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Sample records for super elongation complex

  1. DDX6 transfers P-TEFb kinase to the AF4/AF4N (AFF1) super elongation complex

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    Mück, Fabian; Bracharz, Silvia; Marschalek, Rolf

    2016-01-01

    AF4/AFF1 and AF5/AFF4 are both backbones for the assembly of “super elongation complexes” (SECs) that exert 2 distinct functions after the recruitment of P-TEFb from the 7SK snRNP: (1) initiation and elongation of RNA polymerase II gene transcription, and (2) modification of transcribed gene regions by distinct histone methylation patterns. In this study we aimed to investigate one of the initial steps, namely how P-TEFb is transferred from 7SK snRNPs to the SECs. In particular, we were interested in the role of DDX6 that we have recently identified as part of the AF4 complex. DDX6 is an evolutionarily conserved member of the DEAD-box RNA helicase family that is known to control miRNA and mRNA biology (translation, storage and degradation). Overexpressed DDX6 is associated with different cancer types and with c-Myc protein overexpression. We could demonstrate that DDX6 binds to 7SK snRNA and causes the release and transfer of P-TEFb to the AF4/AF4N SEC. DDX6 also binds stably to AF4 and AF4N as demonstrated by GST pull-down and co-immunoprecipitation experiments. As a consequence, overexpression of either AF4/AF4N or DDX6 resulted in a strong increase of mRNA production (5-6 fold), while their simultaneous expression increased the cellular mRNA production by 11-fold. Conversely, the corresponding knockdown of DDX6 decreased mRNA production by 70%. In conclusion, AF4/AF4N and DDX6 represent key molecules for the elongation process of gene transcription and a model will be proposed for the hand-over process of P-TEFb to SECs. PMID:27679741

  2. P-TEFb, the super elongation complex and mediator regulate a subset of non-paused genes during early Drosophila embryo development.

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    Olle Dahlberg

    2015-02-01

    Full Text Available Positive Transcription Elongation Factor b (P-TEFb is a kinase consisting of Cdk9 and Cyclin T that releases RNA Polymerase II (Pol II into active elongation. It can assemble into a larger Super Elongation Complex (SEC consisting of additional elongation factors. Here, we use a miRNA-based approach to knock down the maternal contribution of P-TEFb and SEC components in early Drosophila embryos. P-TEFb or SEC depletion results in loss of cells from the embryo posterior and in cellularization defects. Interestingly, the expression of many patterning genes containing promoter-proximal paused Pol II is relatively normal in P-TEFb embryos. Instead, P-TEFb and SEC are required for expression of some non-paused, rapidly transcribed genes in pre-cellular embryos, including the cellularization gene Serendipity-α. We also demonstrate that another P-TEFb regulated gene, terminus, has an essential function in embryo development. Similar morphological and gene expression phenotypes were observed upon knock down of Mediator subunits, providing in vivo evidence that P-TEFb, the SEC and Mediator collaborate in transcription control. Surprisingly, P-TEFb depletion does not affect the ratio of Pol II at the promoter versus the 3' end, despite affecting global Pol II Ser2 phosphorylation levels. Instead, Pol II occupancy is reduced at P-TEFb down-regulated genes. We conclude that a subset of non-paused, pre-cellular genes are among the most susceptible to reduced P-TEFb, SEC and Mediator levels in Drosophila embryos.

  3. The RNA polymerase II elongation complex.

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    Aso, T; Conaway, J W; Conaway, R C

    1995-11-01

    The initiation stage of transcription by RNA polymerase II has long been regarded as the primary site for regulation of eukaryotic gene expression. Nevertheless, a growing body of evidence reveals that the RNA polymerase II elongation complex is also a major target for regulation. Biochemical studies are implicating an increasing number of transcription factors in the regulation of elongation, and these transcription factors are being found to function by a diverse collection of mechanisms. Moreover, unexpected features of the structure and catalytic mechanism of RNA polymerase II are forcing a reconsideration of long-held views on the mechanics of some of the most basic aspects of polymerase function. In this review, we will describe recent insights into the structures and functions of RNA polymerase II and the transcription factors that control its activity during the elongation stage of eukaryotic messenger RNA synthesis.

  4. Control of Embryonic Stem Cell Identity by BRD4-Dependent Transcriptional Elongation of Super-Enhancer-Associated Pluripotency Genes

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    Raffaella Di Micco

    2014-10-01

    Full Text Available Transcription factors and chromatin-remodeling complexes are key determinants of embryonic stem cell (ESC identity. Here, we demonstrate that BRD4, a member of the bromodomain and extraterminal domain (BET family of epigenetic readers, regulates the self-renewal ability and pluripotency of ESCs. BRD4 inhibition resulted in induction of epithelial-to-mesenchymal transition (EMT markers and commitment to the neuroectodermal lineage while reducing the ESC multidifferentiation capacity in teratoma assays. BRD4 maintains transcription of core stem cell genes such as OCT4 and PRDM14 by occupying their super-enhancers (SEs, large clusters of regulatory elements, and recruiting to them Mediator and CDK9, the catalytic subunit of the positive transcription elongation factor b (P-TEFb, to allow Pol-II-dependent productive elongation. Our study describes a mechanism of regulation of ESC identity that could be applied to improve the efficiency of ESC differentiation.

  5. Neuroprotective copper bis(thiosemicarbazonato) complexes promote neurite elongation.

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    Bica, Laura; Liddell, Jeffrey R; Donnelly, Paul S; Duncan, Clare; Caragounis, Aphrodite; Volitakis, Irene; Paterson, Brett M; Cappai, Roberto; Grubman, Alexandra; Camakaris, James; Crouch, Peter J; White, Anthony R

    2014-01-01

    Abnormal biometal homeostasis is a central feature of many neurodegenerative disorders including Alzheimer's disease (AD), Parkinson's disease (PD), and motor neuron disease. Recent studies have shown that metal complexing compounds behaving as ionophores such as clioquinol and PBT2 have robust therapeutic activity in animal models of neurodegenerative disease; however, the mechanism of neuroprotective action remains unclear. These neuroprotective or neurogenerative processes may be related to the delivery or redistribution of biometals, such as copper and zinc, by metal ionophores. To investigate this further, we examined the effect of the bis(thiosemicarbazonato)-copper complex, Cu(II)(gtsm) on neuritogenesis and neurite elongation (neurogenerative outcomes) in PC12 neuronal-related cultures. We found that Cu(II)(gtsm) induced robust neurite elongation in PC12 cells when delivered at concentrations of 25 or 50 nM overnight. Analogous effects were observed with an alternative copper bis(thiosemicarbazonato) complex, Cu(II)(atsm), but at a higher concentration. Induction of neurite elongation by Cu(II)(gtsm) was restricted to neurites within the length range of 75-99 µm with a 2.3-fold increase in numbers of neurites in this length range with 50 nM Cu(II)(gtsm) treatment. The mechanism of neurogenerative action was investigated and revealed that Cu(II)(gtsm) inhibited cellular phosphatase activity. Treatment of cultures with 5 nM FK506 (calcineurin phosphatase inhibitor) resulted in analogous elongation of neurites compared to 50 nM Cu(II)(gtsm), suggesting a potential link between Cu(II)(gtsm)-mediated phosphatase inhibition and neurogenerative outcomes.

  6. Neuroprotective copper bis(thiosemicarbazonato complexes promote neurite elongation.

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    Laura Bica

    Full Text Available Abnormal biometal homeostasis is a central feature of many neurodegenerative disorders including Alzheimer's disease (AD, Parkinson's disease (PD, and motor neuron disease. Recent studies have shown that metal complexing compounds behaving as ionophores such as clioquinol and PBT2 have robust therapeutic activity in animal models of neurodegenerative disease; however, the mechanism of neuroprotective action remains unclear. These neuroprotective or neurogenerative processes may be related to the delivery or redistribution of biometals, such as copper and zinc, by metal ionophores. To investigate this further, we examined the effect of the bis(thiosemicarbazonato-copper complex, Cu(II(gtsm on neuritogenesis and neurite elongation (neurogenerative outcomes in PC12 neuronal-related cultures. We found that Cu(II(gtsm induced robust neurite elongation in PC12 cells when delivered at concentrations of 25 or 50 nM overnight. Analogous effects were observed with an alternative copper bis(thiosemicarbazonato complex, Cu(II(atsm, but at a higher concentration. Induction of neurite elongation by Cu(II(gtsm was restricted to neurites within the length range of 75-99 µm with a 2.3-fold increase in numbers of neurites in this length range with 50 nM Cu(II(gtsm treatment. The mechanism of neurogenerative action was investigated and revealed that Cu(II(gtsm inhibited cellular phosphatase activity. Treatment of cultures with 5 nM FK506 (calcineurin phosphatase inhibitor resulted in analogous elongation of neurites compared to 50 nM Cu(II(gtsm, suggesting a potential link between Cu(II(gtsm-mediated phosphatase inhibition and neurogenerative outcomes.

