Circulars

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1966-06-10

    Information circulars are published from time to time under the symbol INFCIRC/. . . . for the purpose of bringing matters of general interest to the attention of all Members of the Agency. A list of the circulars that were current or on the press on 15 May 1966 is given, followed by an index to their subject matter.

  13. Information Circulars

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1965-01-18

    Information circulars are published from time to time under the symbol INFCIRC/. for the purpose of bringing matters of general interest to the attention of all Members of the Agency. A list of the circulars that were current on 31 December 1964 is given, followed by an index to their subject matter.

  14. Detection of DNA damage induced in vivo by a cross-linking agent with a circular channel crucible oscillating viscometer.

    Science.gov (United States)

    Balbi, C; Abelmoschi, M L; Roner, R; Giaretti, W; Parodi, S; Santi, L

    1985-11-01

    DNA damage induced in vivo by the cross-linking agent mitomycin C (MMC) was investigated with a new oscillating crucible viscometer. Viscosity was measured by lysing rat liver nuclei in an alkaline lysing solution (pH 12.5; 25 degrees C). In control samples the viscosity increased very slowly with time, reaching a plateau only after 10-12 h. The process was accelerated and the maximum viscosity was decreased by alkaline single-stranded breaks arising from methylation and subsequent depurination of DNA in vitro with dimethylsulphate (DMS). MMC, when given alone, had no evident effect on the time needed for reaching plateau viscosity but it induced a small increase in maximum viscosity. When MMC was given in association with DMS, the time of disentanglement remained unchanged (accelerated) but maximum viscosity was increased in a dose dependent way. We conclude that these data clearly confirm that the slow steady increase of the viscosity of control DNA with time reflects mainly the process of unwinding of the two strands. The speed of this process seems to depend only from the number of unwinding points in DNA (breaks).

  15. Information Circulars

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1973-09-10

    Information circulars are published from time to time under the symbol INFCIRC/.. for the purpose of bringing matters of general interest to the attention of all Members of the Agency. A subject index to the circulars is presented overleaf. It covers all those published in the last five years (that is, since the beginning of 1968 and ending with INFCIRC/192), as well as others which, for one reason or another, are still considered to be of current rather than merely historical interest. Such circulars can be traced by reference to the indexes that were included in earlier revisions of the present document.

  16. Information Circulars

    International Nuclear Information System (INIS)

    1973-01-01

    Information circulars are published from time to time under the symbol INFCIRC/.. for the purpose of bringing matters of general interest to the attention of all Members of the Agency. A subject index to the circulars is presented overleaf. It covers all those published in the last five years (that is, since the beginning of 1968 and ending with INFCIRC/192), as well as others which, for one reason or another, are still considered to be of current rather than merely historical interest. Such circulars can be traced by reference to the indexes that were included in earlier revisions of the present document.

  17. Circular Updates

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Circular Updates are periodic sequentially numbered instructions to debriefing staff and observers informing them of changes or additions to scientific and specimen...

  18. Information circulars

    International Nuclear Information System (INIS)

    1987-06-01

    The document summarizes the information circulars published by the IAEA for the purpose of bringing matters of general interest to the attention of all Members of the Agency. In the main body of the document only those documents which are regarded as likely to be of current interest are listed. A complete numerical list of information circulars with their titles is reproduced in the Annex

  19. Operational Circulars

    CERN Multimedia

    2003-01-01

    Operational Circular N° 4 - April 2003 Conditions for use by members of the CERN personnel of vehicles belonging to or rented by CERN - This circular has been drawn up. Operational Circular N° 5 - October 2000 Use of CERN computing facilities - Further details on the personal use of CERN computing facilities Operational Circular N° 5 and its Subsidiary Rules http://cern.ch/ComputingRules defines the rules for the use of CERN computing facilities. One of the basic principles governing such use is that it must come within the professional duties of the user concerned, as defined by the user's divisional hierarchy. However, personal use of the computing facilities is tolerated or allowed provided : a) It is in compliance with Operational Circular N° 5 and not detrimental to official duties, including those of other users; b) the frequency and duration is limited and there is a negligible use of CERN resources; c) it does not constitute a political, commercial and/or profit-making activity; d) it is not...

  20. [Polyadenylated RNA and mRNA export factors in extrachromosomal nuclear domains of vitellogenic oocytes of the insect Tenebrio molitor].

    Science.gov (United States)

    Bogoliubov, D S; Kiselev, A M; Shabel'nikov, S V; Parfenov, V N

    2012-01-01

    The nucleus ofvitellogenic oocytes of the yellow mealworm, Tenebrio molitor, contains a karyosphere that consists of the condensed chromatin embedded in an extrachromosomal fibrogranular material. Numerous nuclear bodies located freely in the nucleoplasm are also observed. Amongst these bodies, counterparts of nuclear speckles (= interchromatin granule clusters, IGCs) can be identified by the presence of the marker protein SC35. Microinjections of fluorescently tagged methyloligoribonucleotide probes 2'-O-Me(U)22, complementary to poly(A) tails of RNAs, revealed poly(A)+ RNA in the vast majority of IGCs. We found that all T. molitor oocyte IGCs contain heterogeneous ribonucleoprotein (hnRNP) core protein Al that localizes to IGCs in an RNA-dependent manner. The extrachromosomal material of the karyosphere and a part of nucleoplasmic IGCs also contain the adapter protein Aly that is known to provide a link between pre-mRNA splicing and mRNA export. The essential mRNA export factor/receptor NXF1 was observed to colocalize with Aly. In nucleoplasmic IGCs, NXF1 was found to localize in an RNA-dependent manner whereas it is RNA-independently located in the extrachromosomal material of the karyosphere. We believe our data suggest on a role of the nucleoplasmic IGCs in mRNA biogenesis and retention in a road to nuclear export.

  1. Information circulars

    International Nuclear Information System (INIS)

    1989-04-01

    The document summarizes the Information Circulars published by the IAEA under the symbol INFCIRC/ for the purpose of bringing matters of general interest to the attention of all Members of the Agency. A complete list of INFCIRCs in numerical order with their titles is given in the Annex

  2. ADMINISTRATIVE CIRCULARS

    CERN Multimedia

    Division des ressources humaines

    2000-01-01

    N° 2 (Rev. 1) - March 2000Guidelines and procedures concerning recruitment and probation period of staff membersN° 9 (Rev. 2) - March 2000Staff members contractsN° 16 (Rev. 2) - January 2000TrainingN° 30 (Rev. 1) - January 2000Indemnities and reimbursements upon taking up appointment and termination of contractN° 32 - February 2000Principles and procedures governing complaints of harassmentThese circular have been amended (No 2, N° 9, N° 16 and N° 30) or drawn up (N° 32).Copies are available in the Divisional Secretariats.Note:\tAdministrative and operational circulars, as well as the lists of those in force, are available for consultation in the server SRV4_Home in the Appletalk zone NOVELL (as GUEST or using your Novell username and password), volume PE Division Data Disk.The Word files are available in the folder COM, folder Public, folder ADM.CIRC.docHuman Resources DivisionTel. 74128

  3. Circular RNAs

    DEFF Research Database (Denmark)

    Han, Yi-Neng; Xia, Shengqiang; Zhang, Yuan-Yuan

    2017-01-01

    Circular RNAs (circRNAs) are a novel type of universal and diverse endogenous noncoding RNAs (ncRNAs) and they form a covalently closed continuous loop without 5' or 3' tails unlike linear RNAs. Most circRNAs are presented with characteristics of abundance, stability, conservatism, and often exhi...... and expression regulators, RBP sponges in cancer as well as current research methods of circRNAs, providing evidence for the significance of circRNAs in cancer diagnosis and clinical treatment....

  4. Genes encoded within 8q24 on the amplicon of a large extrachromosomal element are selectively repressed during the terminal differentiation of HL-60 cells.

    Science.gov (United States)

    Hirano, Tetsuo; Ike, Fumio; Murata, Takehide; Obata, Yuichi; Utiyama, Hiroyasu; Yokoyama, Kazunari K

    2008-04-02

    Human acute myeloblastic leukemia HL-60 cells become resistant to differentiation during long-term cultivation. After 150 passages, double minute chromosomes (dmins) found in early-passaged cells are replaced by large extrachromosomal elements (LEEs). In a DNA library derived from a purified fraction of LEEs, 12.6% (23/183) of clones were assigned to 8q24 and 9.2% (17/183) were assigned to 14q11 in the human genome. Fluorescence in situ hybridization (FISH) revealed a small aberrant chromosome, which had not been found in early-passaged cells, in addition to the purified LEEs. We determined that each LEE consisted of six discontinuous segments in a region that extended for 4.4Mb over the 8q24 locus. Five genes, namely, Myc (a proto-oncogene), NSMCE2 (for a SUMO ligase), CCDC26 (for a retinoic acid-dependent modulator of myeloid differentiation), TRIB1 (for a regulator of MAPK kinase) and LOC389637 (for a protein of unknown function), were encoded by the amplicon. Breaks in the chromosomal DNA within the amplicon were found in the NSMCE2 and CCDC26 genes. The discontinuous structure of the amplicon unit of the LEEs was identical with that of dmins in HL-60 early-passaged cells. The difference between them seemed, predominantly, to be the number (10-15 copies per LEE versus 2 or 3 copies per dmin) of constituent units. Expression of the Myc, NSMCE2, CCDC26 and LOC389637 and TRIB1 genes was constitutive in all lines of HL-60 cells and that of the first four genes was repressed during the terminal differentiation of early-passaged HL-60 cells. We also detected abnormal transcripts of CCDC26. Our results suggest that these genes were selected during the development of amplicons. They might be amplified and, sometimes, truncated to contribute to the maintenance of HL-60 cells in an undifferentiated state.

  5. Replication of each copy of the yeast 2 micron DNA plasmid occurs during the S phase.

    Science.gov (United States)

    Zakian, V A; Brewer, B J; Fangman, W L

    1979-08-01

    Saccharomyces cerevisiae contains 50-100 copies per cell of a circular plasmid called 2 micron DNA. Replication of this DNA was studied in two ways. The distribution of replication events among 2 micron DNA molecules was examined by density transfer experiments with asynchronous cultures. The data show that 2 micron DNA replication is similar to chromosomal DNA replication: essentially all 2 micron duplexes were of hybrid density at one cell doubling after the density transfer, with the majority having one fully dense strand and one fully light strand. The results show that replication of 2 micron DNA occurs by a semiconservative mechanism where each of the plasmid molecules replicates once each cell cycle. 2 micron DNA is the only known example of a multiple-copy, extrachromosomal DNA in which every molecule replicates in each cell cycle. Quantitative analysis of the data indicates that 2 micron DNA replication is limited to a fraction of the cell cycle. The period in the cell cycle when 2 micron DNA replicates was examined directly with synchronous cell cultures. Synchronization was accomplished by sequentially arresting cells in G1 phase using the yeast pheromone alpha-factor and incubating at the restrictive temperature for a cell cycle (cdc 7) mutant. Replication was monitored by adding 3H-uracil to cells previously labeled with 14C-uracil, and determining the 3H/14C ratio for purified DNA species. 2 micron DNA replication did not occur during the G1 arrest periods. However, the population of 2 micron DNA doubled during the synchronous S phase at the permissive temperature, with most of the replication occurring in the first third of S phase. Our results indicate that a mechanism exists which insures that the origin of replication of each 2 micron DNA molecule is activated each S phase. As with chromosomal DNA, further activation is prevented until the next cell cycle. We propose that the mechanism which controls the replication initiation of each 2 micron DNA

  6. Analysis of hepatitis B virus intrahepatic covalently closed circular DNA and serum viral markers in treatment-naive patients with acute and chronic HBV infection.

    Directory of Open Access Journals (Sweden)

    Weijie Li

    Full Text Available BACKGROUND: This study aimed to investigate the relationships of intrahepatic cccDNA with serum HBsAg and with HBV DNA in treatment-naive patients throughout acute and chronic HBV infection. METHODS: A total of 120 patients who had a liver biopsy were enrolled, including 19 with acute hepatitis B (AHB, and 101 patients with chronic HBV infection (CHB of whom were 10 in immune-tolerant (IT phase, 59 in immune-clearance (IC phase, 8 in low-replicative (LR phase, and 24 in HBeAg-negative hepatitis (ENH phase. Intrahepatic cccDNA, serum HBsAg and serum HBV DNA levels were comparatively analyzed. RESULTS: The median intrahepatic cccDNA levels were 0.18 4.80, 3.81, 0.22 and 0.97 copies/cell for patients with AHB, CHB-IT, CHB-IC, CHB-LR, and CHB-ENH, respectively. In AHB patients, intrahepatic cccDNA was positively correlated with serum HBsAg (r = 0.665, P = 0.003, as well as serum HBV DNA (r = 0.536, P = 0.022. In CHB patients, intrahepatic cccDNA was positively correlated with serum HBsAg in the IC phase (r = 0.392, P = 0.005, and with serum HBV DNA in the IC phase (r = 0.301, P = 0.036 and ENH phase (r = 0.588, P = 0.013. HBV replicative efficiency, defined as the ratio of serum HBV DNA to intrahepatic cccDNA, was obviously lower in AHB and CHB-LR patients than in CHB-IT, CHB-IC and CHB-ENH patients (0.70 and 0.53 vs. 1.12, 1.09 and 0.99, P<0.001, values were logarithmic transformed for analysis. In CHB-IC patients, HBV replicative efficiency was positively correlated with histological activity index of liver inflammation (r = 0.308, P = 0.009. CONCLUSION: Serum HBsAg and HBV DNA levels may reflect the amount of active intrahepatic cccDNA in treatment-naive AHB and CHB-IC patients. Reduced intrahepatic cccDNA and HBV replicative efficiency may imply effective immune control of HBV infection.

  7. Genetic mutation analysis of HBV covalently closed circular DNA in peripheral blood mononuclear cells from chronic hepatitis B patients with nucleos(tide analog-resistant mutations in serum virions

    Directory of Open Access Journals (Sweden)

    Zhong-bin LI

    2012-06-01

    Full Text Available Objective  To analyze the characteristics of genetic mutations in reverse-transcriptase (RT domain of HBV covalently closed circular DNA (cccDNA in peripheral blood mononuclear cells (PBMCs obtained from chronic hepatitis B (CHB patients with drug-resistant mutations in serum virions during nucleoside/nucleotide analog (NA therapy. Methods  A total of 30 CHB patients admitted to 302 Hospital of PLA from July 2010 to August 2011 were included in this study. All the patients were confirmed to harbor the drug-resistant mutations in serum virions during an NA therapy longer than 6 months. Total DNA was extracted from PBMCs isolated from 30 whole blood samples at the same time point as that of serum analysis. Plasmid-safe ATP-dependent DNase (PSAD digestion in combination with rolling circle amplification and gap-spanning semi-nested PCR were used to amplify the RT region of HBV cccDNA. NA-resistant-associated mutations were analyzed at nine sites. Results  HBV cccDNA was efficiently amplified in 16 out of 30 (53.3% PBMC samples, and the detection rate was not correlated with HBeAg-positive rate, serum ALT level or HBV DNA load. Five of 16 (31.3% patients were sustained to have genotype B HBV infection, and 11 of 16 (68.8% were of genotype C HBV infection, and the result was consistent with the genotyping results using serum HBV. Different from drug-resistant mutations detected in the serum virions, the viruses detected in HBV cccDNA of 16 PBMC samples were all wild-type viruses without NA-resistant-associated mutations in RT region. Conclusions  During NA antiviral treatment, if drug-resistant mutations occur in serum HBV DNA of CHB patients, the dominant species of HBV cccDNA in PBMCs from the same patient is still the original wild-type strains. It is speculated that PBMCs might be the potential "repository" of HBV wild-type strain in vivo.

  8. Differential Salt-Induced Dissociation of the p53 Protein Complexes with Circular and Linear Plasmid DNA Substrates Suggest Involvement of a Sliding Mechanism

    Czech Academy of Sciences Publication Activity Database

    Šebest, Peter; Brázdová, Marie; Fojta, Miroslav; Pivoňková, Hana

    2015-01-01

    Roč. 16, č. 2 (2015), s. 3163-3177 E-ISSN 1422-0067 R&D Projects: GA ČR(CZ) GAP301/11/2076; GA ČR(CZ) GBP206/12/G151 Institutional support: RVO:68081707 Keywords : TUMOR-SUPPRESSOR P53 * CISPLATIN -DAMAGED DNA * SUPERCOILED DNA Subject RIV: BO - Biophysics Impact factor: 3.257, year: 2015

  9. Complete Circular Genome Sequence of Successful ST8/SCCmecIV Community-Associated Methicillin-Resistant Staphylococcus aureus (OC8 in Russia: One-Megabase Genomic Inversion, IS256's Spread, and Evolution of Russia ST8-IV.

    Directory of Open Access Journals (Sweden)

    Tsai-Wen Wan

    Full Text Available ST8/SCCmecIV community-associated methicillin-resistant Staphylococcus aureus (CA-MRSA has been a common threat, with large USA300 epidemics in the United States. The global geographical structure of ST8/SCCmecIV has not yet been fully elucidated. We herein determined the complete circular genome sequence of ST8/SCCmecIVc strain OC8 from Siberian Russia. We found that 36.0% of the genome was inverted relative to USA300. Two IS256, oppositely oriented, at IS256-enriched hot spots were implicated with the one-megabase genomic inversion (MbIN and vSaβ split. The behavior of IS256 was flexible: its insertion site (att sequences on the genome and junction sequences of extrachromosomal circular DNA were all divergent, albeit with fixed sizes. A similar multi-IS256 system was detected, even in prevalent ST239 healthcare-associated MRSA in Russia, suggesting IS256's strong transmission potential and advantage in evolution. Regarding epidemiology, all ST8/SCCmecIVc strains from European, Siberian, and Far Eastern Russia, examined had MbIN, and geographical expansion accompanied divergent spa types and resistance to fluoroquinolones, chloramphenicol, and often rifampicin. Russia ST8/SCCmecIVc has been associated with life-threatening infections such as pneumonia and sepsis in both community and hospital settings. Regarding virulence, the OC8 genome carried a series of toxin and immune evasion genes, a truncated giant surface protein gene, and IS256 insertion adjacent to a pan-regulatory gene. These results suggest that unique single ST8/spa1(t008/SCCmecIVc CA-MRSA (clade, Russia ST8-IVc emerged in Russia, and this was followed by large geographical expansion, with MbIN as an epidemiological marker, and fluoroquinolone resistance, multiple virulence factors, and possibly a multi-IS256 system as selective advantages.

  10. Complete Circular Genome Sequence of Successful ST8/SCCmecIV Community-Associated Methicillin-Resistant Staphylococcus aureus (OC8) in Russia: One-Megabase Genomic Inversion, IS256's Spread, and Evolution of Russia ST8-IV.

    Science.gov (United States)

    Wan, Tsai-Wen; Khokhlova, Olga E; Iwao, Yasuhisa; Higuchi, Wataru; Hung, Wei-Chun; Reva, Ivan V; Singur, Olga A; Gostev, Vladimir V; Sidorenko, Sergey V; Peryanova, Olga V; Salmina, Alla B; Reva, Galina V; Teng, Lee-Jene; Yamamoto, Tatsuo

    2016-01-01

    ST8/SCCmecIV community-associated methicillin-resistant Staphylococcus aureus (CA-MRSA) has been a common threat, with large USA300 epidemics in the United States. The global geographical structure of ST8/SCCmecIV has not yet been fully elucidated. We herein determined the complete circular genome sequence of ST8/SCCmecIVc strain OC8 from Siberian Russia. We found that 36.0% of the genome was inverted relative to USA300. Two IS256, oppositely oriented, at IS256-enriched hot spots were implicated with the one-megabase genomic inversion (MbIN) and vSaβ split. The behavior of IS256 was flexible: its insertion site (att) sequences on the genome and junction sequences of extrachromosomal circular DNA were all divergent, albeit with fixed sizes. A similar multi-IS256 system was detected, even in prevalent ST239 healthcare-associated MRSA in Russia, suggesting IS256's strong transmission potential and advantage in evolution. Regarding epidemiology, all ST8/SCCmecIVc strains from European, Siberian, and Far Eastern Russia, examined had MbIN, and geographical expansion accompanied divergent spa types and resistance to fluoroquinolones, chloramphenicol, and often rifampicin. Russia ST8/SCCmecIVc has been associated with life-threatening infections such as pneumonia and sepsis in both community and hospital settings. Regarding virulence, the OC8 genome carried a series of toxin and immune evasion genes, a truncated giant surface protein gene, and IS256 insertion adjacent to a pan-regulatory gene. These results suggest that unique single ST8/spa1(t008)/SCCmecIVc CA-MRSA (clade, Russia ST8-IVc) emerged in Russia, and this was followed by large geographical expansion, with MbIN as an epidemiological marker, and fluoroquinolone resistance, multiple virulence factors, and possibly a multi-IS256 system as selective advantages.

  11. Some properties of circular proteins

    International Nuclear Information System (INIS)

    Prosselkov, P.; John, P.; Dixon, N.E.; Liepinsh, E.; Williams, N.K.; University of Sydney, NSW; Matthews, J.M.; Otting, G.; Karolinska Institutet, Stockholm,

    2002-01-01

    Full text: Protein backbone cyclization can be achieved by use of a circularly-permuted split mini-intein. We have used the small N-terminal domain of the E coli DnaB helicase (DnaB-N, residues 24-136) as a model protein for cyclization because its structure has been determined both by NMR spectroscopy and X-ray crystallography, and its ends are close together. Joining of the ends of DnaB-N' via a 9-amino acid linker occurs efficiently in vivo, and the circular (cz-) protein is stabilized in comparison to the linear (Hn-) protein against thermal denaturation (ΔΔG ∼2 kcal/mol). DnaB-N exists as a dimer in the crystalline state and in solution at high concentrations. To produce linear and cyclized versions that could not dimerize, Phe102 (at the dimer interface) was changed to Glu. NMR spectra showed that the F102E mutants remained monomeric at high concentrations but otherwise had essentially the same structures as the wild-type domains. Individual rate constants for proton exchange at the amide groups in lin- and cz-DnaB-N were determined at 10 C. Although they varied as expected depending on exposure to solvent, the ratios of rates between corresponding amides in the two proteins were constant. In the same buffer, lin- and cz-DnaB-N both unfolded reversibly, with transition temperatures of 37.9 and 48.5 deg C, respectively. Correlation of the (constant) ratio of amide exchange rates with measured thermodynamic parameters suggests that amide exchange in DnaB-N occurs predominantly in a globally unfolded state. Similar studies with other proteins are underway

  12. Administrative Circulars Rev.

    CERN Multimedia

    2003-01-01

    Administrative Circular N° 19 (Rev. 3) - April 2003 Subsistence indemnity - Other expenses necessarily incurred in the course of duty travelAdministrative Circular N° 25 (Rev. 2) - April 2003 Shift work - Special provisions for the Fire and Rescue Service - These circulars have been revised. Human Resources Division Tel. 74128Copies of these circulars are available in the Divisional Secretariats. In addition, administrative and operational circulars, as well as the lists of those in force, are available for consultation on the Web at: http://humanresources.web.cern.ch/humanresources/internal/admin_services/admincirc/listadmincirc.asp

  13. Biomolecular and Structural Analyses of Cauliflower-like DNAs by Ultraviolet, Circular Dichroism, and Fluorescence Spectroscopies in Comparison with Natural DNA

    OpenAIRE

    Gill, Pooria; Ranjbar, Bijan; Saber, Reza; Khajeh, Khosro; Mohammadian, Mehdi

    2011-01-01

    Cauliflower-like DNAs are stem-loop DNAs that are fabricated periodically in inverted repetitions from deoxyribonucleic acid phosphates (dNTPs) by loop-mediated isothermal amplification (LAMP). Cauliflower-like DNAs have ladder-shape behaviors on gel electrophoresis, and increasing the time of LAMP leads to multiplying the repetitions, stem-loops, and electrophoretic bands. Cauliflower-like DNAs were fabricated via LAMP using two loop primers, two bumper primers, dNTPs, a λ-phage DNA template...

  14. Publication of administrative circular

    CERN Multimedia

    HR Department

    2009-01-01

    ADMINISTRATIVE CIRCULAR NO. 23 (REV. 2) – SPECIAL WORKING HOURS Administrative Circular No. 23 (Rev. 2) entitled "Special working hours", approved following discussion in the Standing Concertation Committee on 9 December 2008, will be available on the intranet site of the Human Resources Department as from 19 December 2008: http://cern.ch/hr-docs/admincirc/admincirc.asp It cancels and replaces Administrative Circular No. 23 (Rev. 1) entitled "Stand-by duty" of April 1988. A "Frequently Asked Questions" information document on special working hours will also be available on this site. Paper copies of this circular will shortly be available in Departmental Secretariats. Human Resources Department Tel. 78003

  15. PUBLICATION OF ADMINISTRATIVE CIRCULAR

    CERN Multimedia

    HR Department

    2008-01-01

    ADMINISTRATIVE CIRCULAR NO. 23 (REV. 2) – SPECIAL WORKING HOURS Administrative Circular No. 23 (Rev. 2) entitled "Special working hours", approved following discussion in the Standing Concertation Committee meeting of 9 December 2008, will be available on the intranet site of the Human Resources Department as from 19 December 2008: http://cern.ch/hr-docs/admincirc/admincirc.asp It cancels and replaces Administrative Circular No. 23 (Rev. 1) entitled "Stand-by duty" of April 1988. A "Frequently Asked Questions" information document on special working hours will also be available on this site. Paper copies of this circular will shortly be available in departmental secretariats. Human Resources Department Tel. 78003

  16. Spontaneous HBsAg loss in Korean patients: relevance of viral genotypes, S gene mutations, and covalently closed circular DNA copy numbers

    Directory of Open Access Journals (Sweden)

    Kyun-Hwan Kim

    2014-09-01

    Full Text Available Background/AimsOccult HBV infection can persist following HBsAg loss and be transmitted, but the virological features are not well defined.MethodsHere we investigated 25 Korean patients who lost HBsAg during follow up, either spontaneously or subsequent to therapy.ResultsWhereas subtype adr (genotype C was found in 96% of HBsAg positive patients, 75 % of patients who lost HBsAg spontaneously were seemed to be infected with the ayw subtype with sequence similar to genotype D. Mutations in the major hydrophilic region (MHR of HBsAg were found in 7 patients who lost HBsAg spontaneously. The mutations include T123S, M125I/N, C139R, D144E, V177A, L192F, and W196L, some of which have not been reported before. Functional analysis via transfection experiments indicate that the C139R and D144E mutations drastically reduced HBsAg antigenicity, while the Y225del mutation found in one interferon-treated patient impaired HBsAg secretion.ConclusionsLack of detectable HBsAg in patient serum could be explained by low level of ccc DNA in liver tissue, low antigenicity of the surface protein, or its secretion defect.

  17. The generalized circular model

    NARCIS (Netherlands)

    Webers, H.M.

    1995-01-01

    In this paper we present a generalization of the circular model. In this model there are two concentric circular markets, which enables us to study two types of markets simultaneously. There are switching costs involved for moving from one circle to the other circle, which can also be thought of as

  18. Circularity and Lambda Abstraction

    DEFF Research Database (Denmark)

    Danvy, Olivier; Thiemann, Peter; Zerny, Ian

    2013-01-01

    unknowns from what is done to them, which we lambda-abstract with functions. The circular unknowns then become dead variables, which we eliminate. The result is a strict circu- lar program a la Pettorossi. This transformation is reversible: given a strict circular program a la Pettorossi, we introduce...

  19. Towards Circular Business Models

    DEFF Research Database (Denmark)

    Guldmann, Eva; Remmen, Arne

    The present report concerns the practical process of developing initiatives based on the circular economy in eight Danish companies. The report outlines how the process of integrating the circular economy was approached in each of the participating companies during 2014 and 2015 and what came out...

  20. Complete Circular Genome Sequence of Successful ST8/SCCmecIV Community-Associated Methicillin-Resistant Staphylococcus aureus (OC8) in Russia: One-Megabase Genomic Inversion, IS256’s Spread, and Evolution of Russia ST8-IV

    Science.gov (United States)

    Wan, Tsai-Wen; Higuchi, Wataru; Hung, Wei-Chun; Reva, Ivan V.; Singur, Olga A.; Gostev, Vladimir V.; Sidorenko, Sergey V.; Peryanova, Olga V.; Salmina, Alla B.; Reva, Galina V.; Teng, Lee-Jene; Yamamoto, Tatsuo

    2016-01-01

    ST8/SCCmecIV community-associated methicillin-resistant Staphylococcus aureus (CA-MRSA) has been a common threat, with large USA300 epidemics in the United States. The global geographical structure of ST8/SCCmecIV has not yet been fully elucidated. We herein determined the complete circular genome sequence of ST8/SCCmecIVc strain OC8 from Siberian Russia. We found that 36.0% of the genome was inverted relative to USA300. Two IS256, oppositely oriented, at IS256-enriched hot spots were implicated with the one-megabase genomic inversion (MbIN) and vSaβ split. The behavior of IS256 was flexible: its insertion site (att) sequences on the genome and junction sequences of extrachromosomal circular DNA were all divergent, albeit with fixed sizes. A similar multi-IS256 system was detected, even in prevalent ST239 healthcare-associated MRSA in Russia, suggesting IS256’s strong transmission potential and advantage in evolution. Regarding epidemiology, all ST8/SCCmecIVc strains from European, Siberian, and Far Eastern Russia, examined had MbIN, and geographical expansion accompanied divergent spa types and resistance to fluoroquinolones, chloramphenicol, and often rifampicin. Russia ST8/SCCmecIVc has been associated with life-threatening infections such as pneumonia and sepsis in both community and hospital settings. Regarding virulence, the OC8 genome carried a series of toxin and immune evasion genes, a truncated giant surface protein gene, and IS256 insertion adjacent to a pan-regulatory gene. These results suggest that unique single ST8/spa1(t008)/SCCmecIVc CA-MRSA (clade, Russia ST8-IVc) emerged in Russia, and this was followed by large geographical expansion, with MbIN as an epidemiological marker, and fluoroquinolone resistance, multiple virulence factors, and possibly a multi-IS256 system as selective advantages. PMID:27741255

  1. Antennas on circular cylinders

    DEFF Research Database (Denmark)

    Knudsen, H. L.

    1959-01-01

    On the basis of the results obtained by Silver and Saunders [4] for the field radiated from an arbitrary slot in a perfectly conducting circular cylinder, expressions have been derived for the field radiated by a narrow helical slot, with an arbitrary aperture field distribution, in a circular...... antenna in a circular cylinder. By a procedure similar to the one used by Silver and Saunders, expressions have been derived for the field radiated from an arbitrary surface current distribution on a cylinder surface coaxial with a perfectly conducting cylinder. The cases where the space between the two...

  2. Utilization of circular dichroism and electrospray ionization mass spectrometry to understand the formation and conversion of G-quadruplex DNA at the human c-myb proto-oncogene.

    Science.gov (United States)

    Fu, Hengqing; Yang, Pengfei; Hai, Jinhui; Li, Huihui

    2018-10-05

    G-quadruplex DNAs are involved in a number of key biological processes, including gene expression, transcription, and apoptosis. The c-myb oncogene contains a number of GGA repeats in its promoter which forms G-quadruplex, thus it could be used as a target in cancer therapeutics. Several in-vitro studies have used Circular Dichroism (CD) spectroscopy or electrospray ionization mass spectrometry (ESI-MS) to demonstrate formation and stability of G-quadruplex DNA structure in the promoter region of human c-myb oncogene. The factors affecting the c-myb G-quadruplex structures were investigated, such as cations (i.e. K + , NH 4 + and Na + ) and co-solutes (methanol and polyethylene glycol). The results indicated that the presence of cations and co-solutes could change the G-quadruplex structural population and promote its thermodynamic stabilization as indicated by CD melting curves. It indicated that the co-solutes preferentially stabilize the c-myb G-quadruplex structure containing both homo- and hetero-stacking. In addition, protopine was demonstrated as a binder of c-myb G-quadruplex as screened from a library of natural alkaloids using ESI-MS method. CD spectra showed that it could selectively stabilize the c-myb G-quadruplex structure compared to other six G-quadruplexes from tumor-related G-rich sequences and the duplex DNAs (both long and short-chain ones). The binding of protopine could induce the change in the G-quadruplex structural populations. Therefore, protopine with its high binding specificity could be considered as a precursor for the design of drugs to target and regulate c-myb oncogene transcription. Copyright © 2018 Elsevier B.V. All rights reserved.

  3. A mechanism of gene amplification driven by small DNA fragments.

    Directory of Open Access Journals (Sweden)

    Kuntal Mukherjee

    Full Text Available DNA amplification is a molecular process that increases the copy number of a chromosomal tract and often causes elevated expression of the amplified gene(s. Although gene amplification is frequently observed in cancer and other degenerative disorders, the molecular mechanisms involved in the process of DNA copy number increase remain largely unknown. We hypothesized that small DNA fragments could be the trigger of DNA amplification events. Following our findings that small fragments of DNA in the form of DNA oligonucleotides can be highly recombinogenic, we have developed a system in the yeast Saccharomyces cerevisiae to capture events of chromosomal DNA amplification initiated by small DNA fragments. Here we demonstrate that small DNAs can amplify a chromosomal region, generating either tandem duplications or acentric extrachromosomal DNA circles. Small fragment-driven DNA amplification (SFDA occurs with a frequency that increases with the length of homology between the small DNAs and the target chromosomal regions. SFDA events are triggered even by small single-stranded molecules with as little as 20-nt homology with the genomic target. A double-strand break (DSB external to the chromosomal amplicon region stimulates the amplification event up to a factor of 20 and favors formation of extrachromosomal circles. SFDA is dependent on Rad52 and Rad59, partially dependent on Rad1, Rad10, and Pol32, and independent of Rad51, suggesting a single-strand annealing mechanism. Our results reveal a novel molecular model for gene amplification, in which small DNA fragments drive DNA amplification and define the boundaries of the amplicon region. As DNA fragments are frequently found both inside cells and in the extracellular environment, such as the serum of patients with cancer or other degenerative disorders, we propose that SFDA may be a common mechanism for DNA amplification in cancer cells, as well as a more general cause of DNA copy number variation

  4. Building a Circular Future

    DEFF Research Database (Denmark)

    Merrild, Heidi

    2016-01-01

    Natural resources are scarce and construction accounts for 40 percent of the material and energy consumption in Europe. This means that a switch to a circular future is necessary. ’Building a Circular Future’ maps out where we are, where we are going, and what is needed for this conversion to take...... on the project’s strategies. The financial result is a profit of DKK 35 million on the structure alone in the demolition of a building built for the cost of DKK 860 million. The total potential for the whole building, calculated in projected material prices, is estimated to be up to 16% of the total construction...... of the circular strategies is not only in the future. Increased flexibility, optimized operation and maintenance, as well as a healthier building, is low-hanging fruit that can be harvested today. The project’s principles can be implemented in industrialized construction in a large scale today. That is proven...

  5. Circular arc structures

    KAUST Repository

    Bo, Pengbo; Pottmann, Helmut; Kilian, Martin; Wang, Wen Ping; Wallner, Johannes

    2011-01-01

    and connecting elements as well as repetition of costly parts. This paper proposes so-called circular arc structures as a means to faithfully realize freeform designs without giving up smooth appearance. In contrast to non-smooth meshes with straight edges where

  6. Wiimote Experiments: Circular Motion

    Science.gov (United States)

    Kouh, Minjoon; Holz, Danielle; Kawam, Alae; Lamont, Mary

    2013-01-01

    The advent of new sensor technologies can provide new ways of exploring fundamental physics. In this paper, we show how a Wiimote, which is a handheld remote controller for the Nintendo Wii video game system with an accelerometer, can be used to study the dynamics of circular motion with a very simple setup such as an old record player or a…

  7. Administrative circular No. 12

    CERN Document Server

    HR Department

    2006-01-01

    On the recommendation of the Standing Concertation Committee, the Director-General has approved the amounts used for the reimbursements mentioned in Administrative Circular No. 12 as follows: The figures, effective from 1 September 2006, are: Paragraph 8a: 17 Swiss francs Paragraph 9a: 682 Swiss francs Paragraph 9b: 34 Swiss francs Human Resources Department Tel. 79257/72862

  8. Radical Circular Economy

    NARCIS (Netherlands)

    Prins, M.; Mohammadi, S.; Slob, N.

    2015-01-01

    Recently the Circular Economy (CE) concept has gained momentum in the Netherlands, propounding that environmental impact reduction can provide a significant positive economical impulse. The government, larger parts of the industry as a whole, as well as the construction industry, has warmly received

  9. Modified circular velocity law

    Science.gov (United States)

    Djeghloul, Nazim

    2018-05-01

    A modified circular velocity law is presented for a test body orbiting around a spherically symmetric mass. This law exhibits a distance scale parameter and allows to recover both usual Newtonian behaviour for lower distances and a constant velocity limit at large scale. Application to the Galaxy predicts the known behaviour and also leads to a galactic mass in accordance with the measured visible stellar mass so that additional dark matter inside the Galaxy can be avoided. It is also shown that this circular velocity law can be embedded in a geometrical description of spacetime within the standard general relativity framework upon relaxing the usual asymptotic flatness condition. This formulation allows to redefine the introduced Newtonian scale limit in term of the central mass exclusively. Moreover, a satisfactory answer to the galactic escape speed problem can be provided indicating the possibility that one can also get rid of dark matter halo outside the Galaxy.

  10. Circular fringe projection profilometry.

    Science.gov (United States)

    Zhao, Hong; Zhang, Chunwei; Zhou, Changquan; Jiang, Kejian; Fang, Meiqi

    2016-11-01

    In this Letter, a novel three-dimensional (3D) measurement method, called the circular fringe projection profilometry (CFPP), is proposed. Similar to the conventional fringe projection profilometry, CFPP also requires fringe pattern projection and capture, phase demodulation, and phase unwrapping. However, it works with a totally different mechanism. CFPP recovers the height of a point by calculating its distance to the optical center of a projector along the optical axis. This distance is calculated with the aid of the divergence angle of a projected light ray and the distance between the measured point and the optical axis. The distance between the measured point and the optical axis is detected by a camera with telecentric lenses, while the divergence angle can be calculated from the phase of a captured circular fringe pattern. The validity of CFPP is confirmed by a set of experiments.

  11. Administrative Circular N° 12

    CERN Multimedia

    2003-01-01

    Following a recommendation by the Standing Concertation Committee, the Director-General has approved the amounts used for the reimbursements mentioned in Administrative Circular N° 12 as follows : The figures, effective from 1 September 2003, are : § 8a : 16.50 Swiss francs (previously 16.- Swiss francs) § 9a : 663 Swiss francs (previously 640.- Swiss francs) § 9b : 33 Swiss francs (previously 32.- Swiss francs) Human Resources Division Tel. 72862/74474

  12. Circular arc structures

    KAUST Repository

    Bo, Pengbo

    2011-07-01

    The most important guiding principle in computational methods for freeform architecture is the balance between cost efficiency on the one hand, and adherence to the design intent on the other. Key issues are the simplicity of supporting and connecting elements as well as repetition of costly parts. This paper proposes so-called circular arc structures as a means to faithfully realize freeform designs without giving up smooth appearance. In contrast to non-smooth meshes with straight edges where geometric complexity is concentrated in the nodes, we stay with smooth surfaces and rather distribute complexity in a uniform way by allowing edges in the shape of circular arcs. We are able to achieve the simplest possible shape of nodes without interfering with known panel optimization algorithms. We study remarkable special cases of circular arc structures which possess simple supporting elements or repetitive edges, we present the first global approximation method for principal patches, and we show an extension to volumetric structures for truly threedimensional designs. © 2011 ACM.

  13. Circular RNAs in cancer

    DEFF Research Database (Denmark)

    Kristensen, L S; Hansen, T B; Venø, M T

    2018-01-01

    Circular RNA (circRNA) is a novel member of the noncoding cancer genome with distinct properties and diverse cellular functions, which is being explored at a steadily increasing pace. The list of endogenous circRNAs involved in cancer continues to grow; however, the functional relevance of the vast...... for circRNA cancer research and current caveats, which must be addressed to facilitate the translation of basic circRNA research into clinical use.Oncogene advance online publication, 9 October 2017; doi:10.1038/onc.2017.361....

  14. Circularly polarized antennas

    CERN Document Server

    Gao, Steven; Zhu, Fuguo

    2013-01-01

    This book presents a comprehensive insight into the design techniques for different types of CP antenna elements and arrays In this book, the authors address a broad range of topics on circularly polarized (CP) antennas. Firstly, it introduces to the reader basic principles, design techniques and characteristics of various types of CP antennas, such as CP patch antennas, CP helix antennas, quadrifilar helix antennas (QHA), printed quadrifilar helix antennas (PQHA), spiral antenna, CP slot antennas, CP dielectric resonator antennas, loop antennas, crossed dipoles, monopoles and CP horns. Adva

  15. Inheritance of the yeast mitochondrial genome

    DEFF Research Database (Denmark)

    Piskur, Jure

    1994-01-01

    Mitochondrion, extrachromosomal genetics, intergenic sequences, genome size, mitochondrial DNA, petite mutation, yeast......Mitochondrion, extrachromosomal genetics, intergenic sequences, genome size, mitochondrial DNA, petite mutation, yeast...

  16. DNA Knots: Theory and Experiments

    Science.gov (United States)

    Sumners, D. W.

    Cellular DNA is a long, thread-like molecule with remarkably complex topology. Enzymes that manipulate the geometry and topology of cellular DNA perform many vital cellular processes (including segregation of daughter chromosomes, gene regulation, DNA repair, and generation of antibody diversity). Some enzymes pass DNA through itself via enzyme-bridged transient breaks in the DNA; other enzymes break the DNA apart and reconnect it to different ends. In the topological approach to enzymology, circular DNA is incubated with an enzyme, producing an enzyme signature in the form of DNA knots and links. By observing the changes in DNA geometry (supercoiling) and topology (knotting and linking) due to enzyme action, the enzyme binding and mechanism can often be characterized. This paper will discuss some personal research history, and the tangle model for the analysis of site-specific recombination experiments on circular DNA.

  17. Circular states of atomic hydrogen

    International Nuclear Information System (INIS)

    Lutwak, R.; Holley, J.; Chang, P.P.; Paine, S.; Kleppner, D.; Ducas, T.

    1997-01-01

    We describe the creation of circular states of hydrogen by adiabatic transfer of a Rydberg state in crossed electric and magnetic fields, and also by adiabatic passage in a rotating microwave field. The latter method permits rapid switching between the two circular states of a given n manifold. The two methods are demonstrated experimentally, and results are presented of an analysis of the field ionization properties of the circular states. An application for the circular states is illustrated by millimeter-wave resonance in hydrogen of the n=29→n=30 transition. copyright 1997 The American Physical Society

  18. Molecular characterization of the pSinB plasmid of the arsenite oxidizing, metallotolerant Sinorhizobium sp. M14 - insight into the heavy metal resistome of sinorhizobial extrachromosomal replicons.