  7. Recent Advances in the Role of the Elongator Complex in Plant Physiology and tRNA Modiifcation:A Review

    Institute of Scientific and Technical Information of China (English)

    YAN Xu; JIN Xiao-huan; WANG You-mei; ZHENG Bo; CHEN Peng

    2014-01-01

    The Elongator complex is a multifunction protein complex which has been shown to be involved in transcriptional elongation, DNA replication and repair, tubulin and histone acetylation, gene silencing and tranfer RNA uridine modiifcation. The composition of the Elongator complex is found to be highly conserved in eukaryotes, protein homologs of various subunits have been identiifed in fungi, plant, animal, and human. Remarkably, mutation in genes encoding the Elongator complex structural components all results in defects of transfer RNA wobble uridine modiifcation, and this function of the Elongator complex is also conserved in eukaryotes. The Elongator complex mutants in higher plants have pleiotropic phenotypes including defects in vegetative growth, abiscisic acid hypersensitivity, elevated tolerance to drought and oxidative stress. What is the relationship between the Elongator complex’s function in nucleoside modiifcation and its activity in other cellular pathways? This review summarizes the recent advances in study of function of the Elongator complex, in the aspects of cell physiology and molecular biology.

  8. Global and local depletion of ternary complex limits translational elongation.

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    Zhang, Gong; Fedyunin, Ivan; Miekley, Oskar; Valleriani, Angelo; Moura, Alessandro; Ignatova, Zoya

    2010-08-01

    The translation of genetic information according to the sequence of the mRNA template occurs with high accuracy and fidelity. Critical events in each single step of translation are selection of transfer RNA (tRNA), codon reading and tRNA-regeneration for a new cycle. We developed a model that accurately describes the dynamics of single elongation steps, thus providing a systematic insight into the sensitivity of the mRNA translation rate to dynamic environmental conditions. Alterations in the concentration of the aminoacylated tRNA can transiently stall the ribosomes during translation which results, as suggested by the model, in two outcomes: either stress-induced change in the tRNA availability triggers the premature termination of the translation and ribosomal dissociation, or extensive demand for one tRNA species results in a competition between frameshift to an aberrant open-reading frame and ribosomal drop-off. Using the bacterial Escherichia coli system, we experimentally draw parallels between these two possible mechanisms.

  9. The role of Glu259 in Escherichia coli elongation factor Tu in ternary complex formation

    DEFF Research Database (Denmark)

    Nautrup Pedersen, Gitte; Rattenborg, Thomas; Knudsen, Charlotte Rohde;

    1998-01-01

    Determination of the crystal structure of the ternary complex formed between elongation factor Tu:GTP and aminoacylated tRNA revealed three regions of interaction between elongation factor Tu and tRNA. The structure indicates that the conserved glutamic acid at position 271 in Thermus aquaticus EF......-Tu could be involved in the binding of the 3' CCA-Phe end of the aminoacylated tRNA. Therefore, the corresponding residue, Glu259, of Escherichia coli EF-Tu was mutated into alanine, aspartic acid, glutamine and tyrosine, in order to substantiate the crystallographic structural evidence and to obtain...... of interaction with tRNA, while mutation to tyrosine abolished completely the interaction with tRNA. Finally, mutation to glutamine resulted in an elongation factor Tu variant behaving like the wild type. In conclusion, the environment around the site binding the CCA-Phe end of the tRNA is very restricted...

  10. Molecular architecture of the yeast Elongator complex reveals an unexpected asymmetric subunit arrangement.

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    Setiaputra, Dheva T; Cheng, Derrick Th; Lu, Shan; Hansen, Jesse M; Dalwadi, Udit; Lam, Cindy Hy; To, Jeffrey L; Dong, Meng-Qiu; Yip, Calvin K

    2017-02-01

    Elongator is a ~850 kDa protein complex involved in multiple processes from transcription to tRNA modification. Conserved from yeast to humans, Elongator is assembled from two copies of six unique subunits (Elp1 to Elp6). Despite the wealth of structural data on the individual subunits, the overall architecture and subunit organization of the full Elongator and the molecular mechanisms of how it exerts its multiple activities remain unclear. Using single-particle electron microscopy (EM), we revealed that yeast Elongator adopts a bilobal architecture and an unexpected asymmetric subunit arrangement resulting from the hexameric Elp456 subassembly anchored to one of the two Elp123 lobes that form the structural scaffold. By integrating the EM data with available subunit crystal structures and restraints generated from cross-linking coupled to mass spectrometry, we constructed a multiscale molecular model that showed the two Elp3, the main catalytic subunit, are located in two distinct environments. This work provides the first structural insights into Elongator and a framework to understand the molecular basis of its multifunctionality.

  11. Structures of coxsackievirus, rhinovirus, and poliovirus polymerase elongation complexes solved by engineering RNA mediated crystal contacts.

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    Gong, Peng; Kortus, Matthew G; Nix, Jay C; Davis, Ralph E; Peersen, Olve B

    2013-01-01

    RNA-dependent RNA polymerases play a vital role in the growth of RNA viruses where they are responsible for genome replication, but do so with rather low fidelity that allows for the rapid adaptation to different host cell environments. These polymerases are also a target for antiviral drug development. However, both drug discovery efforts and our understanding of fidelity determinants have been hampered by a lack of detailed structural information about functional polymerase-RNA complexes and the structural changes that take place during the elongation cycle. Many of the molecular details associated with nucleotide selection and catalysis were revealed in our recent structure of the poliovirus polymerase-RNA complex solved by first purifying and then crystallizing stalled elongation complexes. In the work presented here we extend that basic methodology to determine nine new structures of poliovirus, coxsackievirus, and rhinovirus elongation complexes at 2.2-2.9 Å resolution. The structures highlight conserved features of picornaviral polymerases and the interactions they make with the template and product RNA strands, including a tight grip on eight basepairs of the nascent duplex, a fully pre-positioned templating nucleotide, and a conserved binding pocket for the +2 position template strand base. At the active site we see a pre-bound magnesium ion and there is conservation of a non-standard backbone conformation of the template strand in an interaction that may aid in triggering RNA translocation via contact with the conserved polymerase motif B. Moreover, by engineering plasticity into RNA-RNA contacts, we obtain crystal forms that are capable of multiple rounds of in-crystal catalysis and RNA translocation. Together, the data demonstrate that engineering flexible RNA contacts to promote crystal lattice formation is a versatile platform that can be used to solve the structures of viral RdRP elongation complexes and their catalytic cycle intermediates.

  12. Structures of coxsackievirus, rhinovirus, and poliovirus polymerase elongation complexes solved by engineering RNA mediated crystal contacts.

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    Peng Gong

    Full Text Available RNA-dependent RNA polymerases play a vital role in the growth of RNA viruses where they are responsible for genome replication, but do so with rather low fidelity that allows for the rapid adaptation to different host cell environments. These polymerases are also a target for antiviral drug development. However, both drug discovery efforts and our understanding of fidelity determinants have been hampered by a lack of detailed structural information about functional polymerase-RNA complexes and the structural changes that take place during the elongation cycle. Many of the molecular details associated with nucleotide selection and catalysis were revealed in our recent structure of the poliovirus polymerase-RNA complex solved by first purifying and then crystallizing stalled elongation complexes. In the work presented here we extend that basic methodology to determine nine new structures of poliovirus, coxsackievirus, and rhinovirus elongation complexes at 2.2-2.9 Å resolution. The structures highlight conserved features of picornaviral polymerases and the interactions they make with the template and product RNA strands, including a tight grip on eight basepairs of the nascent duplex, a fully pre-positioned templating nucleotide, and a conserved binding pocket for the +2 position template strand base. At the active site we see a pre-bound magnesium ion and there is conservation of a non-standard backbone conformation of the template strand in an interaction that may aid in triggering RNA translocation via contact with the conserved polymerase motif B. Moreover, by engineering plasticity into RNA-RNA contacts, we obtain crystal forms that are capable of multiple rounds of in-crystal catalysis and RNA translocation. Together, the data demonstrate that engineering flexible RNA contacts to promote crystal lattice formation is a versatile platform that can be used to solve the structures of viral RdRP elongation complexes and their catalytic cycle

  13. DBIRD complex integrates alternative mRNA splicing with RNA polymerase II transcript elongation

    DEFF Research Database (Denmark)

    Close, Pierre; East, Philip; Dirac-Svejstrup, A Barbara;

    2012-01-01

    Alternative messenger RNA splicing is the main reason that vast mammalian proteomic complexity can be achieved with a limited number of genes. Splicing is physically and functionally coupled to transcription, and is greatly affected by the rate of transcript elongation. As the nascent pre...... and help to integrate transcript elongation with mRNA splicing remain unclear. Here we characterize the human interactome of chromatin-associated mRNP particles. This led us to identify deleted in breast cancer 1 (DBC1) and ZNF326 (which we call ZNF-protein interacting with nuclear mRNPs and DBC1 (ZIRD......)) as subunits of a novel protein complex--named DBIRD--that binds directly to RNAPII. DBIRD regulates alternative splicing of a large set of exons embedded in (A + T)-rich DNA, and is present at the affected exons. RNA-interference-mediated DBIRD depletion results in region-specific decreases in transcript...

  14. A conserved PUF-Ago-eEF1A complex attenuates translation elongation.

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    Friend, Kyle; Campbell, Zachary T; Cooke, Amy; Kroll-Conner, Peggy; Wickens, Marvin P; Kimble, Judith

    2012-01-08

    PUF (Pumilio/FBF) RNA-binding proteins and Argonaute (Ago) miRNA-binding proteins regulate mRNAs post-transcriptionally, each acting through similar, yet distinct, mechanisms. Here, we report that PUF and Ago proteins can also function together in a complex with a core translation elongation factor, eEF1A, to repress translation elongation. Both nematode (Caenorhabditis elegans) and mammalian PUF-Ago-eEF1A complexes were identified, using coimmunoprecipitation and recombinant protein assays. Nematode CSR-1 (Ago) promoted repression of FBF (PUF) target mRNAs in in vivo assays, and the FBF-1-CSR-1 heterodimer inhibited EFT-3 (eEF1A) GTPase activity in vitro. Mammalian PUM2-Ago-eEF1A inhibited translation of nonadenylated and polyadenylated reporter mRNAs in vitro. This repression occurred after translation initiation and led to ribosome accumulation within the open reading frame, roughly at the site where the nascent polypeptide emerged from the ribosomal exit tunnel. Together, these data suggest that a conserved PUF-Ago-eEF1A complex attenuates translation elongation.

  15. Three-dimensional structure of photosystem II from Thermosynechococcus elongates in complex with terbutryn

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    Gabdulkhakov, A. G., E-mail: azat@vega.protes.ru; Dontsova, M. V. [Russian Academy of Sciences, Institute of Protein Research (Russian Federation); Saenger, W. [Free University of Berlin, Institute for Chemistry and Biochemistry/Crystallography (Germany)

    2011-11-15

    Photosystem II is a key component of the photosynthetic pathway producing oxygen at the thylakoid membrane of cyanobacteria, green algae, and plants. The three-dimensional structure of photosystem II from the cyanobacterium Thermosynechococcus elongates in a complex with herbicide terbutryn (a photosynthesis inhibitor) was determined for the first time by X-ray diffraction and refined at 3.2 Angstrom-Sign resolution (R{sub factor} = 26.9%, R{sub free} = 29.9%, rmsd for bond lengths is 0.013 Angstrom-Sign , and rmsd for bond angles is 2.2 Degree-Sign ). The terbutryn molecule was located in the binding pocket of the mobile plastoquinone. The atomic coordinates of the refined structure of photosystem II in a complex with terbutryn were deposited in the Protein Data Bank.

  16. [SWI/SNF Protein Complexes Participate in the Initiation and Elongation Stages of Drosophila hsp70 Gene Transcription].

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    Mazina, M Yu; Nikolenko, Yu V; Krasnov, A N; Vorobyeva, N E

    2016-02-01

    The participation of the SWI/SNF chromatin remodeling complex in the stimulation of the RNA polymerase II binding to gene promotors was demonstrated in all model eukaryotic organisms. It was shown eight years ago that the SWI/SNF complex influence on transcription is not limited to its role in initiation but also includes participation in elongation and alternative splicing. In the current work, we describe the subunit composition of the SWI/SNF complexes participating in initiation, preparing for the elongation and elongation of hsp70 gene transcription in Drosophila melanogaster. The data reveal the high mobility of the SWI/SNF complex composition during the hsp 70 gene transcription process. We suggest a model describing the process of sequential SWI/SNF complex formation during heat-shock induced transcription of the hsp 70 gene.

  17. Hydrodynamic properties of DNA and DNA-lipid complex in an elongational flow field.

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    Sasaki, Naoki; Ashitaka, Hidetomo; Ohtomo, Kenji; Fukui, Akimasa

    2007-03-10

    The aim of this study was to determine the difference between hydrodynamic properties of DNA-cetyltrimethylammonium (CTA) complex and those of DNA, which may be related to the difference in fibre-forming ability of DNA-CTA from that of DNA. Responses of DNA and DNA-CTA complex to an elongational flow field were investigated. In both solution systems, results suggesting a coil-stretch transition were obtained. From a critical strain rate value, the radius of gyration of DNA-CTA molecules in ethanol-glycerol solution was revealed to be 0.3-0.5 times of that of DNA in aqueous NaCl solution. Shear viscosity of DNA-CTA solution was much smaller than that of DNA solution, also suggesting a smaller size of DNA-CTA in ethanol-glycerol solution than that of DNA in aqueous NaCl solution. The plateau birefringence value of the DNA-CTA system, a parameter that indicates the local molecular conformation and the molecular arrangement, was only about 1/10 of that of the DNA system. There is an empirically determined molecular model of DNA-CTA complex in which a DNA molecule is sheathed by a cylindrical crust made of CTA chains. This structure reduces the DNA molecular density in a pure elongational flow field region but cannot explain the observed reduction of birefringence intensity. The small plateau birefringence value of DNA-CTA compared with that of DNA was attributed to the reduced molecular polarizability by the particular conformation of DNA molecules and CTA chains in the DNA-CTA system such as that expected by the conformational models.

  18. The PAF complex and Prf1/Rtf1 delineate distinct Cdk9-dependent pathways regulating transcription elongation in fission yeast.

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    Jean Mbogning

    Full Text Available Cyclin-dependent kinase 9 (Cdk9 promotes elongation by RNA polymerase II (RNAPII, mRNA processing, and co-transcriptional histone modification. Cdk9 phosphorylates multiple targets, including the conserved RNAPII elongation factor Spt5 and RNAPII itself, but how these different modifications mediate Cdk9 functions is not known. Here we describe two Cdk9-dependent pathways in the fission yeast Schizosaccharomyces pombe that involve distinct targets and elicit distinct biological outcomes. Phosphorylation of Spt5 by Cdk9 creates a direct binding site for Prf1/Rtf1, a transcription regulator with functional and physical links to the Polymerase Associated Factor (PAF complex. PAF association with chromatin is also dependent on Cdk9 but involves alternate phosphoacceptor targets. Prf1 and PAF are biochemically separate in cell extracts, and genetic analyses show that Prf1 and PAF are functionally distinct and exert opposing effects on the RNAPII elongation complex. We propose that this opposition constitutes a Cdk9 auto-regulatory mechanism, such that a positive effect on elongation, driven by the PAF pathway, is kept in check by a negative effect of Prf1/Rtf1 and downstream mono-ubiquitylation of histone H2B. Thus, optimal RNAPII elongation may require balanced action of functionally distinct Cdk9 pathways.

  19. Promoter Escape with Bacterial Two-component σ Factor Suggests Retention of σ Region Two in the Elongation Complex.

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    Sengupta, Shreya; Prajapati, Ranjit Kumar; Mukhopadhyay, Jayanta

    2015-11-20

    The transition from the formation of the RNA polymerase (RNAP)-promoter open complex step to the productive elongation complex step involves "promoter escape" of RNAP. From the structure of RNAP, a promoter escape model has been proposed that suggests that the interactions between σR4 and RNAP and σR4 and DNA are destabilized upon transition to elongation. This accounts for the reduced affinity of σ to RNAP and stochastic release of σ. However, as the loss of interaction of σR4 with RNAP results in the release of intact σ, assessing this interaction remains challenging to be experimentally verified. Here we study the promoter escape model using a two-component σ factor YvrI and YvrHa from Bacillus subtilis that independently contributes to the functions of σR4 and σR2 in a RNAP-promoter complex. Our results show that YvrI, which mimics σR4, is released gradually as transcription elongation proceeds, whereas YvrHa, which mimics σR2 is retained throughout the elongation complexes. Thus our result validates the proposed model for promoter escape and also suggests that promoter escape involves little or no change in the interaction of σR2 with RNAP.