    Science.gov (United States)

    Romaniuk, Krzysztof; Dziewit, Lukasz; Decewicz, Przemyslaw; Mielnicki, Sebastian; Radlinska, Monika; Drewniak, Lukasz

    2017-01-01

    Sinorhizobium sp. M14 is an As(III)-oxidizing, psychrotolerant strain, capable of growth in the presence of extremely high concentrations of arsenic and many other heavy metals. Metallotolerant abilities of the M14 strain depend upon the presence of two extrachromosomal replicons: pSinA (∼ 109 kb) and pSinB (∼ 300 kb). The latter was subjected to complex analysis. The performed analysis demonstrated that the plasmid pSinB is a narrow-host-range repABC-type replicon, which is fully stabilized by the phd-vapC-like toxin-antitoxin stabilizing system. In silico analysis showed that among the phenotypic gene clusters of the plasmid pSinB, eight modules are potentially involved in heavy metals resistance (HMR). These modules carry genes encoding efflux pumps, permeases, transporters and copper oxidases, which provide resistance to arsenic, cadmium, cobalt, copper, iron, mercury, nickel, silver and zinc. The functional analysis revealed that the HMR modules are active and have an effect on the minimal inhibitory concentration (MIC) values observed for the heterological host cells. The phenotype was manifested by an increase or decrease of the MICs of heavy metals and it was strain specific. The analysis of distribution of the heavy metal resistance genes, i.e. resistome, in Sinorhizobium spp. plasmids, revealed that the HMR modules are common in these replicons. © FEMS 2016. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

  19. The Circular Camera Movement

    DEFF Research Database (Denmark)

    Hansen, Lennard Højbjerg

    2014-01-01

    It has been an accepted precept in film theory that specific stylistic features do not express specific content. Nevertheless, it is possible to find many examples in the history of film in which stylistic features do express specific content: for instance, the circular camera movement is used...... repeatedly to convey the feeling of a man and a woman falling in love. This raises the question of why producers and directors choose certain stylistic features to narrate certain categories of content. Through the analysis of several short film and TV clips, this article explores whether...... or not there are perceptual aspects related to specific stylistic features that enable them to be used for delimited narrational purposes. The article further attempts to reopen this particular stylistic debate by exploring the embodied aspects of visual perception in relation to specific stylistic features...

  20. Operational circular No. 1 (Rev. 1) – Operational circulars

    CERN Multimedia

    HR Department

    2011-01-01

    Operational Circular No. 1 (Rev. 1) is applicable to members of the personnel and other persons concerned. Operational Circular No. 1 (Rev. 1) entitled "Operational circulars", approved following discussion at the Standing Concertation Committee meeting on 4 May 2011, is available on the intranet site of the Human Resources Department: https://hr-docs.web.cern.ch/hr-docs/opcirc/opcirc.asp It cancels and replaces Operational Circular No. 1 entitled "Operational Circulars” of December 1996. This new version clarifies, in particular, that operational circulars do not necessarily arise from the Staff Rules and Regulations, and the functional titles have been updated to bring them into line with the current CERN organigram. Department Head Office  

  1. Circular defects detection in welded joints using circular hough transform

    International Nuclear Information System (INIS)

    Hafizal Yazid; Mohd Harun; Shukri Mohd; Abdul Aziz Mohamed; Shaharudin Sayuti; Muhamad Daud

    2007-01-01

    Conventional radiography is one of the common non-destructive testing which employs manual image interpretation. The interpretation is very subjective and depends much on the inspector experience and working conditions. It is therefore useful to have pattern recognition system in order to assist human interpreter in evaluating the quality of the radiograph sample, especially radiographic image of welded joint. This paper describes a system to detect circular discontinuities that is present in the joints. The system utilizes together 2 different algorithms, which is separability filter to identify the best object candidate and Circular Hough Transform to detect the present of circular shape. The result of the experiment shows a promising output in recognition of circular discontinuities in a radiographic image. This is based on 81.82-100% of radiography film with successful circular detection by using template movement of 10 pixels. (author)

  2. Symplectic methods in circular accelerators

    International Nuclear Information System (INIS)

    Forest, E.

    1994-01-01

    By now symplectic integration has been applied to many problems in classical mechanics. It is my conviction that the field of particle simulation in circular rings is ideally suited for the application of symplectic integration. In this paper, I present a short description symplectic tools in circular storage rings

  3. Design for Circular Behaviour: Considering Users in a Circular Economy

    Directory of Open Access Journals (Sweden)

    Thomas Wastling

    2018-05-01

    Full Text Available In a linear economy, a product is manufactured and sold to a customer. Then, little concern is given to what the user actually does with it when they have it. However, in a circular economy where the aim is to circulate products at their highest level of value, the customer’s behaviour can become an important part of the system. Circular design strategies have tended to focus on the physical aspects of a product (e.g., disassembly, material selection, but the design of products and services can also have an influence on user behaviour and, to date, this aspect of circular design has not been fully explored. This project aims to define what key user behaviours are required for circular business models to work and to outline how design can enable these ‘circular behaviours’. This research project consists of a literature review, case study analysis and expert interviews with practitioners. A theoretical framework for designing products and services to encourage circular behaviour is developed. This work provides an initial step towards a better understanding of the user’s role in the transition to a circular economy as well as a preliminary model for how design for behaviour change strategies could be implemented in this context.

  4. Towards Future Circular Colliders

    CERN Document Server

    AUTHOR|(CDS)2108454; Zimmermann, Frank

    2016-01-01

    The Large Hadron Collider (LHC) at CERN presently provides proton-proton collisions at a centre-of-mass (c.m.) energy of 13 TeV. The LHC design was started more than 30 years ago, and its physics programme will extend through the second half of the 2030’s. The global Future Circular Collider (FCC) study is now preparing for a post-LHC project. The FCC study focuses on the design of a 100-TeV hadron collider (FCC-hh) in a new ∼100 km tunnel. It also includes the design of a high-luminosity electron-positron collider (FCC-ee) as a potential intermediate step, and a lepton-hadron collider option (FCC-he). The scope of the FCC study comprises accelerators, technology, infrastructure, detectors, physics, concepts for worldwide data services, international governance models, and implementation scenarios. Among the FCC core technologies figure 16-T dipole magnets, based on $Nb_3Sn$ superconductor, for the FCC-hh hadron collider, and a highly efficient superconducting radiofrequency system for the FCC-ee lepton c...

  5. Future Circular Colliders

    CERN Document Server

    AUTHOR|(CDS)2108454; Zimmermann, Frank

    2016-01-01

    In response to a request from the 2013 Update of the European Strategy for Particle Physics, the global Future Circular Collider (FCC) study is preparing the foundation for a next-generation large-scale accelerator infrastructure in the heart of Europe. The FCC study focuses on the design of a 100-TeV hadron collider (FCC-hh), to be accommodated in a new ∼100 km tunnel near Geneva. It also includes the design of a high-luminosity electron-positron collider (FCC-ee), which could be installed in the same tunnel as a potential intermediate step, and a lepton-hadron collider option (FCC-he). The scope of the FCC study comprises accelerators, technology, infrastructure, detector, physics, concepts for worldwide data services, international governance models, and implementation scenarios. Among the FCC core technologies figure 16-T dipole magnets, based on Nb$_{3}$Sn superconductor, for the FCC-hh hadron collider, and a highly efficient superconducting radiofrequency system for the FCC-ee lepton collider. The int...

  6. Future Circular Colliders

    CERN Document Server

    AUTHOR|(CDS)2108454; Zimmermann, Frank

    2016-01-01

    In response to a request from the 2013 Update of the European Strategy for Particle Physics, the global Future Circular Collider (FCC) study is preparing the foundation for a next-generation large-scale accelerator infrastructure in the heart of Europe. The FCC study focuses on the design of a 100-TeV hadron collider (FCC-hh), to be accommodated in a new ∼100 km tunnel near Geneva. It also includes the design of a high-luminosity electron-positron collider (FCC-ee), which could be installed in the same tunnel as a potential intermediate step, and a lepton-hadron collider option (FCC-he). The scope of the FCC study comprises accelerators, technology, infrastructure, detectors, physics, concepts for worldwide data services, international governance models, and implementation scenarios. Among the FCC core technologies figure 16-T dipole magnets, based on Nb$_{3}$Sn superconductor, for the FCC-hh hadron collider, and a highly efficient superconducting radiofrequency system for the FCC-ee lepton collider. The in...

  7. Nuclear spin circular dichroism

    International Nuclear Information System (INIS)

    Vaara, Juha; Rizzo, Antonio; Kauczor, Joanna; Norman, Patrick; Coriani, Sonia

    2014-01-01

    Recent years have witnessed a growing interest in magneto-optic spectroscopy techniques that use nuclear magnetization as the source of the magnetic field. Here we present a formulation of magnetic circular dichroism (CD) due to magnetically polarized nuclei, nuclear spin-induced CD (NSCD), in molecules. The NSCD ellipticity and nuclear spin-induced optical rotation (NSOR) angle correspond to the real and imaginary parts, respectively, of (complex) quadratic response functions involving the dynamic second-order interaction of the electron system with the linearly polarized light beam, as well as the static magnetic hyperfine interaction. Using the complex polarization propagator framework, NSCD and NSOR signals are obtained at frequencies in the vicinity of optical excitations. Hartree-Fock and density-functional theory calculations on relatively small model systems, ethene, benzene, and 1,4-benzoquinone, demonstrate the feasibility of the method for obtaining relatively strong nuclear spin-induced ellipticity and optical rotation signals. Comparison of the proton and carbon-13 signals of ethanol reveals that these resonant phenomena facilitate chemical resolution between non-equivalent nuclei in magneto-optic spectra

  8. Design of a titering assay for lentiviral vectors utilizing direct extraction of DNA from transduced cells in microtiter plates

    Directory of Open Access Journals (Sweden)

    Michele E Murphy

    2016-01-01

    Full Text Available Using lentiviral vector products in clinical applications requires an accurate method for measuring transduction titer. For vectors lacking a marker gene, quantitative polymerase chain reaction is used to evaluate the number of vector DNA copies in transduced target cells, from which a transduction titer is calculated. Immune Design previously described an integration-deficient lentiviral vector pseudotyped with a modified Sindbis virus envelope for use in cancer immunotherapy (VP02, of the ZVex platform. Standard protocols for titering integration-competent lentiviral vectors employ commercial spin columns to purify vector DNA from transduced cells, but such columns are not optimized for isolation of extrachromosomal (nonintegrated DNA. Here, we describe a 96-well transduction titer assay in which DNA extraction is performed in situ in the transduction plate, yielding quantitative recovery of extrachromosomal DNA. Vector titers measured by this method were higher than when commercial spin columns were used for DNA isolation. Evaluation of the method's specificity, linear range, and precision demonstrate that it is suitable for use as a lot release assay to support clinical trials with VP02. Finally, the method is compatible with titering both integrating and nonintegrating lentiviral vectors, suggesting that it may be used to evaluate the transduction titer for any lentiviral vector.

  9. Mobile units of DNA in phytoplasma genomes.

    Science.gov (United States)

    Dickinson, Matt

    2010-09-01

    Phytoplasmas are obligate symbionts of plants and insects that are responsible for significant yield losses in diverse crops. Genome sequencing has revealed that many phytoplasma genomes appear to contain repeated genes organized in units of approximately 20 kb. These 'potential mobile units' (PMUs) resemble composite replicative transposons. PMUs contain several genes for recombination and some also contain putative 'virulence genes'. Genome alignments suggest that PMUs are involved in phytoplasma genome instability and recombination. In this edition of Molecular Microbiology, Hogenhout and colleagues report that one PMU from the aster yellows phytoplasma strain Witches' Broom (AY-WB) can exist as both a linear PMU within the chromosome and as an extrachromosomal circular form. The copy number of the circular form is much higher in the insect vector compared with the plant, and expression levels of genes present on the PMU are also higher in the insect. These observations suggest not only that this PMU could be a mobile element, but that it could also be involved in a phase-variation mechanism that allows the phytoplasma to adapt to its different hosts.

  10. Digitalizing the Circular Economy

    Science.gov (United States)

    Reuter, Markus A.

    2016-12-01

    Metallurgy is a key enabler of a circular economy (CE), its digitalization is the metallurgical Internet of Things (m-IoT). In short: Metallurgy is at the heart of a CE, as metals all have strong intrinsic recycling potentials. Process metallurgy, as a key enabler for a CE, will help much to deliver its goals. The first-principles models of process engineering help quantify the resource efficiency (RE) of the CE system, connecting all stakeholders via digitalization. This provides well-argued and first-principles environmental information to empower a tax paying consumer society, policy, legislators, and environmentalists. It provides the details of capital expenditure and operational expenditure estimates. Through this path, the opportunities and limits of a CE, recycling, and its technology can be estimated. The true boundaries of sustainability can be determined in addition to the techno-economic evaluation of RE. The integration of metallurgical reactor technology and systems digitally, not only on one site but linking different sites globally via hardware, is the basis for describing CE systems as dynamic feedback control loops, i.e., the m-IoT. It is the linkage of the global carrier metallurgical processing system infrastructure that maximizes the recovery of all minor and technology elements in its associated refining metallurgical infrastructure. This will be illustrated through the following: (1) System optimization models for multimetal metallurgical processing. These map large-scale m-IoT systems linked to computer-aided design tools of the original equipment manufacturers and then establish a recycling index through the quantification of RE. (2) Reactor optimization and industrial system solutions to realize the "CE (within a) Corporation—CEC," realizing the CE of society. (3) Real-time measurement of ore and scrap properties in intelligent plant structures, linked to the modeling, simulation, and optimization of industrial extractive process

  11. Towards future circular colliders

    Science.gov (United States)

    Benedikt, Michael; Zimmermann, Frank

    2016-09-01

    The Large Hadron Collider (LHC) at the European Organization for Nuclear Research (CERN) presently provides proton-proton collisions at a center-of-mass (c.m.) energy of 13 TeV. The LHC design was started more than 30 years ago, and its physics program will extend through the second half of the 2030's. The global Future Circular Collider (FCC) study is now preparing for a post-LHC project. The FCC study focuses on the design of a 100-TeV hadron collider (FCC-hh) in a new ˜100 km tunnel. It also includes the design of a high-luminosity electron-positron collider (FCCee) as a potential intermediate step, and a lepton-hadron collider option (FCC-he). The scope of the FCC study comprises accelerators, technology, infrastructure, detectors, physics, concepts for worldwide data services, international governance models, and implementation scenarios. Among the FCC core technologies figure 16-T dipole magnets, based on Nb3 S n superconductor, for the FCC-hh hadron collider, and a highly-efficient superconducting radiofrequency system for the FCC-ee lepton collider. Following the FCC concept, the Institute of High Energy Physics (IHEP) in Beijing has initiated a parallel design study for an e + e - Higgs factory in China (CEPC), which is to be succeeded by a high-energy hadron collider (SPPC). At present a tunnel circumference of 54 km and a hadron collider c.m. energy of about 70 TeV are being considered. After a brief look at the LHC, this article reports the motivation and the present status of the FCC study, some of the primary design challenges and R&D subjects, as well as the emerging global collaboration.

  12. Circular polarization observed in bioluminescence

    NARCIS (Netherlands)

    Wynberg, H.; Meijer, E.W.; Hummelen, J.C.; Dekkers, H.P.J.M.; Schippers, P.H.; Carlson, A.D.

    1980-01-01

    The left and right lanterns of live larvae of the fireflies Photuris lucicrescens and P. versicolor emitted circularly polarized light of opposite sense. A possible mechanism is discussed. [on SciFinder (R)

  13. Molecular studies of fibroblasts transfected with hepatitis B virus DNA

    International Nuclear Information System (INIS)

    Chen, M.L.; Hood, A.; Thung, S.N.; Gerber, M.A.

    1987-01-01

    Two subclones (D7 and F8) derived from an NIH 3T3 mouse fibroblast cell line after transfection with hepatitis B virus (HBV) genomes, secreted significantly different amounts of HBsAg and HBeAg. DNA extracted from the subclones revealed only integrated and no extrachromosomal HBV DNA sequences as determined by the Southern blot technique with a /sup 32/P-labeled full length HBV DNA probe. The amount and integration sites of HBV sequences were significantly different in the two subclones. HBV DNA sequences coding for HBsAg and HBcAg were detected by alkaline phosphatase-conjugated, single-stranded synthetic gene-specific oligonucleotide probes revealing a larger number of copies in D7 DNA than in F8 DNA. Using a biotinylated probe for in situ hybridization, HBV DNA was found in the nuclei of all D7 cells with predominant localization to a single chromsome, but only in 10-20% of F8 cells. These observations demonstrate different integration patterns of HBV and DNA in two subclones derived from a transfected cell line and suggest that the amount of integrated HBV DNA is proportional to the amount of HBV antigens produced

  14. Conversion of DNA gyrase into a conventional type II topoisomerase

    DEFF Research Database (Denmark)

    Kampranis, S C; Maxwell, A

    1996-01-01

    DNA gyrase is unique among topoisomerases in its ability to introduce negative supercoils into closed-circular DNA. We have demonstrated that deletion of the C-terminal DNA-binding domain of the A subunit of gyrase gives rise to an enzyme that cannot supercoil DNA but relaxes DNA in an ATP-depend...

  15. Circular polarization observed in bioluminescence

    NARCIS (Netherlands)

    Wijnberg, Hans; Meijer, E.W.; Hummelen, J.C.; Dekkers, H.P.J.M.; Schippers, P.H.; Carlson, A.D.

    1980-01-01

    While investigating circular polarization in luminescence, and having found it in chemiluminescence, we have studied bioluminescence because it is such a widespread and dramatic natural phenomenon. We report here that left and right lanterns of live larvae of the fireflies, Photuris lucicrescens and

  16. 140 CIRCULAR INTERACTION BETWEEN LINGUISTIC ...

    African Journals Online (AJOL)

    economy. Although a country or administrative district should have one or more official languages for obvious reasons, Nelde (1991) proposes that the ... circular interaction between linguistic departments and language departments. Finding an answer to' Plato's abovementioned problem entails that as many languages as ...

  17. High intensity circular proton accelerators

    International Nuclear Information System (INIS)

    Craddock, M.K.

    1987-12-01

    Circular machines suitable for the acceleration of high intensity proton beams include cyclotrons, FFAG accelerators, and strong-focusing synchrotrons. This paper discusses considerations affecting the design of such machines for high intensity, especially space charge effects and the role of beam brightness in multistage accelerators. Current plans for building a new generation of high intensity 'kaon factories' are reviewed. 47 refs

  18. Stable expression and replication of hepatitis B virus genome in an integrated state in a human hepatoma cell line transfected with the cloned viral DNA

    International Nuclear Information System (INIS)

    Tsurimoto, T.; Fujiyama, A.; Matsubara, K.

    1987-01-01

    A human hepatocellular carcinoma cell line (Huh6-c15) was transfected with a recombinant DNA molecule that consists of tandemly arranged hepatitis B virus (HBV) genome and a neomycin-resistant gene. One clone resistant to G-418 produces and releases surface antigen and e antigen into medium at a high level and accumulates core particles intracellularly. This clone has a chromosomally integrated set of the original recombinant DNA and produces a 3.5-kilobase transcript corresponding to the pregenome RNA as well as HBV DNAs in an extrachromosomal form. Most of these DNAs were in single-stranded or partially double-stranded form and were packaged in the intracellular core particles. In the medium, particles were detected that contained HBV DNA and were morphologically indistinguishable from Dane particles. These results demonstrate that the HBV genome in an integrated state acted as a template for viral gene expression and replication. The cells were maintained for more than 6 months without losing the ability to produce the extrachromosomal HBV DNA and Dane-like particles. Thus, the cells can be used as a model system for analyses of gene expression and DNA replication of HBV in human hepatocytes

  19. Architectural Surfaces and Structures from Circular Arcs

    KAUST Repository

    Shi, Ling

    2013-01-01

    the most attention from geometry researchers. In this thesis, we aim to realize this process with simple geometric primitives, circular arcs. We investigate architectural surfaces and structures consisting of circular arcs. Our focus is lying on how

  20. 76 FR 60593 - Title VI; Proposed Circular

    Science.gov (United States)

    2011-09-29

    ..., several of them related to ambiguous language in the existing Circular. The proposed Circular reorganizes... regional entity, and inclusive of public and private entities. This term is used exclusively in Chapter IV... revisions to the Title VI Circular. The section that addresses the existing requirement for a Language...

  1. Circular Business: Collaborate and Circulate : a bookreview

    NARCIS (Netherlands)

    Timmermans, Ratna W.; Witjes, S.|info:eu-repo/dai/nl/381088200

    2016-01-01

    With their book, “Circular Business: Collaborate and Circulate”, Circular Collaboration, Amersfoort, ISBN: 978-90-824902-0-6, €35, Kraaijenhagen et al. (2016) give companies practical guidance on their contribution to the development of a more circular economy by presenting a practical 10-step

  2. Capacitance of circular patch resonator

    International Nuclear Information System (INIS)

    Miano, G.; Verolino, L.; Naples Univ.; Panariello, G.; Vaccaro, V.G.; Naples Univ.

    1995-11-01

    In this paper the capacitance of the circular microstrip patch resonator is computed. It is shown that the electrostatic problem can be formulated as a system of dual integral equations, and the most interesting techniques of solutions of these systems are reviewed. Some useful approximated formulas for the capacitance are derived and plots of the capacitance are finally given in a wide range of dielectric constants

  3. Electron microscopic visualization of the RecA protein-mediated pairing and branch migration phases of DNA strand exchange

    DEFF Research Database (Denmark)

    Register, JC; Christiansen, Gunna; Griffith, J

    1987-01-01

    examined by electron microscopy: supertwisted double-stranded (ds) DNA and linear single-stranded (ss) DNA, linear dsDNA and circular ssDNA, and linear dsDNA and colinear ssDNA. Several major observations were: (i) with RecA protein bound to the DNA, plectonemic joints were ultrastructurally...

  4. Relationships between MDR proteins, bacteriocin production and proteolysis in Lactococcus lactis

    NARCIS (Netherlands)

    Gajic, Olivera

    2003-01-01

    The Gram-positive lactic acid bacterium Lactococcus lactis can harbour a wide variety of circular extrachromosomal DNA molecules, so-called plasmids. Many of the traits that make them useful for manufacturing of fermented food products (e.g. bacteriophage resistance, bacteriocin and proteinase

  5. Local chromatin structure of heterochromatin regulates repeated DNA stability, nucleolus structure, and genome integrity

    Energy Technology Data Exchange (ETDEWEB)

    Peng, Jamy C. [Univ. of California, Berkeley, CA (United States)

    2007-01-01

    Heterochromatin constitutes a significant portion of the genome in higher eukaryotes; approximately 30% in Drosophila and human. Heterochromatin contains a high repeat DNA content and a low density of protein-encoding genes. In contrast, euchromatin is composed mostly of unique sequences and contains the majority of single-copy genes. Genetic and cytological studies demonstrated that heterochromatin exhibits regulatory roles in chromosome organization, centromere function and telomere protection. As an epigenetically regulated structure, heterochromatin formation is not defined by any DNA sequence consensus. Heterochromatin is characterized by its association with nucleosomes containing methylated-lysine 9 of histone H3 (H3K9me), heterochromatin protein 1 (HP1) that binds H3K9me, and Su(var)3-9, which methylates H3K9 and binds HP1. Heterochromatin formation and functions are influenced by HP1, Su(var)3-9, and the RNA interference (RNAi) pathway. My thesis project investigates how heterochromatin formation and function impact nuclear architecture, repeated DNA organization, and genome stability in Drosophila melanogaster. H3K9me-based chromatin reduces extrachromosomal DNA formation; most likely by restricting the access of repair machineries to repeated DNAs. Reducing extrachromosomal ribosomal DNA stabilizes rDNA repeats and the nucleolus structure. H3K9me-based chromatin also inhibits DNA damage in heterochromatin. Cells with compromised heterochromatin structure, due to Su(var)3-9 or dcr-2 (a component of the RNAi pathway) mutations, display severe DNA damage in heterochromatin compared to wild type. In these mutant cells, accumulated DNA damage leads to chromosomal defects such as translocations, defective DNA repair response, and activation of the G2-M DNA repair and mitotic checkpoints that ensure cellular and animal viability. My thesis research suggests that DNA replication, repair, and recombination mechanisms in heterochromatin differ from those in

  6. Best Practice Examples of Circular Business Models

    DEFF Research Database (Denmark)

    Guldmann, Eva

    Best practice examples of circular business models are presented in this report. The purpose is to inform and inspire interested readers, in particular companies that aspire to examine the potentials of the circular economy. Circular business models in two different sectors are examined, namely...... the textile and clothing sector as well as the durable goods sector. In order to appreciate the notion of circular business models, the basics of the circular economy are outlined along with three frameworks for categorizing the various types of circular business models. The frameworks take point of departure...... in resource loops, value bases and business model archetypes respectively, and they are applied for analysing and organizing the business models that are presented throughout the report. The investigations in the report show that circular business models are relevant to businesses because they hold...

  7. Relationship between chromatin complexity and nuclear envelope circularity in hippocampal pyramidal neurons

    International Nuclear Information System (INIS)

    Pantic, Igor; Basailovic, Milos; Paunovic, Jovana; Pantic, Senka

    2015-01-01

    Highlights: •We analyzed chromatin structure and nuclear envelope of 200 hippocampal pyramidal neurons. •Fractal and GLCM mathematical parameters were calculated each chromatin structure. •Nuclear shape was quantified by calculating circularity of the nuclear envelope. •Circularity was in significant relationship with chromatin fractal dimension. •Strong correlation was detected between circularity and some GLCM parameters. -- Abstract: In this study we tested the existence and strength of the relationship between circularity of nuclear envelope and mathematical parameters of chromatin structure. Coronal sections of the brain were made in 10 male albino mice. The brain tissue was stained using a modification of Feulgen method for DNA visualization. A total of 200 hippocampal pyramidal neurons (20 per animal) were visualized using DEM 200 High-Speed Color CMOS Chip and Olympus CX21FS1 microscope. Circularity of the nuclear membrane was calculated in ImageJ (NIH, USA) after the nuclear segmentation, based on the freehand selection of the nuclear regions of interest. Circularity was determined from the values of area and perimeter. For each chromatin structure, using fractal and grey level co-occurrence matrix (GLCM) algorithms, we determined the values of fractal dimension, lacunarity, angular second moment, GLCM entropy, inverse difference moment, GLCM correlation, and GLCM contrast. It was found that circularity is in a significant correlation (p < 0.05) with fractal dimension as the main parameter of fractal complexity analysis. Also, circularity was in a very strong relationship (p < 0.001) with certain parameters of grey level co-occurrence matrix such as the angular second moment and GLCM correlation. This is the first study to indicate that nuclear shape is significantly related to mathematical parameters of higher chromatin organization. Also, it seems that circularity of the nuclear envelope is a good predictor of certain features of chromatin

  8. Enzymatic properties of the bacteriophage phi X174 A protein on superhelical phi X174 DNA: a model for the termination of the rolling circle DNA replication

    NARCIS (Netherlands)

    van der Ende, A.; Langeveld, S. A.; Teertstra, R.; van Arkel, G. A.; Weisbeek, P. J.

    1981-01-01

    Incubation of phi X174 replication form I DNA with the A* protein of phi X174 in the presence of MN2+ results in the formation of three different types of DNA molecules: open circular form DNA (RFII), linear form DNA (RFIII) and the relaxed covalently closed form DNA (RFIV). The RFII and RFIII DNAs

  9. Attenuation in Superconducting Circular Waveguides

    Directory of Open Access Journals (Sweden)

    K. H. Yeap

    2016-09-01

    Full Text Available We present an analysis on wave propagation in superconducting circular waveguides. In order to account for the presence of quasiparticles in the intragap states of a superconductor, we employ the characteristic equation derived from the extended Mattis-Bardeen theory to compute the values of the complex conductivity. To calculate the attenuation in a circular waveguide, the tangential fields at the boundary of the wall are first matched with the electrical properties (which includes the complex conductivity of the wall material. The matching of fields with the electrical properties results in a set of transcendental equations which is able to accurately describe the propagation constant of the fields. Our results show that although the attenuation in the superconducting waveguide above cutoff (but below the gap frequency is finite, it is considerably lower than that in a normal waveguide. Above the gap frequency, however, the attenuation in the superconducting waveguide increases sharply. The attenuation eventually surpasses that in a normal waveguide. As frequency increases above the gap frequency, Cooper pairs break into quasiparticles. Hence, we attribute the sharp rise in attenuation to the increase in random collision of the quasiparticles with the lattice structure.

  10. Chemical Synthesis of Circular Proteins*

    Science.gov (United States)

    Tam, James P.; Wong, Clarence T. T.

    2012-01-01

    Circular proteins, once thought to be rare, are now commonly found in plants. Their chemical synthesis, once thought to be difficult, is now readily achievable. The enabling methodology is largely due to the advances in entropic chemical ligation to overcome the entropy barrier in coupling the N- and C-terminal ends of large peptide segments for either intermolecular ligation or intramolecular ligation in end-to-end cyclization. Key elements of an entropic chemical ligation consist of a chemoselective capture step merging the N and C termini as a covalently linked O/S-ester intermediate to permit the subsequent step of an intramolecular O/S-N acyl shift to form an amide. Many ligation methods exploit the supernucleophilicity of a thiol side chain at the N terminus for the capture reaction, which makes cysteine-rich peptides ideal candidates for the entropy-driven macrocyclization. Advances in desulfurization and modification of the thiol-containing amino acids at the ligation sites to other amino acids add extra dimensions to the entropy-driven ligation methods. This minireview describes recent advances of entropy-driven ligation to prepare circular proteins with or without a cysteinyl side chain. PMID:22700959

  11. Probing electronic coupling between adenine bases in RNA strands from synchrotron radiation circular dichroism experiments

    DEFF Research Database (Denmark)

    Nielsen, Lisbeth Munksgård; Hoffmann, Søren Vrønning; Nielsen, Steen Brøndsted

    2012-01-01

    Circular dichroism spectra (176–330 nm) of RNA adenine oligomers, (rA)n (n = 1–10, 12, 15, and 20), reveal electronic coupling between two bases in short strands. The number of interacting bases in long strands is more and larger than that reported previously for the corresponding DNA strands....

  12. A lateral flow biosensor for detection of single nucleotide polymorphism by circular strand displacement reaction.

    Science.gov (United States)

    Xiao, Zhuo; Lie, Puchang; Fang, Zhiyuan; Yu, Luxin; Chen, Junhua; Liu, Jie; Ge, Chenchen; Zhou, Xuemeng; Zeng, Lingwen

    2012-09-04

    A lateral flow biosensor for detection of single nucleotide polymorphism based on circular strand displacement reaction (CSDPR) has been developed. Taking advantage of high fidelity of T4 DNA ligase, signal amplification by CSDPR, and the optical properties of gold nanoparticles, this assay has reached a detection limit of 0.01 fM.

  13. Circular economy and nuclear energy

    International Nuclear Information System (INIS)

    2016-01-01

    Circular economy means no production of waste through re-using and recycling. As other industries, nuclear industry has committed itself to a policy of sustainability and resource preservation. EDF has developed a 5 point strategy: 1) the closure of the fuel cycle through recycling, 2) operating nuclear power plants beyond 40 years, 3) reducing the volume of waste, 4) diminishing the consumption of energy through the implementation of new processes (for instance the enrichment through centrifugation uses 50 times less power than gaseous diffusion enrichment) and 5) making evolve the prevailing doctrine concerning the management of very low level radioactive waste: making possible the re-use of slightly contaminated steel scrap or concrete instead of storing them in dedicated disposal centers. (A.C.)

  14. Circular economy and nuclear energy

    International Nuclear Information System (INIS)

    2017-01-01

    This article first recalls what circular economy is, and its main principles (sustainable supply, eco-design, industrial and territorial ecology, economy of function rather than of possession, extension of product lifetime, recycling). It outlines its different benefits: improved resilience, inclusion of all actors of the territory, creation of local jobs, a global vision. In the next part, the nuclear industry is presented as a pioneer in this respect through various trends and developments: closure of the fuel cycle and saving of uranium and energy in the upstream part, reduction of wastes in the downstream part, exploitation of plants on a longer term, management of the production of conventional wastes, reduction of energy consumption, evolution of the doctrine in terms of management of very low level radioactive wastes

  15. Ancient DNA

    DEFF Research Database (Denmark)

    Willerslev, Eske; Cooper, Alan

    2004-01-01

    ancient DNA, palaeontology, palaeoecology, archaeology, population genetics, DNA damage and repair......ancient DNA, palaeontology, palaeoecology, archaeology, population genetics, DNA damage and repair...

  16. Circular relativistic motion of two identical bodies

    International Nuclear Information System (INIS)

    Shavokhina, N.S.

    1983-01-01

    Circular relativistic motion of two bodies as a solution of the earlier obtained equations with a deflecting argument where the self-deflection of the argument is an unknown function of time is considered. In case of circular motion the argument deflection is independent from time and it is the root of the transcendental equation obtained in the paper

  17. The circular economy applied to local communities

    NARCIS (Netherlands)

    van der Blonk, Heico; van Spijk, Alex; van der Schoor, Tineke

    2015-01-01

    Based on a theoretical discussion the main difference between models of lineair economy and circular economy are elaborated; (1) Elimination of waste is essential the circulation of circular flows and reclamation of (raw) materials; this requires mechanisms for the return of obsolete materials. (2)

  18. Culture as a Caveat Towards Circular Economy

    DEFF Research Database (Denmark)

    Guerrieri, Valeria

    2015-01-01

    Circular economy represents an economic and political challenge, as well as a cultural one, requiring a massive transformation on all levels of society. But why is cultural change so important to understanding today’s economy and how can the circular model be considered a truly cross-cultural...

  19. A one-step miniprep for the isolation of plasmid DNA and lambda phage particles.

    Directory of Open Access Journals (Sweden)

    George Lezin

    Full Text Available Plasmid DNA minipreps are fundamental techniques in molecular biology. Current plasmid DNA minipreps use alkali and the anionic detergent SDS in a three-solution format. In addition, alkali minipreps usually require additional column-based purification steps and cannot isolate other extra-chromosomal elements, such as bacteriophages. Non-ionic detergents (NIDs have been used occasionally as components of multiple-solution plasmid DNA minipreps, but a one-step approach has not been developed. Here, we have established a one-tube, one-solution NID plasmid DNA miniprep, and we show that this approach also isolates bacteriophage lambda particles. NID minipreps are more time-efficient than alkali minipreps, and NID plasmid DNA performs better than alkali DNA in many downstream applications. In fact, NID crude lysate DNA is sufficiently pure to be used in digestion and sequencing reactions. Microscopic analysis showed that the NID procedure fragments E. coli cells into small protoplast-like components, which may, at least in part, explain the effectiveness of this approach. This work demonstrates that one-step NID minipreps are a robust method to generate high quality plasmid DNA, and NID approaches can also isolate bacteriophage lambda particles, outperforming current standard alkali-based minipreps.

  20. Perceptions of Circular Business Models in SMEs

    Directory of Open Access Journals (Sweden)

    Sebastian-Ion Ceptureanu

    2018-05-01

    Full Text Available Testing circular economy business models is crucial in understanding Circular Economy features across various industries. This paper analyses Circular Economy perceptions in Romanian SMEs by investigating entrepreneurs from PVC joinery industry. Using a multidimensional framework, ReSOLVE, as a conceptual model, and Lewandowski systematization, we measured 6 business actions and their relations with Value creation. The results of our survey can be described as mixed. Of the 6 business actions of ReSOLVE framework, for half of them (Regenerate, Optimize and Exchange we can definitely conclude that these are correlated with Circular Economy in terms of Value Creation, while for a fourth there are variables significantly correlated without being able to conclude its overall contribution in terms of Value creation. Our empirical investigation contributes to literature development on Circular Economy research in SMEs and a step forward to shape future research initiatives.

  1. Sequence analysis of mitochondrial DNA hypervariable region III of ...

    African Journals Online (AJOL)

    The aims of this research were to study mitochondrial DNA hypervariable region III and establish the degree of variation characteristic of a fragment. The mitochondrial DNA (mtDNA) is a small circular genome located within the mitochondria in the cytoplasm of the cell and a smaller 1.2 kb pair fragment, called the control ...

  2. FUTURE CIRCULAR COLLIDER LOGISTICS STUDY

    CERN Document Server

    Beißert, Ulrike; Kuhlmann, Gerd; Nettsträter, Andreas; Prasse, Christian; Wohlfahrt, Andreas

    2018-01-01

    The Large Hadron Collider (LHC) at the European Organization for Nuclear Research CERN in Geneva is the largest and most powerful collider in the world. CERN and its research and experimental infrastructure is not only a focus for the science community but is also very much in the public eye. With the Future Circular Collider (FCC) Study, CERN has begun to examine the feasibility of a new underground accelerator ring with a length of approximately 100 kilometres. Logistics is of great importance for the construction, assembly and operation of the FCC. During the planning, construction and assembly of the LHC, logistics proved to be one of the key factors. As the FCC is even larger than the LHC, logistics will also become more and more significant. This report therefore shows new concepts, methods and analytics for logistics, supply chain and transport concepts as part of the FCC study. This report deals with three different logistics aspects for the planning and construction phase of FCC: 1. A discussion of d...

  3. Heterochromatin position effects on circularized sex chromosomes cause filicidal embryonic lethality in Drosophila melanogaster.

    Science.gov (United States)

    Ferree, Patrick M; Gomez, Karina; Rominger, Peter; Howard, Dagnie; Kornfeld, Hannah; Barbash, Daniel A

    2014-04-01

    Some circularized X-Y chromosomes in Drosophila melanogaster are mitotically unstable and induce early embryonic lethality, but the genetic basis is unknown. Our experiments suggest that a large region of X-linked satellite DNA causes anaphase bridges and lethality when placed into a new heterochromatic environment within certain circularized X-Y chromosomes. These results reveal that repetitive sequences can be incompatible with one another in cis. The lethal phenotype also bears a remarkable resemblance to a case of interspecific hybrid lethality.

  4. Breaking the fault tree circular logic

    International Nuclear Information System (INIS)

    Lankin, M.

    2000-01-01

    Event tree - fault tree approach to model failures of nuclear plants as well as of other complex facilities is noticeably dominant now. This approach implies modeling an object in form of unidirectional logical graph - tree, i.e. graph without circular logic. However, genuine nuclear plants intrinsically demonstrate quite a few logical loops (circular logic), especially where electrical systems are involved. This paper shows the incorrectness of existing practice of circular logic breaking by elimination of part of logical dependencies and puts forward a formal algorithm, which enables the analyst to correctly model the failure of complex object, which involves logical dependencies between system and components, in form of fault tree. (author)

  5. University Students Alternative Conceptions On Circular Motion

    Directory of Open Access Journals (Sweden)

    Ian Phil Canlas

    2015-08-01

    Full Text Available This study attempted to find out university students alternative conceptions on circular motion. An 18-item researcher-compiled and content-validated questionnaire was administered to twenty-six 26 students taking up a program in Bachelor in Secondary Education-Physical Science in their second year enrolled in a course on mechanics. Results revealed that majority of the students possess alternative conceptions on circular motion specifically along velocity acceleration and force. Moreover results showed the inconsistencies in the students understanding of circular motion concepts.

  6. The Circular Economy between Desiderates and Realities.

    Directory of Open Access Journals (Sweden)

    Tăchiciu Laurentiu

    2018-05-01

    Full Text Available The present issue of Amfiteatru Economic Journal addresses the subject of the circular economy, bringing together research contributions to a better understanding of the current state and perspectives of the adoption of economic and business models conceived to give resources’ highest utility and value in every stage by reducing waste, reusing and recycling. Contributors are approaching the circular economy from different perspectives. Some are concerned with the macroeconomic and social conditions accompanying a higher circularity in the economy, while others focus on businesses’ and individuals’ behaviours.

  7. Photocleavage of DNA: irradiation of quinone-containing reagents converts supercoiled to linear DNA

    International Nuclear Information System (INIS)

    Kock, T.; Schuster, G.B.; Ropp, J.D.; Sligar, S.G.

    1993-01-01

    Irradiation (350 nm) of air-saturated solutions of reagents containing an anthraquinone group linked to quaternary alkyl ammonium groups converts supercoiled DNA to circular and to linear DNA. Generation of linear DNA does not occur by accumulation of numerous single-strand cuts but by coincident-site double-strand cleavage of DNA. Irradiation forms the triplet state of the anthraquinone, which reacts either by hydrogen atom abstraction from a sugar of DNA or by electron transfer from a base of the DNA. Subsequent reactions result in chain scission. The quinone is apparently reformed after this sequence and reirradiation leads to double-strand cleavage. (Author)

  8. 17 CFR 230.253 - Offering circular.

    Science.gov (United States)

    2010-04-01

    .... Repetition of information should be avoided; cross-referencing of information within the document is... COMPLETENESS OF ANY OFFERING CIRCULAR OR OTHER SELLING LITERATURE. THESE SECURITIES ARE OFFERED PURSUANT TO AN...

  9. 77 FR 42077 - Environmental Justice: Final Circular

    Science.gov (United States)

    2012-07-17

    ..., rulemaking, and policy formulation. The DOT Order sets forth steps to prevent disproportionately high and... Circular as a whole. Some commenters expressed concerns about perceived administrative and financial... Engagement With Environmental Justice Populations Chapter III contains recommended strategies and techniques...

  10. A Conceptual Framework for Circular Design

    Directory of Open Access Journals (Sweden)

    Mariale Moreno

    2016-09-01

    Full Text Available Design has been recognised in the literature as a catalyst to move away from the traditional model of take-make-dispose to achieve a more restorative, regenerative and circular economy. As such, for a circular economy to thrive, products need to be designed for closed loops, as well as be adapted to generate revenues. This should not only be at the point of purchase, but also during use, and be supported by low-cost return chains and reprocessing structures, as well as effective policy and regulation. To date, most academic and grey literature on the circular economy has focused primarily on the development of new business models, with some of the latter studies addressing design strategies for a circular economy, specifically in the area of resource cycles and design for product life extension. However, these studies primarily consider a limited spectrum of the technical and biological cycles where materials are recovered and restored and nutrients (e.g., materials, energy, water are regenerated. This provides little guidance or clarity for designers wishing to design for new circular business models in practice. As such, this paper aims to address this gap by systematically analysing previous literature on Design for Sustainability (DfX (e.g., design for resource conservation, design for slowing resource loops and whole systems design and links these approaches to the current literature on circular business models. A conceptual framework is developed for circular economy design strategies. From this conceptual framework, recommendations are made to enable designers to fully consider the holistic implications for design within a circular economy.

  11. University Students Alternative Conceptions On Circular Motion

    OpenAIRE

    Ian Phil Canlas

    2015-01-01

    This study attempted to find out university students alternative conceptions on circular motion. An 18-item researcher-compiled and content-validated questionnaire was administered to twenty-six 26 students taking up a program in Bachelor in Secondary Education-Physical Science in their second year enrolled in a course on mechanics. Results revealed that majority of the students possess alternative conceptions on circular motion specifically along velocity acceleration and force. Moreover res...

  12. Single particle dynamics in circular accelerators

    International Nuclear Information System (INIS)

    Ruth, R.D.

    1986-10-01

    The purpose of this paper is to introduce the reader to the theory associated with the transverse dynamics of single particle, in circular accelerators. The discussion begins with a review of Hamiltonian dynamics and canonical transformations. The case of a single particle in a circular accelerator is considered with a discussion of non-linear terms and chromaticity. The canonical perturbation theory is presented and nonlinear resonances are considered. Finally, the concept of renormalization and residue criterion are examined. (FI)

  13. Asymptotic theory of circular polarization memory.

    Science.gov (United States)

    Dark, Julia P; Kim, Arnold D

    2017-09-01

    We establish a quantitative theory of circular polarization memory, which is the unexpected persistence of the incident circular polarization state in a strongly scattering medium. Using an asymptotic analysis of the three-dimensional vector radiative transfer equation (VRTE) in the limit of strong scattering, we find that circular polarization memory must occur in a boundary layer near the portion of the boundary on which polarized light is incident. The boundary layer solution satisfies a one-dimensional conservative scattering VRTE. Through a spectral analysis of this boundary layer problem, we introduce the dominant mode, which is the slowest-decaying mode in the boundary layer. To observe circular polarization memory for a particular set of optical parameters, we find that this dominant mode must pass three tests: (1) this dominant mode is given by the largest, discrete eigenvalue of a reduced problem that corresponds to Fourier mode k=0 in the azimuthal angle, and depends only on Stokes parameters U and V; (2) the polarization state of this dominant mode is largely circular polarized so that |V|≫|U|; and (3) the circular polarization of this dominant mode is maintained for all directions so that V is sign-definite. By applying these three tests to numerical calculations for monodisperse distributions of Mie scatterers, we determine the values of the size and relative refractive index when circular polarization memory occurs. In addition, we identify a reduced, scalar-like problem that provides an accurate approximation for the dominant mode when circular polarization memory occurs.

  14. Unleashing the Power of the Circular Economy

    Energy Technology Data Exchange (ETDEWEB)

    Kok, L.; Wurpel, G.; Ten Wolde, A. [IMSA Amsterdam, Amsterdam (Netherlands)

    2013-04-15

    The concept of circular economy is an economic and industrial system that focuses on the reusability of products and raw materials, reduces value destruction in the overall system and aims at value creation within each tier of the system. This report for Circle Economy (CE) outlines the general direction and concrete steps that must be taken to accomplish a breakthrough to a circular economy. It also provides a knowledge base behind the concept, connecting it to sustainability.

  15. Breaking the Barriers to the Circular Economy

    OpenAIRE

    Kirchherr, J.W.; Hekkert, M.P.; Bour, Ruben; Huijbrechtse-Truijens, Anne; Kostense-Smit, Erica; Muller, Jennifer

    2017-01-01

    The Copernicus Institute of Sustainable Development, Utrecht University, the Netherlands and Deloitte have jointly carried out research on barriers to the Circular Economy (CE) in the European Union. For this research, a survey with 153 businesses, 55 government officials and expert interviews with forty-seven thought leaders on the circular economy from businesses, governments, academia and NGOs have been carried out. Two types of barriers emerged as main barriers Firstly, there are the cult...

  16. Efficient Sleeping Beauty DNA Transposition From DNA Minicircles

    Directory of Open Access Journals (Sweden)

    Nynne Sharma

    2013-01-01

    Full Text Available DNA transposon-based vectors have emerged as new potential delivery tools in therapeutic gene transfer. Such vectors are now showing promise in hematopoietic stem cells and primary human T cells, and clinical trials with transposon-engineered cells are on the way. However, the use of plasmid DNA as a carrier of the vector raises safety concerns due to the undesirable administration of bacterial sequences. To optimize vectors based on the Sleeping Beauty (SB DNA transposon for clinical use, we examine here SB transposition from DNA minicircles (MCs devoid of the bacterial plasmid backbone. Potent DNA transposition, directed by the hyperactive SB100X transposase, is demonstrated from MC donors, and the stable transfection rate is significantly enhanced by expressing the SB100X transposase from MCs. The stable transfection rate is inversely related to the size of circular donor, suggesting that a MC-based SB transposition system benefits primarily from an increased cellular uptake and/or enhanced expression which can be observed with DNA MCs. DNA transposon and transposase MCs are easily produced, are favorable in size, do not carry irrelevant DNA, and are robust substrates for DNA transposition. In accordance, DNA MCs should become a standard source of DNA transposons not only in therapeutic settings but also in the daily use of the SB system.

  17. Circular codes revisited: a statistical approach.

    Science.gov (United States)

    Gonzalez, D L; Giannerini, S; Rosa, R

    2011-04-21

    In 1996 Arquès and Michel [1996. A complementary circular code in the protein coding genes. J. Theor. Biol. 182, 45-58] discovered the existence of a common circular code in eukaryote and prokaryote genomes. Since then, circular code theory has provoked great interest and underwent a rapid development. In this paper we discuss some theoretical issues related to the synchronization properties of coding sequences and circular codes with particular emphasis on the problem of retrieval and maintenance of the reading frame. Motivated by the theoretical discussion, we adopt a rigorous statistical approach in order to try to answer different questions. First, we investigate the covering capability of the whole class of 216 self-complementary, C(3) maximal codes with respect to a large set of coding sequences. The results indicate that, on average, the code proposed by Arquès and Michel has the best covering capability but, still, there exists a great variability among sequences. Second, we focus on such code and explore the role played by the proportion of the bases by means of a hierarchy of permutation tests. The results show the existence of a sort of optimization mechanism such that coding sequences are tailored as to maximize or minimize the coverage of circular codes on specific reading frames. Such optimization clearly relates the function of circular codes with reading frame synchronization. Copyright © 2011 Elsevier Ltd. All rights reserved.

  18. Diverse circular replication-associated protein encoding viruses circulating in invertebrates within a lake ecosystem.

    Science.gov (United States)

    Dayaram, Anisha; Galatowitsch, Mark L; Argüello-Astorga, Gerardo R; van Bysterveldt, Katherine; Kraberger, Simona; Stainton, Daisy; Harding, Jon S; Roumagnac, Philippe; Martin, Darren P; Lefeuvre, Pierre; Varsani, Arvind

    2016-04-01

    Over the last five years next-generation sequencing has become a cost effective and efficient method for identifying known and unknown microorganisms. Access to this technique has dramatically changed the field of virology, enabling a wide range of environmental viral metagenome studies to be undertaken of organisms and environmental samples from polar to tropical regions. These studies have led to the discovery of hundreds of highly divergent single stranded DNA (ssDNA) virus-like sequences encoding replication-associated proteins. Yet, few studies have explored how viruses might be shared in an ecosystem through feeding relationships. Here we identify 169 circular molecules (160 CRESS DNA molecules, nine circular molecules) recovered from a New Zealand freshwater lake, that we have tentatively classified into 51 putatively novel species and five previously described species (DflaCV-3, -5, -6, -8, -10). The CRESS DNA viruses identified in this study were recovered from molluscs (Echyridella menzeisii, Musculium novaezelandiae, Potamopyrgus antipodarum and Physella acuta) and insect larvae (Procordulia grayi, Xanthocnemis zealandica, and Chironomus zealandicus) collected from Lake Sarah, as well as from the lake water and benthic sediments. Extensive diversity was observed across most CRESS DNA molecules recovered. The putative capsid protein of one viral species was found to be most similar to those of members of the Tombusviridae family, thus expanding the number of known RNA-DNA hybrid viruses in nature. We noted a strong association between the CRESS DNA viruses and circular molecules identified in the water and browser organisms (C. zealandicus, P. antipodarum and P. acuta), and between water sediments and undefended prey species (C. zealandicus). However, we were unable to find any significant correlation of viral assemblages to the potential feeding relationships of the host aquatic invertebrates. Copyright © 2016 Elsevier B.V. All rights reserved.

  19. Anti-sense expression of a metallopeptidase gene enhances nuclear entry of HBV-DNA

    International Nuclear Information System (INIS)

    Yeh, C.-T.; Lai, H.-Y.; Chu, S.-P.; Tseng, I-Chu

    2004-01-01

    Although several putative hepatitis B virus (HBV) receptors have been identified, none of them is capable of initiating HBV replication in a non-permissive human cell line. Using an Epstein-Barr virus-based extrachromosomal replication system, we have screened through a human liver cDNA library and successfully identified a clone capable of facilitating nuclear transport of HBV-DNA during the early phase of HBV infection. This clone contained a cDNA encoding a metallopeptidase-like protein in anti-sense orientation. Pretreatment of naive HepG2 cells with 1,10-phenanthroline, an inhibitor for liver metallopeptidases, led to nuclear entry of HBV-DNA after HBV infection. However, cccDNA was still undetectable in the nuclei, indicating other cellular factors required to complete the replication cycle were still missing. Our present data suggest that in the initial stage of HBV infection, liver metallopeptidase constitutes a barrier for effective nuclear entry of HBV genomic DNA. Attenuation of metallopeptidase activity may facilitate HBV infection

  20. Cygnus X-1: Discovery of variable circular polarization

    International Nuclear Information System (INIS)

    Michalsky, J.J.; Swedlund, J.B.; Stokes, R.A.

    1975-01-01

    HDE 226868, the optical counterpart of Cyg X-1, has been observed for circular polarization during 1974. Observations in five colors suggest that circular polarization results from an interstellar effect. Measurements of the blue polarization reveal circular polarization variations synchronous with the 5)./sub /6 orbital period. The circular polarization variation appears to be similar to the blue intensity variation

  1. Intrinsically bent DNA in replication origins and gene promoters.

    Science.gov (United States)

    Gimenes, F; Takeda, K I; Fiorini, A; Gouveia, F S; Fernandez, M A

    2008-06-24

    Intrinsically bent DNA is an alternative conformation of the DNA molecule caused by the presence of dA/dT tracts, 2 to 6 bp long, in a helical turn phase DNA or with multiple intervals of 10 to 11 bp. Other than flexibility, intrinsic bending sites induce DNA curvature in particular chromosome regions such as replication origins and promoters. Intrinsically bent DNA sites are important in initiating DNA replication, and are sometimes found near to regions associated with the nuclear matrix. Many methods have been developed to localize bent sites, for example, circular permutation, computational analysis, and atomic force microscopy. This review discusses intrinsically bent DNA sites associated with replication origins and gene promoter regions in prokaryote and eukaryote cells. We also describe methods for identifying bent DNA sites for circular permutation and computational analysis.

  2. Total and Differential Efficiencies for a Circular Detector Viewing a Circular Radiator of Finite Thickness

    Energy Technology Data Exchange (ETDEWEB)

    Lauber, A; Tollander, B

    1967-08-15

    Total and differential detection efficiencies have been computed for a circular detector viewing a circular radiator of finite thickness. Isotropic, cosines and n-p scattering angular emission distributions of the radiated particles are considered. Tables are given for the total efficiencies as well as for the differential efficiencies in the n-p scattering case.

  3. Bright circularly polarized soft X-ray high harmonics for X-ray magnetic circular dichroism.

    Science.gov (United States)

    Fan, Tingting; Grychtol, Patrik; Knut, Ronny; Hernández-García, Carlos; Hickstein, Daniel D; Zusin, Dmitriy; Gentry, Christian; Dollar, Franklin J; Mancuso, Christopher A; Hogle, Craig W; Kfir, Ofer; Legut, Dominik; Carva, Karel; Ellis, Jennifer L; Dorney, Kevin M; Chen, Cong; Shpyrko, Oleg G; Fullerton, Eric E; Cohen, Oren; Oppeneer, Peter M; Milošević, Dejan B; Becker, Andreas; Jaroń-Becker, Agnieszka A; Popmintchev, Tenio; Murnane, Margaret M; Kapteyn, Henry C

    2015-11-17

    We demonstrate, to our knowledge, the first bright circularly polarized high-harmonic beams in the soft X-ray region of the electromagnetic spectrum, and use them to implement X-ray magnetic circular dichroism measurements in a tabletop-scale setup. Using counterrotating circularly polarized laser fields at 1.3 and 0.79 µm, we generate circularly polarized harmonics with photon energies exceeding 160 eV. The harmonic spectra emerge as a sequence of closely spaced pairs of left and right circularly polarized peaks, with energies determined by conservation of energy and spin angular momentum. We explain the single-atom and macroscopic physics by identifying the dominant electron quantum trajectories and optimal phase-matching conditions. The first advanced phase-matched propagation simulations for circularly polarized harmonics reveal the influence of the finite phase-matching temporal window on the spectrum, as well as the unique polarization-shaped attosecond pulse train. Finally, we use, to our knowledge, the first tabletop X-ray magnetic circular dichroism measurements at the N4,5 absorption edges of Gd to validate the high degree of circularity, brightness, and stability of this light source. These results demonstrate the feasibility of manipulating the polarization, spectrum, and temporal shape of high harmonics in the soft X-ray region by manipulating the driving laser waveform.

  4. Environmental issues elimination through circular economy

    International Nuclear Information System (INIS)

    Špirková, M.; Pokorná, E.; Šujanová, J.; Samáková, J.

    2016-01-01

    Environmental efforts of European Union are currently going towards circular economy. Tools like Extended Producer Responsibility and Eco-design were established. The circular economy deals with resources availability issue on one hand and waste management on the other hand. There are few pioneering companies all over the world with some kind of circular economy practice. Generally the concept is not very wide-spread. The paper aims to evaluate possibility of transition towards circular economy in Slovak industrial companies. They need to have an active approach to material treatment of their products after usage stage. Innovation is another important pre-condition for the transition. Main problem of current cradle to grave system is landfilling of valuable materials after one cycle of usage. Their potential value for next manufacturing cycles is lost. Companies may do not see connection between waste management and material resource prices and volatility of supplies. Municipalities are responsible for municipal waste collection and treatment in Slovakia. The circular economy operates by cradle to cradle principle. Company manages material flow until the material comes back to the beginning of manufacturing process by itself or by another partners. Stable material supplies with quite low costs are provided this way. It is necessary to deal with environmental problems in phase of product design. Questionnaire survey results show on one hand low involvement of industrial companies in waste management area, however on the other hand they are open to environmental innovations in future.

  5. Environmental issues elimination through circular economy

    Energy Technology Data Exchange (ETDEWEB)

    Špirková, M., E-mail: marta.spirkova@stuba.sk; Pokorná, E.; Šujanová, J.; Samáková, J. [Paulínska 16, 917 24 Trnava, Slovakia, Slovak University of Technology in Bratislava, Faculty of Materials Science and Technology in Trnava (Slovakia)

    2016-04-21

    Environmental efforts of European Union are currently going towards circular economy. Tools like Extended Producer Responsibility and Eco-design were established. The circular economy deals with resources availability issue on one hand and waste management on the other hand. There are few pioneering companies all over the world with some kind of circular economy practice. Generally the concept is not very wide-spread. The paper aims to evaluate possibility of transition towards circular economy in Slovak industrial companies. They need to have an active approach to material treatment of their products after usage stage. Innovation is another important pre-condition for the transition. Main problem of current cradle to grave system is landfilling of valuable materials after one cycle of usage. Their potential value for next manufacturing cycles is lost. Companies may do not see connection between waste management and material resource prices and volatility of supplies. Municipalities are responsible for municipal waste collection and treatment in Slovakia. The circular economy operates by cradle to cradle principle. Company manages material flow until the material comes back to the beginning of manufacturing process by itself or by another partners. Stable material supplies with quite low costs are provided this way. It is necessary to deal with environmental problems in phase of product design. Questionnaire survey results show on one hand low involvement of industrial companies in waste management area, however on the other hand they are open to environmental innovations in future.

  6. Environmental issues elimination through circular economy

    Science.gov (United States)

    Špirková, M.; Pokorná, E.; Šujanová, J.; Samáková, J.

    2016-04-01

    Environmental efforts of European Union are currently going towards circular economy. Tools like Extended Producer Responsibility and Eco-design were established. The circular economy deals with resources availability issue on one hand and waste management on the other hand. There are few pioneering companies all over the world with some kind of circular economy practice. Generally the concept is not very wide-spread. The paper aims to evaluate possibility of transition towards circular economy in Slovak industrial companies. They need to have an active approach to material treatment of their products after usage stage. Innovation is another important pre-condition for the transition. Main problem of current cradle to grave system is landfilling of valuable materials after one cycle of usage. Their potential value for next manufacturing cycles is lost. Companies may do not see connection between waste management and material resource prices and volatility of supplies. Municipalities are responsible for municipal waste collection and treatment in Slovakia. The circular economy operates by cradle to cradle principle. Company manages material flow until the material comes back to the beginning of manufacturing process by itself or by another partners. Stable material supplies with quite low costs are provided this way. It is necessary to deal with environmental problems in phase of product design. Questionnaire survey results show on one hand low involvement of industrial companies in waste management area, however on the other hand they are open to environmental innovations in future.

  7. Optics modules for circular accelerator design

    International Nuclear Information System (INIS)

    Brown, K.L.; Servranckx, R.V.

    1986-05-01

    The first-order differential equations of motion for a single particle in a closed circular machine are solved, introducing the concepts of phase shift, beta functions, and the Courant-Snyder invariant. The transfer matrix between two points in the machine is derived as a function of the phase shift and the parameters contained in the Courant-Snyder invariant. Typical optical modules used in circular machine designs are introduced and related to their characteristic transfer matrix elements, the phase shift through them, and the Courant-Snyder-Twiss parameters. The systematics of some elementary phase ellipse matching problems between optical modules are discussed. Second-order optical modules are discussed, including how they are used to provide the momentum bandwidth needed for the design of a typical circular machine

  8. Equatorial circular motion in Kerr spacetime

    International Nuclear Information System (INIS)

    Pugliese, Daniela; Quevedo, Hernando; Ruffini, Remo

    2011-01-01

    We analyze the properties of circular orbits of test particles on the equatorial plane of a rotating central mass whose gravitational field is described by the Kerr spacetime. For rotating black holes and naked singularities we explore all the spatial regions where circular orbits can exist and analyze the behavior of the energy and the angular momentum of the corresponding test particles. In particular, we find all the radii at which a test particle can have zero angular momentum due to the repulsive gravity effects generated by naked singularities. We classify all the stability zones of circular orbits. It is shown that the geometric structure of the stability zones of black holes is completely different from that of naked singularities.

  9. Circular economy and waste to energy

    Science.gov (United States)

    Rada, E. C.; Ragazzi, M.; Torretta, V.; Castagna, G.; Adami, L.; Cioca, L. I.

    2018-05-01

    Waste management in European Union has long being regulated by the 4Rs principle, i.e. reduction, reuse, recycling, recovery, with landfill disposal as the last option. This vision recently led the European Union (especially since 2015) to the introduction of virtuous goals based on the rejection of linear economy in favour of circular economy strongly founded on materials recovery. In this scenario, landfill disposal option will disappear, while energy recovery may appear controversial when not applied to biogas production from anaerobic digestion. The present work aims to analyse the effects that circular economy principles introduced in the European Union context will have on the thermochemical waste treatment plants design. Results demonstrate that indirect combustion (gasification + combustion) along with integrated vitrification of the non-combustible fraction of treated waste will have a more relevant role in the field of waste treatment than in the past, thanks to the compliance of this option with the principles of circular economy.

  10. METHOD OF CONJUGATED CIRCULAR ARCS TRACING

    Directory of Open Access Journals (Sweden)

    N. Ageyev Vladimir

    2017-01-01

    Full Text Available The geometric properties of conjugated circular arcs connecting two points on the plane with set directions of tan- gent vectors are studied in the work. It is shown that pairs of conjugated circular arcs with the same conditions in frontier points create one-parameter set of smooth curves tightly filling all the plane. One of the basic properties of this set is the fact that all coupling points of circular arcs are on the circular curve going through the initially given points. The circle radius depends on the direction of tangent vectors. Any point of the circle curve, named auxiliary in this work, determines a pair of conjugated arcs with given boundary conditions. One more condition of the auxiliary circle curve is that it divides the plane into two parts. The arcs going from the initial point are out of the circle limited by this circle curve and the arcs coming to the final point are inside it. These properties are the basis for the method of conjugated circular arcs tracing pro- posed in this article. The algorithm is rather simple and allows to fulfill all the needed plottings using only the divider and ruler. Two concrete examples are considered. The first one is related to the problem of tracing of a pair of conjugated arcs with the minimal curve jump when going through the coupling point. The second one demonstrates the possibility of trac- ing of the smooth curve going through any three points on the plane under condition that in the initial and final points the directions of tangent vectors are given. The proposed methods of conjugated circular arcs tracing can be applied in solving of a wide variety of problems connected with the tracing of cam contours, for example pattern curves in textile industry or in computer-aided-design systems when programming of looms with numeric control.

  11. Circular polarization memory in single Quantum Dots

    International Nuclear Information System (INIS)

    Khatsevich, S.; Poem, E.; Benny, Y.; Marderfeld, I.; Gershoni, D.; Badolato, A.; Petroff, P. M.

    2010-01-01

    Under quasi-resonant circularly polarized optical excitation, charged quantum dots may emit polarized light. We measured various transitions with either positive, negative or no circular-polarization memory. We explain these observations and quantitatively calculate the polarization spectrum. Our model use the full configuration-interaction method, including the electron-hole exchange interaction, for calculating the quantum dot's confined many-carrier states, along with one assumption regarding the spin relaxation of photoexcited carriers: Electrons maintain their initial spin polarization, while holes do not.

  12. Forced vibrations of rotating circular cylindrical shells

    International Nuclear Information System (INIS)

    Igawa, Hirotaka; Maruyama, Yoshiyuki; Endo, Mitsuru

    1995-01-01

    Forced vibrations of rotating circular cylindrical shells are investigated. Basic equations, including the effect of initial stress due to rotation, are formulated by the finite-element method. The characteristic relations for finite elements are derived from the energy principle by considering the finite strain. The equations of motion can be separated into quasi-static and dynamic ones, i.e., the equations in the steady rotating state and those in the vibration state. Radial concentrated impulses are considered as the external dynamic force. The transient responses of circular cylindrical shells are numerically calculated under various boundary conditions and rotating speeds. (author)

  13. Circularly polarized luminescence of syndiotactic polystyrene

    Science.gov (United States)

    Rizzo, Paola; Abbate, Sergio; Longhi, Giovanna; Guerra, Gaetano

    2017-11-01

    Syndiotactic polystyrene (s-PS) films, when crystallized from the amorphous state by temporary sorption of non-racemic guest molecules (like carvone) not only exhibit unusually high optical activity, both in the UV-Visible and Infrared ranges, but also present circularly polarized luminescence (CPL) with high dissymmetry ratios (g = ΔI/I values in the range 0.02-0.03). Experimental evidences provide support, rather than to the usual molecular circular dichroism, to a supramolecular chiral optical response being extrinsic to the site of photon absorption and emission, possibly associated with a helical morphology of s-PS crystallites.

  14. DNA binding studies of tartrazine food additive.

    Science.gov (United States)

    Kashanian, Soheila; Zeidali, Sahar Heidary

    2011-07-01

    The interaction of native calf thymus DNA with tartrazine in 10 mM Tris-HCl aqueous solution at neutral pH 7.4 was investigated. Tartrazine is a nitrous derivative and may cause allergic reactions, with a potential of toxicological risk. Also, tartrazine induces oxidative stress and DNA damage. Its DNA binding properties were studied by UV-vis and circular dichroism spectra, competitive binding with Hoechst 33258, and viscosity measurements. Tartrazine molecules bind to DNA via groove mode as illustrated by hyperchromism in the UV absorption band of tartrazine, decrease in Hoechst-DNA solution fluorescence, unchanged viscosity of DNA, and conformational changes such as conversion from B-like to C-like in the circular dichroism spectra of DNA. The binding constants (K(b)) of DNA with tartrazine were calculated at different temperatures. Enthalpy and entropy changes were calculated to be +37 and +213 kJ mol(-1), respectively, according to the Van't Hoff equation, which indicated that the reaction is predominantly entropically driven. Also, tartrazine does not cleave plasmid DNA. Tartrazine interacts with calf thymus DNA via a groove interaction mode with an intrinsic binding constant of 3.75 × 10(4) M(-1).

  15. Radicals of DNA and DNA nucleotides generated by ionising radiation

    International Nuclear Information System (INIS)

    Przybytniak, G.

    2004-01-01

    A first stage of cell processes leading to DNA damage of initiated by radical reactions. In a model system such transformations were generated by ionising radiation which involves production of electron loss and electron gain centers of the substrate and radical formation. Using cryogenic ESR spectroscopy it was found that the DNA nucleotides, which convert to radical anions upon electron capture undergo the separation of unpaired spin and charge due to protonation. Circular and linear dichroism studies enabled to conclude that iron ions(III) induce strong changes in the DNA helical structure indicating their coordination with nitrogen bases. The repair of DNA radicals produced via radiolytic oxidation, i.e. the guanine radical cation and the allyl type radical of thymine, is possible at elevated temperatures due to the involvement of sulphydryl groups. The influence of the thiol charge is then limited

  16. Circular arc snakes and kinematic surface generation

    KAUST Repository

    Barton, Michael; Shi, Ling; Kilian, Martin; Wallner, Johannes; Pottmann, Helmut

    2013-01-01

    of circular arcs is well suited for such purposes, and allows us to reduce evolution of curves to the evolution of a control point collection in a certain finite-dimensional shape space. We approach this evolution by a 2-step process: linearized evolution via

  17. Symmetric Circular Matchings and RNA Folding

    DEFF Research Database (Denmark)

    Hofacker, Ivo L.; Reidys, Christian; Stadler, Peter F.

    2012-01-01

    RNA secondary structures can be computed as optimal solutions of certain circular matching problems. An accurate treatment of this energy minimization problem has to account for the small --- but non-negligible --- entropic destabilization of secondary structures with non-trivial automorphisms. S...

  18. Solid angle subtended by two circular discs

    International Nuclear Information System (INIS)

    Gilly, Louis.

    1978-09-01

    Methods of calculation of solid angles, subtended by two circular discs are analysed. Calculus are methodically classified as follow: series development Legendre polynomes, defined integral, elliptic integrals, Bessel integrals, multiple integrals, Monte Carlo method, electrostatic analogy. Applications in Nuclear Physics are added as examples. List of numeric tables completes bibliography [fr

  19. Stability analysis of cylinders with circular cutouts

    Science.gov (United States)

    Almroth, B. O.; Brogan, F. A.; Marlowe, M. B.

    1973-01-01

    The stability of axially compressed cylinders with circular cutouts is analyzed numerically. An extension of the finite-difference method is used which removes the requirement that displacement components be defined in the directions of the grid lines. The results of this nonlinear analysis are found to be in good agreement with earlier experimental results.

  20. Institutional incentives in circular economy transition

    NARCIS (Netherlands)

    Fischer, Aglaia; Pascucci, Stefano

    2017-01-01

    The aim of this paper is to gain insight into how requirements for transitioning to circular economy creates new organizational forms in inter-firm collaborations, and ultimately how they stimulate the emergence of new institutions enhancing sustainability. Two strands of literature, one on

  1. Beam Dynamics and Beam Losses - Circular Machines

    CERN Document Server

    Kain, V

    2016-01-01

    A basic introduction to transverse and longitudinal beam dynamics as well as the most relevant beam loss mechanisms in circular machines will be presented in this lecture. This lecture is intended for physicists and engineers with little or no knowledge of this subject.

  2. Shear stresses around circular cylindrical openings

    NARCIS (Netherlands)

    Hoogenboom, P.C.J.; Van Weelden, C.; Blom, C.M.B.

    2010-01-01

    In this paper stress concentrations are studied around circular cylindrical openings or voids in a linear elastic continuum. The loading is such that a uniform shear stress occurs in the continuum, which is disturbed by the opening. The shear stress is in the direction of the centre axis of the

  3. Magnetohydrodynamic flow past a circular cylinder

    International Nuclear Information System (INIS)

    Swarup, S.; Sinha, P.C.

    1977-01-01

    This paper deals with the slow-flow problem of an incompressible, viscous, electrically conducting fluid past a circular cylinder in an alignment magnetic field. The solutions for the velocity and magnetic fields as sought by the method of matched asymptotic expansions under the assumptions R,Rsub(m) 2 ) and O(R/log M), respectively. (Auth.)

  4. Photoexcitation circular dichroism in chiral molecules

    Science.gov (United States)

    Beaulieu, S.; Comby, A.; Descamps, D.; Fabre, B.; Garcia, G. A.; Géneaux, R.; Harvey, A. G.; Légaré, F.; Mašín, Z.; Nahon, L.; Ordonez, A. F.; Petit, S.; Pons, B.; Mairesse, Y.; Smirnova, O.; Blanchet, V.

    2018-05-01

    Chiral effects appear in a wide variety of natural phenomena and are of fundamental importance in science, from particle physics to metamaterials. The standard technique of chiral discrimination—photoabsorption circular dichroism—relies on the magnetic properties of a chiral medium and yields an extremely weak chiral response. Here, we propose and demonstrate an orders of magnitude more sensitive type of circular dichroism in neutral molecules: photoexcitation circular dichroism. This technique does not rely on weak magnetic effects, but takes advantage of the coherent helical motion of bound electrons excited by ultrashort circularly polarized light. It results in an ultrafast chiral response and the efficient excitation of a macroscopic chiral density in an initially isotropic ensemble of randomly oriented chiral molecules. We probe this excitation using linearly polarized laser pulses, without the aid of further chiral interactions. Our time-resolved study of vibronic chiral dynamics opens a way to the efficient initiation, control and monitoring of chiral chemical change in neutral molecules at the level of electrons.

  5. Time can't be circular

    CERN Multimedia

    2003-01-01

    "Delivering the Albert Einstein lecture at the Centre for Philosophy and Foundations of Science on Tuesday, Nobel Laureate Professor Gerard Hooft said that any notion of time can not be circular or have loops or multi dimensionality" (1/2 page).

  6. 76 FR 60590 - Environmental Justice; Proposed Circular

    Science.gov (United States)

    2011-09-29

    ... oral presentations about the two proposed Circulars and allow attendees an opportunity to ask... of the comfort and safety of all attendees and the maximum seating capacity of meeting rooms, FTA... and non-traditional media, as well as digital media. Additional strategies to increase involvement of...

  7. 78 FR 14620 - Joint Development: Proposed Circular

    Science.gov (United States)

    2013-03-06

    ... development. This circular provides guidance to recipients of Federal Transit Administration (FTA) financial... of opportunities for private sector participation in public transportation projects, and includes the... ``value capture'' mechanisms, such as income derived from rental or lease payments, and private sector...

  8. Circular symmetry in topologically massive gravity

    International Nuclear Information System (INIS)

    Deser, S; Franklin, J

    2010-01-01

    We re-derive, compactly, a topologically massive gravity (TMG) decoupling theorem: source-free TMG separates into its Einstein and Cotton sectors for spaces with a hypersurface-orthogonal Killing vector, here concretely for circular symmetry. We then generalize the theorem to include matter; surprisingly, the single Killing symmetry also forces conformal invariance, requiring the sources to be null. (note)

  9. NOTE: Circular symmetry in topologically massive gravity

    Science.gov (United States)

    Deser, S.; Franklin, J.

    2010-05-01

    We re-derive, compactly, a topologically massive gravity (TMG) decoupling theorem: source-free TMG separates into its Einstein and Cotton sectors for spaces with a hypersurface-orthogonal Killing vector, here concretely for circular symmetry. We then generalize the theorem to include matter; surprisingly, the single Killing symmetry also forces conformal invariance, requiring the sources to be null.

  10. Circular symmetry in topologically massive gravity

    Energy Technology Data Exchange (ETDEWEB)

    Deser, S [Physics Department, Brandeis University, Waltham, MA 02454 (United States); Franklin, J, E-mail: deser@brandeis.ed, E-mail: jfrankli@reed.ed [Reed College, Portland, OR 97202 (United States)

    2010-05-21

    We re-derive, compactly, a topologically massive gravity (TMG) decoupling theorem: source-free TMG separates into its Einstein and Cotton sectors for spaces with a hypersurface-orthogonal Killing vector, here concretely for circular symmetry. We then generalize the theorem to include matter; surprisingly, the single Killing symmetry also forces conformal invariance, requiring the sources to be null. (note)

  11. Periodic Solutions for Circular Restricted -Body Problems

    Directory of Open Access Journals (Sweden)

    Xiaoxiao Zhao

    2013-01-01

    Full Text Available For circular restricted -body problems, we study the motion of a sufficiently small mass point (called the zero mass point in the plane of equal masses located at the vertices of a regular polygon. By using variational minimizing methods, for some , we prove the existence of the noncollision periodic solution for the zero mass point with some fixed wingding number.

  12. Administrative Circular n° 12

    CERN Document Server

    2005-01-01

    Following a recommendation by the Standing Concertation Committee, the Director-General has approved the amounts used for the reimbursements mentioned in Administrative Circular N° 12 as follows : The figures, effective from 1 September 2005, are : § 8a : 16.50 Swiss francs § 9a : 662 Swiss francs § 9b : 33 Swiss francs

  13. the mathematics of ghanaian circular musical drumheads

    African Journals Online (AJOL)

    User

    overtones. INTRODUCTION. The mathematics of percussion drums and other musical instruments has been delved into by lots of researchers tackling it from different angles, and especially for circular drumheads with constant tension. Such drums include the conga which usually produces rhythmic sounds. But little or no ...

  14. Home Sewage Disposal. Special Circular 212.

    Science.gov (United States)

    Wooding, N. Henry

    This circular provides current information for homeowners who must repair or replace existing on-lot sewage disposal systems. Site requirements, characteristics and preparation are outlined for a variety of alternatives such as elevated sand mounds, sand-lined beds and trenches, and oversized absorption area. Diagrams indicating construction…

  15. Breaking the Barriers to the Circular Economy

    NARCIS (Netherlands)

    Kirchherr, J.W.; Hekkert, M.P.; Bour, Ruben; Huijbrechtse-Truijens, Anne; Kostense-Smit, Erica; Muller, Jennifer

    2017-01-01

    The Copernicus Institute of Sustainable Development, Utrecht University, the Netherlands and Deloitte have jointly carried out research on barriers to the Circular Economy (CE) in the European Union. For this research, a survey with 153 businesses, 55 government officials and expert interviews with

  16. Falling aprons at circular piers under currents

    NARCIS (Netherlands)

    De Sonneville, B.; Van Velzen, G.; Verheij, H.J.; Dorst, K.

    2012-01-01

    Traditional guidelines on rock protection at circular piers predominantly focus on preventing shear failure (by choosing a sufficiently large rock size), winnowing failure (by designing an appropriate filter) and edge failure (by selecting a sufficient extent). In particular areas (e.g. in an

  17. Visualizing Single-molecule DNA Replication with Fluorescence Microscopy

    NARCIS (Netherlands)

    Tanner, Nathan A.; Loparo, Joseph J.; Oijen, Antoine M. van

    2009-01-01

    We describe a simple fluorescence microscopy-based real-time method for observing DNA replication at the single-molecule level. A circular, forked DNA template is attached to a functionalized glass coverslip and replicated extensively after introduction of replication proteins and nucleotides. The

  18. Porcine circovirus: transcription and rolling-circle DNA replication

    Science.gov (United States)

    This review summarizes the molecular studies pertaining to porcine circovirus (PCV) transcription and DNA replication. The genome of PCV is circular, single-stranded DNA and contains 1759-1768 nucleotides. Both the genome-strand (packaged in the virus particle) and the complementary-strand (synthesi...

  19. Solid Angle Computations for a Circular Radiator and a Circular Detector

    Energy Technology Data Exchange (ETDEWEB)

    Konijn, J; Tollander, B

    1963-02-15

    The problem of particle detection, when using an isotropic neutron point source at different distances from a circular target or a radioactive source as seen by a circular detector, e. g. a solid state counter, is dealt with. Tables are given for different distances of the source when the reaction at the target has an isotropic or a cosine angular distribution in the laboratory system.

  20. Advisory Circular checklist and status of other FAA publications

    Science.gov (United States)

    1997-08-15

    This 1997 circular transmits the revised checklist of the Federal Aviation : Administration's (FAA) Advisory Circulars (AC's). It also lists certain other : FAA publications sold by the Superintendent of Documents.

  1. Development pattern of circular economy in Jiangsu coastland

    OpenAIRE

    Wang, Liang

    2009-01-01

    Circular economy is an effective development pattern to balance economic growth, social development and environmental protection. Based on apprehending the connotation of circular economy, this paper fully considers and studies on the future trends in this area according to the theory of circular economy and the empirical circumstances of Jiangsu Coastland. This paper also discusses the circular economy development pattern adopted by Jiangsu coastland during economic and social development fr...

  2. A product design framework for a circular economy

    NARCIS (Netherlands)

    Van den Berg, M.R.; Bakker, C.A.

    2015-01-01

    The paper provides a circular economy framework from a product design perspective with tools to aid product designers in applying circular product design in practice. Design research for circular economy has so far mainly been limited to referring to existing fields of research such as design for

  3. 12 CFR 563g.8 - Use of the offering circular.

    Science.gov (United States)

    2010-01-01

    ... 12 Banks and Banking 5 2010-01-01 2010-01-01 false Use of the offering circular. 563g.8 Section 563g.8 Banks and Banking OFFICE OF THRIFT SUPERVISION, DEPARTMENT OF THE TREASURY SECURITIES OFFERINGS § 563g.8 Use of the offering circular. (a) An offering circular or amendment declared effective by the...

  4. Photoinduced Circular Anisotropy in Side-Chain Azobenzene Polyesters

    DEFF Research Database (Denmark)

    Nikolova, L.; Todorov, T.; Ivanov, M.

    1997-01-01

    We report for the first time the inducing of large circular anisotropy in previously unoriented films of side-chain azobenzene polyesters on illumination with circularly polarized light at a wavelength of 488 nm. The circular dichroism and optical activity are measured simultaneously in real time...

  5. The Circular Economy: In Practice-focused Undergraduate Engineering Education

    DEFF Research Database (Denmark)

    Knudby, Torben; Larsen, Samuel

    2017-01-01

    The growth of the planet’s population makes the traditional industrial model of “take, make and waste” unsustainable. The circular economy, in which resources are continuously reused, offers a solution. For manufacturers of durable goods the circular economy requires a well-functioning circular...

  6. DNA polymerase. beta. reaction with ultraviolet-irradiated DNA incised by correndonuclease

    Energy Technology Data Exchange (ETDEWEB)

    Nowak, R; Zarebska, Z [Instytut Onkologii, Warsaw (Poland); Zmudzka, B [Polska Akademia Nauk, Warsaw. Inst. Biochemii i Biofizyki

    1980-09-19

    Covalently closed circular Col E1 DNA was ultraviolet-irradiated with a dose of 60 J/m/sup 2/, thus introducing about 3.2 pyrimidine dimers per DNA molecule. Treatment of irradiated Col E1 DNA with Micrococcus luteus correndonuclease resulted, in the vicinity of pyrimidine dimers, in an average of 3.3 incisions per DNA molecule, and converted DNA to the open circular form. Incised Col E1 DNA stimulated no reaction with calf thymus DNA polymerase ..cap alpha.. but was recognized as a template by DNA polymerase ..beta... The latter enzyme incorporated about 1.6 molecules of dTMP (corresponding to 6 molecules of dNMP) per one correndonuclease incision. The length of the DNA polymerase ..beta.. product was comparable to the anticipated length of the DNA region within which the hydrogen bonds were disrupted owing to dimer formation. The enzyme required Mg/sup 2 +/ and four dNTPs for reaction and was resistant to N-ethylmaleimide or p-mercuribenzoate.

  7. Simulation of car movement along circular path

    Science.gov (United States)

    Fedotov, A. I.; Tikhov-Tinnikov, D. A.; Ovchinnikova, N. I.; Lysenko, A. V.

    2017-10-01

    Under operating conditions, suspension system performance changes which negatively affects vehicle stability and handling. The paper aims to simulate the impact of changes in suspension system performance on vehicle stability and handling. Methods. The paper describes monitoring of suspension system performance, testing of vehicle stability and handling, analyzes methods of suspension system performance monitoring under operating conditions. The mathematical model of a car movement along a circular path was developed. Mathematical tools describing a circular movement of a vehicle along a horizontal road were developed. Turning car movements were simulated. Calculation and experiment results were compared. Simulation proves the applicability of a mathematical model for assessment of the impact of suspension system performance on vehicle stability and handling.

  8. Behaviour of a stiffened circular slab

    International Nuclear Information System (INIS)

    Kulkarni, M.G.; Subramanian, K.V.

    1975-01-01

    Configuration of intake structure for cooling water system for Madras Atomic Power Project was studied on a hydraulic model and it was recommended to provide a circular slab in the structure to give directional property to the inflow and reduce air entrainment. This slab, as indicated by hydraulic model tests was required to withstand hydrodynamic pressures of the order of 10T/m 2 due to breaking waves of about 6 m height. Analysis of this circular cover slab, Stiffened by radial and circumferential beams, carried with the help of an analysis based on grid idealisation is presented. Results of approximate design analysis to assess behaviour of radial stiffener have been compared. Actual design is based on judgement of actual degree of fixity possessed by the supports or restraints. (author)

  9. Design of circular differential microphone arrays

    CERN Document Server

    Benesty, Jacob; Cohen, Israel

    2015-01-01

    Recently, we proposed a completely novel and efficient way to design differential beamforming algorithms for linear microphone arrays. Thanks to this very flexible approach, any order of differential arrays can be designed. Moreover, they can be made robust against white noise amplification, which is the main inconvenience in these types of arrays. The other well-known problem with linear arrays is that electronic steering is not really feasible.  In this book, we extend all these fundamental ideas to circular microphone arrays and show that we can design small and compact differential arrays of any order that can be electronically steered in many different directions and offer a good degree of control of the white noise amplification problem, high directional gain, and frequency-independent response. We also present a number of practical examples, demonstrating that differential beamforming with circular microphone arrays is likely one of the best candidates for applications involving speech enhancement (i....

  10. Injection and extraction techniques in circular accelerators

    International Nuclear Information System (INIS)

    Tang Jingyu

    2008-01-01

    Injection and extraction are usually the key systems in circular accelerators. They play important roles in transferring the beam from one stage acceleration to the other or to experimental stations. It is also in the injection and extraction regions where beam losses happen mostly. Due to the tight space and to reduce the perturbation to the circulating orbit, the devices are usually designed to meet special requirements such as compactness, small stray field, fast rise time or fall time, etc. Usual injection and extraction devices include septum magnets, kicker magnets, electrostatic deflectors, slow bump magnets and strippers. In spite of different accelerators and specification for the injection and extraction devices, many techniques are shared in the design and manufacturing. This paper gives a general review on the techniques employed in the major circular accelerators in China. (authors)

  11. Introduction to transfer lines and circular machines

    International Nuclear Information System (INIS)

    Bryant, P.J.

    1984-01-01

    This course was given in the 1983-84 Academic Training Programme. It is designed as an elementary introduction to both the theory and the hardware for transfer lines and circular machines. The course is limited to linear problems and treates the topics of single particle motion in the transverse and longitudinal planes, emittance ellipses, parameterisation, optical properties of some specific modules, stabilities in the transverse and longitudinal planes, field and gradient errors, and scattering in thin windows. (orig.)

  12. Notas sobre una escuela circular prefabricada

    Directory of Open Access Journals (Sweden)

    Neutra, Richard J.