  20. Structural basis of transcription: an RNA polymerase II elongation complex at 3.3 A resolution.

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    Gnatt, A L; Cramer, P; Fu, J; Bushnell, D A; Kornberg, R D

    2001-06-08

    The crystal structure of RNA polymerase II in the act of transcription was determined at 3.3 A resolution. Duplex DNA is seen entering the main cleft of the enzyme and unwinding before the active site. Nine base pairs of DNA-RNA hybrid extend from the active center at nearly right angles to the entering DNA, with the 3' end of the RNA in the nucleotide addition site. The 3' end is positioned above a pore, through which nucleotides may enter and through which RNA may be extruded during back-tracking. The 5'-most residue of the RNA is close to the point of entry to an exit groove. Changes in protein structure between the transcribing complex and free enzyme include closure of a clamp over the DNA and RNA and ordering of a series of "switches" at the base of the clamp to create a binding site complementary to the DNA-RNA hybrid. Protein-nucleic acid contacts help explain DNA and RNA strand separation, the specificity of RNA synthesis, "abortive cycling" during transcription initiation, and RNA and DNA translocation during transcription elongation.

  1. A complex distribution of elongation family GTPases EF1A and EFL in basal alveolate lineages.

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    Mikhailov, Kirill V; Janouškovec, Jan; Tikhonenkov, Denis V; Mirzaeva, Gulnara S; Diakin, Andrei Yu; Simdyanov, Timur G; Mylnikov, Alexander P; Keeling, Patrick J; Aleoshin, Vladimir V

    2014-09-01

    Translation elongation factor-1 alpha (EF1A) and the related GTPase EF-like (EFL) are two proteins with a complex mutually exclusive distribution across the tree of eukaryotes. Recent surveys revealed that the distribution of the two GTPases in even closely related taxa is frequently at odds with their phylogenetic relationships. Here, we investigate the distribution of EF1A and EFL in the alveolate supergroup. Alveolates comprise three major lineages: ciliates and apicomplexans encode EF1A, whereas dinoflagellates encode EFL. We searched transcriptome databases for seven early-diverging alveolate taxa that do not belong to any of these groups: colpodellids, chromerids, and colponemids. Current data suggest all seven are expected to encode EF1A, but we find three genera encode EFL: Colpodella, Voromonas, and the photosynthetic Chromera. Comparing this distribution with the phylogeny of alveolates suggests that EF1A and EFL evolution in alveolates cannot be explained by a simple horizontal gene transfer event or lineage sorting.

  2. hELP3 Subunit of the Elongator Complex Regulates the Transcription of HSP70 Gene in Human Cells

    Institute of Scientific and Technical Information of China (English)

    Qiuju HAN; Xiaozhe HOU; Dongmei SU; Lina PAN; Jizhou DUAN; Liguo CUI; Baiqu HUANG; Jun LU

    2007-01-01

    The human Elongator complex is remarkably similar to its yeast counterpart in several aspects.In a previous study, we analyzed the functions of the human elongation protein 3 (hELP3) subunit of the human Elongator by using an in vivo yeast complementation system. However, direct evidence for hELP3 functions in regulating gene expression in human cells was not obtained. In this study, we used hELP3 antisense oligonucleotide inhibitors to knock down hELP3 gene expression to investigate its function in human 293T cells. The results showed that specific reduction of hELP3 mRNA and protein caused a significant suppression of HSP70-2 gene expression, and this was accompanied by histone H3 hypoacetylation and decreased RNA polymerase Ⅱ density at the HSP70-2 gene. Moreover, the data also showed that hELP3 exerted the transcriptional regulatory function directly through its presence on the HSP70-2 gene. Data presented in this report provide further insight and direct evidence of the functions of hELP3 in HSP70-2 gene transcriptional elongation in human cells.

  3. Super-resolution with complex masks using a phase-only LCD.

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    Alcalá Ochoa, Noé; Pérez-Santos, Carlos

    2013-12-15

    Two methods to achieve super-resolution with complex masks displayed in one-phase-only liquid crystal display (LCD) are described. The first method decomposes the complex mask into two phase-only elements with a posterior recombination using an interferometer, and the second method simultaneously encodes the amplitude and the phase by modulating the amplitude of the carrier phase. Experimental results are presented using a liquid crystal on silicon spatial light modulator under reflection.

  4. Reconstitution of Qbeta RNA replicase from a covalently bonded elongation factor Tu-Ts complex

    DEFF Research Database (Denmark)

    Brown, S; Blumenthal, T

    1976-01-01

    (C) and Qbeta RNA normally and had approximately the same specific activity as control enzyme. Denatured Qbeta replicase formed with crosslinked EF-Tu-Ts was found to renature much more rapidly than untreated enzyme and, in contrast to normal replicase, its renaturation was not inhibited by GDP. The results...... by its ability to replace EF-Tu and EF-Ts in the renaturation of denatured Qbeta replicase. A sample of Qbeta replicase with crosslinked EF-Tu-Ts replacing the individual elongation factors was prepared. Although it lacked EF-Tu and EF-Ts activities, it could initiate transcription of both poly...

  5. Identifying Super-Spreader Nodes in Complex Networks

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    Yu-Hsiang Fu

    2015-01-01

    Full Text Available Identifying the most influential individuals spreading information or infectious diseases can assist or hinder information dissemination, product exposure, and contagious disease detection. Hub nodes, high betweenness nodes, high closeness nodes, and high k-shell nodes have been identified as good initial spreaders, but efforts to use node diversity within network structures to measure spreading ability are few. Here we describe a two-step framework that combines global diversity and local features to identify the most influential network nodes. Results from susceptible-infected-recovered epidemic simulations indicate that our proposed method performs well and stably in single initial spreader scenarios associated with various complex network datasets.

  6. Simple expressions for performance parameters of complex filters, with applications to super-Gaussian phase filters.

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    Ledesma, Silvia; Campos, Juan; Escalera, Juan Carlos; Yzuel, María J

    2004-05-01

    To study the three-dimensional (3-D) behavior produced by complex filters, we have extended the expressions for the axial and the transverse gain to the case in which the best image plane is not near the paraxial focus. Super-Gaussian phase filters are proposed to control the 3-D image response of an optical system. Super-Gaussian phase filters depend on several parameters that modify the shape of the phase filter, producing tunable control of the 3-D response of the optical system. The filters are capable of producing a wide range of optical effects: transverse superresolution with high depth of focus, 3-D superresolution, and transverse apodization with different axial responses.

  7. Correlative super-resolution fluorescence and electron microscopy of the nuclear pore complex with molecular resolution.

    Science.gov (United States)

    Löschberger, Anna; Franke, Christian; Krohne, Georg; van de Linde, Sebastian; Sauer, Markus

    2014-10-15

    Here, we combine super-resolution fluorescence localization microscopy with scanning electron microscopy to map the position of proteins of nuclear pore complexes in isolated Xenopus laevis oocyte nuclear envelopes with molecular resolution in both imaging modes. We use the periodic molecular structure of the nuclear pore complex to superimpose direct stochastic optical reconstruction microscopy images with a precision of <20 nm on electron micrographs. The correlative images demonstrate quantitative molecular labeling and localization of nuclear pore complex proteins by standard immunocytochemistry with primary and secondary antibodies and reveal that the nuclear pore complex is composed of eight gp210 (also known as NUP210) protein homodimers. In addition, we find subpopulations of nuclear pore complexes with ninefold symmetry, which are found occasionally among the more typical eightfold symmetrical structures.

  8. Structural basis of transcription arrest by coliphage HK022 Nun in an Escherichia coli RNA polymerase elongation complex.

    Science.gov (United States)

    Kang, Jin Young; Olinares, Paul Dominic B; Chen, James; Campbell, Elizabeth A; Mustaev, Arkady; Chait, Brian T; Gottesman, Max E; Darst, Seth A

    2017-03-20

    Coliphage HK022 Nun blocks superinfection by coliphage λ by stalling RNA polymerase (RNAP) translocation specifically on λ DNA. To provide a structural framework to understand how Nun blocks RNAP translocation, we determined structures of Escherichia coli RNAP ternary elongation complexes (TECs) with and without Nun by single-particle cryo-electron microscopy. Nun fits tightly into the TEC by taking advantage of gaps between the RNAP and the nucleic acids. The C-terminal segment of Nun interacts with the RNAP β and β' subunits inside the RNAP active site cleft as well as with nearly every element of the nucleic acid scaffold, essentially crosslinking the RNAP and the nucleic acids to prevent translocation, a mechanism supported by the effects of Nun amino acid substitutions. The nature of Nun interactions inside the RNAP active site cleft suggests that RNAP clamp opening is required for Nun to establish its interactions, explaining why Nun acts on paused TECs.

  9. Purification of Components of the Translation Elongation Factor Complex of Plasmodium falciparum by Tandem Affinity Purification▿

    OpenAIRE

    2007-01-01

    Plasmodium falciparum is the causative agent of severe human malaria, responsible for over 2 million deaths annually. Of the 5,300 polypeptides predicted to control the parasite life cycle in mosquitoes and humans, 60% are of unknown function. A major challenge of malaria postgenomic biology is to understand how the 5,300 predicted proteins coexist and interact to perform the essential tasks that define the complex life cycle of the parasite. One approach to assign function to these proteins ...

  10. Transcription elongation

    Science.gov (United States)

    Imashimizu, Masahiko; Shimamoto, Nobuo; Oshima, Taku; Kashlev, Mikhail

    2014-01-01

    Regulation of transcription elongation via pausing of RNA polymerase has multiple physiological roles. The pausing mechanism depends on the sequence heterogeneity of the DNA being transcribed, as well as on certain interactions of polymerase with specific DNA sequences. In order to describe the mechanism of regulation, we introduce the concept of heterogeneity into the previously proposed alternative models of elongation, power stroke and Brownian ratchet. We also discuss molecular origins and physiological significances of the heterogeneity. PMID:25764114

  11. Design of stereoelectronically promoted super lewis acids and unprecedented chemistry of their complexes.

    Science.gov (United States)

    Foroutan-Nejad, Cina; Vicha, Jan; Marek, Radek

    2014-09-01

    A new family of stereoelectronically promoted aluminum and scandium super Lewis acids is introduced on the basis of state-of-the-art computations. Structures of these molecules are designed to minimize resonance electron donation to central metal atoms in the Lewis acids. Acidity of these species is evaluated on the basis of their fluoride-ion affinities relative to the antimony pentafluoride reference system. It is demonstrated that introduced changes in the stereochemistry of the designed ligands increase acidity considerably relative to Al and Sc complexes with analogous monodentate ligands. The high stability of fluoride complexes of these species makes them ideal candidates to be used as weakly coordinating anions in combination with highly reactive cations instead of conventional Lewis acid-fluoride complexes. Further, the interaction of all designed molecules with methane is investigated. All studied acids form stable pentavalent-carbon complexes with methane. In addition, interactions of the strongest acid of this family with very weak bases, namely, H2, N2, carbon oxides, and noble gases were investigated; it is demonstrated that this compound can form considerably stable complexes with the aforementioned molecules. To the best of our knowledge, carbonyl and nitrogen complexes of this species are the first hypothetical four-coordinated carbonyl and nitrogen complexes of aluminum. The nature of bonding in these systems is studied in detail by various bonding analysis approaches. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  12. Peroxisome proliferator-activated receptor gamma recruits the positive transcription elongation factor b complex to activate transcription and promote adipogenesis

    DEFF Research Database (Denmark)

    Iankova, Irena; Petersen, Rasmus K; Annicotte, Jean-Sébastien

    2006-01-01

    Positive transcription elongation factor b (P-TEFb) phosphorylates the C-terminal domain of RNA polymerase II, facilitating transcriptional elongation. In addition to its participation in general transcription, P-TEFb is recruited to specific promoters by some transcription factors such as c-Myc...

  13. Super resolution nano-information recording in a new hydrazone metal complex material

    Science.gov (United States)

    Zhang, Kui; Wei, Jingsong; Chen, Zhimin; Wei, Tao; Geng, Yongyou; Wang, Yang; Wu, Yiqun

    2016-10-01

    Laser thermal lithography has been proposed for a few years, which has the advantages of breaking through the optical diffraction limit, operation in far-field and in air, and low production cost. In this paper, a new hydrazone metal complex is used as the laser thermal lithography material due to its feature of the one-step fabrication of micro/nano structure without mask and wet-etching process. Based on the laser thermal lithography method, super resolution nano-information pits are directly written on the surface of hydrazone metal complex thin films. Pits with a minimum feature size of about 79 nm are successfully obtained, which is only about 1/7 of the writing spot size. Moreover, the reactive ion etching method can be applied to transfer the pits onto a silica substrate. These results suggest the potential applications of the new material in high density optical data storage and semiconductor industries.

  14. Silencing SlELP2L, a tomato Elongator complex protein 2-like gene, inhibits leaf growth, accelerates leaf, sepal senescence, and produces dark-green fruit.

    Science.gov (United States)

    Zhu, Mingku; Li, Yali; Chen, Guoping; Ren, Lijun; Xie, Qiaoli; Zhao, Zhiping; Hu, Zongli

    2015-01-09

    The multi-subunit complex Elongator interacts with elongating RNA polymerase II (RNAPII) and is thought to facilitate transcription through histone acetylation. Elongator is highly conserved in eukaryotes, yet has multiple kingdom-specific functions in diverse organisms. Recent genetic studies performed in Arabidopsis have demonstrated that Elongator functions in plant growth and development, and in response to biotic and abiotic stress. However, little is known about its roles in other plant species. Here, we study the function of an Elongator complex protein 2-like gene in tomato, here designated as SlELP2L, through RNAi-mediated gene silencing. Silencing SlELP2L in tomato inhibits leaf growth, accelerates leaf and sepal senescence, and produces dark-green fruit with reduced GA and IAA contents in leaves, and increased chlorophyll accumulation in pericarps. Gene expression analysis indicated that SlELP2L-silenced plants had reduced transcript levels of ethylene- and ripening-related genes during fruit ripening with slightly decreased carotenoid content in fruits, while the expression of DNA methyltransferase genes was up-regulated, indicating that SlELP2L may modulate DNA methylation in tomato. Besides, silencing SlELP2L increases ABA sensitivity in inhibiting seedling growth. These results suggest that SlELP2L plays important roles in regulating plant growth and development, as well as in response to ABA in tomato.

  15. Translation complex profile sequencing to study the in vivo dynamics of mRNA-ribosome interactions during translation initiation, elongation and termination.

    Science.gov (United States)

    Shirokikh, Nikolay E; Archer, Stuart K; Beilharz, Traude H; Powell, David; Preiss, Thomas

    2017-04-01

    Messenger RNA (mRNA) translation is a tightly controlled process that is integral to gene expression. It features intricate and dynamic interactions of the small and large subunits of the ribosome with mRNAs, aided by multiple auxiliary factors during distinct initiation, elongation and termination phases. The recently developed ribosome profiling method can generate transcriptome-wide surveys of translation and its regulation. Ribosome profiling records the footprints of fully assembled ribosomes along mRNAs and thus primarily interrogates the elongation phase of translation. Importantly, it does not monitor multiple substeps of initiation and termination that involve complexes between the small ribosomal subunit (SSU) and mRNA. Here we describe a related method, termed 'translation complex profile sequencing' (TCP-seq), that is uniquely capable of recording positions of any type of ribosome-mRNA complex transcriptome-wide. It uses fast covalent fixation of translation complexes in live cells, followed by RNase footprinting of translation intermediates and their separation into complexes involving either the full ribosome or the SSU. The footprints derived from each type of complex are then deep-sequenced separately, generating native distribution profiles during the elongation, as well as the initiation and termination stages of translation. We provide the full TCP-seq protocol for Saccharomyces cerevisiae liquid suspension culture, including a data analysis pipeline. The protocol takes ∼3 weeks to complete by a researcher who is well acquainted with standard molecular biology techniques and who has some experience in ultracentrifugation and the preparation of RNA sequencing (RNA-seq) libraries. Basic Bash and UNIX/Linux command skills are required to use the bioinformatics tools provided.