    1961-09-01

    Full Text Available En 1930, la idea de una planta circular para escuela, abarcando un espacio exterior frente a un edificio de usos varios, era ya antigua por lo menos en diez años. El Museo de Arte Moderno de Nueva York, que por aquellos tiempos instaló y preparó en sus nuevas dependencias la primera exposición masiva de Arquitectura moderna, dispuso una magnífica maqueta de este proyecto de Richard J. Neutra.

  13. Vibration of circular bladed disk with imperfections

    Czech Academy of Sciences Publication Activity Database

    Půst, Ladislav; Pešek, Luděk

    2011-01-01

    Roč. 21, č. 10 (2011), s. 2893-2904 ISSN 0218-1274 R&D Projects: GA ČR GA101/09/1166 Institutional research plan: CEZ:AV0Z20760514 Keywords : circular bladed disk * vibration * imperfection * nonlinear damping Subject RIV: BI - Acoustics Impact factor: 0.755, year: 2011 http://www.worldscinet.com/ijbc/21/2110/S0218127411030210.html

  14. Circular Intensity Differential Scattering of chiral molecules

    Energy Technology Data Exchange (ETDEWEB)

    Bustamante, C.J.

    1980-12-01

    In this thesis a theory of the Circular Intensity Differential Scattering (CIDS) of chiral molecules as modelled by a helix oriented with respect to the direction of incidence of light is presented. It is shown that a necessary condition for the existence of CIDS is the presence of an asymmetric polarizability in the scatterer. The polarizability of the scatterer is assumed generally complex, so that both refractive and absorptive phenomena are taken into account.

  15. Self-organization in circular shear layers

    DEFF Research Database (Denmark)

    Bergeron, K.; Coutsias, E.A.; Lynov, Jens-Peter

    1996-01-01

    Experiments on forced circular shear layers performed in both magnetized plasmas and in rotating fluids reveal qualitatively similar self-organization processes leading to the formation of patterns of coherent vortical structures with varying complexity. In this paper results are presented from...... both weakly nonlinear analysis and full numerical simulations that closely reproduce the experimental observations. Varying the Reynolds number leads to bifurcation sequences accompanied by topological changes in the distribution of the coherent structures as well as clear transitions in the total...

  16. Magnetic circular dichroism in electron microscopy

    Czech Academy of Sciences Publication Activity Database

    Rusz, Ján; Novák, Pavel; Rubino, S.; Hébert, C.; Schattschneider, P.

    2008-01-01

    Roč. 113, č. 1 (2008), s. 599-604 ISSN 0587-4246. [CSMAG'07. Košice, 09.07.2007-12.07.2007] EU Projects: European Commission(XE) 508971 - CHIRALTEM Institutional research plan: CEZ:AV0Z10100521 Keywords : magnetic circular dichroism * electron microscopy Subject RIV: BM - Solid Matter Physics ; Magnetism Impact factor: 0.321, year: 2008

  17. How to Assess Product Performance in the Circular Economy? Proposed Requirements for the Design of a Circularity Measurement Framework

    OpenAIRE

    Saidani , Michael; YANNOU , Bernard; Leroy , Yann; Cluzel , François

    2017-01-01

    International audience; Assessing product circularity performance is not straightforward. Meanwhile, it gains increasingly importance for businesses and industrial practitioners who are willing to effectively take benefits from circular economy promises. Thus, providing methods and tools to evaluate then enhance product performance—in the light of circular economy—becomes a significant but still barely addressed topic. Following a joint agreement on the need to measure product circularity per...

  18. FROM CIRCULAR ECONOMY TO BLUE ECONOMY

    Directory of Open Access Journals (Sweden)

    Iustin-Emanuel, ALEXANDRU

    2014-11-01

    Full Text Available Addressing the subject of this essay is based on the background ideas generated by a new branch of science - Biomimicry. According to European Commissioner for the Environment, "Nature is the perfect model of circular economy". Therefore, by imitating nature, we are witnessing a process of cycle redesign: production-consumption-recycling. The authors present some reflections on the European Commission's decision to adopt after July 1, 2014 new measures concerning the development of more circular economies. Starting from the principles of Ecolonomy, which is based on the whole living paradigm, this paper argues for the development within each economy of entrepreneurial policies related to the Blue economy. In its turn, Blue economy is based on scientific analyses that identify the best solutions in a business. Thus, formation of social capital will lead to healthier and cheaper products, which will stimulate entrepreneurship. Blue economy is another way of thinking economic practice and is a new model of business design. It is a healthy, sustainable business, designed for people. In fact, it is the core of the whole living paradigm through which, towards 2020, circular economy will grow more and more.

  19. Circular induction accelerator for borehole logging

    International Nuclear Information System (INIS)

    Chen, F.K.; Bertozzi, W.; Corris, G.W.; Diamond, W.; Doucet, J.A.; Schweitzer, J.S.

    1992-01-01

    This patent describes a downhole logging sonde adapted to be moved through a borehole, a source of gamma rays in the sonde for irradiating earth formations traversed by the borehole, one or more gamma ray detectors for detecting gamma rays scattered back to the sonde from the irradiated earth formations, and means for transmitting signals representative of the detected gamma rays to the earth's surface for processing. This patent describes improvement in the gamma ray source comprises a magnetic induction particle accelerator, including: a magnetic circuit having a field magnet, generally circular opposed pole pieces, and a core magnet metal ions from the group consisting of Mn, Zn and Ni; an excitation circuit including a field coil surrounding the field magnet and the core magnet and a core coil surrounding the central axially leg of the core magnet; an annular acceleration chamber interposed between the pole pieces; means for applying time-varying acceleration voltage pulses across the primary excitation circuit; means for injecting charged particles into orbit within the acceleration chamber; means for compressing the particle orbits to trap particles within generally circular orbits within the acceleration chamber; means for generating a particle accelerating magnetic flux in the magnetic circuit; and means for ejecting charged particles from the generally circular orbits and into contact with a target to produce gamma ray photons

  20. Development of circular filters for active facilities

    International Nuclear Information System (INIS)

    Pratt, R.P.

    1986-01-01

    An assessment of problems associated with remote handling, changing and disposal of filters suggested that significant improvements to filtration systems could be made if circular geometries were adopted in place of conventional systems. Improved systems have been developed and are now available for a range of applications and air flow rates. Where primary filters are installed within the active cell or cave, circular filters incorporating a lip seal have been developed which enable the filters to be sealed into the facility without recourse to clamping. For smaller cells, a range of push-through filter change systems have been developed, the principal feature being that the filter is passed into the housing from the clean side, but transferred from the housing directly into the cell for subsequent disposal. For plant room applications, circular bag change canister systems have been developed which ease the sealing and bag change operation. Such systems have a rated air flow of up to 3000 m 3 /h whilst still allowing ultimate disposal via the 200 litre waste drum route without prior volume reduction of the filter inserts. (author)

  1. Application of circular polarized synchrotron radiation

    International Nuclear Information System (INIS)

    Miyahara, Tsuneaki; Kawata, Hiroshi

    1988-03-01

    The idea of using the polarizing property of light for physical experiment by controlling it variously has been known from old time, and the Faraday effect and the research by polarizing microscopy are its examples. The light emitted from the electron orbit of an accelerator has the different polarizing characteristics from those of the light of a laboratory light source, and as far as observing it within the electron orbit plane, it becomes linearly polarized light. By utilizing this property well, research is carried out at present in synchrotron experimental facilities. Recently, the technology related to the insert type light cources using permanent magnets has advanced remarkably, and circular polarized light has become to be producible. If the light like this can be obtained with the energy not only in far ultraviolet region but also to x-ray region at high luminance, new possibility should open. At the stage that the design of an insert type light source was finished, and its manufacture was started, the research on the method of evaluating the degree of circular polarization and the research on the utilization of circular polarized synchrotron radiation are earnestly carried out. In this report, the results of researches presented at the study meeting are summarized. Moreover, the design and manufacture of the beam lines for exclusive use will be carried out. (Kako, I.)

  2. System for circular and complex tomography

    International Nuclear Information System (INIS)

    Hellstrom, M.J.

    1979-01-01

    This invention discloses a system for conducting circular as well as complex tomographic procedures utilizing apparatus which has no mechanical linkage between the X-ray source and the X-ray receptor. The path of travel of the X-ray source both circularly and linearly is sensed by electromagnetic radiation and more particularly by light radiation which is generated by a laser. The linear travel is sensed by means of reflected laser radiation directed to the X-ray source and fed to an interferometer. The circular travel, on the other hand, is sensed by means of a laser gyroscope also receiving light radiation from a laser. Optical energy sensing means is thus used to generate command signals which are coupled to respective drive motors which act to rotate and when desirable, translate the X-ray receptor so that its motion follows the motion, both orbital and linear, of the X-ray source for performing any desired type of tomographic procedure

  3. DNA-PK dependent targeting of DNA-ends to a protein complex assembled on matrix attachment region DNA sequences

    International Nuclear Information System (INIS)

    Mauldin, S.K.; Getts, R.C.; Perez, M.L.; DiRienzo, S.; Stamato, T.D.

    2003-01-01

    Full text: We find that nuclear protein extracts from mammalian cells contain an activity that allows DNA ends to associate with circular pUC18 plasmid DNA. This activity requires the catalytic subunit of DNA-PK (DNA-PKcs) and Ku since it was not observed in mutants lacking Ku or DNA-PKcs but was observed when purified Ku/DNA-PKcs was added to these mutant extracts. Competition experiments between pUC18 and pUC18 plasmids containing various nuclear matrix attachment region (MAR) sequences suggest that DNA ends preferentially associate with plasmids containing MAR DNA sequences. At a 1:5 mass ratio of MAR to pUC18, approximately equal amounts of DNA end binding to the two plasmids were observed, while at a 1:1 ratio no pUC18 end-binding was observed. Calculation of relative binding activities indicates that DNA-end binding activities to MAR sequences was 7 to 21 fold higher than pUC18. Western analysis of proteins bound to pUC18 and MAR plasmids indicates that XRCC4, DNA ligase IV, scaffold attachment factor A, topoisomerase II, and poly(ADP-ribose) polymerase preferentially associate with the MAR plasmid in the absence or presence of DNA ends. In contrast, Ku and DNA-PKcs were found on the MAR plasmid only in the presence of DNA ends. After electroporation of a 32P-labeled DNA probe into human cells and cell fractionation, 87% of the total intercellular radioactivity remained in nuclei after a 0.5M NaCl extraction suggesting the probe was strongly bound in the nucleus. The above observations raise the possibility that DNA-PK targets DNA-ends to a repair and/or DNA damage signaling complex which is assembled on MAR sites in the nucleus

  4. Electrokinetic acceleration of DNA hybridization in microsystems.

    Science.gov (United States)

    Lei, Kin Fong; Wang, Yun-Hsiang; Chen, Huai-Yi; Sun, Jia-Hong; Cheng, Ji-Yen

    2015-06-01

    In this work, electrokinetic acceleration of DNA hybridization was investigated by different combinations of frequencies and amplitudes of actuating electric signals. Because the frequencies from low to high can induce different kinds of electrokinetic forces, i.e., electroosmotic to electrothermal forces, this work provides an in-depth investigation of electrokinetic enhanced hybridization. Concentric circular Cr/Au microelectrodes of 350 µm in diameter were fabricated on a glass substrate and probe DNA was immobilized on the electrode surface. Target DNA labeled with fluorescent dyes suspending in solution was then applied to the electrode. Different electrokinetic forces were induced by the application of different electric signals to the circular microelectrodes. Local microfluidic vortexes were generated to increase the collision efficiency between the target DNA suspending in solution and probe DNA immobilized on the electrode surface. DNA hybridization on the electrode surface could be accelerated by the electrokinetic forces. The level of hybridization was represented by the fluorescent signal intensity ratio. Results revealed that such 5-min dynamic hybridization increased 4.5 fold of signal intensity ratio as compared to a 1-h static hybridization. Moreover, dynamic hybridization was found to have better differentiation ability between specific and non-specific target DNA. This study provides a strategy to accelerate DNA hybridization in microsystems. Copyright © 2015 Elsevier B.V. All rights reserved.

  5. Architectural Surfaces and Structures from Circular Arcs

    KAUST Repository

    Shi, Ling

    2013-12-01

    In recent decades, the popularity of freeform shapes in contemporary architecture poses new challenges to digital design. One of them is the process of rationalization, i.e. to make freeform skins or structures affordable to manufacture, which draws the most attention from geometry researchers. In this thesis, we aim to realize this process with simple geometric primitives, circular arcs. We investigate architectural surfaces and structures consisting of circular arcs. Our focus is lying on how to employ them nicely and repetitively in architectural design, in order to decrease the cost in manufacturing. Firstly, we study Darboux cyclides, which are algebraic surfaces of order ≤ 4. We provide a computational tool to identify all families of circles on a given cyclide based on the spherical model of M ̈obius geometry. Practical ways to design cyclide patches that pass through certain inputs are presented. In particular, certain triples of circle families on Darboux cyclides may be suitably arranged as 3-webs. We provide a complete classification of all possible 3-webs of circles on Darboux cyclides. We then investigate the circular arc snakes, which are smooth sequences of circu- lar arcs. We evolve the snakes such that their curvature, as a function of arc length, remains unchanged. The evolution of snakes is utilized to approximate given surfaces by circular arcs or to generated freeform shapes, and it is realized by a 2-step pro- cess. More interestingly, certain 6-arc snake with boundary constraints can produce a smooth self motion, which can be employed to build flexible structures. Another challenging topic is approximating smooth freeform skins with simple panels. We contribute to this problem area by approximating a negatively-curved 5 surface with a smooth union of rational bilinear patches. We provide a proof for vertex consistency of hyperbolic nets using the CAGD approach of the rational B ́ezier form. Moreover, we use Darboux transformations for the

  6. Circular RNAs as Promising Biomarkers: A mini-review

    Directory of Open Access Journals (Sweden)

    Nadiah Abu

    2016-08-01

    Full Text Available The interest in circular RNAs has resurfaced in the past few years. What was considered as junk for nearly two decades is now one of the most interesting molecules. Circular RNAs are non-coding RNAs that are formed by back-splicing events and have covalently closed loops with no poly-adenylated tails. The regulation of circular RNAs is distinctive and they are selectively abundant in different types of tissues. Based on the current knowledge of circular RNAs, these molecules have the potential to be the next big thing especially as biomarkers for different diseases. This mini-review attempts to concisely look at the biology of circular RNAs, the putative functional activities, the prevalence of circular RNAs, and the possible role of circular RNA as biomarkers for diagnosis or measuring drug response.

  7. Computational simulations of hydrogen circular migration in protonated acetylene induced by circularly polarized light

    Energy Technology Data Exchange (ETDEWEB)

    Shi, Xuetao; Li, Wen; Schlegel, H. Bernhard, E-mail: hbs@chem.wayne.edu [Department of Chemistry, Wayne State University, Detroit, Michigan 48202 (United States)

    2016-08-28

    The hydrogens in protonated acetylene are very mobile and can easily migrate around the C{sub 2} core by moving between classical and non-classical structures of the cation. The lowest energy structure is the T-shaped, non-classical cation with a hydrogen bridging the two carbons. Conversion to the classical H{sub 2}CCH{sup +} ion requires only 4 kcal/mol. The effect of circularly polarized light on the migration of hydrogens in oriented C{sub 2}H{sub 3}{sup +} has been simulated by Born-Oppenheimer molecular dynamics. Classical trajectory calculations were carried out with the M062X/6-311+G(3df,2pd) level of theory using linearly and circularly polarized 32 cycle 7 μm cosine squared pulses with peak intensity of 5.6 × 10{sup 13} W/cm{sup 2} and 3.15 × 10{sup 13} W/cm{sup 2}, respectively. These linearly and circularly polarized pulses transfer similar amounts of energy and total angular momentum to C{sub 2}H{sub 3}{sup +}. The average angular momentum vectors of the three hydrogens show opposite directions of rotation for right and left circularly polarized light, but no directional preference for linearly polarized light. This difference results in an appreciable amount of angular displacement of the three hydrogens relative to the C{sub 2} core for circularly polarized light, but only an insignificant amount for linearly polarized light. Over the course of the simulation with circularly polarized light, this corresponds to a propeller-like motion of the three hydrogens around the C{sub 2} core of protonated acetylene.

  8. Propagation and radiation characteristics of the circular electric, circular magnetic and hybrid waveguide modes

    International Nuclear Information System (INIS)

    Crenn, J.P.

    1996-06-01

    The field distributions and propagation constants of the circular electric, circular magnetic and hybrid modes of oversized waveguides are expressed, taking the effects of walls into account. The near and far field patterns are derived in the case of real wall functions. It is shown that, for very oversized waveguides, the terms containing wall functions can be ignored in the calculations, and it results that the expressions of fields and propagation constants become independent of the types of waveguides. An application to corrugated waveguides for Electron Cyclotron Resonance Heating experiments shows the variations of the radiation characteristics versus geometric parameters of the corrugations and determines the ranges of interest for these parameters. (author)

  9. DNA maintenance in plastids and mitochondria of plants

    Directory of Open Access Journals (Sweden)

    Delene J Oldenburg

    2015-10-01

    Full Text Available The DNA molecules in plastids and mitochondria of plants have been studied for over 40 years. Here, we review the data on the circular or linear form, replication, repair, and persistence of the organellar DNA (orgDNA in plants. The bacterial origin of orgDNA appears to have profoundly influenced ideas about the properties of chromosomal DNA molecules in these organelles to the point of dismissing data inconsistent with ideas from the 1970s. When found at all, circular genome-sized molecules comprise a few percent of orgDNA. In cells active in orgDNA replication, most orgDNA is found as linear and branched-linear forms larger than the size of the genome, likely a consequence of a virus-like DNA replication mechanism. In contrast to the stable chromosomal DNA molecules in bacteria and the plant nucleus, the molecular integrity of orgDNA declines during leaf development at a rate that varies among plant species. This decline is attributed to degradation of damaged-but-not-repaired molecules, with a proposed repair cost-saving benefit most evident in grasses. All orgDNA maintenance activities are proposed to occur on the nucleoid tethered to organellar membranes by developmentally-regulated proteins.

  10. [Haikou issues circular on planned parenthood].

    Science.gov (United States)

    1981-02-03

    The Organization Department of the Haikou Municipal CCP Committee, the municipal grain, finance, commerce, education bureau, personnel, public security, labor, civil affairs, public health, and housing bureaus, supply and marketing cooperative, and planned parenthood office recently issued a joint circular on implementing the provincial planned parenthood regulations. The circular demanded that the marriage registration and census system be seriously implemented. When people are registering for marriage, we must teach them to have only 1 child. We must give priority in housing and employment to an only child and his parents. When commercial, supply, and marketing departments are distributing coupons for fuel, and nonstaple food, they should supply a double amount to the only child. We must carry out serious health care for an only child and give them regular physical check-ups. When they are ill, hospitals should give them priority in registration, treatment, reservation of beds and medicines. The circular reiterated: We must seriously implement the stipulations on rewards and punishments contained in the provincial planned parenthood regulations. Cadres, staff, or workers who apply to have only 1 child must be given lump sums in addition to enjoying the relevant rewards stipulated by the regulations. Cadres, staff, workers, inhabitants, and commune workers who depend on state grain who violate the regulations must be punished according to the regulation. As for those who have 3 or more than 3 children, a 2nd child without planning, or an illegitimate child, the child's grain ration will be sold at negotiated price up to the age of 14. The grain department will distribute to them a supply ticket for negotiated price grain to buy grain in assigned grain shops. full text

  11. MHD stability of an almost circular tokamak

    International Nuclear Information System (INIS)

    Roy, A.

    1990-10-01

    In a tokamak, the ratio β between the plasma pressure and that of the magnetic field is limited by the appearance of instabilities. The magnetic field in a tokamak reactor will always be limited by technological constraints. It is therefore crucial to know what factors have an effect on the β limit, since a zero resistivity plasma fluid model allows for theoretical reproduction of the β limits observed experimentally. Theoretical studies have shown that the distributions of pressure and current density may have a substantial effect on the β limit. The effect of the current density and pressure distributions on the β limit has been studied for tokamak with a circular core section. The best results are obtained when the current density is concentrated in the centre of the section and is nil at the periphery. But the second region of stability against ballooning modes cannot be obtained in a circular tokamak owing to the destabilisation of the universal modes. This study was then extended to the stability of plasmas the section of which is almost circular and has a point of reflection. Such configurations are vital for fusion since they allow systems in which the confinement time does not deteriorate with an increase in the additional heating power. The β limit was calculated for different positions of the reflection point. The results show that when it is displaced from the interior towards the exterior of the torus, the stability of the overall modes is progressively improved until it is vertical. But if the point of reflection is further displaced from this vertical position towards the exterior of the torus, localised modes close to the edge of the plasma are destabilised and bring about a drop in the β limit. (author) figs., tabs., 80 refs

  12. Multipole Analysis of Circular Cylindircal Magnetic Systems

    Energy Technology Data Exchange (ETDEWEB)

    Selvaggi, Jerry P. [Rensselaer Polytechnic Inst., Troy, NY (United States)

    2005-12-01

    This thesis deals with an alternate method for computing the external magnetic field from a circular cylindrical magnetic source. The primary objective is to characterize the magnetic source in terms of its equivalent multipole distribution. This multipole distribution must be valid at points close to the cylindrical source and a spherical multipole expansion is ill-equipped to handle this problem; therefore a new method must be introduced. This method, based upon the free-space Green's function in cylindrical coordinates, is developed as an alternative to the more familiar spherical harmonic expansion. A family of special functions, called the toroidal functions or Q-functions, are found to exhibit the necessary properties for analyzing circular cylindrical geometries. In particular, the toroidal function of zeroth order, which comes from the integral formulation of the free-space Green's function in cylindrical coordinates, is employed to handle magnetic sources which exhibit circular cylindrical symmetry. The toroidal functions, also called Q-functions, are the weighting coefficients in a ''Fourier series-like'' expansion which represents the free-space Green's function. It is also called a toroidal expansion. This expansion can be directly employed in electrostatic, magnetostatic, and electrodynamic problems which exhibit cylindrical symmetry. Also, it is shown that they can be used as an alternative to the Elliptic integral formulation. In fact, anywhere that an Elliptic integral appears, one can replace it with its corresponding Q-function representation. A number of problems, using the toroidal expansion formulation, are analyzed and compared to existing known methods in order to validate the results. Also, the equivalent multipole distribution is found for most of the solved problems along with its corresponding physical interpretation. The main application is to characterize the external magnetic field due to a six

  13. Chiral surface waves for enhanced circular dichroism

    Science.gov (United States)

    Pellegrini, Giovanni; Finazzi, Marco; Celebrano, Michele; Duò, Lamberto; Biagioni, Paolo

    2017-06-01

    We present a novel chiral sensing platform that combines a one-dimensional photonic crystal design with a birefringent surface defect. The platform sustains simultaneous transverse electric and transverse magnetic surface modes, which are exploited to generate chiral surface waves. The present design provides homogeneous and superchiral fields of both handednesses over arbitrarily large areas in a wide spectral range, resulting in the enhancement of the circular dichroism signal by more than two orders of magnitude, thus paving the road toward the successful combination of surface-enhanced spectroscopies and electromagnetic superchirality.

  14. Vortex Shedding from Finned Circular Cylinders

    Science.gov (United States)

    1980-11-01

    FINNED CIRCULAR CYLINDERSo ,rm"" 1..UTNOI .)R*., r. *.040, 111SPOR- / T NuMBII f.John G. elute asOHans J.’/, ugt -. . . , ,<-. -. ,:. =., .. Siil P3RPIO...fins and other sharp protuberances. These purely two-dimensional flows then may be used in a strip theory to include at least some aspects of three...boundary- layer theory . Such a prediction method, together with a technique to provide for a vortex sheet at the separation point, will be included in

  15. Future Circular Collider study week 2017

    CERN Document Server

    2017-01-01

    The annual meetings of the worldwide Future Circular Collider study (FCC) are major international events that review the progress in every domain which is relevant to develop feasible concepts for a next generation frontier particle accelerate based high-energy physics research infrastructure. This 3rd meeting is jointly organised by CERN and DESY. It is also the annual meeting of the EuroCirCol EC Horizon 2020 Research and Innovation Action project. Previous events took place in Washington and Rome. In 2017 the FCC Week will take place in Berlin, Germany between May 29 and June 2.

  16. Porphyrin Protonation Studied by Magnetic Circular Dichroism

    Czech Academy of Sciences Publication Activity Database

    Štěpánek, Petr; Andrushchenko, Valery; Ruud, K.; Bouř, Petr

    2012-01-01

    Roč. 116, č. 1 (2012), s. 778-783 ISSN 1089-5639 R&D Projects: GA ČR GAP208/11/0105; GA ČR GA203/09/2037; GA ČR GAP208/10/0559; GA MŠk(CZ) LH11033 Institutional research plan: CEZ:AV0Z40550506 Keywords : magnetic circular dichroism ( MCD ) * TPPS * spectra simulations * porphyrin protonation Subject RIV: CF - Physical ; Theoretical Chemistry Impact factor: 2.771, year: 2012

  17. A Circularly Arranged Sextuple Triptycene Gear Molecule.

    Science.gov (United States)

    Ube, Hitoshi; Yamada, Ryo; Ishida, Jun-Ichi; Sato, Hiroyasu; Shiro, Motoo; Shionoya, Mitsuhiko

    2017-11-22

    Herein we report the synthesis of a circularly arranged sextuple triptycene gear molecule, hexakis(10-dodecyloxy-9-triptycyl)ethynylbenzene, via the trimerization of the corresponding triyne with a cobalt catalyst. The six triptycene gears are closely engaged with each other as confirmed by single crystal X-ray structure analysis, and their motion in solution was established by NMR spectroscopy. Notably, when one bulky RuCp* complex was attached to one triptycene gear, the whole movement of the six gears was highly restricted via their mechanical engagement. Development of such a multigear molecule would provide a structural basis for molecular motion transmission systems with a switching function.

  18. Complex forms of mitochondrial DNA in human B cells transformed by Epstein-Barr virus (EBV)

    DEFF Research Database (Denmark)

    Christiansen, Gunna; Christiansen, C; Zeuthen, J

    1983-01-01

    Human lymphocytes and lymphoid cell lines were analyzed for the presence of complex forms of mitochondrial DNA (mtDNA) by electron microscopy. A high frequency (9%-14.5%) of catenated dimers, circular dimers, or oligomers were found in samples from Epstein-Barr-virus-(EBV) transformed lymphoblast......Human lymphocytes and lymphoid cell lines were analyzed for the presence of complex forms of mitochondrial DNA (mtDNA) by electron microscopy. A high frequency (9%-14.5%) of catenated dimers, circular dimers, or oligomers were found in samples from Epstein-Barr-virus-(EBV) transformed...

  19. Interaction of nogalamycin and analogs with DNA and other biopolymers

    Energy Technology Data Exchange (ETDEWEB)

    Krueger, W C [Univ. of Minnesota, Minneapolis; Pschigoda, L M; Schpok, S L.F.; Moscowitz, A.; McGovren, J P; Neta, P; Merritt, M V; Li, L H

    1981-01-01

    The interaction with calf thymus DNA of the anthracycline antibiotics, nogalamycin and its analogs, was studied by electronic absorption, circular dichroism (CD), thermal denaturation, solvent partition and pulse radiolysis techniques. The Scatchard, thermal denaturation (..delta..T/sub m/), difference circular dichroism (..delta..CD) and solvent partition binding parameters gave the same order of relative binding on a given lot of DNA, but some parameters were DNA-lot-dependent. In general, molecules containing the sugar moiety nogalose at C-7 or those having the natural or dis stereochemistry of nogalamycin at C-7 bound more strongly to DNA than did the molecules lacking nogalose or those with the opposite configuration at C-7 (con stereochemistry). This stereochemical-binding correlation differs from that found for adriamycin which has the con stereochemistry, but which binds strongly to DNA. Scatchard binding parameters could not be obtained from the pulse radiolysis or solvent partition techniques because of solubility difficulties.

  20. Conformational effects in photoelectron circular dichroism

    Science.gov (United States)

    Turchini, S.

    2017-12-01

    Photoelectron circular dichroism (PECD) is a novel type of spectroscopy, which presents surprising sensitivity to conformational effects in chiral systems. While classical photoelectron spectroscopy mainly responds to conformational effects in terms of energy level shifts, PECD provides a rich and detailed response to tiny changes in electronic and structural properties by means of the intensity dispersion of the circular dichroism as a function of photoelectron kinetic energy. In this work, the basics of PECD will be outlined, emphasizing the role of interference from the l,l+/- 1 outgoing partial wave of the photoelectron in the PECD transition matrix element, which is responsible for the extreme sensitivity to conformational effects. Examples using molecular systems and interfaces will shed light on the powerful application of PECD to classical conformational effects such as group substitution, isomerism, conformer population and clustering. Moreover, the PECD results will be reported in challenging new fields where conformations play a key role, such as vibrational effects, transient chirality and time- resolved experiments. To date, PECD has mostly been based on synchrotron radiation facilities, but it also has a future as a table-top lab experiment by means of multiphoton ionization. An important application of PECD as an analytical tool will be reported. The aim of this review is to illustrate that in PECD, the presence of conformational effects is essential for understanding a wide range of effects from a new perspective, making it different from classical spectroscopy.

  1. High Performance Circularly Polarized Microstrip Antenna

    Science.gov (United States)

    Bondyopadhyay, Probir K. (Inventor)

    1997-01-01

    A microstrip antenna for radiating circularly polarized electromagnetic waves comprising a cluster array of at least four microstrip radiator elements, each of which is provided with dual orthogonal coplanar feeds in phase quadrature relation achieved by connection to an asymmetric T-junction power divider impedance notched at resonance. The dual fed circularly polarized reference element is positioned with its axis at a 45 deg angle with respect to the unit cell axis. The other three dual fed elements in the unit cell are positioned and fed with a coplanar feed structure with sequential rotation and phasing to enhance the axial ratio and impedance matching performance over a wide bandwidth. The centers of the radiator elements are disposed at the corners of a square with each side of a length d in the range of 0.7 to 0.9 times the free space wavelength of the antenna radiation and the radiator elements reside in a square unit cell area of sides equal to 2d and thereby permit the array to be used as a phased array antenna for electronic scanning and is realizable in a high temperature superconducting thin film material for high efficiency.

  2. Stresses in Circular Plates with Rigid Elements

    Science.gov (United States)

    Velikanov, N. L.; Koryagin, S. I.; Sharkov, O. V.

    2018-05-01

    Calculations of residual stress fields are carried out by numerical and static methods, using the flat cross-section hypothesis. The failure of metal when exposed to residual stresses is, in most cases, brittle. The presence in the engineering structures of rigid elements often leads to the crack initiation and structure failure. This is due to the fact that rigid elements under the influence of external stresses are stress concentrators. In addition, if these elements are fixed by welding, the residual welding stresses can lead to an increase in stress concentration and, ultimately, to failure. The development of design schemes for such structures is a very urgent task for complex technical systems. To determine the stresses in a circular plate with a welded circular rigid insert under the influence of an external load, one can use the solution of the plane stress problem for annular plates in polar coordinates. The polar coordinates of the points are the polar radius and the polar angle, and the stress state is determined by normal radial stresses, tangential and shearing stresses. The use of the above mentioned design schemes, formulas, will allow more accurate determination of residual stresses in annular welded structures. This will help to establish the most likely directions of failure and take measures at the stages of designing, manufacturing and repairing engineering structures to prevent these failures. However, it must be taken into account that the external load, the presence of insulation can lead to a change in the residual stress field.

  3. Zernike vs. Bessel circular functions in visual optics.

    Science.gov (United States)

    Trevino, Juan P; Gómez-Correa, Jesus E; Iskander, D Robert; Chávez-Cerda, Sabino

    2013-07-01

    We propose the Bessel Circular Functions as alternatives of the Zernike Circle Polynomials to represent relevant circular ophthalmic surfaces. We assess the fitting capabilities of the orthogonal Bessel Circular Functions by comparing them to Zernike Circle Polynomials for approximating a variety of computationally generated surfaces which can represent ophthalmic surfaces. The Bessel Circular Functions showed better modelling capabilities for surfaces with abrupt variations such as the anterior eye surface at the limbus region, and influence functions. From our studies we find that the Bessel Circular Functions can be more suitable for studying particular features of post surgical corneal surfaces. We show that given their boundary conditions and free oscillating properties, the Bessel Circular Functions are an alternative for representing specific wavefronts and can be better than the Zernike Circle Polynomials for some important cases of corneal surfaces, influence functions and the complete anterior corneal surface. © 2013 The Authors Ophthalmic & Physiological Optics © 2013 The College of Optometrists.

  4. Modeling DNA

    Science.gov (United States)

    Robertson, Carol

    2016-01-01

    Deoxyribonucleic acid (DNA) is life's most amazing molecule. It carries the genetic instructions that almost every organism needs to develop and reproduce. In the human genome alone, there are some three billion DNA base pairs. The most difficult part of teaching DNA structure, however, may be getting students to visualize something as small as a…

  5. Enhancement of DNA-transfection frequency by X-rays

    Energy Technology Data Exchange (ETDEWEB)

    Iwamoto, Ryota; Fushimi, Kazuo; Hiraki, Yoshio; Namba, Masayoshi [Okayama University Medical School (Japan). Institute of Cellular and Molecular Biology

    1997-02-01

    This study was conducted to evaluate the frequency of DNA transfection into human cells following X-ray irradiation. We transfected plasmid DNA (pSV2neo) into human cells, HeLa and PA-1, by either calcium phosphate precipitation or the lipofection method immediately after irradiating the cells with various doses of X-rays. The transfection frequency was evaluated by counting the number of G418-resistant colonies. When circular plasmid DNA was used, irradiation up to a dose of 2 Gy dose-dependently increased the transfection frequency, which reached a maximum of 5 to 10-fold that of the control unirradiated cells. When linear plasmid DNA was used, the transfection frequency was 2 times higher than that of circular DNA. All five of the clones that were randomly chosen expressed the transfected neo gene. In addition, the pSV2neo gene was randomly integrated into the genomic DNA of each clone. These findings indicate that X-ray treatment can facilitate foreign DNA transfer into human cells and that radiation-induced DNA breaks may promote the insertion of foreign DNA into host DNA. The enhancement of DNA transfection with X-rays may be instrumental in practicing gene therapy. (author)

  6. Enhancement of DNA-transfection frequency by X-rays

    International Nuclear Information System (INIS)

    Iwamoto, Ryota; Fushimi, Kazuo; Hiraki, Yoshio; Namba, Masayoshi

    1997-01-01

    This study was conducted to evaluate the frequency of DNA transfection into human cells following X-ray irradiation. We transfected plasmid DNA (pSV2neo) into human cells, HeLa and PA-1, by either calcium phosphate precipitation or the lipofection method immediately after irradiating the cells with various doses of X-rays. The transfection frequency was evaluated by counting the number of G418-resistant colonies. When circular plasmid DNA was used, irradiation up to a dose of 2 Gy dose-dependently increased the transfection frequency, which reached a maximum of 5 to 10-fold that of the control unirradiated cells. When linear plasmid DNA was used, the transfection frequency was 2 times higher than that of circular DNA. All five of the clones that were randomly chosen expressed the transfected neo gene. In addition, the pSV2neo gene was randomly integrated into the genomic DNA of each clone. These findings indicate that X-ray treatment can facilitate foreign DNA transfer into human cells and that radiation-induced DNA breaks may promote the insertion of foreign DNA into host DNA. The enhancement of DNA transfection with X-rays may be instrumental in practicing gene therapy. (author)

  7. Calibration of circular aperture area using vision probe at inmetro

    Directory of Open Access Journals (Sweden)

    Costa Pedro Bastos

    2016-01-01

    Full Text Available Circular aperture areas are standards of high importance for the realization of photometric and radiometric measurements, where the accuracy of these measures is related to the accuracy of the circular aperture area calibrations. In order to attend the requirement for traceability was developed in Brazilian metrology institute, a methodology for circular aperture area measurement as requirements from the radiometric and photometric measurements. In the developed methodology apertures are measured by non-contact measurement through images of the aperture edges captured by a camera. These images are processed using computer vision techniques and then the values of the circular aperture area are determined.

  8. The role of DNA polymerase {iota} in UV mutational spectra

    Energy Technology Data Exchange (ETDEWEB)

    Choi, Jun-Hyuk [Division of Biology, Beckman Research Institute, City of Hope, Duarte, CA 91010 (United States); Besaratinia, Ahmad [Division of Biology, Beckman Research Institute, City of Hope, Duarte, CA 91010 (United States); Lee, Dong-Hyun [Division of Biology, Beckman Research Institute, City of Hope, Duarte, CA 91010 (United States); Lee, Chong-Soon [Department of Biochemistry, College of Natural Sciences, Yeungnam University, Gyongsan 712-749 (Korea, Republic of); Pfeifer, Gerd P. [Division of Biology, Beckman Research Institute, City of Hope, Duarte, CA 91010 (United States)]. E-mail: gpfeifer@coh.org

    2006-07-25

    UVB (280-320 nm) and UVC (200-280 nm) irradiation generate predominantly cyclobutane pyrimidine dimers (CPDs) and (6-4) photoproducts in DNA. CPDs are thought to be responsible for most of the UV-induced mutations. Thymine-thymine CPDs, and probably also CPDs containing cytosine, are replicated in vivo in a largely accurate manner by a DNA polymerase {eta} (Pol {eta}) dependent process. Pol {eta} is a DNA damage-tolerant and error-prone DNA polymerase encoded by the POLH (XPV) gene in humans. Another member of the Y family of error-prone DNA polymerases is POLI encoding DNA polymerase iota (Pol {iota}). In order to clarify the specific role of Pol {iota} in UV mutagenesis, we have used an siRNA knockdown approach in combination with a supF shuttle vector which replicates in mammalian cells, similar as we have previously done for Pol {eta}. Synthetic RNA duplexes were used to efficiently inhibit Pol {iota} expression in 293T cells. The supF shuttle vector was irradiated with 254 nm UVC and replicated in 293T cells in presence of anti-Pol {iota} siRNA. Surprisingly, there was a consistent reduction of recovered plasmid from cells with Pol {iota} knockdown and this was independent of UV irradiation of the plasmid. The supF mutant frequency was unchanged in the siRNA knockdown cells relative to control cells confirming that Pol {iota} does not play an important role in UV mutagenesis. UV-induced supF mutants were sequenced from siRNA-treated cells and controls. Neither the type of mutations nor their distribution along the supF gene were significantly different between controls and siRNA knockdown cells and were predominantly C to T and CC to TT transitions at dipyrimidine sites. These results show that Pol {iota} has no significant role in UV lesion bypass and mutagenesis in vivo and provides some initial data suggesting that this polymerase may be involved in replication of extrachromosomal DNA.

  9. Purification of supercoiled DNA of plasmid Col E1 by RPC-5 chromatography

    Energy Technology Data Exchange (ETDEWEB)

    Best, A.N.; Allison, D.P.; Novelli, G.D.

    1981-07-01

    Col E1 DNA can be purified to a high degree by RPC-5 chromatography of a partially purified cell lysate with a very shallow linear NaC1 gradient at pH 7.8. Electron micrographs demonstrated that the purest fractions were composed of 93% supercoiled (form I) DNA and 7% open circular (form II) DNA. The actual chromatography can be accomplished in 13 to 14 h and is designed for the production of several milligrams of plasmid DNA.

  10. NUMERICAL MODELING OF STRESSES NEAR THE SURFACE IN THE INGOT OF CIRCULAR SECTION, CRYSTALLIZABLE AT CIRCULAR TORCH SECONDARY COOLING

    Directory of Open Access Journals (Sweden)

    A. N. Chichko

    2004-01-01

    Full Text Available The results of computer calculations of the stresses, generated in outside layer of ingot of steel 20 of circular section with diameter 300 mm, in application to one of the industrial technological schemas of RUP “BMZ”, are presented. The segments of compressive and tensile stresses formation along the length of ingot are determined and the principal possibility of production of continuously cast slug of circular section at circular-torch spray cooling is shown.

  11. Circular waveguide mode converters at 140 GHz

    International Nuclear Information System (INIS)

    Trulsen, J.; Woskoboinikow, P.; Temkin, R.J.

    1986-01-01

    A unified derivation of the coupled mode equations for circular waveguide is presented. Also, approximate design criteria for TE/sub 0n/ to TE/sub 0n'/ axisymmetric, TE 01 to TE 11 wriggle, and TE 01 to TM 11 bend converters are reviewed. Numerically solving the coupled mode equations, an optimized set of mode converters has been designed for conversion of a 2 millimeter wave TE 03 mode into TE 11 . This set consists of axisymmetric TE 03 to TE 02 and TE 02 to TE 01 converters followed by a wriggle TE 01 to TE 11 converter. This mode converter set was fabricated and tested using a 3 kW, 137 GHz gyrotron. A TE 11 mode purity of better than 97% was achieved. The TE 01 to TE 11 wriggle converter was experimentally optimized for a measured conversion efficiency of better than 99% not including ohmic losses

  12. Circular magnetoplasmonic modes in gold nanoparticles.

    Science.gov (United States)

    Pineider, Francesco; Campo, Giulio; Bonanni, Valentina; Fernández, César de Julián; Mattei, Giovanni; Caneschi, Andrea; Gatteschi, Dante; Sangregorio, Claudio

    2013-10-09

    The quest for efficient ways of modulating localized surface plasmon resonance is one of the frontiers in current research in plasmonics; the use of a magnetic field as a source of modulation is among the most promising candidates for active plasmonics. Here we report the observation of magnetoplasmonic modes on colloidal gold nanoparticles detected by means of magnetic circular dichroism (MCD) spectroscopy and provide a model that is able to rationalize and reproduce the experiment with unprecedented qualitative and quantitative accuracy. We believe that the steep slope observed at the plasmon resonance in the MCD spectrum can be very efficient in detecting changes in the refractive index of the surrounding medium, and we give a simple proof of principle of its possible implementation for magnetoplasmonic refractometric sensing.

  13. A conceptual design of circular Higgs factory

    Energy Technology Data Exchange (ETDEWEB)

    Cai, Yunhai

    2016-11-30

    Similar to a super B-factory, a circular Higgs factory (CHF) will require strong focusing systems near the interaction points and a low-emittance lattice in the arcs to achieve a factory luminosity. At electron beam energy of 125 GeV, beamstrahlung effects during the collision pose an additional challenge to the collider design. In particular, a large momentum acceptance at the 2% level is necessary to retain an adequate beam lifetime. This turns out to be the most challenging aspect in the design of a CHF. In this paper, an example will be provided to illustrate the beam dynamics in a CHF, emphasizing the chromatic optics. Basic optical modules and advanced analysis will be presented. Most importantly, we will show that 2% momentum aperture is achievable.

  14. Irradiated target cooling using circular air jet

    International Nuclear Information System (INIS)

    Selvaraj, P.; Natesan, K.; Velusamy, K.; Baskaran, V.; Sundararajan, T.