  16. Structural basis of transcription elongation.

    Science.gov (United States)

    Martinez-Rucobo, Fuensanta W; Cramer, Patrick

    2013-01-01

    For transcription elongation, all cellular RNA polymerases form a stable elongation complex (EC) with the DNA template and the RNA transcript. Since the millennium, a wealth of structural information and complementary functional studies provided a detailed three-dimensional picture of the EC and many of its functional states. Here we summarize these studies that elucidated EC structure and maintenance, nucleotide selection and addition, translocation, elongation inhibition, pausing and proofreading, backtracking, arrest and reactivation, processivity, DNA lesion-induced stalling, lesion bypass, and transcriptional mutagenesis. In the future, additional structural and functional studies of elongation factors that control the EC and their possible allosteric modes of action should result in a more complete understanding of the dynamic molecular mechanisms underlying transcription elongation. This article is part of a Special Issue entitled: RNA polymerase II Transcript Elongation. Copyright © 2012 Elsevier B.V. All rights reserved.

  17. Crystal structure of 70S ribosome with both cognate tRNAs in the E and P sites representing an authentic elongation complex.

    Directory of Open Access Journals (Sweden)

    Shu Feng

    Full Text Available During the translation cycle, a cognate deacylated tRNA can only move together with the codon into the E site. We here present the first structure of a cognate tRNA bound to the ribosomal E site resulting from translocation by EF-G, in which an entire L1 stalk (L1 protein and L1 rRNA interacts with E-site tRNA (E-tRNA, representing an authentic ribosome elongation complex. Our results revealed that the Watson-Crick base pairing is formed at the first and second codon-anticodon positions in the E site in the ribosome elongation complex, whereas the codon-anticodon interaction in the third position is indirect. Analysis of the observed conformations of mRNA and E-tRNA suggests that the ribosome intrinsically has the potential to form codon-anticodon interaction in the E site, independently of the mRNA configuration. We also present a detailed description of the biologically relevant position of the entire L1 stalk and its interacting cognate E-tRNA, which provides a better understanding of the structural basis for translation elongation. Furthermore, to gain insight into translocation, we report the positioning of protein L6 contacting EF-G, as well as the conformational change of the C-terminal tail of protein S13 in the decoding center.

  18. Ubiquitin fusion constructs allow the expression and purification of multi-KOW domain complexes of the Saccharomyces cerevisiae transcription elongation factor Spt4/5.

    Science.gov (United States)

    Blythe, Amanda; Gunasekara, Sanjika; Walshe, James; Mackay, Joel P; Hartzog, Grant A; Vrielink, Alice

    2014-08-01

    Spt4/5 is a hetero-dimeric transcription elongation factor that can both inhibit and promote transcription elongation by RNA polymerase II (RNAPII). However, Spt4/5's mechanism of action remains elusive. Spt5 is an essential protein and the only universally-conserved RNAP-associated transcription elongation factor. The protein contains multiple Kyrpides, Ouzounis and Woese (KOW) domains. These domains, in other proteins, are thought to bind RNA although there is little direct evidence in the literature to support such a function in Spt5. This could be due, at least in part, to difficulties in expressing and purifying recombinant Spt5. When expressed in Escherichia coli (E. coli), Spt5 is innately insoluble. Here we report a new approach for the successful expression and purification of milligram quantities of three different multi-KOW domain complexes of Saccharomyces cerevisiae Spt4/5 for use in future functional studies. Using the E. coli strain Rosetta2 (DE3) we have developed strategies for co-expression of Spt4 and multi-KOW domain Spt5 complexes from the bi-cistronic pET-Duet vector. In a second strategy, Spt4/5 was expressed via co-transformation of Spt4 in the vector pET-M11 with Spt5 ubiquitin fusion constructs in the vector pHUE. We characterized the multi-KOW domain Spt4/5 complexes by Western blot, limited proteolysis, circular dichroism, SDS-PAGE and size exclusion chromatography-multiangle light scattering and found that the proteins are folded with a Spt4:Spt5 hetero-dimeric stoichiometry of 1:1. These expression constructs encompass a larger region of Spt5 than has previously been reported, and will provide the opportunity to elucidate the biological function of the multi-KOW containing Spt5.

  19. Events during eucaryotic rRNA transcription initiation and elongation: Conversion from the closed to the open promoter complex requires nucleotide substrates

    Energy Technology Data Exchange (ETDEWEB)

    Bateman, E.; Paule, M.R.

    1988-05-01

    Chemical footprinting and topological analysis were carried out on the Acanthamoeba castellanii rRNA transcription initiation factor (TIF) and RNA polymerase I complexes with DNA during transcription initiation and elongation. The results show that the binding of TIF and polymerase to the promoter does not alter the supercoiling of the DNA template and the template does not become sensitive to modification by diethylpyro-carbonate, which can identify melted DNA regions. Thus, in contrast to bacterial RNA polymerase, the eucaryotic RNA polymerase I-promoter complex is in a closed configuration preceding addition of nucleotides in vitro. Initiation and 3'-O-methyl CTP-limited translocation by RNA polymerase I results in separation of the polymerase-TIF footprints, leaving the TIF footprint unaltered. In contrast, initiation and translocation result in a significant change in the conformation of the polymerase-DNA complex, culminating in an unwound DNA region of at least 10 base pairs.

  20. DFT studies of carbohydrate solvation: II. MD-DFTr of a super-molecule complex of glucose, explicit waters, and an implicit solvent (COSMO)

    Science.gov (United States)

    MD-DFTr studies are carried out on the super-molecule solvated complexes of glucose described in paper I. Included were ten explicit water molecules and an implicit solvation model, COSMO, superimposed upon the complex. Starting configurations were taken from DFTr optimized complexes resulting from ...

  1. Thermodynamic Model of Transcription Elongation

    Science.gov (United States)

    Tadigotla, Vasisht; O'Maoileidigh, Daibhid; Sengupta, Anirvan; Epshtein, Vitaly; Ebright, Richard; Nudler, Evgeny; Ruckenstein, Andrei

    2006-03-01

    We present a statistical mechanics approach to the prediction of backtracked pauses in prokaryotic transcription elongation derived from structural models of the transcription elongation complex (TEC). Our algorithm is based on the thermodynamic stability of TEC along the DNA template calculated from the sequence dependent free-energy of DNA-DNA, DNA-RNA and RNA-RNA base pairing associated with (a) the translocation and size fluctuations of the transcription bubble; (b) the changes in the DNA-RNA hybrid; and (c) the changes in the RNA folding free-energy. The calculations involve no adjustable parameters apart from a cutoff used to discriminate paused from non-paused complexes. When applied to 100 experimental pauses in transcription elongation by E. coli RNA polymerase on ten DNA templates the approach produces highly statistically significant results. Transcription elongation is an inherently kinetic process and a simplified kinetic model with the same predictive power is presented separately.

  2. Poly(vinyl alcohol) composite films with high percent elongation prepared from amylose-fatty ammonium salt inclusion complexes

    Science.gov (United States)

    Amylose inclusion complexes prepared from cationic fatty ammonium salts and jet-cooked high amylose starch were combined with poly(vinyl alcohol) (PVOH) to form glycerol-plasticized films. Their tensile properties were compared with similar films prepared previously with analogous anionic fatty acid...

  3. Short-chain 3-hydroxyacyl-coenzyme A dehydrogenase associates with a protein super-complex integrating multiple metabolic pathways.

    Science.gov (United States)

    Narayan, Srinivas B; Master, Stephen R; Sireci, Anthony N; Bierl, Charlene; Stanley, Paige E; Li, Changhong; Stanley, Charles A; Bennett, Michael J

    2012-01-01

    Proteins involved in mitochondrial metabolic pathways engage in functionally relevant multi-enzyme complexes. We previously described an interaction between short-chain 3-hydroxyacyl-coenzyme A dehydrogenase (SCHAD) and glutamate dehydrogenase (GDH) explaining the clinical phenotype of hyperinsulinism in SCHAD-deficient patients and adding SCHAD to the list of mitochondrial proteins capable of forming functional, multi-pathway complexes. In this work, we provide evidence of SCHAD's involvement in additional interactions forming tissue-specific metabolic super complexes involving both membrane-associated and matrix-dwelling enzymes and spanning multiple metabolic pathways. As an example, in murine liver, we find SCHAD interaction with aspartate transaminase (AST) and GDH from amino acid metabolic pathways, carbamoyl phosphate synthase I (CPS-1) from ureagenesis, other fatty acid oxidation and ketogenesis enzymes and fructose-bisphosphate aldolase, an extra-mitochondrial enzyme of the glycolytic pathway. Most of the interactions appear to be independent of SCHAD's role in the penultimate step of fatty acid oxidation suggesting an organizational, structural or non-enzymatic role for the SCHAD protein.