    2015-01-01

    To study the effect of irradiation on materials, sample coupons are irradiated in cyclotron facilities. During the irradiation process, these samples produce significant heat. This heat needs to be continuously removed from the samples in order to avoid melting of the samples as well as to keep the samples at a particular temperature during irradiation. The area available for heat transfer is limited due to the small size of the samples. To increase the heat transfer rate, jet cooling is used as it provides large heat transfer co-efficient. To understand the heat transfer characteristics of jet cooling under these conditions, experiments have been carried out. Electric Joule heating is adopted to simulate irradiation heat in stainless steel samples. An array of circular nozzles is used to create air jet. From the study the values of the parameters correspond to the maximum heat removal rate are found out. The results are also compared with an empirical correlation from the literature. (author)

  15. Waste to chemicals for a circular economy.

    Science.gov (United States)

    Iaquaniello, Gaetano; Centi, Gabriele; Annarita Salladini, Annarita; Palo, Emma; Perathoner, Siglinda

    2018-06-25

    The implementation of a circular economy is a fundamental step to create a greater and more sustainable future for a better use of resources and energy. Wastes and in particular municipal solid waste represent an untapped source of carbon (and hydrogen) to produce a large range of chemicals from methane to alcohols (as methanol or ethanol) or urea. The waste to chemical (WtC) process and related economics are assessed in this concept article to show the validity of such solution both from an economic point of view and from an environmental perspective considering the sensible reduction in greenhouse gas emissions with respect to conventional production from fossil fuels. © 2018 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  16. Circular arc snakes and kinematic surface generation

    KAUST Repository

    Barton, Michael

    2013-05-01

    We discuss the theory, discretization, and numerics of curves which are evolving such that part of their shape, or at least their curvature as a function of arc length, remains unchanged. The discretization of a curve as a smooth sequence of circular arcs is well suited for such purposes, and allows us to reduce evolution of curves to the evolution of a control point collection in a certain finite-dimensional shape space. We approach this evolution by a 2-step process: linearized evolution via optimized velocity fields, followed by optimization in order to exactly fulfill all geometric side conditions. We give applications to freeform architecture, including "rationalization" of a surface by congruent arcs, form finding and, most interestingly, non-static architecture. © 2013 The Author(s) Computer Graphics Forum © 2013 The Eurographics Association and Blackwell Publishing Ltd.

  17. Tangent hyperbolic circular frequency diverse array radars

    Directory of Open Access Journals (Sweden)

    Sarah Saeed

    2016-03-01

    Full Text Available Frequency diverse array (FDA with uniform frequency offset (UFO has been in spot light of research for past few years. Not much attention has been devoted to non-UFOs in FDA. This study investigates tangent hyperbolic (TH function for frequency offset selection scheme in circular FDAs (CFDAs. Investigation reveals a three-dimensional single-maximum beampattern, which promises to enhance system detection capability and signal-to-interference plus noise ratio. Furthermore, by utilising the versatility of TH function, a highly configurable type array system is achieved, where beampatterns of three different configurations of FDA can be generated, just by adjusting a single function parameter. This study further examines the utility of the proposed TH-CFDA in some practical radar scenarios.

  18. Perturbation analysis of octupoles in circular accelerators

    International Nuclear Information System (INIS)

    Moohyun Yoon

    1998-01-01

    The octupole effects in a circular accelerator are analyzed using a first-order canonical perturbation theory. It is shown that, to the first order, the nonlinear amplitude-dependent tune shifts due to an octupole are composed of two types: terms of second order and terms of fourth order in betatron-oscillation amplitudes. The fourth-order part of tune shifts is expressed in terms of distortion functions. Distortion functions are also expanded in harmonics to express the higher-order tune shifts in harmonically expanded form. Finally, the results are applied to an accelerator and compared with the results of numerical tracking of particles. Laskar's algorithm for numerical analysis of the fundamental frequency is used to determine tunes from the tracking data, in which the error becomes inversely proportional to the cube of the number of data points. (author)

  19. Absorption of circularly polarized light by solids

    International Nuclear Information System (INIS)

    Jalbert, G.; Brandi, H.S.

    1984-03-01

    The multiphoton absorption rate of circularly polarized light, by direct gap crystals, was investigated following a non-perturbative scheme proposed by Jones and Reiss. It was possible to derive closed analytical solutions, for the N-photon transition rate, valid for all field strenghts of practical interest. The accuracy of the approximations introduced in deriving these results was determined comparing the numerical computations of the multiphoton transition rate ('exact') with the analytical solutions. Specific calculations are done for ZnS and GaAs in the presence of a Nd-laser. It is shown that this formalism leads to a total transition rate which has not the tunneling behavior previously discussed by several authors within similar contexts. (Author) [pt

  20. Towards Quantum Simulation with Circular Rydberg Atoms

    Directory of Open Access Journals (Sweden)

    T. L. Nguyen

    2018-02-01

    Full Text Available The main objective of quantum simulation is an in-depth understanding of many-body physics, which is important for fundamental issues (quantum phase transitions, transport, … and for the development of innovative materials. Analytic approaches to many-body systems are limited, and the huge size of their Hilbert space makes numerical simulations on classical computers intractable. A quantum simulator avoids these limitations by transcribing the system of interest into another, with the same dynamics but with interaction parameters under control and with experimental access to all relevant observables. Quantum simulation of spin systems is being explored with trapped ions, neutral atoms, and superconducting devices. We propose here a new paradigm for quantum simulation of spin-1/2 arrays, providing unprecedented flexibility and allowing one to explore domains beyond the reach of other platforms. It is based on laser-trapped circular Rydberg atoms. Their long intrinsic lifetimes, combined with the inhibition of their microwave spontaneous emission and their low sensitivity to collisions and photoionization, make trapping lifetimes in the minute range realistic with state-of-the-art techniques. Ultracold defect-free circular atom chains can be prepared by a variant of the evaporative cooling method. This method also leads to the detection of arbitrary spin observables with single-site resolution. The proposed simulator realizes an XXZ spin-1/2 Hamiltonian with nearest-neighbor couplings ranging from a few to tens of kilohertz. All the model parameters can be dynamically tuned at will, making a large range of simulations accessible. The system evolution can be followed over times in the range of seconds, long enough to be relevant for ground-state adiabatic preparation and for the study of thermalization, disorder, or Floquet time crystals. The proposed platform already presents unrivaled features for quantum simulation of regular spin chains. We

  1. Towards Quantum Simulation with Circular Rydberg Atoms

    Science.gov (United States)

    Nguyen, T. L.; Raimond, J. M.; Sayrin, C.; Cortiñas, R.; Cantat-Moltrecht, T.; Assemat, F.; Dotsenko, I.; Gleyzes, S.; Haroche, S.; Roux, G.; Jolicoeur, Th.; Brune, M.

    2018-01-01

    The main objective of quantum simulation is an in-depth understanding of many-body physics, which is important for fundamental issues (quantum phase transitions, transport, …) and for the development of innovative materials. Analytic approaches to many-body systems are limited, and the huge size of their Hilbert space makes numerical simulations on classical computers intractable. A quantum simulator avoids these limitations by transcribing the system of interest into another, with the same dynamics but with interaction parameters under control and with experimental access to all relevant observables. Quantum simulation of spin systems is being explored with trapped ions, neutral atoms, and superconducting devices. We propose here a new paradigm for quantum simulation of spin-1 /2 arrays, providing unprecedented flexibility and allowing one to explore domains beyond the reach of other platforms. It is based on laser-trapped circular Rydberg atoms. Their long intrinsic lifetimes, combined with the inhibition of their microwave spontaneous emission and their low sensitivity to collisions and photoionization, make trapping lifetimes in the minute range realistic with state-of-the-art techniques. Ultracold defect-free circular atom chains can be prepared by a variant of the evaporative cooling method. This method also leads to the detection of arbitrary spin observables with single-site resolution. The proposed simulator realizes an X X Z spin-1 /2 Hamiltonian with nearest-neighbor couplings ranging from a few to tens of kilohertz. All the model parameters can be dynamically tuned at will, making a large range of simulations accessible. The system evolution can be followed over times in the range of seconds, long enough to be relevant for ground-state adiabatic preparation and for the study of thermalization, disorder, or Floquet time crystals. The proposed platform already presents unrivaled features for quantum simulation of regular spin chains. We discuss

  2. PCDDB: the Protein Circular Dichroism Data Bank, a repository for circular dichroism spectral and metadata.

    Science.gov (United States)

    Whitmore, Lee; Woollett, Benjamin; Miles, Andrew John; Klose, D P; Janes, Robert W; Wallace, B A

    2011-01-01

    The Protein Circular Dichroism Data Bank (PCDDB) is a public repository that archives and freely distributes circular dichroism (CD) and synchrotron radiation CD (SRCD) spectral data and their associated experimental metadata. All entries undergo validation and curation procedures to ensure completeness, consistency and quality of the data included. A web-based interface enables users to browse and query sample types, sample conditions, experimental parameters and provides spectra in both graphical display format and as downloadable text files. The entries are linked, when appropriate, to primary sequence (UniProt) and structural (PDB) databases, as well as to secondary databases such as the Enzyme Commission functional classification database and the CATH fold classification database, as well as to literature citations. The PCDDB is available at: http://pcddb.cryst.bbk.ac.uk.

  3. DNAzyme Feedback Amplification: Relaying Molecular Recognition to Exponential DNA Amplification.

    Science.gov (United States)

    Liu, Meng; Yin, Qingxin; McConnell, Erin M; Chang, Yangyang; Brennan, John D; Li, Yingfu

    2018-03-26

    Technologies capable of linking DNA amplification to molecular recognition are very desirable for ultrasensitive biosensing applications. We have developed a simple but powerful isothermal DNA amplification method, termed DNAzyme feedback amplification (DFA), that is capable of relaying molecular recognition to exponential DNA amplification. The method incorporates both an RNA-cleaving DNAzyme (RCD) and rolling circle amplification (RCA) carried out by a special DNA polymerase using a circular DNA template. DFA begins with a stimulus-dependent RCA reaction, producing tandemly linked RCDs in long-chain DNA products. These RCDs cleave an RNA-containing DNA sequence to form additional primers that hybridize to the circular DNA molecule, giving rise to DNA assemblies that act as the new inputs for RCA. The RCA reaction and the cleavage event keep on feeding each other autonomously, resulting in exponential growth of repetitive DNA sequences that can be easily detected. This method can be used for the detection of both nucleic acid based targets and non-nucleic acid analytes. In this article, we discuss the conceptual framework of the feedback amplification approach, the essential features of this method as well as remaining challenges and possible solutions. © 2018 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

  4. 5 CFR 1310.5 - List of current circulars.

    Science.gov (United States)

    2010-01-01

    ... 5 Administrative Personnel 3 2010-01-01 2010-01-01 false List of current circulars. 1310.5 Section 1310.5 Administrative Personnel OFFICE OF MANAGEMENT AND BUDGET OMB DIRECTIVES OMB CIRCULARS § 1310.5... and Use of Voluntary Consensus Standards and in Conformity Assessment Activities” A-122—“Cost...

  5. 12 CFR 563g.2 - Offering circular requirement.

    Science.gov (United States)

    2010-01-01

    ... 12 Banks and Banking 5 2010-01-01 2010-01-01 false Offering circular requirement. 563g.2 Section 563g.2 Banks and Banking OFFICE OF THRIFT SUPERVISION, DEPARTMENT OF THE TREASURY SECURITIES OFFERINGS § 563g.2 Offering circular requirement. (a) General. No savings association shall offer or sell, directly...

  6. On the Recognition of Fuzzy Circular Interval Graphs

    OpenAIRE

    Oriolo, Gianpaolo; Pietropaoli, Ugo; Stauffer, Gautier

    2011-01-01

    Fuzzy circular interval graphs are a generalization of proper circular arc graphs and have been recently introduced by Chudnovsky and Seymour as a fundamental subclass of claw-free graphs. In this paper, we provide a polynomial-time algorithm for recognizing such graphs, and more importantly for building a suitable representation.

  7. Role of Food Logistics Management in a circular economy

    NARCIS (Netherlands)

    Bloemhof-Ruwaard, J.M.; Groot, J.J.; Snels, J.C.M.A.

    2016-01-01

    In this paper we will discuss the role of food logistics management in a circular economy. Specific pillars in Circular Economy such as Closed Loop supply Chain management and Industrial Ecology will be discussed. Apart from a research agenda, we will provide exemplary cases in practice showing the

  8. Band vs. Circular Sawmills: Relative Labor & Maintenance Costs

    Science.gov (United States)

    Philip H. Steele; Philip A. Araman

    1997-01-01

    Substantial sawmill lumber yield increases from kerf and sawing variation reductions can be realized by employing band rather than circular headrigs. Softwood sawmills rapidly adopted bandsaw headrig technology to the extent that it is currently unusual to find circular saw headrigs in a softwood sawmill. Hardwood sawmills, faced with a different economic situation,...

  9. Product design and business model strategies for a circular economy

    NARCIS (Netherlands)

    Bocken, N.M.P.; de Pauw, I.C.; Bakker, C.A.; van der Grinten, B.

    The transition within business from a linear to a circular economy brings with it a range of practical challenges for companies. The following question is addressed: What are the product design and business model strategies for
    companies that want to move to a circular economy model? This paper

  10. An analysis of near-circular lunar mapping orbits

    Indian Academy of Sciences (India)

    Numerical investigations have been carried out to analyse the evolution of lunar circular orbits and the influence of the higher order harmonics of the lunar gravity field. The aim is to select the appropriate near-circular orbit characteristics, which extend orbit life through passive orbit maintenance. The spherical harmonic ...

  11. Chemical detection of cysteine-rich circular petides in selected ...

    African Journals Online (AJOL)

    Cysteine-rich circular peptides (CRCs) comprise a large family of gene encoded and low molecular weight polypeptides that has recently engaged the attention of scientists. This class of peptides exhibit a continuous circular configuration and a cystine knot backbone, which defines their resilient nature-directed structural ...

  12. static analysis of circular cylindrical shell under hydrostatic and ring

    African Journals Online (AJOL)

    DEPT OF AGRICULTURAL ENGINEERING

    (Golzan et al, 2008). Circular cylindrical shells are used in a large variety of civil engineering structures, e.g. off-shore platforms, chimneys, silos, pipelines, bridge arches or wind turbine towers (Winterstetter et al, 2002). This work is concerned with the analysis of circular cylindri- cal shell subjected to hydrostatic pressure in.

  13. Flow-induced vibration of circular cylindrical structures

    International Nuclear Information System (INIS)

    Chen, S.S.

    1985-06-01

    This report summarizes the flow-induced vibration of circular cylinders in quiescent fluid, axial flow, and crossflow, and applications of the analytical methods and experimental data in design evaluation of various system components consisting of circular cylinders. 219 figs., 30 tabs

  14. Circular braiding take-up speed generation using inverse kinematics

    NARCIS (Netherlands)

    van Ravenhorst, J.H.; Akkerman, Remko

    2014-01-01

    Circular overbraiding of composite preforms on complex mandrels currently lacks automatic generation of machine control data. To solve this limitation, an inverse kinematics-based procedure was designed and implemented for circular braiding machines with optional guide rings, resulting in a take-up

  15. Broadband Circularly Polarized Slot Antenna Loaded by a Multiple-Circular-Sector Patch.

    Science.gov (United States)

    Trinh-Van, Son; Yang, Youngoo; Lee, Kang-Yoon; Hwang, Keum Cheol

    2018-05-15

    In this paper, a microstrip-fed broadband circularly polarized (CP) slot antenna is presented. CP operation can be attained simply by embedding an S-shaped strip. By loading with a multiple-circular-sector patch, which consists of 12 circular-sector patches with identical central angles of 30° and different radii, the 3 dB axial ratio (AR) bandwidth is significantly broadened. To validate the performance of the proposed antenna, an antenna prototype is fabricated and tested. The fabricated antenna is 54 mm × 54 mm × 0.8 mm in size. The measured -10 dB reflection and 3 dB AR bandwidths are 81.06% (1.68⁻3.97 GHz) and 70.55% (1.89⁻3.95 GHz), respectively. Within the 3 dB AR bandwidth, the measured peak gain is 3.81 dBic. Reasonable agreement is also obtained between the measured and simulated results.

  16. Human mitochondrial DNA (mtDNA) types in Malaysia

    International Nuclear Information System (INIS)

    Lian, L.H.; Koh, C.L.; Lim, M.E.

    2000-01-01

    Each human cell contains hundreds of mitochondria and thousands of double-stranded circular mtDNA. The delineation of human mtDNA variation and genetics over the past decade has provided unique and often startling insights into human evolution, degenerative diseases, and aging. Each mtDNA of 16,569 base pairs, encodes 13 polypeptides essential to the enzymes of the mitochondrial energy generating pathway, plus the necessary tRNAs and rRNAs. The highly polymorphic noncoding D-(displacement) loop region, also called the control region, is approximately 1.2 kb long. It contains two well-characterized hypervariable (HV-) regions, HV1 and HV2. MtDNA identification is usually based on these sequence differences. According to the TWTGDAM (Technical Working Group for DNA Analysis Methods), the minimum requirement for a mtDNA database for HV1 is from positions 16024 to 16365 and for HV2, from positions 00073 to 00340. The targeted Malaysian population subgroups for this study were mainly the Malays, Chinese, Indians, and indigenous Ibans, Bidayuhs, Kadazan-Dusuns, and Bajaus. Research methodologies undertaken included DNA extraction of samples from unrelated individuals, amplification of the specific regions via the polymerase chain reaction (PCR), and preparation of template DNA for sequencing by using an automated DNA sequencer. Sufficient nucleotide sequence data were generated from the mtDNA analysis. When the sequences were analyzed, sequence variations were found to be caused by nucleotide substitutions, insertions, and deletions. Of the three causes of the sequence variations, nucleotide substitutions (86.1%) accounted for the vast majority of polymorphism. It is noted that transitions (83.5%) were predominant when compared to the significantly lower frequencies of transversions (2.6%). Insertions (0.9%) and deletions (13.0%) were rather rare and found only in HV2. The data generated will also form the basis of a Malaysian DNA sequence database of mtDNA D

  17. DNA Camouflage

    Science.gov (United States)

    2016-01-08

    1 DNA Camouflage Supplementary Information Bijan Zakeri1,2*, Timothy K. Lu1,2*, Peter A. Carr2,3* 1Department of Electrical Engineering and...ll.mit.edu). Distribution A: Public Release   2 Supplementary Figure 1 DNA camouflage with the 2-state device. (a) In the presence of Cre, DSD-2[α...10 1 + Cre 1 500 1,000 length (bp) chromatogram alignment template − Cre   4 Supplementary Figure 3 DNA camouflage with a switchable

  18. Administrative Circular No. 26 (Rev.10) - Recognition of merit

    CERN Multimedia

    2014-01-01

    Administrative Circular No. 26 (Rev. 10) entitled “Recognition of Merit”, approved by the Director-General following discussion at the Standing Concertation Committee meeting of 5 December 2013 and entering into force on 1 January 2014, is available on the intranet site of the Human Resources Department (see here).   This circular is applicable to staff members. It cancels and replaces Administrative Circular No. 26 (Rev. 9) entitled “Recognition of Merit” of December 2011. The circular was revised in order to take into account the work performed in the framework of an elective mandate during the exercise of merit recognition of staff members. In addition, the circular was revised to provide that, in the case of staff members on special leave for professional reasons for a period equal to or longer than half a year, it will no longer be possible to grant an exceptional advancement. Department Head Office HR Department

  19. Nearest Neighbor Estimates of Entropy for Multivariate Circular Distributions

    Directory of Open Access Journals (Sweden)

    Neeraj Misra

    2010-05-01

    Full Text Available In molecular sciences, the estimation of entropies of molecules is important for the understanding of many chemical and biological processes. Motivated by these applications, we consider the problem of estimating the entropies of circular random vectors and introduce non-parametric estimators based on circular distances between n sample points and their k th nearest neighbors (NN, where k (≤ n – 1 is a fixed positive integer. The proposed NN estimators are based on two different circular distances, and are proven to be asymptotically unbiased and consistent. The performance of one of the circular-distance estimators is investigated and compared with that of the already established Euclidean-distance NN estimator using Monte Carlo samples from an analytic distribution of six circular variables of an exactly known entropy and a large sample of seven internal-rotation angles in the molecule of tartaric acid, obtained by a realistic molecular-dynamics simulation.

  20. Characteristics of a Circular Logic and Its Treatment

    International Nuclear Information System (INIS)

    Lim, Ho-Gon; Han, Sang-Hoon; Yang, Joon Eon

    2007-01-01

    A circular logic or a logical loop is defined as the infinite circulation of supporting relations due to their mutual dependencies among the systems in the Fault Tree Analysis (FTA). While many methods to break the circular logic have been developed and used in the fault tree quantification codes, the general solution for a circular logic and its breaking methods are not generally known as yet. This paper presents an analytic solution for circular logics in which the systems are linearly interrelated with each other. Then, a general treatment of circular logics is discussed. To formulate the analytic solution, the relations among systems in the fault tree structure are described by the Boolean equations. The solution is, then, obtained from the successive substitutions of the Boolean equations, which is equivalent to the attaching processes of interrelated system's fault tree to a given fault tree. The solution for three interrelated systems and their independent fault tree structures are given as an example

  1. Voltammetric determination of attomolar levels of a sequence derived from the genom of hepatitis B virus by using molecular beacon mediated circular strand displacement and rolling circle amplification.

    Science.gov (United States)

    Huang, Shan; Feng, Mengmeng; Li, Jiawen; Liu, Yi; Xiao, Qi

    2018-03-03

    The authors describe an electrochemical method for the determination of the single-stranded DNA (ssDNA) oligonucleotide with a sequence derived from the genom of hepatitis B virus (HBV). It is making use of circular strand displacement (CSD) and rolling circle amplification (RCA) strategies mediated by a molecular beacon (MB). This ssDNA hybridizes with the loop portion of the MB immobilized on the surface of a gold electrode, while primer DNA also hybridizes with the rest of partial DNA sequences of MB. This triggers the MB-mediated CSD. The RCA is then initiated to produce a long DNA strand with multiple tandem-repeat sequences, and this results in a significant increase of the differential pulse voltammetric response of the electrochemical probe Methylene Blue at a rather low working potential of -0.24 V (vs. Ag/AgCl). Under optimal experimental conditions, the assay displays an ultrahigh sensitivity (with a 2.6 aM detection limit) and excellent selectivity. Response is linear in the 10 to 700 aM DNA concentration range. Graphical abstract Schematic of a voltammetric method for the determination of attomolar levels of target DNA. It is based on molecular beacon mediated circular strand displacement and rolling circle amplification strategies. Under optimal experimental conditions, the assay displays an ultrahigh sensitivity with a 2.6 aM detection limit and excellent selectivity.

  2. A computational protocol for the study of circularly polarized phosphorescence and circular dichroism in spin-forbidden absorption

    DEFF Research Database (Denmark)

    Kaminski, Maciej; Cukras, Janusz; Pecul, Magdalena

    2015-01-01

    We present a computational methodology to calculate the intensity of circular dichroism (CD) in spinforbidden absorption and of circularly polarized phosphorescence (CPP) signals, a manifestation of the optical activity of the triplet–singlet transitions in chiral compounds. The protocol is based...

  3. Paramagnetic decoration of DNA origami nanostructures by Eu³⁺ coordination.

    Science.gov (United States)

    Opherden, Lars; Oertel, Jana; Barkleit, Astrid; Fahmy, Karim; Keller, Adrian

    2014-07-15

    The folding of DNA into arbitrary two- and three-dimensional shapes, called DNA origami, represents a powerful tool for the synthesis of functional nanostructures. Here, we present the first approach toward the paramagnetic functionalization of DNA origami nanostructures by utilizing postassembly coordination with Eu(3+) ions. In contrast to the usual formation of toroidal dsDNA condensates in the presence of trivalent cations, planar as well as rod-like DNA origami maintain their shape and monomeric state even under high loading with the trivalent lanthanide. Europium coordination was demonstrated by the change in Eu(3+) luminescence upon binding to the two DNA origami. Their natural circular dichroism in the Mg(2+)- and Eu(3+)-bound state was found to be very similar to that of genomic DNA, evidencing little influence of the DNA origami superstructure on the local chirality of the stacked base pairs. In contrast, the magnetic circular dichroism of the Mg(2+)-bound DNA origami deviates from that of genomic DNA. Furthermore, the lanthanide affects the magnetic properties of DNA in a superstructure-dependent fashion, indicative of the existence of superstructure-specific geometry of Eu(3+) binding sites in the DNA origami that are not formed in genomic DNA. This simple approach lays the foundation for the generation of magneto-responsive DNA origami nanostructures. Such systems do not require covalent modifications and can be used for the magnetic manipulation of DNA nanostructures or for the paramagnetic alignment of molecules in NMR spectroscopy.

  4. A Role for the Host DNA Damage Response in Hepatitis B Virus cccDNA Formation—and Beyond?

    Directory of Open Access Journals (Sweden)

    Sabrina Schreiner

    2017-05-01

    Full Text Available Chronic hepatitis B virus (HBV infection puts more than 250 million people at a greatly increased risk to develop end-stage liver disease. Like all hepadnaviruses, HBV replicates via protein-primed reverse transcription of a pregenomic (pg RNA, yielding an unusually structured, viral polymerase-linked relaxed-circular (RC DNA as genome in infectious particles. Upon infection, RC-DNA is converted into nuclear covalently closed circular (ccc DNA. Associating with cellular proteins into an episomal minichromosome, cccDNA acts as template for new viral RNAs, ensuring formation of progeny virions. Hence, cccDNA represents the viral persistence reservoir that is not directly targeted by current anti-HBV therapeutics. Eliminating cccDNA will thus be at the heart of a cure for chronic hepatitis B. The low production of HBV cccDNA in most experimental models and the associated problems in reliable cccDNA quantitation have long hampered a deeper understanding of cccDNA molecular biology. Recent advancements including cccDNA-dependent cell culture systems have begun to identify select host DNA repair enzymes that HBV usurps for RC-DNA to cccDNA conversion. While this list is bound to grow, it may represent just one facet of a broader interaction with the cellular DNA damage response (DDR, a network of pathways that sense and repair aberrant DNA structures and in the process profoundly affect the cell cycle, up to inducing cell death if repair fails. Given the divergent interactions between other viruses and the DDR it will be intriguing to see how HBV copes with this multipronged host system.

  5. Recovery of DNA from agarose gel by trap method | Xia | African ...

    African Journals Online (AJOL)

    Recovery of DNA from agarose gel electrophoresis is a basic operation during molecular cloning. Circular or linear DNA fragments which vary from 1.5 to 6.5 kb and correspond to 1 kb marker can be recovered from 0.8 to 1.0% agarose gel smoothly with a simple and rapid trap method. The recovery efficiency could be ...

  6. Regulation Mechanism of HBV cccDNA

    Directory of Open Access Journals (Sweden)

    Cheng Jun

    2012-06-01

    Full Text Available Covalently closed circular (ccc DNA of hepatitis B virus (HBV existed in the nuclei of HBV infected hepatocytes with a half-life time of 14.3 years in a mathematic model. Viral protein feedback regulation in HBV life cycle to maintain vital viral replication is an important mechanism. Interleukin-6, epithelial growth factor, heme oxygenase-1, histones, and hepatocyte nuclear factors are demonstrated as the key regulators for HBV life cycle. CpG island structure and methylation status are involved in the regulation of HBV DNA replication. Nucleos(tide analogues are widely used in the clinical practice for the treatment of chronic hepatitis B patients, although no evidence indicating a direct inhibiton of HBV cccDNA. In the future, along with the study of HBV life cycle, new drugs including RNA interference technique, will pave the way to eliminate the HBV cccDNA from infected hepatocytes resulting final cure of chronic hepatitis B.

  7. DNA glue

    DEFF Research Database (Denmark)

    Filichev, Vyacheslav V; Astakhova, Irina V.; Malakhov, Andrei D.

    2008-01-01

    Significant alterations in thermal stability of parallel DNA triplexes and antiparallel duplexes were observed upon changing the attachment of ethynylpyrenes from para to ortho in the structure of phenylmethylglycerol inserted as a bulge into DNA (TINA). Insertions of two ortho-TINAs as a pseudo...

  8. Hyperstretching DNA

    NARCIS (Netherlands)

    Schakenraad, Koen; Biebricher, Andreas S.; Sebregts, Maarten; Ten Bensel, Brian; Peterman, Erwin J.G.; Wuite, Gijs J L; Heller, Iddo; Storm, Cornelis; Van Der Schoot, Paul

    2017-01-01

    The three-dimensional structure of DNA is highly susceptible to changes by mechanical and biochemical cues in vivo and in vitro. In particular, large increases in base pair spacing compared to regular B-DNA are effected by mechanical (over)stretching and by intercalation of compounds that are widely

  9. Raman spectroscopic study of plasma-treated salmon DNA

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Geon Joon; Kim, Yong Hee; Choi, Eun Ha [Plasma Bioscience Research Center, Kwangwoon University, Seoul 139-701 (Korea, Republic of); Kwon, Young-Wan [Department of Chemistry, Korea University, Seoul 136-701 (Korea, Republic of)

    2013-01-14

    In this research, we studied the effect of plasma treatment on the optical/structural properties of the deoxyribonucleic acid (DNA) extracted from salmon sperm. DNA-cetyltrimethylammonium (CTMA) films were obtained by complexation of DNA with CTMA. Circular dichroism (CD) and Raman spectra indicated that DNA retained its double helical structure in the solid film. The Raman spectra exhibited several vibration modes corresponding to the nuclear bases and the deoxyribose-phosphate backbones of the DNA, as well as the alkylchains of CTMA. Dielectric-barrier-discharge (DBD) plasma treatment induced structural modification and damage to the DNA, as observed by changes in the ultraviolet-visible absorption, CD, and Raman spectra. The optical emission spectra of the DBD plasma confirmed that DNA modification was induced by plasma ions such as reactive oxygen species and reactive nitrogen species.

  10. Circular SAR Optimization Imaging Method of Buildings

    Directory of Open Access Journals (Sweden)

    Wang Jian-feng

    2015-12-01

    Full Text Available The Circular Synthetic Aperture Radar (CSAR can obtain the entire scattering properties of targets because of its great ability of 360° observation. In this study, an optimal orientation of the CSAR imaging algorithm of buildings is proposed by applying a combination of coherent and incoherent processing techniques. FEKO software is used to construct the electromagnetic scattering modes and simulate the radar echo. The FEKO imaging results are compared with the isotropic scattering results. On comparison, the optimal azimuth coherent accumulation angle of CSAR imaging of buildings is obtained. Practically, the scattering directions of buildings are unknown; therefore, we divide the 360° echo of CSAR into many overlapped and few angle echoes corresponding to the sub-aperture and then perform an imaging procedure on each sub-aperture. Sub-aperture imaging results are applied to obtain the all-around image using incoherent fusion techniques. The polarimetry decomposition method is used to decompose the all-around image and further retrieve the edge information of buildings successfully. The proposed method is validated with P-band airborne CSAR data from Sichuan, China.

  11. Circular Conditional Autoregressive Modeling of Vector Fields.

    Science.gov (United States)

    Modlin, Danny; Fuentes, Montse; Reich, Brian

    2012-02-01

    As hurricanes approach landfall, there are several hazards for which coastal populations must be prepared. Damaging winds, torrential rains, and tornadoes play havoc with both the coast and inland areas; but, the biggest seaside menace to life and property is the storm surge. Wind fields are used as the primary forcing for the numerical forecasts of the coastal ocean response to hurricane force winds, such as the height of the storm surge and the degree of coastal flooding. Unfortunately, developments in deterministic modeling of these forcings have been hindered by computational expenses. In this paper, we present a multivariate spatial model for vector fields, that we apply to hurricane winds. We parameterize the wind vector at each site in polar coordinates and specify a circular conditional autoregressive (CCAR) model for the vector direction, and a spatial CAR model for speed. We apply our framework for vector fields to hurricane surface wind fields for Hurricane Floyd of 1999 and compare our CCAR model to prior methods that decompose wind speed and direction into its N-S and W-E cardinal components.

  12. On Introducing Asymmetry into Circular Distributions

    Directory of Open Access Journals (Sweden)

    Dale Umbach

    2012-07-01

    Full Text Available Normal 0 false false false EN-US X-NONE X-NONE /* Style Definitions */ table.MsoNormalTable {mso-style-name:"Table Normal"; mso-tstyle-rowband-size:0; mso-tstyle-colband-size:0; mso-style-noshow:yes; mso-style-priority:99; mso-style-parent:""; mso-padding-alt:0in 5.4pt 0in 5.4pt; mso-para-margin:0in; mso-para-margin-bottom:.0001pt; mso-pagination:widow-orphan; font-size:10.0pt; font-family:"Times New Roman","serif";} We give a brief history of the results which led to the introduction of asymmetry into symmetric circular distributions. This is followed by the presentation of another method of introducing asymmetry. Some properties of the induced distributions are studied. Finally, this new distribution is shown to be a reasonable fit to the Jander ant data as presented in Fisher (1993.

  13. Status of the Future Circular Collider Study

    CERN Document Server

    AUTHOR|(CDS)2108454; Zimmermann, Frank

    2016-01-01

    Following the 2013 update of the European Strategy for Particle Physics, the international Future Circular Collider (FCC) Study has been launched by CERN as host institute. Its main purpose and long-term goal is to design an energyfrontier hadron collider (FCC-hh) with a centre-of-mass energy of about 100 TeV in a new 80–100 km tunnel. The FCC study also includes the design of a 90–350 GeV highluminosity lepton collider (FCC-ee) installed in the same tunnel, serving as Higgs, top and Z factory, as a potential intermediate step, as well as an electron-proton collider option (FCC-he). The physics cases for such machines are being assessed and concepts for experiments will be developed by the end of 2018, in time for the next update of the European Strategy for Particle Physics. This overview summarizes the status of machine designs and parameters, and it discusses the essential technical components being developed in the frame of the FCC study. Key elements are superconducting accelerator-dipole magnets wit...

  14. Challenges for highest energy circular colliders

    CERN Document Server

    Benedikt, M; Wenninger, J; Zimmermann, F

    2014-01-01

    A new tunnel of 80–100 km circumference could host a 100 TeV centre-of-mass energy-frontier proton collider (FCC-hh/VHE-LHC), with a circular lepton collider (FCCee/TLEP) as potential intermediate step, and a leptonhadron collider (FCC-he) as additional option. FCC-ee, operating at four different energies for precision physics of the Z, W, and Higgs boson and the top quark, represents a significant push in terms of technology and design parameters. Pertinent R&D efforts include the RF system, topup injection scheme, optics design for arcs and final focus, effects of beamstrahlung, beam polarization, energy calibration, and power consumption. FCC-hh faces other challenges, such as high-field magnet design, machine protection and effective handling of large synchrotron radiation power in a superconducting machine. All these issues are being addressed by a global FCC collaboration. A parallel design study in China prepares for a similar, but smaller collider, called CepC/SppC.

  15. Physicians’ circularity in health regions in Brazil

    Directory of Open Access Journals (Sweden)

    Paulo Henrique Seixas

    Full Text Available Abstract Objectives: to characterize the medical circularity in Brazil and to discuss the case in the North and South Barretos regions, São Paulo. Methods: a cross-sectional study using secondary data from the national registrations and a case study of physician’s sample in the North-Barretos and South-Barretos regions. Results: in the health regions in Brazil, on an average, 45% of the physicians in activities circulate in more than one region. The Capitals of the States have more stable physicians while more than 50% of the medical workforce work in other regions. The professionals with the greatest tendency to move from one work place to another are those who work in surgical specialties in services to uphold the diagnostic and therapy. Conclusions: there is a high circulation of physicians among the regions, with distinct characteristics between geographical and health regions. In case of Barretos area, the professionals move from one workplace to another according to their professional association and specialized practice.

  16. SEAMLESS TECHNOLOGY ON CIRCULAR KNITTING MACHINES

    Directory of Open Access Journals (Sweden)

    CRETU Viorica

    2014-05-01

    Full Text Available With industrial progress, the advancements in garment manufacturing have evolved from cut & sew to complete garment knitting, which produces one entire garment without sewing or linking process. Seamless knitting technology is similar to sock manufacture, the specialized circular knitting machines producing 3 dimensional garments with no side seams, with the waistband integrated with body of the garment and with knitted washing instructions and logos. The paper starts by presenting the main advantages of seamless garments but also some limitations because the technology. Because for a seamless garment, which is realized as a knitted tub, is very important to ensure the required final chest size, it was presented the main components involved: the knitting machine, the garment design and the yarns used. The knitting machines, beside the values of diameters and gauges with a great impact on the chest size, are characterized by a very innovative and complex construction. The design of a seamless garment is fundamental different compared to garments produced on a traditional way because the designer must to work backwards from a finished garment to create the knitting programme that will ultimately give the correct finished size. On the end of the paper it was presented some of the applications of the seamless products that cover intimate apparel and other bodywear, outwear, activewear and functional sportswear, upholstery, industrial, automotive and medical textiles.

  17. Administrative Circular No. 14 (Rev. 2)

    CERN Document Server

    HR Department

    2007-01-01

    The HR Department wishes to draw the attention of members of the personnel to a number of amendments to Administrative Circular No. 14 (Rev. 2) entitled "Protection of members of the personnel against the financial consequences of illness, accident and disability" which came into force on 1st July 2006 (cf. Weekly Bulletin of 14 and 21 August 2006). Occupational Accident Declaration Form (HS50) https://cern.ch/service-procedures/AdminMan/Forms/HS50E.doc •\tIt must be completed within 10 working days of the date on which the accident occurred (§ 29.2.1), unless the person concerned is materially unable to meet this deadline. • The completed formula must be accompanied by a medical certificate giving details of any bodily injuries resulting from the accident (Annex 1, § 5). The medical certificate must be obtained from the doctor who has been consulted for that purpose. Benefits resulting from illnesses and accidents Medical treatment will cease to be reimbursed under ...

  18. Calorimetry for the Future Circular Collider experiments

    CERN Document Server

    AUTHOR|(INSPIRE)INSPIRE-00510572; Kisiel, Adam

    2017-11-21

    The Future Circular Collider (FCC) Collaboration is preparing the next generation of experiments in high energy physics. The goal is to collide protons at 100 TeV centre–of–mass energy, seven times higher than at the most powerful existing accelerator, the Large Hadron Collider (LHC). Such machine would extend the research carried out at the LHC including the study of the Higgs boson, the search for the origin of the baryon asymmetry, the mass of neutrinos, and the dark matter. The detectors designed for the FCC experiments need to tackle the harsh conditions of the unprecedented collision energy and luminosity. At the same time, they need to provide precise measurements in a wider range of pseudorapidity than the existing experiments. The focus of this thesis is a design and performance studies of one of the sub-detectors, the electromagnetic calorimeter. Its aim is to measure the energy and the position of electrons, positrons, and photons produced in the collisions. The detector proposed in this thesis...

  19. Infrared circular photogalvanic effect in topological insulators

    Science.gov (United States)

    Luo, Siyuan

    2018-04-01

    Topological insulators have attracted a lot of attention in recent years due to its unique phenomena. Circular photogalvanic effect (CPGE) is one of the important phenomena in topological insulators. Bi2Se3, as one of the 3D topological insulators, consist of a single Dirac cone at the Γ point in k-space [1], corresponding to the surface states. Controlled by the Berry curvature of the surface band, the dominant photo response due to the interband transition is helicity dependent [2]. In addition, due to the spin-momentum locking in topological insulators' surface, the sign of spin-angular-momentum of obliquely incident light and photo currents are locked together. On the other hand, Bi2Se3 consists of quintuple layers which make it possible to be exfoliated and transferred based on graphene fabrication. In this paper, Bi2Se3 devices were fabricated and Ohm contact was achieved. We experimentally demonstrated the CPGE in Bi2Se3 using 1550nm incident laser.

  20. Coulomb-interacting billiards in circular cavities

    International Nuclear Information System (INIS)

    Solanpää, J; Räsänen, E; Nokelainen, J; Luukko, P J J

    2013-01-01

    We apply a molecular dynamics scheme to analyze classically chaotic properties of a two-dimensional circular billiard system containing two Coulomb-interacting electrons. As such, the system resembles a prototype model for a semiconductor quantum dot. The interaction strength is varied from the noninteracting limit with zero potential energy up to the strongly interacting regime where the relative kinetic energy approaches zero. At weak interactions the bouncing maps show jumps between quasi-regular orbits. In the strong-interaction limit we find an analytic expression for the bouncing map. Its validity in the general case is assessed by comparison with our numerical data. To obtain a more quantitative view on the dynamics as the interaction strength is varied, we compute and analyze the escape rates of the system. Apart from very weak or strong interactions, the escape rates show consistently exponential behavior, thus suggesting strongly chaotic dynamics and a phase space without significant sticky regions within the considered time scales. (paper)

  1. Psoralens cleave pBR322 DNA under ultraviolet radiation

    International Nuclear Information System (INIS)

    Kagan, J.; Xinsheng Chen; Wang, T.P.

    1992-01-01

    Supercoiled (SC) pBR322 was used to probe the recent claim that 5-geranoxylpsoralen (5-GOP) did not photoreact with DNA. Contrary to expectations, 5-GOP was found to damage DNA in the presence of UV-A through two competing pathways; (a) single strand breaks, identified by the conversion of supercoiled into open circular and linear DNA, and (b) cross-linking, revealed by the fluence-dependent decrease in the extent of denaturation of the double stranded supercoiled DNA to single stranded circular DNA. In addition, a fluence-dependent modification reduced the ability of the restriction enzyme EcoR I to linearize the photosensitized DNA, and alkali-labile lesions were generated. Psoralen, 5-methoxypsoralen, and 8-methoxypsoralen, which are well-known to undergo cycloaddition to DNA, had a more pronounced effect on supercoiled DNA. Single strand breaks occurred more readily than with 5-GOP, and the surviving SC form remaining had reduced electrophoretic mobility in agarose gels. In all cases, the DNA damage was more prominent when oxygen was absent. (author)

  2. In vitro DNA binding studies of Aspartame, an artificial sweetener.

    Science.gov (United States)

    Kashanian, Soheila; Khodaei, Mohammad Mehdi; Kheirdoosh, Fahimeh

    2013-03-05

    A number of small molecules bind directly and selectively to DNA, by inhibiting replication, transcription or topoisomerase activity. In this work the interaction of native calf thymus DNA (CT-DNA) with Aspartame (APM), an artificial sweeteners was studied at physiological pH. DNA binding study of APM is useful to understand APM-DNA interaction mechanism and to provide guidance for the application and design of new and safer artificial sweeteners. The interaction was investigated using spectrophotometric, spectrofluorometric competition experiment and circular dichroism (CD). Hypochromism and red shift are shown in UV absorption band of APM. A strong fluorescence quenching reaction of DNA to APM was observed and the binding constants (Kf) of DNA with APM and corresponding number of binding sites (n) were calculated at different temperatures. Thermodynamic parameters, enthalpy changes (ΔH) and entropy changes (ΔS) were calculated to be +181kJmol(-1) and +681Jmol(-1)K(-1) according to Van't Hoff equation, which indicated that reaction is predominantly entropically driven. Moreover, spectrofluorometric competition experiment and circular dichroism (CD) results are indicative of non-intercalative DNA binding nature of APM. We suggest that APM interacts with calf thymus DNA via groove binding mode with an intrinsic binding constant of 5×10(+4)M(-1). Copyright © 2013 Elsevier B.V. All rights reserved.

  3. The Baltics on Their Way towards a Circular Economy

    Directory of Open Access Journals (Sweden)

    Grigoryan A. A.

    2017-10-01

    Full Text Available Circular economy has been studied extensively both in Europe and worldwide. It is largely viewed as a potential strategy for societal development, aimed to increase prosperity while reducing dependence on raw materials and energy. Many businesses regard circular economy as a way to enhance economic growth and increase profits. Governments across the world actively engage in the discussion about the benefits of a transition to a circular economy and about its impact on employment, economic growth, and the environment. This paper aims to study the major issues of circular economy, to identify its advantages, and to offer an insight into the transition stage the Baltic States are undergoing today on their way to circular economy. It is stressed that the Baltic countries are not fully using the opportunities offered by a circular economy. For example, Latvia’s, Lithuania’s, and Estonia’s recycling rates are significantly below those of other European countries. The Baltics depend heavily on EU financial support. An increase in funding will contribute to the implementation of circular economy technologies.

  4. Administrative Circular No. 26 (Rev. 9) – Recognition of Merit

    CERN Multimedia

    2012-01-01

    Administrative Circular No. 26 (Rev. 9) entitled "Recognition of Merit”, approved by the Director-General following discussion in the Standing Concertation Committee meeting on 27 September 2011 is available on the intranet site of the Human Resources Department: https://cern.ch/hr-docs/admincirc/admincirc.asp The circular was above all revised in order to integrate the new CERN Competency Model into the annual procedure of performance appraisal. It cancels and replaces Administrative Circular No. 26 (Rev. 8) entitled "Recognition of merit” of September 2008. Department Head Office HR Department

  5. Administrative Circular No. 26 (Rev. 7) – May 2007

    CERN Multimedia

    HR Department

    2007-01-01

    Recognition of Merit of Staff Members Administrative Circular No. 26 (Rev. 7) is now available on the intranet site of the Human Resources Department. This circular cancels and replaces Administrative Circular No. 26 (Rev. 6) - Procedures governing the career development of staff members. Copies will shortly be available in Departmental secretariats. If you require any additional information on the new staff-member merit assessment and recognition system, you may consult the FAQ, which has been available on the Human Resources Department intranet site since February 2007. Human Resources Department Tel. 78003

  6. Filtered backprojection for modifying the impulse response of circular tomosynthesis

    International Nuclear Information System (INIS)

    Stevens, Grant M.; Fahrig, Rebecca; Pelc, Norbert J.

    2001-01-01

    A filtering technique has been developed to modify the three-dimensional impulse response of circular motion tomosynthesis to allow the generation of images whose appearance is like those of some other imaging geometries. In particular, this technique can reconstruct images with a blurring function which is more homogeneous for off-focal plane objects than that from circular tomosynthesis. In this paper, we describe the filtering process, and demonstrate the ability to alter the impulse response in circular motion tomosynthesis from a ring to a disk. This filtering may be desirable because the blurred out-of-plane objects appear less structured

  7. How can design science contribute to a circular economy?

    DEFF Research Database (Denmark)

    Pigosso, Daniela Cristina Antelmi; McAloone, Tim C.

    2017-01-01

    Circular Economy is increasingly seen as a key approach to operationalising goals and supporting the transition to a sustainable society by enhancing competitiveness and economic growth. Creating a Circular Economy requires fundamental changes throughout the value chain, from innovation, product...... design and production processes all the way to end of life, new business models and consumption patterns. This paper explores how design science can support the transition from the traditional linear 'take-make-consume-dispose' approach, to a Circular Economy. By means of a systematic literature review...

  8. Absorbed Power Minimization in Cellular Users with Circular Antenna Arrays

    Science.gov (United States)

    Christofilakis, Vasilis; Votis, Constantinos; Tatsis, Giorgos; Raptis, Vasilis; Kostarakis, Panos

    2010-01-01

    Nowadays electromagnetic pollution of non ionizing radiation generated by cellular phones concerns millions of people. In this paper the use of circular antenna array as a means of minimizing the absorbed power by cellular phone users is introduced. In particular, the different characteristics of radiation patterns produced by a helical conventional antenna used in mobile phones operating at 900 MHz and those produced by a circular antenna array, hypothetically used in the same mobile phones, are in detail examined. Furthermore, the percentage of decrement of the power absorbed in the head as a function of direction of arrival is estimated for the circular antenna array.

  9. DNA probes

    International Nuclear Information System (INIS)

    Castelino, J.

    1992-01-01

    The creation of DNA probes for detection of specific nucleotide segments differs from ligand detection in that it is a chemical rather than an immunological reaction. Complementary DNA or RNA is used in place of the antibody and is labelled with 32 P. So far, DNA probes have been successfully employed in the diagnosis of inherited disorders, infectious diseases, and for identification of human oncogenes. The latest approach to the diagnosis of communicable and parasitic infections is based on the use of deoxyribonucleic acid (DNA) probes. The genetic information of all cells is encoded by DNA and DNA probe approach to identification of pathogens is unique because the focus of the method is the nucleic acid content of the organism rather than the products that the nucleic acid encodes. Since every properly classified species has some unique nucleotide sequences that distinguish it from every other species, each organism's genetic composition is in essence a finger print that can be used for its identification. In addition to this specificity, DNA probes offer other advantages in that pathogens may be identified directly in clinical specimens

  10. DNA probes

    Energy Technology Data Exchange (ETDEWEB)

    Castelino, J

    1993-12-31

    The creation of DNA probes for detection of specific nucleotide segments differs from ligand detection in that it is a chemical rather than an immunological reaction. Complementary DNA or RNA is used in place of the antibody and is labelled with {sup 32}P. So far, DNA probes have been successfully employed in the diagnosis of inherited disorders, infectious diseases, and for identification of human oncogenes. The latest approach to the diagnosis of communicable and parasitic infections is based on the use of deoxyribonucleic acid (DNA) probes. The genetic information of all cells is encoded by DNA and DNA probe approach to identification of pathogens is unique because the focus of the method is the nucleic acid content of the organism rather than the products that the nucleic acid encodes. Since every properly classified species has some unique nucleotide sequences that distinguish it from every other species, each organism`s genetic composition is in essence a finger print that can be used for its identification. In addition to this specificity, DNA probes offer other advantages in that pathogens may be identified directly in clinical specimens 10 figs, 2 tabs

  11. The histone H3K9 methylation and RNAi pathways regulate normalnucleolar and repeated DNA organization by inhibiting formation ofextrachromosomal DNAs

    Energy Technology Data Exchange (ETDEWEB)

    Peng, Jamy C.; Karpen, Gary H.

    2006-06-15

    In order to identify regulators of nuclear organization, Drosophila mutants in the Su(var)3-9 histone H3K9 methyltransferase, RNAi pathway components, and other regulators of heterochromatin-mediated gene silencing were examined for altered nucleoli and positioning of repeated DNAs. Animals lacking components of the H3K9 methylation and RNAi pathways contained disorganized nucleoli, ribosomal DNA (rDNA) and satellite DNAs. The levels of H3K9 dimethylation (H3K9me2) in chromatin associated with repeated DNAs decreased dramatically in Su(var)3-9 and dcr-2 (dicer-2) mutant tissues compared to wild type. We also observed a substantial increase in extrachromosomal repeated DNAs in mutant tissues. The disorganized nucleolus phenotype depends on the presence of Ligase 4 (Lig4), and ecc DNA formation is not induced by removal of cohesin. We conclude that H3K9 methylation of rDNA and satellites, maintained by Su(var)3-9, HP1, and the RNAi pathway, is necessary for the structural stability of repeated DNAs, which is mediated through suppression of non-homologous end joining (NHEJ). These results suggest a mechanism for how local chromatin structure can regulate genome stability, and the organization of chromosomal elements and nuclear organelles.

  12. Preparation of Phi29 DNA polymerase free of amplifiable DNA using ethidium monoazide, an ultraviolet-free light-emitting diode lamp and trehalose.

    Directory of Open Access Journals (Sweden)

    Hirokazu Takahashi

    Full Text Available We previously reported that multiply-primed rolling circle amplification (MRPCA using modified random RNA primers can amplify tiny amounts of circular DNA without producing any byproducts. However, contaminating DNA in recombinant Phi29 DNA polymerase adversely affects the outcome of MPRCA, especially for negative controls such as non-template controls. The amplified DNA in negative control casts doubt on the result of DNA amplification. Since Phi29 DNA polymerase has high affinity for both single-strand and double-stranded DNA, some amount of host DNA will always remain in the recombinant polymerase. Here we describe a procedure for preparing Phi29 DNA polymerase which is essentially free of amplifiable DNA. This procedure is realized by a combination of host DNA removal using appropriate salt concentrations, inactivation of amplifiable DNA using ethidium monoazide, and irradiation with visible light from a light-emitting diode lamp. Any remaining DNA, which likely exists as oligonucleotides captured by the Phi29 DNA polymerase, is degraded by the 3'-5' exonuclease activity of the polymerase itself in the presence of trehalose, used as an anti-aggregation reagent. Phi29 DNA polymerase purified by this procedure has little amplifiable DNA, resulting in reproducible amplification of at least ten copies of plasmid DNA without any byproducts and reducing reaction volume. This procedure could aid the amplification of tiny amounts DNA, thereby providing clear evidence of contamination from laboratory environments, tools and reagents.

  13. DNA nanotechnology for nanophotonic applications.

    Science.gov (United States)

    Samanta, Anirban; Banerjee, Saswata; Liu, Yan

    2015-02-14

    DNA nanotechnology has touched the epitome of miniaturization by integrating various nanometer size particles with nanometer precision. This enticing bottom-up approach has employed small DNA tiles, large multi-dimensional polymeric structures or more recently DNA origami to organize nanoparticles of different inorganic materials, small organic molecules or macro-biomolecules like proteins, and RNAs into fascinating patterns that are difficult to achieve by other conventional methods. Here, we are especially interested in the self-assembly of nanomaterials that are potentially attractive elements in the burgeoning field of nanophotonics. These materials include plasmonic nanoparticles, quantum dots, fluorescent organic dyes, etc. DNA based self-assembly allows excellent control over distance, orientation and stoichiometry of these nano-elements that helps to engineer intelligent systems that can potentially pave the path for future technology. Many outstanding structures have been fabricated that are capable of fine tuning optical properties, such as fluorescence intensity and lifetime modulation, enhancement of Raman scattering and emergence of circular dichroism responses. Within the limited scope of this review we have tried to give a glimpse of the development of this still nascent but highly promising field to its current status as well as the existing challenges before us.

  14. Circular RNAs and systemic lupus erythematosus

    Energy Technology Data Exchange (ETDEWEB)

    Li, Lian-Ju; Huang, Qing; Pan, Hai-Feng; Ye, Dong-Qing, E-mail: ydqahmu@gmail.com

    2016-08-15

    Circular RNAs (circRNAs) are a large class of noncoding RNAs that form covalently closed RNA circles. The discovery of circRNAs discloses a new layer of gene regulation occurred post-transcriptionally. Identification of endogenous circRNAs benefits from the advance in high-throughput RNA sequencing and remains challenging. Many studies probing into the mechanisms of circRNAs formation occurred cotranscriptionally or posttranscriptionally emerge and conclude that canonical splicing mechanism, sequence properties, and certain regulatory factors are at play in the process. Although our knowledge on functions of circRNAs is rather limited, a few circRNAs are shown to sponge miRNA and regulate gene transcription. The clearest case is one circRNA CDR1as that serves as sponge of miR-7. Researches on circRNAs in human diseases such as cancers highlight the function and physical relevance of circRNAs. Given the implication of miRNAs in the initiation and progression of systemic lupus erythematosus (SLE) and the roles of circRNAs in sponging miRNA and gene regulation, it is appealing to speculate that circRNAs may associate with SLE and may be potential therapeutic targets for treatment of SLE. Future studies should attach more importance to the relationship between circRNAs and SLE. This review will concern identification, biogenesis, and function of circRNAs, introduce reports exploring the association of circRNAs with human diseases, and conjecture the potential roles of circRNAs in SLE. - Highlights: • Studies have discovered thousands of circRNAs and interpreted their biogenesis. • Cytoplasmic circRNAs sponge miRNA and nuclear circRNAs modulate gene transcription. • Aberrant expression of circRNAs has been observed in various cancers. • CircRNAs may partake in the pathogenesis of systemic lupus erythematosus.

  15. Circular RNAs and systemic lupus erythematosus

    International Nuclear Information System (INIS)

    Li, Lian-Ju; Huang, Qing; Pan, Hai-Feng; Ye, Dong-Qing

    2016-01-01

    Circular RNAs (circRNAs) are a large class of noncoding RNAs that form covalently closed RNA circles. The discovery of circRNAs discloses a new layer of gene regulation occurred post-transcriptionally. Identification of endogenous circRNAs benefits from the advance in high-throughput RNA sequencing and remains challenging. Many studies probing into the mechanisms of circRNAs formation occurred cotranscriptionally or posttranscriptionally emerge and conclude that canonical splicing mechanism, sequence properties, and certain regulatory factors are at play in the process. Although our knowledge on functions of circRNAs is rather limited, a few circRNAs are shown to sponge miRNA and regulate gene transcription. The clearest case is one circRNA CDR1as that serves as sponge of miR-7. Researches on circRNAs in human diseases such as cancers highlight the function and physical relevance of circRNAs. Given the implication of miRNAs in the initiation and progression of systemic lupus erythematosus (SLE) and the roles of circRNAs in sponging miRNA and gene regulation, it is appealing to speculate that circRNAs may associate with SLE and may be potential therapeutic targets for treatment of SLE. Future studies should attach more importance to the relationship between circRNAs and SLE. This review will concern identification, biogenesis, and function of circRNAs, introduce reports exploring the association of circRNAs with human diseases, and conjecture the potential roles of circRNAs in SLE. - Highlights: • Studies have discovered thousands of circRNAs and interpreted their biogenesis. • Cytoplasmic circRNAs sponge miRNA and nuclear circRNAs modulate gene transcription. • Aberrant expression of circRNAs has been observed in various cancers. • CircRNAs may partake in the pathogenesis of systemic lupus erythematosus.

  16. Circular mucosal anopexy: Experience and technical considerations.

    Science.gov (United States)

    Hidalgo Grau, Luis Antonio; Ruiz Edo, Neus; Llorca Cardeñosa, Sara; Heredia Budó, Adolfo; Estrada Ferrer, Óscar; Del Bas Rubia, Marta; García Torralbo, Eva María; Suñol Sala, Xavier

    2016-05-01

    Circular mucosal anopexy (CMA) achieves a more comfortable postoperative period than resective techniques. But complications and recurrences are not infrequent. This study aims to evaluate of the efficacy of CMA in the treatment of hemorrhoids and rectal mucosal prolapse (RMP). From 1999 to 2011, 613 patients underwent surgery for either hemorrhoids or RMP in our hospital. CMA was performed in 327 patients. Gender distribution was 196 male and 131 female. Hemorrhoidal grades were distributed as follows: 28 patients had RMP, 46 2nd grade, 146 3rd grade and 107 4th grade. Major ambulatory surgery (MAS) was performed in 79.9%. Recurrence of hemorrhoids was studied and groups of recurrence and no-recurrence were compared. Postoperative pain was evaluated by Visual Analogical Scale (VAS) as well as early complications. A total of 31 patients needed reoperation (5 RMP, 2 with 2nd grade, 17 with 3rd grade,/with 4th grade). No statistically significant differences were found between the non-recurrent group and the recurrent group with regards to gender, surgical time or hemorrhoidal grade, but there were differences related to age. In the VAS, 81.3% of patients expressed a postoperative pain ≤ 2 at the first week. Five patients needed reoperation for early postoperative bleeding. Six patients needed admission for postoperative pain. Recurrence rate is higher in CMA than in resective techniques. CMA is a useful technique for the treatment of hemorrhoids in MAS. Pain and the rate of complications are both low. Copyright © 2016 AEC. Publicado por Elsevier España, S.L.U. All rights reserved.

  17. Status of the Future Circular Collider Study

    Science.gov (United States)

    Benedikt, Michael

    2016-03-01

    Following the 2013 update of the European Strategy for Particle Physics, the international Future Circular Collider (FCC) Study has been launched by CERN as host institute, to design an energy frontier hadron collider (FCC-hh) in a new 80-100 km tunnel with a centre-of-mass energy of about 100 TeV, an order of magnitude beyond the LHC's, as a long-term goal. The FCC study also includes the design of a 90-350 GeV high-luminosity lepton collider (FCC-ee) installed in the same tunnel, serving as Higgs, top and Z factory, as a potential intermediate step, as well as an electron-proton collider option (FCC-he). The physics cases for such machines will be assessed and concepts for experiments will be developed in time for the next update of the European Strategy for Particle Physics by the end of 2018. The presentation will summarize the status of machine designs and parameters and discuss the essential technical components to be developed in the frame of the FCC study. Key elements are superconducting accelerator-dipole magnets with a field of 16 T for the hadron collider and high-power, high-efficiency RF systems for the lepton collider. In addition the unprecedented beam power presents special challenges for the hadron collider for all aspects of beam handling and machine protection. First conclusions of geological investigations and implementation studies will be presented. The status of the FCC collaboration and the further planning for the study will be outlined.

  18. Frenkel-exciton decomposition analysis of circular dichroism and circularly polarized luminescence for multichromophoric systems.

    Science.gov (United States)

    Shiraogawa, Takafumi; Ehara, Masahiro; Jurinovich, Sandro; Cupellini, Lorenzo; Mennucci, Benedetta

    2018-06-15

    Recently, a method to calculate the absorption and circular dichroism (CD) spectra based on the exciton coupling has been developed. In this work, the method was utilized for the decomposition of the CD and circularly polarized luminescence (CPL) spectra of a multichromophoric system into chromophore contributions for recently developed through-space conjugated oligomers. The method which has been implemented using rotatory strength in the velocity form and therefore it is gauge-invariant, enables us to evaluate the contribution from each chromophoric unit and locally excited state to the CD and CPL spectra of the total system. The excitonic calculations suitably reproduce the full calculations of the system, as well as the experimental results. We demonstrate that the interactions between electric transition dipole moments of adjacent chromophoric units are crucial in the CD and CPL spectra of the multichromophoric systems, while the interactions between electric and magnetic transition dipole moments are not negligible. © 2018 Wiley Periodicals, Inc. © 2018 Wiley Periodicals, Inc.

  19. Circular polarimetry of the magnetic compact binary AM Herculis

    Energy Technology Data Exchange (ETDEWEB)

    Piirola, V; Vilhu, O; Tuominen, I

    1982-01-01

    Circular polarimetry in the red and simultaneous photometric observations in the UBVRI bands during the period June 1 to 3, 1981, of AM Herculis are discussed. Peak value of negative circular polarization (- 15 %) is stronger than observed in 1976 to 1979. Variations in the shape of the polarization and light curves occur from night to night. Positive crossover and reversal of the sign of the circular polarization are only marginal. Long term changes in polarization may be partly due to precession of the axis of rotation of the white dwarf about the binary axis. However, the duration of the phase interval where circular polarization remains close to zero changes on a time scale of days, casting doubt on precession models. The changing shape and position of the accretion columns with respect to the magnetic axis could explain short term variations. (ESA)

  20. Evaluation of circularity error in drilling of syntactic foam composites

    Science.gov (United States)

    Ashrith H., S.; Doddamani, Mrityunjay; Gaitonde, Vinayak

    2018-04-01

    Syntactic foams are widely used in structural applications of automobiles, aircrafts and underwater vehicles due to their lightweight properties combined with high compression strength and low moisture absorption. Structural application requires drilling of holes for assembly purpose. In this investigation response surface methodology based mathematical models are used to analyze the effects of cutting speed, feed, drill diameter and filler content on circularity error both at entry and exit level in drilling of glass microballoon reinforced epoxy syntactic foam. Experiments are conducted based on full factorial design using solid coated tungsten carbide twist drills. The parametric analysis reveals that circularity error is highly influenced by drill diameter followed by spindle speed at the entry and exit level. Parametric analysis also reveals that increasing filler content decreases circularity error by 13.65 and 11.96% respectively at entry and exit levels. Average circularity error at the entry level is found to be 23.73% higher than at the exit level.

  1. Light Emitting Diode (LED) circular traffic signal lifetime management system.

    Science.gov (United States)

    2011-02-01

    The objective of this research is to build lifetime curves for red, yellow, and green LED circular traffic signals through 20,000-hr. accelerated stress testing of samples operating under Louisianas environmental conditions.

  2. Primal-dual path-following algorithms for circular programming

    Directory of Open Access Journals (Sweden)

    Baha Alzalg

    2017-06-01

    Full Text Available Circular programming problems are a new class of convex optimization problems that include second-order cone programming problems as a special case‎. ‎Alizadeh and Goldfarb [Math‎. ‎Program‎. ‎Ser‎. ‎A 95 (2003 3--51] introduced primal-dual path-following algorithms for solving second-order cone programming problems‎. ‎In this paper‎, ‎we generalize their work by using the machinery of Euclidean Jordan algebras associated with the circular cones to derive primal-dual path-following interior point algorithms for circular programming problems‎. ‎We prove polynomial convergence of the proposed algorithms by showing that the circular logarithmic barrier is a strongly self-concordant barrier‎. ‎The numerical examples show the path-following algorithms are simple and efficient‎.

  3. Defense Outsourcing: The OMB Circular A-76 Policy

    National Research Council Canada - National Science Library

    Grasso, Valerie B

    2005-01-01

    This report provides information on the Office of Management and Budget s (OMB) Circular A-76, Performance of Commercial Activities, and the impact of a related reform initiative, the Federal Activities Inventory Reform Act (FAIR...

  4. Defense Outsourcing: The OMB Circular A-76 Policy

    National Research Council Canada - National Science Library

    Grasso, Valerie B

    2005-01-01

    This report provides information on the Office of Management and Budget's (0MB) Circular A-76, "Performance of Commercial Activities," and the impact of a related reform initiative, the Federal Activities Inventory Reform Act (FAIR...

  5. Launching transverse-electric Localized Waves from a circular waveguide

    KAUST Repository

    Salem, Mohamed; Niver, Edip

    2011-01-01

    Axially symmetric transverse electric (TE) modes of a circular waveguide section are used to synthesize the vector TE Localized Wave (LW) field at the open end of the waveguide section. The necessary excitation coefficients of these modes

  6. Administrative Circular No. 23 (Rev. 4) - Special working hours

    CERN Document Server

    Department Head Office - HR Department

    2016-01-01

    Administrative Circular No. 23 (Rev. 4) entitled "Special working hours", approved by the Director-General following discussion in the Standing Concertation Committee meeting on 22 March 2016, will be available on 1st September 2016 via the following link: https://cds.cern.ch/record/2208539.   This revised circular cancels and replaces Administrative Circular No. 23 (Rev. 3) also entitled "Special working hours" of January 2013. This document contains modifications to reflect the new career structure and ensuring the provision consistent with practice that compensation or remuneration of special working hours performed remotely is possible only in case of emergency.   This circular will enter into force on 1st September 2016.

  7. CSR perception as a signpost for circular economy

    NARCIS (Netherlands)

    Esken, Björn; Franco-Garcia, Laura; Fisscher, Olaf A.M.

    2018-01-01

    Purpose: This paper aims to identify managerial implications for multinational corporations (MNCs) with regard to circular economy (CE) by using data on corporate social responsibility (CSR) perception in different types of market economies owing to diverse institutional contexts. These managerial

  8. Circular, explosion-proof lamp provides uniform illumination

    Science.gov (United States)

    1966-01-01

    Circular explosion-proof fluorescent lamp is fitted around a TV camera lens to provide shadowless illumination with a low radiant heat flux. The lamp is mounted in a transparent acrylic housing sealed with clear silicone rubber.

  9. Generation of circular polarization of the cosmic microwave background

    International Nuclear Information System (INIS)

    Alexander, Stephon; Ochoa, Joseph; Kosowsky, Arthur

    2009-01-01

    The standard cosmological model, which includes only Compton scattering photon interactions at energy scales near recombination, results in zero primordial circular polarization of the cosmic microwave background. In this paper we consider a particular renormalizable and gauge-invariant standard model extension coupling photons to an external vector field via a Chern-Simons term, which arises as a radiative correction if gravitational torsion couples to fermions. We compute the transport equations for polarized photons from a Boltzmann-like equation, showing that such a coupling will source circular polarization of the microwave background. For the particular coupling considered here, the circular polarization effect is always negligible compared to the rotation of the linear polarization orientation, also derived using the same formalism. We note the possibility that limits on microwave background circular polarization may probe other photon interactions and related fundamental effects such as violations of Lorentz invariance.

  10. Molecular photoelectron holography with circularly polarized laser pulses.

    Science.gov (United States)

    Yang, Weifeng; Sheng, Zhihao; Feng, Xingpan; Wu, Miaoli; Chen, Zhangjin; Song, Xiaohong

    2014-02-10

    We investigate the photoelectron momentum distribution of molecular-ion H2+driven by ultrashort intense circularly polarized laser pulses. Both numerical solutions of the time-dependent Schrödinger equation (TDSE) and a quasiclassical model indicate that the photoelectron holography (PH) with circularly polarized pulses can occur in molecule. It is demonstrated that the interference between the direct electron wave and rescattered electron wave from one core to its neighboring core induces the PH. Moreover, the results of the TDSE predict that there is a tilt angle between the interference pattern of the PH and the direction perpendicular to the molecular axis. Furthermore, the tilt angle is sensitively dependent on the wavelength of the driven circularly polarized pulse, which is confirmed by the quasiclassical calculations. The PH induced by circularly polarized laser pulses provides a tool to resolve the electron dynamics and explore the spatial information of molecular structures.

  11. Shear strength of reinforced concrete circular cross-section beams

    Directory of Open Access Journals (Sweden)

    P. W. G. N. Teixeira

    Full Text Available A proposed adequation of NBR 6118, Item 7.4, related to shear strength of reinforced concrete beams is presented with aims to application on circular cross-section. The actual expressions are most suitable to rectangular cross-section and some misleading occurs when applied to circular sections at determination of VRd2, Vc and Vsw, as consequence of bw (beam width and d (effective depth definitions as well as the real effectiveness of circular stirrups. The proposed adequation is based on extensive bibliographic review and practical experience with a great number of infrastructure elements, such as anchored retaining pile walls, where the use of circular reinforced concrete members is frequent.

  12. DNA methylation

    DEFF Research Database (Denmark)

    Williams, Kristine; Christensen, Jesper; Helin, Kristian

    2012-01-01

    DNA methylation is involved in key cellular processes, including X-chromosome inactivation, imprinting and transcriptional silencing of specific genes and repetitive elements. DNA methylation patterns are frequently perturbed in human diseases such as imprinting disorders and cancer. The recent...... discovery that the three members of the TET protein family can convert 5-methylcytosine (5mC) into 5-hydroxymethylcytosine (5hmC) has provided a potential mechanism leading to DNA demethylation. Moreover, the demonstration that TET2 is frequently mutated in haematopoietic tumours suggests that the TET...... proteins are important regulators of cellular identity. Here, we review the current knowledge regarding the function of the TET proteins, and discuss various mechanisms by which they contribute to transcriptional control. We propose that the TET proteins have an important role in regulating DNA methylation...

  13. DNA data

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Raw DNA chromatogram data produced by the ABI 373, 377, 3130 and 3730 automated sequencing machines in ABI format. These are from fish (primarily Sebastes spp.,...

  14. DNA nanotechnology

    Science.gov (United States)

    Seeman, Nadrian C.; Sleiman, Hanadi F.

    2018-01-01

    DNA is the molecule that stores and transmits genetic information in biological systems. The field of DNA nanotechnology takes this molecule out of its biological context and uses its information to assemble structural motifs and then to connect them together. This field has had a remarkable impact on nanoscience and nanotechnology, and has been revolutionary in our ability to control molecular self-assembly. In this Review, we summarize the approaches used to assemble DNA nanostructures and examine their emerging applications in areas such as biophysics, diagnostics, nanoparticle and protein assembly, biomolecule structure determination, drug delivery and synthetic biology. The introduction of orthogonal interactions into DNA nanostructures is discussed, and finally, a perspective on the future directions of this field is presented.

  15. Entropic derivation of F=ma for circular motion

    International Nuclear Information System (INIS)

    Duncan, Michael; Myrzakulov, Ratbay; Singleton, Douglas

    2011-01-01

    We examine the entropic picture of Newton's second law for the case of circular motion. It is shown that one must make modifications to the derivation of F=ma due to a change in the effective Unruh temperature for circular motion. These modifications present a challenge to the entropic derivation of Newton's second law, but also open up the possibility to experimentally test and constrain this model for large centripetal accelerations.

  16. Circular dichroism beamline B23 at the Diamond Light Source.

    Science.gov (United States)

    Hussain, Rohanah; Jávorfi, Tamás; Siligardi, Giuliano

    2012-01-01

    Synchrotron radiation circular dichroism (SRCD) is a well established technique in structural biology. The first UV-VIS beamline, dedicated to circular dichroism, at Diamond Light Source Ltd, a third-generation synchrotron facility in south Oxfordshire, UK, has recently become operational and it is now available for the user community. Herein the main characteristics of the B23 SRCD beamline, the ancillary facilities available for users, and some of the recent advances achieved are summarized.

  17. A Review of the Circular Economy and its Implementation

    OpenAIRE

    Heshmati, Almas

    2015-01-01

    Circular economy (CE) is a sustainable development strategy that is being proposed to tackle urgent problems of environmental degradation and resource scarcity. CE's 3R principles are to reduce, reuse and recycle materials. The principles account for a circular system where all materials are recycled, all energy is derived from renewables; activities support and rebuild the ecosystem and support human health and a healthy society and resources are used to generate value. This study is a revie...

  18. Circularly organized quantum dot nanostructures of Ge on Si substrates

    International Nuclear Information System (INIS)

    Cai, Qijia; Chen, Peixuan; Zhong, Zhenyang; Jiang, Zuimin; Lu, Fang; An, Zhenghua

    2009-01-01

    A novel circularly arranged structure of germanium quantum dots has been fabricated by combining techniques including electron beam lithography, wet etching and molecular beam epitaxy. It was observed that both pattern and growth parameters affect the morphology of the quantum dot molecules. Meanwhile, the oxidation mask plays a vital role in the formation of circularly organized quantum dots. The experimental results demonstrate the possibilities of investigating the properties of quantum dot molecules as well as single quantum dots

  19. Circular Bioassay Platforms for Applications in Microwave-Accelerated Techniques.

    Science.gov (United States)

    Mohammed, Muzaffer; Clement, Travis C; Aslan, Kadir

    2014-12-02

    In this paper, we present the design of four different circular bioassay platforms, which are suitable for homogeneous microwave heating, using theoretical calculations (i.e., COMSOL™ multiphysics software). Circular bioassay platforms are constructed from poly(methyl methacrylate) (PMMA) for optical transparency between 400-800 nm, has multiple sample capacity (12, 16, 19 and 21 wells) and modified with silver nanoparticle films (SNFs) to be used in microwave-accelerated bioassays (MABs). In addition, a small monomode microwave cavity, which can be operated with an external microwave generator (100 W), for use with the bioassay platforms in MABs is also developed. Our design parameters for the circular bioassay platforms and monomode microwave cavity during microwave heating were: (i) temperature profiles, (ii) electric field distributions, (iii) location of the circular bioassay platforms inside the microwave cavity, and (iv) design and number of wells on the circular bioassay platforms. We have also carried out additional simulations to assess the use of circular bioassay platforms in a conventional kitchen microwave oven (e.g., 900 W). Our results show that the location of the circular bioassay platforms in the microwave cavity was predicted to have a significant effect on the homogeneous heating of these platforms. The 21-well circular bioassay platform design in our monomode microwave cavity was predicted to offer a homogeneous heating pattern, where inter-well temperature was observed to be in between 23.72-24.13°C and intra-well temperature difference was less than 0.21°C for 60 seconds of microwave heating, which was also verified experimentally.

  20. Self-complementary circular codes in coding theory.

    Science.gov (United States)

    Fimmel, Elena; Michel, Christian J; Starman, Martin; Strüngmann, Lutz

    2018-04-01

    Self-complementary circular codes are involved in pairing genetic processes. A maximal [Formula: see text] self-complementary circular code X of trinucleotides was identified in genes of bacteria, archaea, eukaryotes, plasmids and viruses (Michel in Life 7(20):1-16 2017, J Theor Biol 380:156-177, 2015; Arquès and Michel in J Theor Biol 182:45-58 1996). In this paper, self-complementary circular codes are investigated using the graph theory approach recently formulated in Fimmel et al. (Philos Trans R Soc A 374:20150058, 2016). A directed graph [Formula: see text] associated with any code X mirrors the properties of the code. In the present paper, we demonstrate a necessary condition for the self-complementarity of an arbitrary code X in terms of the graph theory. The same condition has been proven to be sufficient for codes which are circular and of large size [Formula: see text] trinucleotides, in particular for maximal circular codes ([Formula: see text] trinucleotides). For codes of small-size [Formula: see text] trinucleotides, some very rare counterexamples have been constructed. Furthermore, the length and the structure of the longest paths in the graphs associated with the self-complementary circular codes are investigated. It has been proven that the longest paths in such graphs determine the reading frame for the self-complementary circular codes. By applying this result, the reading frame in any arbitrary sequence of trinucleotides is retrieved after at most 15 nucleotides, i.e., 5 consecutive trinucleotides, from the circular code X identified in genes. Thus, an X motif of a length of at least 15 nucleotides in an arbitrary sequence of trinucleotides (not necessarily all of them belonging to X) uniquely defines the reading (correct) frame, an important criterion for analyzing the X motifs in genes in the future.

  1. DNA expressions - A formal notation for DNA

    NARCIS (Netherlands)

    Vliet, Rudy van

    2015-01-01

    We describe a formal notation for DNA molecules that may contain nicks and gaps. The resulting DNA expressions denote formal DNA molecules. Different DNA expressions may denote the same molecule. Such DNA expressions are called equivalent. We examine which DNA expressions are minimal, which

  2. Core nucleosomes by digestion of reconstructed histone-DNA complexes

    Energy Technology Data Exchange (ETDEWEB)

    Bryan, P N; Wright, E B; Olins, D E

    1979-04-01

    Reconstructed complexes of the inner histones (H2A, H2B, H3, H4) and a variety of DNAs were digested with micrococcal nuclease to yield very homogeneous populations of core nucleosomes (..nu../sub 1/). Nucleosomes containing Micrococcus luteus DNA (72% G+C); chicken DNA (43% G+C), Clostridium perfringens DNA (29% G+C); or poly(dA-dT).poly(dA-dT) have been examined by circular dichroism, thermal denaturation, electron microscopy, and DNAse I digestion. Circular dichroism spectra of all particles show a typically suppressed ellipticity at 260 to 280 nm and a prominent ..cap alpha..-helix signal at 222 nm. All particles show biphasic melting except ..nu../sub 1/(dA-dT), which show three prominent melting transitions at ionic strength less than or equal to 1 mM. DNAse I digestion of ..nu../sub 1/ (dA-dT) produces a ladder of DNA fragments differing in length by one base residue. ..nu../sub 1/ (dA-dT) contain 146 base pairs of DNA and exhibit an average DNA helix pitch of 10.4 to 10.5 bases per turn. There appear to be two regions of different DNA pitch within ..nu../sub 1/ (dA-dT). It is suggested that the two regions of DNA pitch might correspond to the two regions of the melting profiles.

  3. Research on the development and countermeasures for circular economy

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    Ecological economics and sustainable development economics are the basic theories to research on circular economy. Through the systemically research on the relationship of the three above, this paper thinks that the reuse and recycle of circular economy ts a way that the stall is mended after a sheep is lost. Although the reduction technically controls the production process, it cannot solve the waste caused by blind production and excess competition. We have experienced variety obstacles when implementing the circular economy, whose main reason ts the conflict between the individual ration and the social ration. Therefore, only when the individual ration and social ration incline to conformity,the cooperating Nash equilibrium will be appeared. In order to realize the harmony of ecology, economy and society, we have to explore effective evaluation theory. This paper cites the "five flows of wealth operation theory"from professor Ma Chuandong to search operation mechanism of circular economy, makes clear the developing thoughts of circular economy based on the realities, and brings forward some countermeasures to develop circular economy based on the above theoretical analysis.

  4. [Integrated evaluation of circular agriculture system: a life cycle perspective].

    Science.gov (United States)

    Liang, Long; Chen, Yuan-Quan; Gao, Wang-Sheng

    2010-11-01

    For the point of view that recycling economy system is one of ways to achieve the low-carbon economy, we have made an evaluation on a typical circular agriculture duck industry in Hunan Province, China, through improving the framework of life cycle assessment (LCA). The analysis indicated that the consumption of non-renewable resources, land and water were 48.629 MJ, 2.36 m2 and 1 321.41 kg, while the potential greenhouse gas (GHGs), acidification, eutrophication, human toxicity, freshwater ecotoxicity and terrestrial ecotoxicity were 11 543.26 g (CO2 eq), 52.36g (SO2eq), 25.83g (PO4eq), 1.26, 60.74 and 24.65 g (1,4-DCBeq), respectively. The potential damage of aquatic eutrophication, freshwater ecotoxicity and terrestrial ecotoxicity was more serious than that of GHGs. Main results were following: i. the circular agricultural chain promoted the principle of "moderate circulation", which based on the traditional production methods; ii. circular agriculture could not blindly pursue low carbon development. Instead, soil and biological carbon sequestration should be considered, in addition to reducing carbon emissions; iii. circular economy and circular agriculture should take other potential environmental impacts into account such as acidification, eutrophication and ecotoxicity,with the exception to carbon emissions,to developed integrated system assessment; iv. LCA could provide a comprehensive assessment of circular agriculture, and it was worth of further study.

  5. Molecular electron recollision dynamics in intense circularly polarized laser pulses

    Science.gov (United States)

    Bandrauk, André D.; Yuan, Kai-Jun

    2018-04-01

    Extreme UV and x-ray table top light sources based on high-order harmonic generation (HHG) are focused now on circular polarization for the generation of circularly polarized attosecond pulses as new tools for controlling electron dynamics, such as charge transfer and migration and the generation of attosecond quantum electron currents for ultrafast magneto-optics. A fundamental electron dynamical process in HHG is laser induced electron recollision with the parent ion, well established theoretically and experimentally for linear polarization. We discuss molecular electron recollision dynamics in circular polarization by theoretical analysis and numerical simulation. The control of the polarization of HHG with circularly polarized ionizing pulses is examined and it is shown that bichromatic circularly polarized pulses enhance recollision dynamics, rendering HHG more efficient, especially in molecules because of their nonspherical symmetry. The polarization of the harmonics is found to be dependent on the compatibility of the rotational symmetry of the net electric field created by combinations of bichromatic circularly polarized pulses with the dynamical symmetry of molecules. We show how the field and molecule symmetry influences the electron recollision trajectories by a time-frequency analysis of harmonics. The results, in principle, offer new unique controllable tools in the study of attosecond molecular electron dynamics.

  6. Swarm Robotics with Circular Formation Motion Including Obstacles Avoidance

    Directory of Open Access Journals (Sweden)

    Nabil M. Hewahi

    2017-07-01

    Full Text Available The robots science has been developed over the past few years, where robots have become used to accomplish difficult, repetitive or accurate tasks, which are very hard for humans to carry out. In this paper, we propose an algorithm to control the motion of a swarm of robots and make them able to avoid obstacles. The proposed solution is based on forming the robots in circular fashion. A group set of robots consists of multiple groups of robots, each group of robots consists of robots forming a circular shape and each group set is a circular form of robots. The proposed algorithm is concerned with first locating the randomly generated robots in groups and secondly with the swarm robot motion and finally with the swarm obstacle avoidance and swarm reorganization after crossing the obstacle. The proposed algorithm has been simulated with five different obstacles with various numbers of randomly generated robots. The results show that the swarm in the circular form can deal with the obstacles very effectively by passing the obstacles smoothly. The proposed algorithm has been compared with flocking algorithm and it is shown that the circular formation algorithm does not need extensive computation after obstacle avoidance whereas the flocking algorithm needs extensive computation. In addition, the circular formation algorithm maintains every robot in its group after avoiding the obstacles whereas with flocking algorithm does not.

  7. pH-induced fabrication of DNA/chitosan/α-ZrP nanocomposite and DNA release

    International Nuclear Information System (INIS)

    Liu Limin; Zhang Haitang; Shen Bo; He Weijiang; Lu Guoyuan; Liu Yuge; Zhu Junjie

    2010-01-01

    With positively charged chitosan as an intermediary, herring sperm DNA was intercalated into the interlayer galleries of negatively charged α-ZrP to form DNA/chitosan/α-ZrP ternary hybrids at pH 5.5. Fourier-transform IR, x-ray diffraction and scanning electron microscopy confirmed not only the coexistence of DNA, chitosan and α-ZrP in the composite but also the layered composite structure with an interlayer distance of 4.25 nm. Circular dichroism (CD) and UV spectroscopic studies disclosed that the restraint of DNA by the layered α-ZrP favors stabilization of the double-helical conformation of DNA and enhances the denaturation temperature. The intercalated DNA can be effectively released from the ternary nanocomposites at pHs higher than 6.5, and the released DNA displayed a similar CD spectrum to that of free DNA. The current research displays the promising potential to obtain a non-viral gene vector by intercalating DNA into negatively charged inorganic layered materials in the presence of a positively charged intermediary.

  8. What Is Mitochondrial DNA?

    Science.gov (United States)

    ... DNA What is mitochondrial DNA? What is mitochondrial DNA? Although most DNA is packaged in chromosomes within ... proteins. For more information about mitochondria and mitochondrial DNA: Molecular Expressions, a web site from the Florida ...

  9. Modeling of contact theories for the manipulation of biological micro/nanoparticles in the form of circular crowned rollers based on the atomic force microscope

    International Nuclear Information System (INIS)

    Korayem, M. H.; Khaksar, H.; Taheri, M.