  4. Short-Chain 3-Hydroxyacyl-Coenzyme A Dehydrogenase Associates with a Protein Super-Complex Integrating Multiple Metabolic Pathways

    Science.gov (United States)

    Narayan, Srinivas B.; Master, Stephen R.; Sireci, Anthony N.; Bierl, Charlene; Stanley, Paige E.; Li, Changhong; Stanley, Charles A.; Bennett, Michael J.

    2012-01-01

    Proteins involved in mitochondrial metabolic pathways engage in functionally relevant multi-enzyme complexes. We previously described an interaction between short-chain 3-hydroxyacyl-coenzyme A dehydrogenase (SCHAD) and glutamate dehydrogenase (GDH) explaining the clinical phenotype of hyperinsulinism in SCHAD-deficient patients and adding SCHAD to the list of mitochondrial proteins capable of forming functional, multi-pathway complexes. In this work, we provide evidence of SCHAD's involvement in additional interactions forming tissue-specific metabolic super complexes involving both membrane-associated and matrix-dwelling enzymes and spanning multiple metabolic pathways. As an example, in murine liver, we find SCHAD interaction with aspartate transaminase (AST) and GDH from amino acid metabolic pathways, carbamoyl phosphate synthase I (CPS-1) from ureagenesis, other fatty acid oxidation and ketogenesis enzymes and fructose-bisphosphate aldolase, an extra-mitochondrial enzyme of the glycolytic pathway. Most of the interactions appear to be independent of SCHAD's role in the penultimate step of fatty acid oxidation suggesting an organizational, structural or non-enzymatic role for the SCHAD protein. PMID:22496890

  5. Short-chain 3-hydroxyacyl-coenzyme A dehydrogenase associates with a protein super-complex integrating multiple metabolic pathways.

    Directory of Open Access Journals (Sweden)

    Srinivas B Narayan

    Full Text Available Proteins involved in mitochondrial metabolic pathways engage in functionally relevant multi-enzyme complexes. We previously described an interaction between short-chain 3-hydroxyacyl-coenzyme A dehydrogenase (SCHAD and glutamate dehydrogenase (GDH explaining the clinical phenotype of hyperinsulinism in SCHAD-deficient patients and adding SCHAD to the list of mitochondrial proteins capable of forming functional, multi-pathway complexes. In this work, we provide evidence of SCHAD's involvement in additional interactions forming tissue-specific metabolic super complexes involving both membrane-associated and matrix-dwelling enzymes and spanning multiple metabolic pathways. As an example, in murine liver, we find SCHAD interaction with aspartate transaminase (AST and GDH from amino acid metabolic pathways, carbamoyl phosphate synthase I (CPS-1 from ureagenesis, other fatty acid oxidation and ketogenesis enzymes and fructose-bisphosphate aldolase, an extra-mitochondrial enzyme of the glycolytic pathway. Most of the interactions appear to be independent of SCHAD's role in the penultimate step of fatty acid oxidation suggesting an organizational, structural or non-enzymatic role for the SCHAD protein.

  6. Ultrasonographic-guided retrieval of cumulus oocyte complexes after super-stimulation in dromedary camel (Camelus dromedarius).

    Science.gov (United States)

    Wani, N A; Skidmore, J A

    2010-08-01

    In Experiment 1, studies were conducted to apply the transvaginal ultrasound guided ovum pick-up (OPU) technique in dromedary camels after their ovarian super-stimulation and in vivo oocyte maturation. In Experiment 2, the developmental potential of two commonly used oocyte types, i.e., in vivo matured oocytes collected by OPU and abattoir derived in vitro-matured oocytes was compared after their chemical activation. In Experiment 3, developmental competence of oocytes collected from super-stimulated camels by OPU, matured either in vivo or in vitro, was compared after their chemical activation. Mature female dromedary camels super-stimulated with a combination of eCG and pFSH were given an injection of 20 microg of the GnRH analogue, buserelin 24, 26, or 28 h before the scheduled OPU. For collection of cumulus oocyte complexes (COCs) the transducer was guided through the vulva into the cranial most portion of the vagina and 17-gauge, 55 cm single-lumen needle was placed in the needle guide of the ultrasound probe and advanced through the vaginal fornix and into the follicle. Follicular fluid was aspirated using a regulated vacuum pump into tubes containing embryo-flushing media. Aspirates were searched for COCs using a stereomicroscope, and they were then denuded of cumulus cells by hyaluronidase and repeated pipetting. The oocytes were classified as mature (with a visible polar body), immature (with no visible polar body), activated (with divided or fragmented ooplasm) and others (degenerated and abnormal). Overall an average of 12.12 +/- 7.9 COCs were aspirated per animal with an oocyte recovery rate from the aspirated follicles of about 77%. The majority (> 90%) of the collected COCs by OPU were with loose and expanded cumulus cells. The proportion of matured oocytes obtained at 28-29 h (91.2 +/- 4.1) and 26-27 h (82.1 +/- 3.4) were higher (P dromedary camels 26-28 h after GnRH administration. The developmental response, to chemical activation, of in vivo

  7. The dynamical status of ZwCl 2341.1+0000: a very elongated galaxy structure with a complex radio emission

    CERN Document Server

    Boschin, W; Barrena, R

    2013-01-01

    We study the dynamical status of the galaxy system ZwCl 2341.1+0000, a filamentary multi-Mpc galaxy structure associated with a complex diffuse radio emission. Our analysis is mainly based on new spectroscopic data for 128 galaxies acquired at the TNG telescope. We also use optical data available in the SDSS and X-ray data from the Chandra archive. We select 101 cluster member galaxies and compute the cluster redshift ~0.2693 and the global LOS velocity dispersion ~1000 km/s. Our optical analysis agrees with the presence of at least three, likely four or more, optical subclusters causing the SSE-NNW elongation of the galaxy distribution and a significant velocity gradient in the S-N direction. In particular, we detect an important low-velocity subclump in the southern region, roughly coincident with the brightest peak of the diffuse radio emission but with a clear offset between the optical and radio peaks. We also detect one (or two) optical subcluster(s) at north, in correspondence with the second brightest...

  8. Structural analysis of intermolecular interactions in the kinesin adaptor complex fasciculation and elongation protein zeta 1/ short coiled-coil protein (FEZ1/SCOCO.

    Directory of Open Access Journals (Sweden)

    Marcos Rodrigo Alborghetti

    Full Text Available Cytoskeleton and protein trafficking processes, including vesicle transport to synapses, are key processes in neuronal differentiation and axon outgrowth. The human protein FEZ1 (fasciculation and elongation protein zeta 1 / UNC-76, in C. elegans, SCOCO (short coiled-coil protein / UNC-69 and kinesins (e.g. kinesin heavy chain / UNC116 are involved in these processes. Exploiting the feature of FEZ1 protein as a bivalent adapter of transport mediated by kinesins and FEZ1 protein interaction with SCOCO (proteins involved in the same path of axonal growth, we investigated the structural aspects of intermolecular interactions involved in this complex formation by NMR (Nuclear Magnetic Resonance, cross-linking coupled with mass spectrometry (MS, SAXS (Small Angle X-ray Scattering and molecular modelling. The topology of homodimerization was accessed through NMR (Nuclear Magnetic Resonance studies of the region involved in this process, corresponding to FEZ1 (92-194. Through studies involving the protein in its monomeric configuration (reduced and dimeric state, we propose that homodimerization occurs with FEZ1 chains oriented in an anti-parallel topology. We demonstrate that the interaction interface of FEZ1 and SCOCO defined by MS and computational modelling is in accordance with that previously demonstrated for UNC-76 and UNC-69. SAXS and literature data support a heterotetrameric complex model. These data provide details about the interaction interfaces probably involved in the transport machinery assembly and open perspectives to understand and interfere in this assembly and its involvement in neuronal differentiation and axon outgrowth.

  9. Isolation and characterization of PSI-LHCI super-complex and their sub-complexes from a red alga Cyanidioschyzon merolae.