    2013-01-01

    This article has dealt with the development and modeling of various contact theories for biological nanoparticles shaped as cylinders and circular crowned rollers for application in the manipulation of different biological micro/nanoparticles based on Atomic Force Microscope. First, the effective contact forces were simulated, and their impact on contact mechanics simulation was investigated. In the next step, the Hertz contact model was simulated and compared for gold and DNA nanoparticles with the three types of spherical, cylindrical, and circular crowned roller type contact geometries. Then by reducing the length of the cylindrical section in the circular crowned roller geometry, the geometry of the body was made to approach that of a sphere, and the results were compared for DNA nanoparticles. To anticipatory validate the developed theories, the results of the cylindrical and the circular crowned roller contacts were compared with the results of the existing spherical contact simulations. Following the development of these contact models for the manipulation of various biological micro/nanoparticles, the cylindrical and the circular crowned roller type contact theories were modeled based on the theories of Lundberg, Dowson, Nikpur, Heoprich, and Hertz for the manipulation of biological micro/nanoparticles. Then, for a more accurate validation, the results obtained from the simulations were compared with those obtained by the finite element method and with the experimental results available in previous articles. The previous research works on the simulation of nanomanipulation have mainly investigated the contact theories used in the manipulation of spherical micro/nanoparticles. However since in real biomanipulation situations, biological micro/nanoparticles of more complex shapes need to be displaced in biological environments, this article therefore has modeled and compared, for the first time, different contact theories for use in the biomanipulation of

  10. Chiral retrieval method based on right circularly polarized and left circularly polarized waves

    International Nuclear Information System (INIS)

    Martín, Ernesto; Muñoz, Juan; Margineda, José; Molina-Cuberos, Gregorio J; García-Collado, Ángel J

    2014-01-01

    The free-wave characterization of metamaterials is usually carried out by illuminating a sample with a linearly polarized plane electromagnetic wave. At points before and after the sample, sensors are introduced to measure the transverse components of the field, in order to compute the reflection and transmission coefficients related with the co- and cross-polar field components. Based on this information, retrieval algorithms allow parameters like rotation angle, effective chirality and refraction index to be calculated. Here we propose to use the transmission signals under illumination with plane circularly polarized waves, without sensing the reflection signal, to calculate the chirality parameter and the rotation angle due to the electromagnetic activity of the material. This new method, which allows a simpler characterization of a chiral slab, is applied to the study of metamaterials composed of both periodic and random distributions of metallic structures with chiral symmetry. The experimental results are contrasted with simulations and alternative measurements obtained using linearly polarized waves. (paper)

  11. Using the clustered circular layout as an informative method for visualizing protein-protein interaction networks.

    Science.gov (United States)

    Fung, David C Y; Wilkins, Marc R; Hart, David; Hong, Seok-Hee

    2010-07-01

    The force-directed layout is commonly used in computer-generated visualizations of protein-protein interaction networks. While it is good for providing a visual outline of the protein complexes and their interactions, it has two limitations when used as a visual analysis method. The first is poor reproducibility. Repeated running of the algorithm does not necessarily generate the same layout, therefore, demanding cognitive readaptation on the investigator's part. The second limitation is that it does not explicitly display complementary biological information, e.g. Gene Ontology, other than the protein names or gene symbols. Here, we present an alternative layout called the clustered circular layout. Using the human DNA replication protein-protein interaction network as a case study, we compared the two network layouts for their merits and limitations in supporting visual analysis.

  12. Highly sensitive chemiluminescent point mutation detection by circular strand-displacement amplification reaction.

    Science.gov (United States)

    Shi, Chao; Ge, Yujie; Gu, Hongxi; Ma, Cuiping

    2011-08-15

    Single nucleotide polymorphism (SNP) genotyping is attracting extensive attentions owing to its direct connections with human diseases including cancers. Here, we have developed a highly sensitive chemiluminescence biosensor based on circular strand-displacement amplification and the separation by magnetic beads reducing the background signal for point mutation detection at room temperature. This method took advantage of both the T4 DNA ligase recognizing single-base mismatch with high selectivity and the strand-displacement reaction of polymerase to perform signal amplification. The detection limit of this method was 1.3 × 10(-16)M, which showed better sensitivity than that of most of those reported detection methods of SNP. Additionally, the magnetic beads as carrier of immobility was not only to reduce the background signal, but also may have potential apply in high through-put screening of SNP detection in human genome. Copyright © 2011 Elsevier B.V. All rights reserved.

  13. Quinolone resistance-associated amino acid substitutions affect enzymatic activity of Mycobacterium leprae DNA gyrase.

    Science.gov (United States)

    Yamaguchi, Tomoyuki; Yokoyama, Kazumasa; Nakajima, Chie; Suzuki, Yasuhiko

    2017-07-01

    Quinolones are important antimicrobials for treatment of leprosy, a chronic infectious disease caused by Mycobacterium leprae. Although it is well known that mutations in DNA gyrase are responsible for quinolone resistance, the effect of those mutations on the enzymatic activity is yet to be studied in depth. Hence, we conducted in vitro assays to observe supercoiling reactions of wild type and mutated M. leprae DNA gyrases. DNA gyrase with amino acid substitution Ala91Val possessed the highest activity among the mutants. DNA gyrase with Gly89Cys showed the lowest level of activity despite being found in clinical strains, but it supercoiled DNA like the wild type does if applied at a sufficient concentration. In addition, patterns of time-dependent conversion from relaxed circular DNA into supercoiled DNA by DNA gyrases with clinically unreported Asp95Gly and Asp95Asn were observed to be distinct from those by the other DNA gyrases.

  14. Properties of the chromatin assembled on DNA injected into Xenopus oocytes and eggs

    International Nuclear Information System (INIS)

    Gargiulo, G.; Wasserman, W.; Worcel, A.

    1983-01-01

    The onset of DNA synthesis occurs between 10 and 30 minutes after activation of the egg and thus the transition from nuclease-sensitive to nuclease-resistant supercoils may take place on the newly replicated DNA. To test this possibility, the nonradioactive circular 5-kb DNA carrying the Drosophila histone gene repeat and [α -32 P]dCTP were coinjected into fertilized eggs. Such protocol labels both the injected, replicated heterologous DNA and the replicated endogenous, maternal Xenopus DNA. The labeled, presumably replicated, supercoiled DNA is resistant to micrococcal nuclease as expected. The endogenous, high-molecular-weight Xenopus DNA is degraded to 180-bp nucleosomal DNA. Thus, the nuclease resistance is not a general property of chromatin during the cleavage stage of the Xenopus embryo but is a peculiar feature of the injected DNA. 42 references, 5 figures

  15. Fission yeast strains with circular chromosomes require the 9-1-1 checkpoint complex for the viability in response to the anti-cancer drug 5-fluorodeoxyuridine.

    Directory of Open Access Journals (Sweden)

    Hossain Mohammad Shamim

    Full Text Available Thymidine kinase converts 5-fluorodeoxyuridine to 5-fluorodeoxyuridine monophosphate, which causes disruption of deoxynucleotide triphosphate ratios. The fission yeast Schizosaccharomyces pombe does not express endogenous thymidine kinase but 5-fluorodeoxyuridine inhibits growth when exogenous thymidine kinase is expressed. Unexpectedly, we found that 5-fluorodeoxyuridine causes S phase arrest even without thymidine kinase expression. DNA damage checkpoint proteins such as the 9-1-1 complex were required for viability in the presence of 5-fluorodeoxyuridine. We also found that strains with circular chromosomes, due to loss of pot1+, which have higher levels of replication stress, were more sensitive to loss of the 9-1-1 complex in the presence of 5-fluorodeoxyuridine. Thus, our results suggest that strains carrying circular chromosomes exhibit a greater dependence on DNA damage checkpoints to ensure viability in the presence of 5-fluorodeoxyuridine compared to stains that have linear chromosomes.

  16. Fission yeast strains with circular chromosomes require the 9-1-1 checkpoint complex for the viability in response to the anti-cancer drug 5-fluorodeoxyuridine.

    Science.gov (United States)

    Shamim, Hossain Mohammad; Minami, Yukako; Tanaka, Daiki; Ukimori, Shinobu; Murray, Johanne M; Ueno, Masaru

    2017-01-01

    Thymidine kinase converts 5-fluorodeoxyuridine to 5-fluorodeoxyuridine monophosphate, which causes disruption of deoxynucleotide triphosphate ratios. The fission yeast Schizosaccharomyces pombe does not express endogenous thymidine kinase but 5-fluorodeoxyuridine inhibits growth when exogenous thymidine kinase is expressed. Unexpectedly, we found that 5-fluorodeoxyuridine causes S phase arrest even without thymidine kinase expression. DNA damage checkpoint proteins such as the 9-1-1 complex were required for viability in the presence of 5-fluorodeoxyuridine. We also found that strains with circular chromosomes, due to loss of pot1+, which have higher levels of replication stress, were more sensitive to loss of the 9-1-1 complex in the presence of 5-fluorodeoxyuridine. Thus, our results suggest that strains carrying circular chromosomes exhibit a greater dependence on DNA damage checkpoints to ensure viability in the presence of 5-fluorodeoxyuridine compared to stains that have linear chromosomes.

  17. A novel x-ray circularly polarized ranging method

    International Nuclear Information System (INIS)

    Song Shi-Bin; Xu Lu-Ping; Zhang Hua; Shen Yang-He; Gao Na

    2015-01-01

    Range measurement has found multiple applications in deep space missions. With more and further deep space exploration activities happening now and in the future, the requirement for range measurement has risen. In view of the future ranging requirement, a novel x-ray polarized ranging method based on the circular polarization modulation is proposed, termed as x-ray circularly polarized ranging (XCPolR). XCPolR utilizes the circular polarization modulation to process x-ray signals and the ranging information is conveyed by the circular polarization states. As the circular polarization states present good stability in space propagation and x-ray detectors have light weight and low power consumption, XCPolR shows great potential in the long-distance range measurement and provides an option for future deep space ranging. In this paper, we present a detailed illustration of XCPolR. Firstly, the structure of the polarized ranging system is described and the signal models in the ranging process are established mathematically. Then, the main factors that affect the ranging accuracy, including the Doppler effect, the differential demodulation, and the correlation error, are analyzed theoretically. Finally, numerical simulation is carried out to evaluate the performance of XCPolR. (paper)

  18. Success Factors of Sustainable Social Enterprises Through Circular Economy Perspective

    Directory of Open Access Journals (Sweden)

    Stratan Dumitru

    2017-05-01

    Full Text Available The scope of the research is to find out how social entrepreneurship operations can be modelled within existing business methods using circular economy principles. A literature review was undertaken in order to clarify and find out different opinions regarding circularity and social businesses models. Moreover, the author interviewed managers of different social mission organizations in order to find out the critical factors that determine the sustainability and performances of the organizations. Using the results of the field and desk research, the author suggests the following business model elements to be considered by social enterprises aiming to implement circular economy principles: Desired social and environment vision; Value proposition; Alignment of organizations to the strategy and acceleration of change through executive leadership implication; Financial sustainable perspective: a to increase financial resources and b to manage costs; Stakeholders perspective: a customers segments, b users, c employees, d community beneficiaries, e channels, f customer relationships, g Key partnerships; Internal process perspective: a processes necessary to use circular economy principles; b impact measurement and key activities; c internal and external communication; Resources perspective: a networks; b skills on circular principles and social impact; c information and technologies.`

  19. Novel Single-Stranded DNA Virus Genomes Recovered from Chimpanzee Feces Sampled from the Mambilla Plateau in Nigeria

    Science.gov (United States)

    Walters, Matthew; Bawuro, Musa; Christopher, Alfred; Knight, Alexander; Kraberger, Simona; Stainton, Daisy; Chapman, Hazel

    2017-01-01

    ABSTRACT Metagenomic approaches are rapidly expanding our knowledge of the diversity of viruses. In the fecal matter of Nigerian chimpanzees we recovered three gokushovirus genomes, one circular replication-associated protein encoding single-stranded DNA virus (CRESS), and a CRESS DNA molecule. PMID:28254982

  20. DNA Vaccines

    Indian Academy of Sciences (India)

    diseases. Keywords. DNA vaccine, immune response, antibodies, infectious diseases. GENERAL .... tein vaccines require expensive virus/protein purification tech- niques as ... sphere continue to remain major health hazards in developing nations. ... significance since it can be produced at a very low cost and can be stored ...

  1. DNA Investigations.

    Science.gov (United States)

    Mayo, Ellen S.; Bertino, Anthony J.

    1991-01-01

    Presents a simulation activity that allow students to work through the exercise of DNA profiling and to grapple with some analytical and ethical questions involving a couple arranging with a surrogate mother to have a baby. Can be used to teach the principles of restriction enzyme digestion, gel electrophoresis, and probe hybridization. (MDH)

  2. Studies of interaction between two alkaloids and double helix DNA

    International Nuclear Information System (INIS)

    Sun, Yantao; Peng, Tingting; Zhao, Lei; Jiang, Dayu; Cui, Yuncheng

    2014-01-01

    This article presents the study on the interaction of two alkaloids (matrine and evodiamine) and hs-DNA by absorption, fluorescence, circular dichroism (CD), DNA melting and viscosity experiments. The spectroscopic studies suggested that two alkaloids can bind to DNA through an intercalative mode. The viscosity measurement and thermal denaturation also indicated that two alkaloids can intercalate to DNA. The binding constants (K A ) and the number of binding sites (n) were determined. At the same time, some significant thermodynamic parameters of the binding of the alkaloids to DNA were obtained. Competitive binding studies revealed that alkaloids had an effect on ethidium bromide (EB) bound DNA. In addition, it was also proved that the fluorescence quenching was influenced by ionic strength. - Highlights: • Interaction between two alkaloids and DNA is studied by spectral methods. • The binding constant and the binding sites between two alkaloids and DNA are obtained. • There are a classical intercalative mode between alkaloids and DNA. • The binding of matrine with DNA is weaker than that of evodiamine. • It is important for us to understand the alkaloids–DNA interactions at a molecular level

  3. Expression, purification, and DNA-binding activity of the Herbaspirillum seropedicae RecX protein.

    Science.gov (United States)

    Galvão, Carolina W; Pedrosa, Fábio O; Souza, Emanuel M; Yates, M Geoffrey; Chubatsu, Leda S; Steffens, Maria Berenice R

    2004-06-01

    The Herbaspirillum seropedicae RecX protein participates in the SOS response: a process in which the RecA protein plays a central role. The RecX protein of the H. seropedicae, fused to a His-tag sequence (RecX His-tagged), was over-expressed in Escherichia coli and purified by metal-affinity chromatography to yield a highly purified and active protein. DNA band-shift assays showed that the RecX His-tagged protein bound to both circular and linear double-stranded DNA and also to circular single-stranded DNA. The apparent affinity of RecX for DNA decreased in the presence of Mg(2+) ions. The ability of RecX to bind DNA may be relevant to its function in the SOS response.

  4. The Conjugative Relaxase TrwC Promotes Integration of Foreign DNA in the Human Genome.

    Science.gov (United States)

    González-Prieto, Coral; Gabriel, Richard; Dehio, Christoph; Schmidt, Manfred; Llosa, Matxalen

    2017-06-15

    Bacterial conjugation is a mechanism of horizontal DNA transfer. The relaxase TrwC of the conjugative plasmid R388 cleaves one strand of the transferred DNA at the oriT gene, covalently attaches to it, and leads the single-stranded DNA (ssDNA) into the recipient cell. In addition, TrwC catalyzes site-specific integration of the transferred DNA into its target sequence present in the genome of the recipient bacterium. Here, we report the analysis of the efficiency and specificity of the integrase activity of TrwC in human cells, using the type IV secretion system of the human pathogen Bartonella henselae to introduce relaxase-DNA complexes. Compared to Mob relaxase from plasmid pBGR1, we found that TrwC mediated a 10-fold increase in the rate of plasmid DNA transfer to human cells and a 100-fold increase in the rate of chromosomal integration of the transferred DNA. We used linear amplification-mediated PCR and plasmid rescue to characterize the integration pattern in the human genome. DNA sequence analysis revealed mostly reconstituted oriT sequences, indicating that TrwC is active and recircularizes transferred DNA in human cells. One TrwC-mediated site-specific integration event was detected, proving that TrwC is capable of mediating site-specific integration in the human genome, albeit with very low efficiency compared to the rate of random integration. Our results suggest that TrwC may stabilize the plasmid DNA molecules in the nucleus of the human cell, probably by recircularization of the transferred DNA strand. This stabilization would increase the opportunities for integration of the DNA by the host machinery. IMPORTANCE Different biotechnological applications, including gene therapy strategies, require permanent modification of target cells. Long-term expression is achieved either by extrachromosomal persistence or by integration of the introduced DNA. Here, we studied the utility of conjugative relaxase TrwC, a bacterial protein with site

  5. Perturbation approach to design of circularly polarised microstrip antennas

    Science.gov (United States)

    Lo, Y. T.; Richards, W. F.

    1981-05-01

    One of the most interesting applications of microstrip antennas is its use for transmitting or receiving circularly polarized (CP) waves. A description is given of a simple but accurate method to determine the critical dimensions needed to produce circular polarization for nearly square and nearly circular microstrip antennas. Shen (1981) in connection with the determination of the proper dimensions of an elliptical patch CP microstrip antenna first expressed the modal field in terms of Mathieu functions. To avoid the complicated numerical computation of the Mathieu functions, he approximated these functions in terms of Bessel functions. It is pointed out that the computation of Mathieu functions, or their approximate expressions can be avoided altogether if a perturbation method is applied to find the resonant frequencies of the two orthogonal modes. The implementation of this approach is demonstrated.

  6. Inkjet printed circularly polarized antennas for GPS applications

    KAUST Repository

    Farooqui, Muhammad Fahad

    2014-07-01

    Two novel, inkjet printed circularly polarized antenna designs are presented for GPS applications. First antenna design comprises a planar monopole which has been made circularly polarized by the introduction of an L-shaped slit. The antenna shows a gain of 0.2 dBi at 1.575 GHz with 3-dB axial ratio bandwidth of 3.8%. The second antenna design comprises a modified monopole in the form of an inverted L and has been termed as circularly polarized inverted L antenna (CILA). The antenna shows a gain of -2 dBi at 1.575 GHz with 3-dB axial ratio bandwidth of 4.1%. Both the antenna designs are attractive for mobile applications.

  7. Eco-Innovation in Circular Agri-Business

    Directory of Open Access Journals (Sweden)

    Dong-Her Shih

    2018-04-01

    Full Text Available This study constructs a theory of eco-innovation in circular agri-business. Although previous studies have discussed eco-innovation in circular agri-business, they did not address eco-innovation from the perspective of a closed-loop sustainable supply chain. Hence, this study applied the fuzzy TOPSIS method to conduct the analysis and determine the interrelationship between eco-innovation and the closed-loop concept. The results are consistent with the theory and a significant improvement in terms of the decisive attributes. The findings suggest that improving water management, relationships with suppliers, knowledge sharing, environmental management systems, and new product and service development are the most effective and efficient ways to build eco-innovation in circular agri-business. The managerial and theoretical implications are discussed.

  8. Interactions of circular Rydberg atoms with charged particles

    International Nuclear Information System (INIS)

    Wang, J.

    1994-01-01

    Recent progress in experimental cross-field techniques has made it possible to produce oriented Rydberg atoms of any angular momentum l within a given n manifold. The largest angular momentum state l max = n - 1 of a given n manifold is of particular interest because of its semiclassical properties for n much-gt 1. The corresponding classical Kepler orbit is circular with highly localized phase space distribution. The circular Rydberg atoms afford the opportunity to study various interactions in the semiclassical regime. The authors report electron capture from circular Rydberg atoms by protons and positrons at speeds comparable to the electron orbital speed. They find orientation dependent, novel peak structures for both protons and positrons in the angular scattering of the particles. The structures may be understood in terms of quasi Thomas double scattering mechanism for capture. Other related aspects including final state population and orientation indulged scattering asymmetry will also be discussed

  9. There exists circularity between WACC and value? Another solution

    Directory of Open Access Journals (Sweden)

    Ignacio Vélez-Pareja

    2006-01-01

    Full Text Available Although we know there exists a simple approach to solve the circularity between value and the discount rate, known as the Adjusted Present Value proposed by Myers, 1974, it seems that practitioners still rely on the traditional Weighted Average Cost of Capital, WACC approach of weig-hting the cost of debt, Kd and the costof equity, Ke and discounting the Free Cash Flow, FCF. We show how to solve circularity when calculating value with the free cash flow, FCF and the WACC. As a result of the solution wearrive at a known solution when we assume the discount rate of the tax savings as Ke, the cost of unlevered equity: the capital cash flow, CCF discounted at Ku. When assuming Kdas the discount rate for the tax savings, we find an expression for calculating value that does not implies circularity. We do this for a single period and for N periods.

  10. Slotted Circularly Polarized Microstrip Antenna for RFID Application

    Directory of Open Access Journals (Sweden)

    S. Kumar

    2017-12-01

    Full Text Available A single layer coaxial fed rectangular microstrip slotted antenna for circular polarization (CP is proposed for radio frequency identification (RFID application. Two triangular shaped slots and one rectangular slot along the diagonal axis of a square patch have been embedded. Due to slotted structure along the diagonal axis and less surface area, good quality of circular polarization has been obtained with the reduction in the size of microstrip antenna by 4.04 %. Circular polarization radiation performance has been studied by size and angle variation of diagonally slotted structures. The experimental result found for 10-dB return loss is 44 MHz with 10MHz of 3dB Axial Ratio (AR bandwidth respectively at the resonant frequency 910 MHz. The overall proposed antenna size including the ground plane is 80 mm x 80 mm x 4.572 mm.

  11. The Potential of Circular Economy in Sustainable Buildings

    DEFF Research Database (Denmark)

    Malabi Larsen, Leonora Charlotte; Birgisdottir, Harpa; Birkved, Morten

    2018-01-01

    benefits of designing the buildings concrete structure for disassembly, with the purpose of reuse, as well as to exemplify how circular economy can be applied in future building projects. Moreover, the paper aims at suggesting a more industry focused approach towards circular economy in order to seize...... the inherent potentials. As a result, it was found that recycling and energy recovery are the most common circular economy practices in the building industry, even though the economic and environmental benefits of reuse are believed to be much higher. This observation is supported by the findings of the case...... and glass, thereby enabling easier disassembly for both reuse and recycling. However, main challenges preventing the industry from seizing these potentials are identified as: focus on short term goals, complex supply chains, lack of collaboration between stakeholders and absence of a commonly agreed...

  12. On the ''circular vacuum noise'' in electron storage rings

    International Nuclear Information System (INIS)

    Rosu, H.

    1992-02-01

    We clarify in some essential points the proposal of Bell and Leinaas to measure the circular Unruh effect in storage rings. In particular the term 'circular Unruh effect' is inappropriate and should be replaced by the better 'circular vacuum noise'. This concept has been used by Takagi in his PTP Supplement of 1986 and corresponds best to the BL discussion. The BL resonance behavior does not fit to the SPEAR first order betatron resonance at 3.605 GeV, but of course, the real experimental situation is much more complicated, corresponding, as a matter of fact, to the rather general term 'synchrotron noise'. The detailed aspects of the synchrotron noise are, as yet, not very well understood. Besides, the much more practical accelerator jargon is to be preferred. We also include a section with comments on radiometry at storage rings. (author). 27 refs

  13. Particle transport across a circular shear layer with coherent structures

    International Nuclear Information System (INIS)

    Nielsen, A.H.; Lynov, J.P.; Juul Rasmussen, J.

    1998-01-01

    In the study of the dynamics of coherent structures, forced circular shear flows offer many desirable features. The inherent quantisation of circular geometries due to the periodic boundary conditions makes it possible to design experiments in which the spatial and temporal complexity of the coherent structures can be accurately controlled. Experiments on circular shear flows demonstrating the formation of coherent structures have been performed in different physical systems, including quasi-neutral plasmas, non-neutral plasmas and rotating fluids. In this paper we investigate the evolution of such coherent structures by solving the forced incompressible Navier-Stokes equations numerically using a spectral code. The model is formulated in the context of a rotating fluid but apply equally well to low frequency electrostatic oscillations in a homogeneous magnetized plasma. In order to reveal the Lagrangian properties of the flow and in particular to investigate the transport capacity in the shear layer, passive particles are traced by the velocity field. (orig.)

  14. FUCHS—towards full circular RNA characterization using RNAseq

    Directory of Open Access Journals (Sweden)

    Franziska Metge

    2017-02-01

    Full Text Available Circular RNAs (circRNAs belong to a recently re-discovered species of RNA that emerge during RNA maturation through a process called back-splicing. A downstream 5′ splice site is linked to an upstream 3′ splice site to form a circular transcript instead of a canonical linear transcript. Recent advances in next-generation sequencing (NGS have brought circRNAs back into the focus of many scientists. Since then, several studies reported that circRNAs are differentially expressed across tissue types and developmental stages, implying that they are actively regulated and not merely a by-product of splicing. Though functional studies have shown that some circRNAs could act as miRNA-sponges, the function of most circRNAs remains unknown. To expand our understanding of possible roles of circular RNAs, we propose a new pipeline that could fully characterizes candidate circRNA structure from RNAseq data—FUCHS: FUll CHaracterization of circular RNA using RNA-Sequencing. Currently, most computational prediction pipelines use back-spliced reads to identify circular RNAs. FUCHS extends this concept by considering all RNA-seq information from long reads (typically >150 bp to learn more about the exon coverage, the number of double break point fragments, the different circular isoforms arising from one host-gene, and the alternatively spliced exons within the same circRNA boundaries. This new knowledge will enable the user to carry out differential motif enrichment and miRNA seed analysis to determine potential regulators during circRNA biogenesis. FUCHS is an easy-to-use Python based pipeline that contributes a new aspect to the circRNA research.

  15. Metallization of DNA on silicon surface

    International Nuclear Information System (INIS)

    Puchkova, Anastasiya Olegovna; Sokolov, Petr; Petrov, Yuri Vladimirovich; Kasyanenko, Nina Anatolievna

    2011-01-01

    New simple way for silver deoxyribonucleic acid (DNA)-based nanowires preparation on silicon surface was developed. The electrochemical reduction of silver ions fixed on DNA molecule provides the forming of tightly matched zonate silver clusters. Highly homogeneous metallic clusters have a size about 30 nm. So the thickness of nanowires does not exceed 30–50 nm. The surface of n-type silicon monocrystal is the most convenient substrate for this procedure. The comparative analysis of DNA metallization on of n-type silicon with a similar way for nanowires fabrication on p-type silicon, freshly cleaved mica, and glass surface shows the advantage of n-type silicon, which is not only the substrate for DNA fixation but also the source of electrons for silver reduction. Images of bound DNA molecules and fabricated nanowires have been obtained using an atomic force microscope and a scanning ion helium microscope. DNA interaction with silver ions in a solution was examined by the methods of ultraviolet spectroscopy and circular dichroism.

  16. Sourcewise represented green's function of the circular waveguide

    International Nuclear Information System (INIS)

    Prijmenko, S.D.; Bondarenko, L.A.

    2007-01-01

    Singular part of the Green's function of unbounded space is singled out in explicit form and contains all singularities, including a delta-shaped singularity. The problem of construction of Green's function for a field is solved, as a problem for diffraction of potential and rotational components electric field intensity of a point current source on the circular waveguide walls. The singling out of the electric field intensity singularity in an explicit form about a source enables to develop an effective algorithm of Green's function calculation at any distance between the source point and observation point in a circular waveguide

  17. Innermost stable circular orbit of Kerr-MOG black hole

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Hyun-Chul; Han, Yong-Jin [Soonchunhyang University, Department of Physics, Asan (Korea, Republic of)

    2017-10-15

    We study the innermost stable circular orbit (ISCO) of the metric of the Kerr black hole in modified gravity (Kerr-MOG black hole), which is one of the exact solutions of the field equation of modified gravity in the strong gravity regime. The Kerr-MOG metric is constructed; it is the commonly known Kerr metric in Boyer-Lindquist coordinates by adding a repulsive term like the Yukawa force, which is explained in quantum gravity. In this paper, we numerically calculate the circular orbit of a photon and the ISCO of a test particle of Kerr-MOG black holes. (orig.)

  18. Characterization of a microfocused circularly polarized x-ray probe

    International Nuclear Information System (INIS)

    Pollmann, J.; Srajer, G.; Maser, J.; Lang, J. C.; Nelson, C. S.; Venkataraman, C. T.; Isaacs, E. D.

    2000-01-01

    We report on the development of a circularly polarized x-ray microprobe in the intermediate energy range from 5 to 10 keV. In this experiment linearly polarized synchrotron radiation was circularly polarized by means of a Bragg-diffracting diamond phase retarder and subsequently focused down to a spot size of about 4x2 μm 2 by a Fresnel zone plate. The properties of the microprobe were characterized, and the technique was applied to the two-dimensional mapping of magnetic domains in HoFe 2 . (c) 2000 American Institute of Physics

  19. Phase Radiation Characteristics of an Open-Ended Circular Waveguide

    DEFF Research Database (Denmark)

    Shishkova, A.V.; Pivnenko, Sergiy; Kim, O.S.

    2002-01-01

    Analytic expressions for phase radiation characteristics of a semi-infinite open-ended circular waveguide regardless of its aperture size and operating frequency have been obtained making use of the rigorous Weinstein's theory. The analysis of phase radiation patterns has been carried out...... for the dominant mode (TE11) as well as for the high order modes TM01 and TE01, both for a single and multimode propagation. The measurement of radiation characteristics of an open-ended circular waveguide has been carried out at the DTU-ESA Spherical Near-Field Antenna Test Facility. It is shown...

  20. Structure analysis of biomolecules using synchrotron radiation circular dichroism spectrophotometer

    International Nuclear Information System (INIS)

    Gekko, Kunihiko; Matsuo, Koichi

    2004-01-01

    We constructed the vacuum-ultraviolet circular dichroism (VUVCD) spectrophotometer, which is capable of measuring circular dichroism spectra to 140 nm for aqueous solutions at temperature from -30 to 70degC, using a small-scale SR source at Hiroshima Synchrotron Radiation Center (HiSOR). This spectrophotometer was used for structural analyses of amino acids, saccharides, and proteins in water. The obtained results demonstrate that a synchrotron radiation VUVCD spectroscopy provides more detailed and new information on the structures of biomolecules, based on the high energy transitions of chromophores such as hydroxyl, acetal, and peptide groups. (author)

  1. Electrically small circularly polarized spherical antenna with air core

    DEFF Research Database (Denmark)

    Kim, O. S.

    2013-01-01

    An electrically small circularly polarized self-resonant spherical antenna with air core is presented. The antenna is a modified multiarm spherical helix exciting TM10 and TE10 spherical modes with equal radiated power, and thus yielding perfect circular polarization over the entire far......-field sphere (except the polar regions, where the radiation is low). The self-resonance is achieved by exciting higher-order TM modes, which provide the necessary electric stored energy in the near-field, while contributing negligibly to the far-field radiation of the antenna. The antenna has electrical size...

  2. Transition towards Circular Economy in the Food System

    Directory of Open Access Journals (Sweden)

    Alexandra Jurgilevich

    2016-01-01

    Full Text Available Growing population and increased demand for food, inefficient resource use and food distribution, environmental impacts, and high rates of food wasted at all stages of the food system are all calling for transition towards more sustainable practices. In this article we apply the concept of circular economy to the case of a sustainable food system. Furthermore, we explore the transition towards a circular food system through the lens of socio-technical transition theory towards sustainability. We discuss challenges and potential solutions for the production stage (focusing on nutrient flow, the consumption stage (focusing on meat consumption, and food waste and surplus management and prevention.

  3. Analytical estimation of the dynamic apertures of circular accelerators

    International Nuclear Information System (INIS)

    Gao, J.

    2000-02-01

    By considering delta function sextupole, octupole, and deca-pole perturbations and using difference action-angle variable equations, we find some useful analytical formulae for the estimation of the dynamic apertures of circular accelerators due to single sextupole, single octupole, single deca-pole (single 2 m pole in general). Their combined effects are derived based on the Chirikov criterion of the onset of stochastic motions. Comparisons with numerical simulations are made, and the agreement is quite satisfactory. These formulae have been applied to determine the beam-beam limited dynamic aperture in a circular collider. (author)

  4. Lung Cancer-Specific Circular RNAs as Biomarkers

    Science.gov (United States)

    2017-08-01

    determine whether differential expression of circular RNAs can also be detected in cell culture models. Third, we will determine whether circular RNAs can...four of them as representative differentially expressed circRNAs in Table 1. For example , hsa_circRNA_400633 and hsa_circRNA_101100 were upregulated...sequence for hsa_circRNA_400633 and hsa_circRNA_101100, as shown in Figs. 1 and 2 as an example . The top part is the actual sequence and the

  5. Zero-point field in a circular-motion frame

    International Nuclear Information System (INIS)

    Kim, S.K.; Soh, K.S.; Yee, J.H.

    1987-01-01

    The energy spectrum of zero-point fields of a massless scalar field observed by a detector in circular motion is studied by analyzing the Wightman function. It is shown to be quite different from the Planck spectrum which would have been expected from the result of a uniformly accelerated detector. In a nonrelativistic limit zero-point fields with frequencies only up to the first harmonics of the circular-motion frequency contribute dominantly. In an extremely relativistic case the energy spectrum is dominated by a particular pole in the complex proper-time plane

  6. Inflation of polymer melts into elliptic and circular cylinders

    DEFF Research Database (Denmark)

    Rasmussen, Henrik Koblitz; Christensen, Jens Horslund; Gøttsche, Søren

    2000-01-01

    A thin sheet (membrane) of the polymeric material is clamped between a Teflon-coated thermostated plate and a thermostated aluminium cylinder. By applying thermostated air through the plate, the polymer membrane deforms into an elliptic or a circular cylinder. The position of the top of the infla......A thin sheet (membrane) of the polymeric material is clamped between a Teflon-coated thermostated plate and a thermostated aluminium cylinder. By applying thermostated air through the plate, the polymer membrane deforms into an elliptic or a circular cylinder. The position of the top...

  7. Negative circular polarization as a universal property of quantum dots

    International Nuclear Information System (INIS)

    Taylor, Matthew W.; Spencer, Peter; Murray, Ray

    2015-01-01

    This paper shows that negative circular polarization, a spin flip of polarized carriers resulting in emission of opposite helicity, can be observed in undoped, n-doped, and p-doped InAs/GaAs quantum dots. These results contradict the usual interpretation of the effect. We show using power dependent and time resolved spectroscopy that the generation of negative circular polarization correlates with excited state emission. Furthermore, a longer spin lifetime of negatively polarized excitons is observed where emission is largely ground state in character

  8. Magnetic field, inductance of circular coil and solenoids

    International Nuclear Information System (INIS)

    Ramirez Hoyos, P.; Barbero Garcia, A.J.; Mafe Matoses, S.

    1995-01-01

    The self-inductance of a current-carrying circular coil and the mutual inductances of the Helmholtz coils and coil-sole-noid systems have been measured and calculated theoretically. The experiments and the required equipment are suited to an undergraduate laboratory. The theoretical calculation involve the use of simple numerical integration methods for evaluating the magnetic field of the circular coil and the inductances. The calculated values agree with the measurements within the experimental error. The material presented can be proposed to the students as a laboratory project. (Author) 7 refs

  9. Modeling and Simulation of Nonlinear Micro-electromechanical Circular Plate

    Directory of Open Access Journals (Sweden)

    Chin-Chia Liu

    2013-09-01

    Full Text Available In the present study, the hybrid differential transformation and finite difference method is applied to analyze the dynamic behavior of the nonlinear micro-electromechanical circular plate actuated by combined DC / AC loading schemes. The analysis takes account of the axial residual stress and hydrostatic pressure acting on micro circular plate upper surface. The dynamic response of the plate as a function of the magnitude of the AC driving voltage is explored. Moreover, the effect of the initial gap height on the pull-in voltage of the plate is systematically explored.

  10. Modeling magnetic circular dichroism within the polarizable embedding approach

    DEFF Research Database (Denmark)

    Nørby, Morten Steen; Coriani, Sonia; Kongsted, Jacob

    2018-01-01

    Magnetic circular dichroism (MCD) is defined as the differential absorption of left and right circularly polarized light in a sample subjected to an external magnetic field. In order to interpret the results of MCD measurements, theoretical predictions of key MCD parameters can be of utmost...... importance. From an experimental point of view, MCD spectra of molecules are often measured in an environment and most notably in a solution. Thus, it may be very important that the method used to predict the MCD parameters is able to correctly account for medium effects. In this paper, we investigate...

  11. Equipotential doming in flooded circular basins on the moon

    Science.gov (United States)

    Roth, L. E.; Elachi, C.; Phillips, R. J.

    1977-01-01

    A procedure is presented that permits determination of the shape of the gravity field due to an arbitrary mass configuration with circular symmetry. The procedure is used to model the shape of the field associated with the lunar circular basins. The mean slopes of the equipotential surfaces generated by a superisostatic deposit corresponding to a near-surface Crisium-size mascon are calculated to fall within the range from 1:700 to 1:1000; those generated by a mantle rebound of the same excess mass, at 60 km below the lunar surface, cluster around the value of 1:1500.

  12. Collection of ministerial circulars on the transport of radioactive substances

    International Nuclear Information System (INIS)

    1977-10-01

    This publication by the CNEN reproduces the full texts of Ministerial Circulars on the transport by road, rail, air and sea of radioactive substances, made in implementation of Act No. 1860 on the peaceful uses of nuclear energy of 1962, as amended by Decree No. 1704 of 1965, laying down that regulatory standards should be elaborated for such transport in accordance with the Euratom basic radiation protection standards and the IAEA Regulations on the Safe Transport of Radioactive Materials. These Circulars are set out in chronological order with reference to the national and international provisions under which they were made. (NEA) [fr

  13. Two circular chromosomes of unequal copy number make up the mitochondrial genome of the rotifer Brachionus plicatilis.

    Science.gov (United States)

    Suga, Koushirou; Mark Welch, David B; Tanaka, Yukari; Sakakura, Yoshitaka; Hagiwara, Atsushi

    2008-06-01

    The monogonont rotifer Brachionus plicatilis is an emerging model system for a diverse array of questions in limnological ecosystem dynamics, the evolution of sexual recombination, cryptic speciation, and the phylogeny of basal metazoans. We sequenced the complete mitochondrial genome of B. plicatilis sensu strictu NH1L and found that it is composed of 2 circular chromosomes, designated mtDNA-I (11,153 bp) and mtDNA-II (12,672 bp). Hybridization to DNA isolated from mitochondria demonstrated that mtDNA-I is present at 4 times the copy number of mtDNA-II. The only nucleotide similarity between the 2 chromosomes is a 4.9-kbp region of 99.5% identity including a transfer RNA (tRNA) gene and an extensive noncoding region that contains putative D-loop and control sequence. The mtDNA-I chromosome encodes 4 proteins (ATP6, COB, NAD1, and NAD2), 13 tRNAs, and the large and small subunit ribosomal RNAs; mtDNA-II encodes 8 proteins (COX1-3, NAD3-6, and NAD4L) and 9 tRNAs. Gene order is not conserved between B. plicatilis and its closest relative with a sequenced mitochondrial genome, the acanthocephalan Leptorhynchoides thecatus, or other sequenced mitochondrial genomes. Polymerase chain reaction assays and Southern hybridization to DNA from 18 strains of Brachionus suggest that the 2-chromosome structure has been stable for millions of years. The novel organization of the B. plicatilis mitochondrial genome into 2 nearly equal chromosomes of 4-fold different copy number may provide insight into the evolution of metazoan mitochondria and the phylogenetics of rotifers and other basal animal phyla.

  14. Exploration of disulfiram dealings with calf thymus DNA using spectroscopic, electrochemical and molecular docking techniques

    International Nuclear Information System (INIS)

    Subastri, A.; Durga, A.; Harikrishna, K.; Sureshkumar, M.; Jeevaratnam, K.; Girish, K.S.; Thirunavukkarasu, C.

    2016-01-01

    Disulfiram (C 10 H 20 N 2 S 4 ) is an acetaldehyde dehydrogenase inhibitor used in the treatment of chronic alcoholism and it has also been subjected to the clinical trial for cancer in recent times. However, there is no report on the binding effect of this emerging drug with DNA. Hence, the present investigation was taken up to study the binding effect of disulfiram on DNA under physiological conditions. UV–vis absorption spectroscopy, fluorescence emission spectroscopy, circular dichroism spectroscopy, cyclic voltammetry and molecular docking techniques were employed to determine the interaction mode of disulfiram with DNA. Further, DNA cleavage property of disulfiram was carried out by using agarose gel electrophoresis. The UV–vis absorption, emission and cyclic voltammetry measurements revealed that disulfiram showed the intercalative mode of interaction with DNA. The circular dichroism study exhibited structural changes of partial transition from B-conformation to A-conformation in DNA upon addition of disulfiram. Molecular docking study of disulfiram with DNA depicted intercalative mode of binding by formation of hydrogen and hydrophobic interaction along with docking score of −3.07 kcal/mol. The DNA cleavage study revealed that low concentration of disulfiram (50 µM) protected the DNA from oxidative damage sequentially, while high concentration of disulfiram (100 µM) showed less protective activity. Conversely, it caused DNA damage in the presence of hydroxyl radical oxidative system. Hence, the results obtained from the present investigations provide detailed discernment into DNA interaction effects of disulfiram.

  15. The protein circular dichroism data bank, a Web-based site for access to circular dichroism spectroscopic data.

    Science.gov (United States)

    Whitmore, Lee; Woollett, Benjamin; Miles, Andrew J; Janes, Robert W; Wallace, B A

    2010-10-13

    The Protein Circular Dichroism Data Bank (PCDDB) is a newly released resource for structural biology. It is a web-accessible (http://pcddb.cryst.bbk.ac.uk) data bank for circular dichroism (CD) and synchrotron radiation circular dichroism (SRCD) spectra and their associated experimental and secondary metadata, with links to protein sequence and structure data banks. It is designed to provide a public repository for CD spectroscopic data on macromolecules, to parallel the Protein Data Bank (PDB) for crystallographic, electron microscopic, and nuclear magnetic resonance spectroscopic data. Similarly to the PDB, it includes validation checking procedures to ensure good practice and the integrity of the deposited data. This paper reports on the first public release of the PCDDB, which provides access to spectral data that comprise standard reference datasets. Copyright © 2010 Elsevier Ltd. All rights reserved.

  16. DNA repair

    International Nuclear Information System (INIS)

    Setlow, R.

    1978-01-01

    Some topics discussed are as follows: difficulty in extrapolating data from E. coli to mammalian systems; mutations caused by UV-induced changes in DNA; mutants deficient in excision repair; other postreplication mechanisms; kinds of excision repair systems; detection of repair by biochemical or biophysical means; human mutants deficient in repair; mutagenic effects of UV on XP cells; and detection of UV-repair defects among XP individuals

  17. Chiral Binaphthylbis(4,4'-Bipyridin-1-Ium)/Cucurbit[8]Uril Supramolecular System and Its Induced Circularly Polarized Luminescence.

    Science.gov (United States)

    Chen, Xu-Man; Chen, Yong; Liang, Lu; Liu, Qiu-Jun; Liu, Yu

    2018-05-01

    Circularly polarized luminescence (CPL) induced by host-guest complexation remains a challenge in supramolecular chemistry. Herein, a couple of CPL-silent enantiomeric guest binaphthylbis(4,4'-bipyridinium) salts can emit obvious CPL in the presence of cucurbit[8]uril in aqueous media, due to the restriction of molecular rotation limitation effect. Such CPL can be reversibly adjusted by the addition of acid and base. Furthermore, the resultant supramolecular systems can interact with DNA, accompanied by the morphological conversion from branched supramolecular nanowires to exfoliated nanowires, which can enable to the exploration of such supramolecular systems as DNA markers by CPL signals. © 2018 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  18. Method for assessing damage to mitochondrial DNA caused by radiation and epichlorohydrin

    International Nuclear Information System (INIS)

    Singh, G.; Hauswirth, W.W.; Ross, W.E.; Neims, A.H.

    1985-01-01

    This paper describes a rapid and reliable method for quantification of damage to mitochondrial DNA (mtDNA), especially strand breaks. The degree of damage to mtDNA is assessed by the proportion of physical forms (i.e., supercoiled versus open-circular and linear forms) upon agarose gel electrophoresis, blotting, and visualization by hybridization with [ 32 P]mtDNA probes. The use of a radiolabeled probe is a crucial step in the procedure because it provides both a means to quantify by radioautography and to obtain the mtDNA specificity required to eliminate misinterpretation due to nuclear DNA contamination. To demonstrate the utility of this technique, X-irradiation and epichlorohydrin are shown to damage both isolated mtDNA and mtDNA in whole cells in a dose-dependent fashion

  19. Testing the magnetar scenario for superluminous supernovae with circular polarimetry

    Science.gov (United States)

    Cikota, Aleksandar; Leloudas, Giorgos; Bulla, Mattia; Inserra, Cosimo; Chen, Ting-Wan; Spyromilio, Jason; Patat, Ferdinando; Cano, Zach; Cikota, Stefan; Coughlin, Michael W.; Kankare, Erkki; Lowe, Thomas B.; Maund, Justyn R.; Rest, Armin; Smartt, Stephen J.; Smith, Ken W.; Wainscoat, Richard J.; Young, David R.

    2018-05-01

    Superluminous supernovae (SLSNe) are at least ˜5 times more luminous than common supernovae (SNe). Especially hydrogen-poor SLSN-I are difficult to explain with conventional powering mechanisms. One possible scenario that might explain such luminosities is that SLSNe-I are powered by an internal engine, such as a magnetar or an accreting black hole. Strong magnetic fields or collimated jets can circularly polarize light. In this work, we measured circular polarization of two SLSNe-I with the FOcal Reducer and low dispersion Spectrograph (FORS2) mounted at the ESO's Very Large Telescope (VLT). PS17bek, a fast evolving SLSN-I, was observed around peak, while OGLE16dmu, a slowly evolving SLSN-I, was observed 100 days after maximum. Neither SLSN shows evidence of circularly polarized light, however, these non-detections do not rule out the magnetar scenario as the powering engine for SLSNe-I. We calculate the strength of the magnetic field and the expected circular polarization as a function of distance from the magnetar, which decreases very fast. Additionally, we observed no significant linear polarization for PS17bek at four epochs, suggesting that the photosphere near peak is close to spherical symmetry.

  20. The Panther Mountain circular structure, a possible buried meteorite crater

    Science.gov (United States)

    Isachsen, Y. W.; Wright, S. F.; Revetta, F. A.; Duneen, R. J.

    Panther Mountain, located near Phoenicia, New York, is part of the Catskill Mountains, which form the eastern end of the Allegheny Plateau in New York. It is a circular mass defined physiographically by an anomalous circular drainage pattern produced by Esopus Creek and its tributary Woodland Creek. The circular valley that rings the mountain is fracture-controlled; where bedrock is exposed, it shows a joint density 5 to 10 times greater than that on either side of the valley. Where obscured by alluvial valley fill, the bedrock's low seismic velocity suggests that this anomalous fracturing is continuous in the bedrock underlying the rim valley. North-south and east-west gravity and magnetic profiles were made across the structure. Terrane-corrected, residual gravity profiles show an 18-mgal negative anomaly, and very steep gradients indicate a near-surface source. Several possible explanations of the gravity data were modeled. We conclude that the Panther Mountain circular structure is probably a buried meteorite crater that formed contemporaneously with marine or fluvial sedimentation during Silurian or Devonian time. An examination of drill core and cuttings in the region is underway to search for ejecta deposits and possible seismic and tsunami effects in the sedimentary section. Success would result in both dating the impact and furnishing a chronostratigraphic marker horizon.

  1. Direct access to polyisocyanide screw sense using vibrational circular dichroism

    NARCIS (Netherlands)

    Schwartz, E.; Domingos, S.R.; Vdovin, A.; Koepf, M.; Buma, W.J.; Cornelissen, J.J.L.M.; Rowan, A.E.; Nolte, R.J.M.; Woutersen, S.

    2010-01-01

    We show that the screw sense of polyisocyanide helices can be determined in a simple manner from the vibrational circular dichroism (VCD) of their CN-stretching mode. The relation between VCD and molecular structure is obtained using the coupled-oscillator approximation. It is shown that since the

  2. Structures of generalized 3-circular projections for symmetric norms

    Indian Academy of Sciences (India)

    Generalized bi-circular projection has been studied by many authors (see the subse- quent paragraph and references at the end of this paper). In particular, Botelho [4] and. Botelho and Jamison [5–8] extensively investigated the structures of GBPs for different. Banach spaces whose isometry group has concrete description ...

  3. Study on Green Supply Chain Management Based on Circular Economy

    Science.gov (United States)

    Ying, Jiang; Li-jun, Zhou

    The article starts with circular economy and the connotation of green supply chain, then analyzes the difference between green supply chain and traditional supply chain and elaborates the content of green supply chain management. On that basis, the approach to implement green supply chain management in china shall be put forward.

  4. Impact Modelling for Circular Economy: Geodesign Discussion Support Environment

    NARCIS (Netherlands)

    Šileryte, R.; Wandl, A.; van Timmeren, A.; Bregt, Arnold; Sarjakoski, Tapani; van Lammeren, Ron; Rip, Frans

    2017-01-01

    Transitioning towards circular economy requires changes in the current system which yield a number of impacts on such fundamental values as human health, natural environment, exhaustible resources, social well-being and prosperity. Moreover, this process involves multiple actors and requires careful

  5. Near-field circular polarization probed by chiral polyfluorene

    NARCIS (Netherlands)

    Savoini, M.; Biagioni, P.; Lakhwani, G.; Meskers, S.C.J.; Duò, L.; Finazzi, M.

    2009-01-01

    We demonstrate that a high degree of circular polarization can be delivered to the near field (NF) of an aperture at the apex of hollow-pyramid probes for scanning optical microscopy. This result is achieved by analyzing the dichroic properties of an annealed thin polymer film containing a chiral

  6. Circular sawing experiments on a radial arm saw

    Science.gov (United States)

    Charles W. McMillin; J.L. Lubxin

    1959-01-01

    Several years ago, the American Machine and Foundry Co. decided to conduct a comprehensive investigation in the field of cutting processes. The initial emphasis has been on circular sawing because of the product line of the company's DeWalt Division. As a nevessary antecedent to theoretical and experimental investigations, an extensive review of the literature on...

  7. Lattice Boltzmann simulation of flow around a confined circular cyclinder

    International Nuclear Information System (INIS)

    Ashrafizaadeh, M.; Zadehgol, A.

    2002-01-01

    A two dimensional lattice Boltzmann model (LBM) based on a single time relaxation BGK model has been developed. Several benchmark problems including the Poiseuille flow, the lid driven cavity flow and the flow around a circular cylinder have been performed employing a d2q9 lattice. The laminar flow around a circular cylinder within a channel has been extensively investigated using the present lattice Boltzmann model. Both symmetric and asymmetric placement configurations of the circular cylinder within the channel have been considered. A new treatment for the outlet velocity and pressure (density) boundary conditions has been proposed and validated. The present LBM results are in excellent agreement with those of the other existing CFD results. Careful examination of the LBM results and an appropriate calculation of the lift coefficient based on the rectangular lattice representation of the circular cylinder reveals that the periodic oscillation of the lift coefficient has a second harmonic when the cylinder is placed asymmetrically within the channel. The second harmonic could be associated with an asymmetrical shedding pattern of the vortices behind the cylinder from the upper and lower sides of the cylinder. (author)

  8. A New Limit on CMB Circular Polarization from SPIDER

    Science.gov (United States)

    Nagy, J. M.; Ade, P. A. R.; Amiri, M.; Benton, S. J.; Bergman, A. S.; Bihary, R.; Bock, J. J.; Bond, J. R.; Bryan, S. A.; Chiang, H. C.; Contaldi, C. R.; Doré, O.; Duivenvoorden, A. J.; Eriksen, H. K.; Farhang, M.; Filippini, J. P.; Fissel, L. M.; Fraisse, A. A.; Freese, K.; Galloway, M.; Gambrel, A. E.; Gandilo, N. N.; Ganga, K.; Gudmundsson, J. E.; Halpern, M.; Hartley, J.; Hasselfield, M.; Hilton, G.; Holmes, W.; Hristov, V. V.; Huang, Z.; Irwin, K. D.; Jones, W. C.; Kuo, C. L.; Kermish, Z. D.; Li, S.; Mason, P. V.; Megerian, K.; Moncelsi, L.; Morford, T. A.; Netterfield, C. B.; Nolta, M.; Padilla, I. L.; Racine, B.; Rahlin, A. S.; Reintsema, C.; Ruhl, J. E.; Runyan, M. C.; Ruud, T. M.; Shariff, J. A.; Soler, J. D.; Song, X.; Trangsrud, A.; Tucker, C.; Tucker, R. S.; Turner, A. D.; Van Der List, J. F.; Weber, A. C.; Wehus, I. K.; Wiebe, D. V.; Young, E. Y.

    2017-08-01

    We present a new upper limit on cosmic microwave background (CMB) circular polarization from the 2015 flight of Spider, a balloon-borne telescope designed to search for B-mode linear polarization from cosmic inflation. Although the level of circular polarization in the CMB is predicted to be very small, experimental limits provide a valuable test of the underlying models. By exploiting the nonzero circular-to-linear polarization coupling of the half-wave plate polarization modulators, data from Spider's 2015 Antarctic flight provide a constraint on Stokes V at 95 and 150 GHz in the range 33< {\\ell }< 307. No other limits exist over this full range of angular scales, and Spider improves on the previous limit by several orders of magnitude, providing 95% C.L. constraints on {\\ell }({\\ell }+1){C}{\\ell }{VV}/(2π ) ranging from 141 to 255 μK2 at 150 GHz for a thermal CMB spectrum. As linear CMB polarization experiments become increasingly sensitive, the techniques described in this paper can be applied to obtain even stronger constraints on circular polarization.

  9. Circularly polarized antennas for active holographic imaging through barriers

    Science.gov (United States)

    McMakin, Douglas L [Richland, WA; Severtsen, Ronald H [Richland, WA; Lechelt, Wayne M [West Richland, WA; Prince, James M [Kennewick, WA

    2011-07-26

    Circularly-polarized antennas and their methods of use for active holographic imaging through barriers. The antennas are dielectrically loaded to optimally match the dielectric constant of the barrier through which images are to be produced. The dielectric loading helps to remove barrier-front surface reflections and to couple electromagnetic energy into the barrier.

  10. Simulation of erasure of photoinduced anisotropy by circularly polarized light

    DEFF Research Database (Denmark)

    Sajti, Sz.; Kerekes, Á.; Barabás, M.

    2001-01-01

    The temporal evolution of photoinduced birefringence is investigated on the basis of a model proposed by Pedersen and co-workers, This model is extended for the case of elliptically polarized light, and used to describe the erasure of photoinduced birefringence by circularly polarized light...

  11. Diffusion weighted imaging with circularly polarized oscillating gradients

    DEFF Research Database (Denmark)

    Lundell, Henrik; Sønderby, Casper Kaae; Dyrby, Tim B

    2015-01-01

    presented. One major hurdle in practical implementation is the low effective diffusion weighting provided at high frequency with limited gradient strength. THEORY: As a solution to the low diffusion weighting of OGSE, circularly polarized OGSE (CP-OGSE) is introduced. CP-OGSE gives a twofold increase...

  12. Investigating circular patterns in linear polarization observations of Venus

    NARCIS (Netherlands)

    Mahapatra, G.; Stam, D.M.; Rossi, L.C.G.; Rodenhuis, M.; Snik, Frans; Keller, C.U.

    2017-01-01

    In this work, we analyse linear polarization data of the planet at a distance, obtained with the Extreme Polarimeter (ExPo) on the William Herschel Telescope
    on La Palma. These spatially resolved, high-accuracy polarization observations of Venus show faint circular patterns centered on the

  13. Gas pressure in bubble attached to tube circular outlet

    OpenAIRE

    Salonen, A; Gay, Cyprien; Maestro, A; Drenckhan, W; Rio, Emmanuelle

    2016-01-01

    In the present Supplementary notes to our work ``Arresting bubble coarsening: A two-bubble experiment to investigate grain growth in presence of surface elasticity'' (accepted in EPL), we derive the expression of the gas pressure inside a bubble located above and attached to the circular outlet of a vertical tube.

  14. Codon Distribution in Error-Detecting Circular Codes

    Directory of Open Access Journals (Sweden)

    Elena Fimmel

    2016-03-01

    Full Text Available In 1957, Francis Crick et al. suggested an ingenious explanation for the process of frame maintenance. The idea was based on the notion of comma-free codes. Although Crick’s hypothesis proved to be wrong, in 1996, Arquès and Michel discovered the existence of a weaker version of such codes in eukaryote and prokaryote genomes, namely the so-called circular codes. Since then, circular code theory has invariably evoked great interest and made significant progress. In this article, the codon distributions in maximal comma-free, maximal self-complementary C3 and maximal self-complementary circular codes are discussed, i.e., we investigate in how many of such codes a given codon participates. As the main (and surprising result, it is shown that the codons can be separated into very few classes (three, or five, or six with respect to their frequency. Moreover, the distribution classes can be hierarchically ordered as refinements from maximal comma-free codes via maximal self-complementary C3 codes to maximal self-complementary circular codes.

  15. A Calculus of Circular Proofs and its Categorical Semantics

    DEFF Research Database (Denmark)

    Santocanale, Luigi

    2002-01-01

    We present a calculus of “circular proofs”: the graph underlying a proof is not a finite tree but instead it is allowed to contain a certain amount of cycles.The main challenge in developing a theory for the calculus is to define the semantics of proofs, since the usual method by induction...

  16. 49 CFR 1544.305 - Security Directives and Information Circulars.

    Science.gov (United States)

    2010-10-01

    ... threat assessment or to a specific threat against civil aviation, TSA issues a Security Directive setting... 49 Transportation 9 2010-10-01 2010-10-01 false Security Directives and Information Circulars...) TRANSPORTATION SECURITY ADMINISTRATION, DEPARTMENT OF HOMELAND SECURITY CIVIL AVIATION SECURITY AIRCRAFT OPERATOR...

  17. 49 CFR 1548.19 - Security Directives and Information Circulars.

    Science.gov (United States)

    2010-10-01

    ... CARRIER SECURITY § 1548.19 Security Directives and Information Circulars. (a) TSA may issue an Information... aviation, TSA issues a Security Directive setting forth mandatory measures. (1) Each indirect air carrier... Security Directive that TSA issues to it, within the time prescribed in the Security Directive for...

  18. A Note on Longest Paths in Circular Arc Graphs

    Directory of Open Access Journals (Sweden)

    Joos Felix

    2015-08-01

    Full Text Available As observed by Rautenbach and Sereni [SIAM J. Discrete Math. 28 (2014 335-341] there is a gap in the proof of the theorem of Balister et al. [Combin. Probab. Comput. 13 (2004 311-317], which states that the intersection of all longest paths in a connected circular arc graph is nonempty. In this paper we close this gap.

  19. Introducing the Circular Flow Diagram to Business Students

    Science.gov (United States)

    Daraban, Bogdan

    2010-01-01

    The circular flow of income diagram is a simplified representation of the functioning of a free-market economic system. It illustrates how businesses interact with the other economic participants within the key macroeconomic markets that coordinate the flow of income through the national economy. Therefore, it can provide students of business with…

  20. Thermal performance in circular tube fitted with coiled square wires

    International Nuclear Information System (INIS)

    Promvonge, Pongjet

    2008-01-01

    The effects of wires with square cross section forming a coil used as a turbulator on the heat transfer and turbulent flow friction characteristics in a uniform heat flux, circular tube are experimentally investigated in the present work. The experiments are performed for flows with Reynolds numbers ranging from 5000 to 25,000. Two different spring coiled wire pitches are introduced. The results are also compared with those obtained from using a typical coiled circular wire, apart from the smooth tube. The experimental results reveal that the use of coiled square wire turbulators leads to a considerable increase in heat transfer and friction loss over those of a smooth wall tube. The Nusselt number increases with the rise of Reynolds number and the reduction of pitch for both circular and square wire coils. The coiled square wire provides higher heat transfer than the circular one under the same conditions. Also, performance evaluation criteria to assess the real benefits in using both coil wires of the enhanced tube are determined

  1. Discovering the bacterial circular proteins : bacteriocins, cyanobactins, and pilins

    NARCIS (Netherlands)

    Montalban-Lopez, Manuel; Sanchez-Hidalgo, Marina; Cebrian, Ruben; Maqueda, Mercedes

    2012-01-01

    Over recent years, several examples of natural ribosomally synthesized circular proteins and peptides from diverse organisms have been described. They are a group of proteins for which the precursors must be post-translationally modified to join the N and C termini with a peptide bond. This feature

  2. Simulation of tail distributions in electron-positron circular colliders

    International Nuclear Information System (INIS)

    Irwin, J.

    1992-02-01

    In addition to the Gaussian shaped core region, particle bunches in electron-positron circular colliders have a rarefied halo region of importance in determining beam lifetimes and backgrounds in particle detectors. A method is described which allows simulation of halo particle distributions

  3. The Diagonal Compression Field Method using Circular Fans

    DEFF Research Database (Denmark)

    Hansen, Thomas

    2006-01-01

    is a modification of the traditional method, the modification consisting of the introduction of circular fan stress fields. To ensure proper behaviour for the service load the -value ( = cot, where  is the angle relative to the beam axis of the uniaxial concrete compression) chosen should not be too large...

  4. Determination of the Static Friction Coefficient from Circular Motion

    Science.gov (United States)

    Molina-Bolívar, J. A.; Cabrerizo-Vílchez, M. A.

    2014-01-01

    This paper describes a physics laboratory exercise for determining the coefficient of static friction between two surfaces. The circular motion of a coin placed on the surface of a rotating turntable has been studied. For this purpose, the motion is recorded with a high-speed digital video camera recording at 240 frames s[superscript-1], and the…

  5. Broadband, Low Sidelobe, Zero Height, Slotted Circular Disk Antenna

    African Journals Online (AJOL)

    A rigorous mathematical theory for a rotationally symmetrical slotted circular disk antenna was developed. The theory applies the principle of "Gradient Invariance" of electromagnetic fields to determine the field components that are unique and single valued at any point in space. To detemine the radiation characteristics of ...

  6. Polymer photovoltaic cells sensitive to the circular polarization ofl light

    NARCIS (Netherlands)

    Gilot, J.; Abbel, R.J.; Lakhwani, G.; Meijer, E.W.; Schenning, A.P.H.J.; Meskers, S.C.J.

    2009-01-01

    Chiral conjugated polymer is used to construct a photovoltaic cell whose response depends on the circular polarization of the incoming light. The selectivity for left and right polarized light as a function of the thickness of the polymer layer is accounted for by modeling of the optical properties

  7. A Calculus of Circular Proofs and its Categorical Semantics

    DEFF Research Database (Denmark)

    Santocanale, Luigi

    2002-01-01

    We present a calculus of "circular proofs": the graph underlying a proof is not a finite tree but instead it is allowed to contain a certain amount of cycles.The main challenge in developing a theory for the calculus is to define the semantics of proofs, since the usual method by induction...

  8. Inkjet printed circularly polarized antennas for GPS applications

    KAUST Repository

    Farooqui, Muhammad Fahad; Shamim, Atif

    2014-01-01

    gain of 0.2 dBi at 1.575 GHz with 3-dB axial ratio bandwidth of 3.8%. The second antenna design comprises a modified monopole in the form of an inverted L and has been termed as circularly polarized inverted L antenna (CILA). The antenna shows a gain

  9. Risk management of hazardous substances in a circular economy.

    Science.gov (United States)

    Bodar, Charles; Spijker, Job; Lijzen, Johannes; Waaijers-van der Loop, Susanne; Luit, Richard; Heugens, Evelyn; Janssen, Martien; Wassenaar, Pim; Traas, Theo

    2018-04-15

    The ambitions for a circular economy are high and unambiguous, but day-to-day experience shows that the transition still has many difficulties to overcome. One of the current hurdles is the presence of hazardous substances in waste streams that enter or re-enter into the environment or the technosphere. The key question is: do we have the appropriate risk management tools to control any risks that might arise from the re-using and recycling of materials? We present some recent cases that illustrate current practice and complexity in the risk management of newly-formed circular economy chains. We also highlight how separate legal frameworks are still disconnected from each other in these cases, and how circular economy initiatives interlink with the European REACH regulation. Furthermore, we introduce a novel scheme describing how to decide whether a(n)(additional) risk assessment is necessary with regard to the re-use of materials containing hazardous substances. Finally, we present our initial views on new concepts for the fundamental integration of sustainability and safety aspects. These concepts should be the building blocks for the near future shifts in both policy frameworks and voluntary initiatives that support a sound circular economy transition. Copyright © 2018 Elsevier Ltd. All rights reserved.

  10. Codon Distribution in Error-Detecting Circular Codes.

    Science.gov (United States)

    Fimmel, Elena; Strüngmann, Lutz

    2016-03-15

    In 1957, Francis Crick et al. suggested an ingenious explanation for the process of frame maintenance. The idea was based on the notion of comma-free codes. Although Crick's hypothesis proved to be wrong, in 1996, Arquès and Michel discovered the existence of a weaker version of such codes in eukaryote and prokaryote genomes, namely the so-called circular codes. Since then, circular code theory has invariably evoked great interest and made significant progress. In this article, the codon distributions in maximal comma-free, maximal self-complementary C³ and maximal self-complementary circular codes are discussed, i.e., we investigate in how many of such codes a given codon participates. As the main (and surprising) result, it is shown that the codons can be separated into very few classes (three, or five, or six) with respect to their frequency. Moreover, the distribution classes can be hierarchically ordered as refinements from maximal comma-free codes via maximal self-complementary C(3) codes to maximal self-complementary circular codes.

  11. Inducing circular vection with tactile stimulation encircling the waist

    NARCIS (Netherlands)

    Tinga, A.M.; Jansen, C.; Smagt, M.J. van der; Nijboer, T.C.W.; Erp, J.B.F. van

    2018-01-01

    In general, moving sensory stimuli (visual and auditory) can induce illusory sensations of self-motion (i.e. vection) in the direction opposite of the sensory stimulation. The aim of the current study was to examine whether tactile stimulation encircling the waist could induce circular vection

  12. Conceptualizing the circular economy: An analysis of 114 definitions

    NARCIS (Netherlands)

    Kirchherr, Julian|info:eu-repo/dai/nl/411261487; Reike, Denise|info:eu-repo/dai/nl/413319512; Hekkert, Marko|info:eu-repo/dai/nl/143777629

    2017-01-01

    Abstract The circular economy concept has gained momentum both among scholars and practitioners. However, critics claim that it means many different things to different people. This paper provides further evidence for these critics. The aim of this paper is to create transparency regarding the

  13. Parenting on Your Own. Circulars 1245-1258.

    Science.gov (United States)

    Hughes, Robert, Jr.; And Others

    These 14 circulars for single parents provide advice about several aspects of parenting. Contents discuss developing self-esteem, conquering loneliness, managing stress, obtaining social support, managing time, controlling finances, getting and using credit, developing job-readiness skills, searching for a job, disciplining children effectively,…

  14. Linearly tapered slot antenna circular array for mobile communications

    Science.gov (United States)

    Simons, Rainee N.; Kelly, Eron; Lee, Richard Q.; Taub, Susan R.

    1993-01-01

    The design, fabrication and testing of a conformal K-band circular array is presented. The array consists of sixteen linearly tapered slot antennas (LTSA). It is fed by a 1:16 microstrip line power splitter via electromagnetic coupling. The array has an omni-directional pattern in the azimuth plane. In the elevation plane the beam is displaced above the horizon.

  15. 1st Annual Meeting of the Future Circular Collider study

    CERN Document Server

    2015-01-01

    This first Annual Meeting of the Future Circular Collider study is an important milestone to conclude the first, exploratory phase, leading to the identification of the baseline for the further study. Organized as an IEEE conference, it will provide the opportunity for re-enforcing the cohesion of the community and to catalyse cross-fertilization within the FCC study.

  16. Magnetic circular dichroism of chlorofullerenes: Experimental and computational study

    Czech Academy of Sciences Publication Activity Database

    Štěpánek, Petr; Straka, Michal; Šebestík, Jaroslav; Bouř, Petr

    2016-01-01

    Roč. 647, Mar (2016), s. 117-121 ISSN 0009-2614 R&D Projects: GA ČR GA13-03978S; GA ČR(CZ) GA14-03564S Institutional support: RVO:61388963 Keywords : chlorofullerenes * magnetic circular dichroism * density functional theory Subject RIV: CF - Physical ; Theoretical Chemistry Impact factor: 1.815, year: 2016

  17. Wigner distribution function of circularly truncated light beams

    NARCIS (Netherlands)

    Bastiaans, M.J.; Nijhawan, O.P.; Gupta, A.K.; Musla, A.K.; Singh, Kehar

    1998-01-01

    Truncating a light beam is expressed as a convolution of its Wigner distribution function and the WDF of the truncating aperture. The WDF of a circular aperture is derived and an approximate expression - which is exact in the space and the spatial-frequency origin and whose integral over the spatial

  18. Flow-induced vibrations of circular cylindrical structures

    International Nuclear Information System (INIS)

    Chen, S.

    1977-06-01

    The problems of flow-induced vibrations of circular cylindrical structures are reviewed. First, the general method of analysis and classification of structural responses are presented. Then, the presentation is broken up along the lines with stationary fluid, parallel flow, and cross flow. Finally, design considerations and future research needs are pointed out. 234 references

  19. The Bearing Capacity of Circular Footings in Sand

    DEFF Research Database (Denmark)

    Krabbenhøft, Sven; Clausen, Johan; Damkilde, Lars

    2012-01-01

    dependent on the stress level and on the basis of the test results, a non linear Mohr failure criterion has been proposed. This yield criterion has been implemented in a finite element program and an analysis of the bearing capacity of a circular shaped model foundation, diameter 100mm, has been conducted...

  20. Experimental investigation of complex circular Airy beam characteristics

    Science.gov (United States)

    Porfirev, A. P.; Fomchenkov, S. A.; Khonina, S. N.

    2018-04-01

    We demonstrate a new type of circular Airy beams, the so-called azimuthally modulated circular Airy beams, generated by utilizing a diffraction element, whose transmission function is the sum of the transmission function of the element generating a "petal" pattern and the transmission function of the element generating a circular Airy beam. We experimentally investigate the propagation dynamics of such beams and demonstrate that their autofocusing and selfhealing properties are strongly dependent on the number of generated petals. These beams are a combination of a conventional circular Airy beam and vortex laser beams (or their superpositions). Using a spatial light modulator, we demonstrate that these beams have unique properties such as autofocusing, "nondiffractive" propagation and self-healing after passing through an obstacle. The experimental results are in good agreement with the simulation. We believe that these results can be very useful for lensless laser fabrication and laser manipulation techniques, as well as for development of new filament plasma multi-channel formation methods.

  1. Boundary layer flow past a circular cylinder in axial flow

    International Nuclear Information System (INIS)

    Sawchuk, S.P.; Zamir, M.; Camiletti, S.E.

    1985-01-01

    This paper discusses a study of the laminar boundary layer on a semi-infinite circular cylinder in axial incompressible flow. Unlike previous studies, the present study investigates a full range of this boundary layer problem to determine skin friction, heat transfer and other integral properties of the boundary layer

  2. Soil and land management in a circular economy.

    Science.gov (United States)

    Breure, A M; Lijzen, J P A; Maring, L

    2018-05-15

    This article elaborates the role of soil and land management in a circular economy. The circular economy is highly dependent on the functioning of soils and land for the production of food and other biomass; the storage, filtration and transformation of many substances including water, carbon, and nitrogen; the provision of fresh mineral resources and fossil fuels; and the use of their functions as the platform for nature and human activities. Resource demand is increasing as a result of the growing human population. In addition to the shrinking availability of resources resulting from their unsustainable use in the past, our planet's diminishing potential for resource production, due to a range of reasons, is leading to resource scarcity, especially in the case of depletable resources. As an economic system that focuses on maximizing the reuse of resources and products and minimizing their depreciation, the circular economy greatly influences, and depends on, soil and land management. The concise management of the resources, land and soil is thus necessary, to make a circular economy successful. Copyright © 2017 Elsevier B.V. All rights reserved.

  3. Tunable plasmonic filter with circular metal–insulator– metal ring ...

    Indian Academy of Sciences (India)

    The mechanism based on circular ring resonators with narrow gaps may provide a novel method for designing all-optical integrated components in optical communication and computing. Keywords. Metal–insulator–metal waveguide; surface plasmon; optical filters; ring resonator. PACS Nos 42.79.−e; 73.20.Mf; 78.20.Bh. 1.

  4. Circular economy and real estate: alternatives for operational lease

    NARCIS (Netherlands)

    Ploeger, H.D.; Prins, M.; Straub, A.; van den Brink, R.

    2017-01-01

    The concept that suppliers retain ownership of building products and the materials encapsulated within these products and that their customers ‘only’ pay for services is a paradigm in Circular Economy. However in many legal systems, elements incorporated in a building such as the facade or the roof,

  5. A New Limit on CMB Circular Polarization from SPIDER

    Energy Technology Data Exchange (ETDEWEB)

    Nagy, J. M.; Ade, P. A. R.; Amiri, M.; Benton, S. J.; Bergman, A. S.; Bihary, R.; Bock, J. J.; Bond, J. R.; Bryan, S. A.; Chiang, H. C.; Contaldi, C. R.; Doré, O.; Duivenvoorden, A. J.; Eriksen, H. K.; Farhang, M.; Filippini, J. P.; Fissel, L. M.; Fraisse, A. A.; Freese, K.; Galloway, M.; Gambrel, A. E.; Gandilo, N. N.; Ganga, K.; Gudmundsson, J. E.; Halpern, M.; Hartley, J.; Hasselfield, M.; Hilton, G.; Holmes, W.; Hristov, V. V.; Huang, Z.; Irwin, K. D.; Jones, W. C.; Kuo, C. L.; Kermish, Z. D.; Li, S.; Mason, P. V.; Megerian, K.; Moncelsi, L.; Morford, T. A.; Netterfield, C. B.; Nolta, M.; Padilla, I. L.; Racine, B.; Rahlin, A. S.; Reintsema, C.; Ruhl, J. E.; Runyan, M. C.; Ruud, T. M.; Shariff, J. A.; Soler, J. D.; Song, X.; Trangsrud, A.; Tucker, C.; Tucker, R. S.; Turner, A. D.; List, J. F. Van Der; Weber, A. C.; Wehus, I. K.; Wiebe, D. V.; Young, E. Y.

    2017-08-01

    We present a new upper limit on CMB circular polarization from the 2015 flight of SPIDER, a balloon-borne telescope designed to search for $B$-mode linear polarization from cosmic inflation. Although the level of circular polarization in the CMB is predicted to be very small, experimental limits provide a valuable test of the underlying models. By exploiting the non-zero circular-to-linear polarization coupling of the HWP polarization modulators, data from SPIDER's 2015 Antarctic flight provides a constraint on Stokes $V$ at 95 and 150 GHz from $33<\\ell<307$. No other limits exist over this full range of angular scales, and SPIDER improves upon the previous limit by several orders of magnitude, providing 95% C.L. constraints on $\\ell (\\ell+1)C_{\\ell}^{VV}/(2\\pi)$ ranging from 141 $\\mu K ^2$ to 203 $\\mu K ^2$ at 150 GHz for a thermal CMB spectrum. As linear CMB polarization experiments become increasingly sensitive, the techniques described in this paper can be applied to obtain stronger constraints on circular polarization.

  6. Design guide for calculating fluid damping for circular cylindrical structures

    International Nuclear Information System (INIS)

    Chen, S.S.

    1983-06-01

    Fluid damping plays an important role for structures submerged in fluid, subjected to flow, or conveying fluid. This design guide presents a summary of calculational procedures and design data for fluid damping for circular cylinders vibrating in quiescent fluid, crossflow, and parallel flow

  7. Sound radiation quantities arising from a resilient circular radiator

    NARCIS (Netherlands)

    Aarts, R.M.; Janssen, A.J.E.M.

    2009-01-01

    Power series expansions in ka are derived for the pressure at the edge of a radiator, the reaction force on the radiator, and the total radiated power arising from a harmonically excited, resilient, flat, circular radiator of radius a in an infinite baffle. The velocity profiles on the radiator are

  8. Circular polarization measurements with a Ge(Li) detector

    DEFF Research Database (Denmark)

    Kopecký, J.; Warming, Inge Elisabeth

    1969-01-01

    This paper presents the results obtained in measurements of the degree of circular polarization of gamma transitions to bound states of 33S, 36Cl, 49Ti, 56Mn, 57Fe, 60Co and 64Cu following the capture of polarized thermal neutrons. Spin values have been determined on the basis of these results....

  9. Nonlinear spin-up in a circular cylinder

    NARCIS (Netherlands)

    van de Konijnenberg, J.A.; Heijst, van G.J.F.

    1995-01-01

    Nonlinear spin-up in a circular cylindrical tank is investigated experimentally and compared with the Wedemeyer model. The experiments were performed with water, using tracer particles floating at the free surface in order to visualize the flow field. The experimentally determined vorticity profiles

  10. Analysis of radial vibrations of poroelastic circular cylindrical shells ...

    African Journals Online (AJOL)

    DR OKE

    vanished, the considered problem reduces to the problem of radial vibrations of fluid-filled poroelastic circular cylindrical shell. (2). When the .... the volume change of the solid to that of liquid. ..... When the outer fluid density is zero, that is, ρof = 0 then the poroelastic cylindrical shell immersed in an acoustic medium will.

  11. Experience with Livaditis circular myotomy in management of long ...

    African Journals Online (AJOL)

    Experience with Livaditis circular myotomy in management of long gap TEF. A Singh, M Bajpai, N Sharma, SS Panda. Abstract. Background: Management of long gap oesophageal atresia with tracheoesophageal fi stula (OA TEF) is challenging. Various intra-operative and preoperative manures have been described to ...

  12. Shielding calculations for changing from circular to a Rectangular ...

    African Journals Online (AJOL)

    The Radiation Technology Centre (RTC) of the Ghana Atomic Energy Commission operates a 1.85 PBq Co-60 gamma irradiator for research, food preservation and medical sterilization. It has become necessary to improve the do-se rate delivered by changing the circular arrangement of sources to a rectangular one.

  13. Classical transport in a non-circular z-pinch

    International Nuclear Information System (INIS)

    Eriksson, G.

    1987-05-01

    A method is devised, in which particle and heat fluxes are found by solving the heat balance equation self-consistently for specified profiles. The procedure is applied to an equilibrium which corresponds to a non-circular z-pinch. (author)

  14. Theoretical and numerical treatment of diffraction through a circular aperture

    NARCIS (Netherlands)

    Bouwkamp, C.J.

    1970-01-01

    The three-dimensional diffraction of a scalar plane wave through a circular aperture in an infinite plane screen is analyzed and numerically computed for the case of normal incidence. A modified Babinet's principle is formulated, and this is used to find the diffraction of sound by an acoustically

  15. Modeling of circular-grating surface-emitting lasers

    Science.gov (United States)

    Shams-Zadeh-Amiri, Ali M.

    Grating-coupled surface-emitting lasers became an area of growing interest due to their salient features. Emission from a broad area normal to the wafer surface, makes them very well suited in high power applications and two- dimensional laser arrays. These new possibilities have caused an interest in different geometries to fully develop their potential. Among them, circular-grating lasers have the additional advantage of producing a narrow beam with a circular cross section. This special feature makes them ideal for coupling to optical fibers. All existing theoretical models dealing with circular- grating lasers only consider first-order gratings, or second-order gratings, neglecting surface emission. In this thesis, the emphasis is to develop accurate models describing the laser performance by considering the radiation field. Toward this aim, and due to the importance of the radiation modes in surface-emitting structures, a theoretical study of these modes in multilayer planar structures has been done in a rigorous and systematic fashion. Problems like orthogonality of the radiation modes have been treated very accurately. We have considered the inner product of radiation modes using the distribution theory. Orthogonality of degenerate radiation modes is an important issue. We have examined its validity using the transfer matrix method. It has been shown that orthogonality of degenerate radiation modes in a very special case leads to the Brewster theorem. In addition, simple analytical formulas for the normalization of radiation modes have been derived. We have shown that radiation modes can be handled in a much easier way than has been thought before. A closed-form spectral dyadic Green's function formulation of multilayer planar structures has been developed. In this formulation, both rectangular and cylindrical structures can be treated within the same mathematical framework. The Hankel transform of some auxiliary functions defined on a circular aperture has

  16. Unprecedented large inverted repeats at the replication terminus of circular bacterial chromosomes suggest a novel mode of chromosome rescue

    Science.gov (United States)

    El Kafsi, Hela; Loux, Valentin; Mariadassou, Mahendra; Blin, Camille; Chiapello, Hélène; Abraham, Anne-Laure; Maguin, Emmanuelle; van de Guchte, Maarten

    2017-01-01

    The first Lactobacillus delbrueckii ssp. bulgaricus genome sequence revealed the presence of a very large inverted repeat (IR), a DNA sequence arrangement which thus far seemed inconceivable in a non-manipulated circular bacterial chromosome, at the replication terminus. This intriguing observation prompted us to investigate if similar IRs could be found in other bacteria. IRs with sizes varying from 38 to 76 kbp were found at the replication terminus of all 5 L. delbrueckii ssp. bulgaricus chromosomes analysed, but in none of 1373 other chromosomes. They represent the first naturally occurring very large IRs detected in circular bacterial genomes. A comparison of the L. bulgaricus replication terminus regions and the corresponding regions without IR in 5 L. delbrueckii ssp. lactis genomes leads us to propose a model for the formation and evolution of the IRs. The DNA sequence data are consistent with a novel model of chromosome rescue after premature replication termination or irreversible chromosome damage near the replication terminus, involving mechanisms analogous to those proposed in the formation of very large IRs in human cancer cells. We postulate that the L. delbrueckii ssp. bulgaricus-specific IRs in different strains derive from a single ancestral IR of at least 93 kbp. PMID:28281695

  17. A circular aperture array for ultrasonic tomography and quantitative NDE

    Energy Technology Data Exchange (ETDEWEB)

    Nielsen, S A

    1998-08-01

    The main topics of this thesis are ultrasonic tomography and ultrasonic determination of elastic stiffness constants. Both issues are based on a synthetic array with transducer elements distributed uniformly along a circular aperture, i.e., a circular aperture array. The issues are treated both theoretically and experimentally by broadband pulse techniques. Ultrasonic tomography, UCT, from a circular aperture is a relatively new imaging technique in Non-destructive Evaluation (NDE) to acquire cross sectional images in bulk materials. A filtered back-projection algorithm is used to reconstruct images in four different experiments and results of attenuation, velocity and reflection tomograms in Plexiglas of AlSi-alloy cylinders are presented. Two kinds of ultrasonic tomography are introduced: bistatic and monostatic imaging. Both techniques are verified experimentally by Plexiglas cylinders. Different reconstruction artifacts are discussed and theoretical resolution constraints are discussed for various configurations of the circular aperture array. The monostatic technique is used in volumetric imaging. In the experimental verification artificial and real discontinuities in a cylindrical AlSi-alloy are compared with similar discontinuities in a Plexiglas specimen. Finally, some limitations to UCT are discussed. The circular aperture array is used to determine five independent elastic stiffness constants of a unidirectional glass/PET (Poly Ethylene Teraphtalate) laminate. Energy flux propagation and attenuation of ultrasonic waves are considered and velocity surfaces are calculated for different planes of interest. Relations between elastic stiffness constants and engineering constants (i.e., Young`s moduli, shear moduli and Poisson`s ratios) are discussed for an orthotropic composite. Six micromechanical theories are reviewed, and expressions predicting the elastic engineering constants are evaluated. The micromechanical predicted elastic stiffness constants for the

  18. DNA repair

    International Nuclear Information System (INIS)

    Van Zeeland, A.A.

    1984-01-01

    In this chapter a series of DNA repair pathways are discussed which are available to the cell to cope with the problem of DNA damaged by chemical or physical agents. In the case of microorganisms our knowledge about the precise mechanism of each DNA repair pathway and the regulation of it has been improved considerably when mutants deficient in these repair mechanisms became available. In the case of mammalian cells in culture, until recently there were very little repair deficient mutants available, because in almost all mammalian cells in culture at least the diploid number of chromosomes is present. Therefore the frequency of repair deficient mutants in such populations is very low. Nevertheless because replica plating techniques are improving some mutants from Chinese hamsters ovary cells and L5178Y mouse lymphoma cells are now available. In the case of human cells, cultures obtained from patients with certain genetic diseases are available. A number of cells appear to be sensitive to some chemical or physical mutagens. These include cells from patients suffering from xeroderma pigmentosum, Ataxia telangiectasia, Fanconi's anemia, Cockayne's syndrome. However, only in the case of xeroderma pigmentosum cells, has the sensitivity to ultraviolet light been clearly correlated with a deficiency in excision repair of pyrimidine dimers. Furthermore the work with strains obtained from biopsies from man is difficult because these cells generally have low cloning efficiencies and also have a limited lifespan in vitro. It is therefore very important that more repair deficient mutants will become available from established cell lines from human or animal origin

  19. Circular RNA profiling reveals that circular RNAs from ANXA2 can be used as new biomarkers for multiple sclerosis.

    Science.gov (United States)

    Iparraguirre, Leire; Muñoz-Culla, Maider; Prada-Luengo, Iñigo; Castillo-Triviño, Tamara; Olascoaga, Javier; Otaegui, David

    2017-09-15

    Multiple sclerosis is an autoimmune disease, with higher prevalence in women, in whom the immune system is dysregulated. This dysregulation has been shown to correlate with changes in transcriptome expression as well as in gene-expression regulators, such as non-coding RNAs (e.g. microRNAs). Indeed, some of these have been suggested as biomarkers for multiple sclerosis even though few biomarkers have reached the clinical practice. Recently, a novel family of non-coding RNAs, circular RNAs, has emerged as a new player in the complex network of gene-expression regulation. MicroRNA regulation function through a 'sponge system' and a RNA splicing regulation function have been proposed for the circular RNAs. This regulating role together with their high stability in biofluids makes them seemingly good candidates as biomarkers. Given the dysregulation of both protein-coding and non-coding transcriptome that have been reported in multiple sclerosis patients, we hypothesised that circular RNA expression may also be altered. Therefore, we carried out expression profiling of 13.617 circular RNAs in peripheral blood leucocytes from multiple sclerosis patients and healthy controls finding 406 differentially expressed (P-value  1.5) and demonstrate after validation that, circ_0005402 and circ_0035560 are underexpressed in multiple sclerosis patients and could be used as biomarkers of the disease. © The Author 2017. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

  20. Characterization of a Xenopus laevis mitochondrial protein with a high affinity for supercoiled DNA.

    OpenAIRE

    Mignotte, B; Barat, M

    1986-01-01

    A DNA binding protein of 31 Kd -mtDBPC- has been isolated from X. laevis oocyte mitochondria. It is present in large amounts in the organelle and does not show any enzymatic activity. Its binding to the superhelical form of a DNA is higher than for any other form, or for RNA. No sequence specificity could be found for any mtDNA fragments tested, including both origins of replication. It is able to introduce superhelical turns into relaxed circular DNA in the presence of a topoisomerase I acti...