    Science.gov (United States)

    Tian, Lirong; Liu, Zheyi; Wang, Fangjun; Shen, Liangliang; Chen, Jinghua; Chang, Lijing; Zhao, Songhao; Han, Guangye; Wang, Wenda; Kuang, Tingyun; Qin, Xiaochun; Shen, Jian-Ren

    2017-09-01

    Photosystem I (PSI)-light-harvesting complex I (LHCI) super-complex and its sub-complexes PSI core and LHCI, were purified from a unicellular red alga Cyanidioschyzon merolae and characterized. PSI-LHCI of C. merolae existed as a monomer with a molecular mass of 580 kDa. Mass spectrometry analysis identified 11 subunits (PsaA, B, C, D, E, F, I, J, K, L, O) in the core complex and three LHCI subunits, CMQ142C, CMN234C, and CMN235C in LHCI, indicating that at least three Lhcr subunits associate with the red algal PSI core. PsaG was not found in the red algae PSI-LHCI, and we suggest that the position corresponding to Lhca1 in higher plant PSI-LHCI is empty in the red algal PSI-LHCI. The PSI-LHCI complex was separated into two bands on native PAGE, suggesting that two different complexes may be present with slightly different protein compositions probably with respective to the numbers of Lhcr subunits. Based on the results obtained, a structural model was proposed for the red algal PSI-LHCI. Furthermore, pigment analysis revealed that the C. merolae PSI-LHCI contained a large amount of zeaxanthin, which is mainly associated with the LHCI complex whereas little zeaxanthin was found in the PSI core. This indicates a unique feature of the carotenoid composition of the Lhcr proteins and may suggest an important role of Zea in the light-harvesting and photoprotection of the red algal PSI-LHCI complex.

  10. Purification of the Cytochrome c Reductase/Cytochrome c Oxidase Super Complex of Yeast Mitochondria

    OpenAIRE

    Braun, Hans-Peter; Sunderhaus, Stephanie; Boekema, Egbert J.; Kouřil, Roman

    2009-01-01

    The protein complexes of the respiratory chain interact by forming large protein particles called respiratory supercomplexes or ‘‘respirasomes’’. Biochemical characterization of these particles proved to be difficult because of their instability. Here we describe a strategy to isolate and characterize the cytochrome c reductase/cytochrome c oxidase supercomplex of yeast, also termed the III + IV supercomplex, which is based on lactate cultivation of yeast, gentle isolation of mitochondria, me...

  11. Synthesis of Elongated Microcapsules

    Science.gov (United States)

    Li, Wenyan; Buhrow, Jerry; Calle, Luz M.

    2011-01-01

    One of the factors that influence the effectiveness of self-healing in functional materials is the amount of liquid healing agents that can be delivered to the damaged area. The use of hollow tubes or fibers and the more sophisticated micro-vascular networks has been proposed as a way to increase the amount of healing agents that can be released when damage is inflicted. Although these systems might be effective in some specific applications, they are not practical for coatings applications. One possible practical way to increase the healing efficiency is to use microcapsules with high-aspect-ratios, or elongated microcapsules. It is understood that elongated microcapsules will be more efficient because they can release more healing agent than a spherical microcapsule when a crack is initiated in the coating. Although the potential advantage of using elongated microcapsules for self healing applications is clear, it is very difficult to make elongated microcapsules from an emulsion system because spherical microcapsules are normally formed due to the interfacial tension between the dispersed phase and the continuous phase. This paper describes the two methods that have been developed by the authors to synthesize elongated microcapsules. The first method involves the use of an emulsion with intermediate stability and the second involves the application of mechanical shear conditions to the emulsion.

  12. Super-quantum curves from super-eigenvalue models

    CERN Document Server

    Ciosmak, Paweł; Manabe, Masahide; Sułkowski, Piotr

    2016-01-01

    In modern mathematical and theoretical physics various generalizations, in particular supersymmetric or quantum, of Riemann surfaces and complex algebraic curves play a prominent role. We show that such supersymmetric and quantum generalizations can be combined together, and construct supersymmetric quantum curves, or super-quantum curves for short. Our analysis is conducted in the formalism of super-eigenvalue models: we introduce $\\beta$-deformed version of those models, and derive differential equations for associated $\\alpha/\\beta$-deformed super-matrix integrals. We show that for a given model there exists an infinite number of such differential equations, which we identify as super-quantum curves, and which are in one-to-one correspondence with, and have the structure of, super-Virasoro singular vectors. We discuss potential applications of super-quantum curves and prospects of other generalizations.

  13. Super-quantum curves from super-eigenvalue models

    Science.gov (United States)

    Ciosmak, Paweł; Hadasz, Leszek; Manabe, Masahide; Sułkowski, Piotr

    2016-10-01

    In modern mathematical and theoretical physics various generalizations, in particular supersymmetric or quantum, of Riemann surfaces and complex algebraic curves play a prominent role. We show that such supersymmetric and quantum generalizations can be combined together, and construct supersymmetric quantum curves, or super-quantum curves for short. Our analysis is conducted in the formalism of super-eigenvalue models: we introduce β-deformed version of those models, and derive differential equations for associated α/ β-deformed super-matrix integrals. We show that for a given model there exists an infinite number of such differential equations, which we identify as super-quantum curves, and which are in one-to-one correspondence with, and have the structure of, super-Virasoro singular vectors. We discuss potential applications of super-quantum curves and prospects of other generalizations.

  14. Super-quantum curves from super-eigenvalue models

    Energy Technology Data Exchange (ETDEWEB)

    Ciosmak, Paweł [Faculty of Mathematics, Informatics and Mechanics, University of Warsaw,ul. Banacha 2, 02-097 Warsaw (Poland); Hadasz, Leszek [M. Smoluchowski Institute of Physics, Jagiellonian University,ul. Łojasiewicza 11, 30-348 Kraków (Poland); Manabe, Masahide [Faculty of Physics, University of Warsaw,ul. Pasteura 5, 02-093 Warsaw (Poland); Sułkowski, Piotr [Faculty of Physics, University of Warsaw,ul. Pasteura 5, 02-093 Warsaw (Poland); Walter Burke Institute for Theoretical Physics, California Institute of Technology,1200 E. California Blvd, Pasadena, CA 91125 (United States)

    2016-10-10

    In modern mathematical and theoretical physics various generalizations, in particular supersymmetric or quantum, of Riemann surfaces and complex algebraic curves play a prominent role. We show that such supersymmetric and quantum generalizations can be combined together, and construct supersymmetric quantum curves, or super-quantum curves for short. Our analysis is conducted in the formalism of super-eigenvalue models: we introduce β-deformed version of those models, and derive differential equations for associated α/β-deformed super-matrix integrals. We show that for a given model there exists an infinite number of such differential equations, which we identify as super-quantum curves, and which are in one-to-one correspondence with, and have the structure of, super-Virasoro singular vectors. We discuss potential applications of super-quantum curves and prospects of other generalizations.

  15. Temperature dependence of the crystal structure and g-values of trans-diaquabis(methoxyacetato)copper(II): evidence for a thermal equilibrium between complexes with tetragonally elongated and compressed geometries.

    Science.gov (United States)

    Simmons, Charles J; Stratemeier, Horst; Hitchman, Michael A; Reinen, Dirk; Masters, Vanessa M; Riley, Mark J

    2011-06-06

    The crystal structures of trans-diaquabis(methoxyacetato)copper(II) and the isostructural nickel(II) complex have been determined over a wide temperature range. In conjunction with the reported behavior of the g-values, the structural data suggest that the copper(II) compound exhibits a thermal equilibrium between three structural forms, two having orthorhombically distorted, tetragonally elongated geometries but with the long and intermediate bonds to different atoms, and the third with a tetragonally compressed geometry. This is apparently the first reported example of a copper(II) complex undergoing an equilibrium between tetragonally elongated and compressed forms. The optical spectrum of single crystals of the copper(II) compound is used to obtain metal-ligand bonding parameters which yield the g-values of the compressed form of the complex and hence the proportions of the complex in each structural form at every temperature. When combined with estimates of the Jahn-Teller distortions of the different forms, the latter produce excellent agreement with the observed temperature dependence of the bond lengths. The behavior of an infrared combination band is consistent with such a thermal equilibrium, as is the temperature dependence of the thermal ellipsoid parameters and the XAFS. The potential surfaces of the different forms of the copper(II) complex have been calculated by a model based upon Jahn-Teller coupling. It is suggested that cooperative effects may cause the development of the population of tetragonally compressed complexes, and the crystal packing is consistent with this hypothesis, though the present model may oversimplify the diversity of structural forms present at high temperature. © 2011 American Chemical Society

  16. Super Special Codes using Super Matrices

    CERN Document Server

    Kandasamy, W B Vasantha; Ilanthenral, K

    2010-01-01

    The new classes of super special codes are constructed in this book using the specially constructed super special vector spaces. These codes mainly use the super matrices. These codes can be realized as a special type of concatenated codes. This book has four chapters. In chapter one basic properties of codes and super matrices are given. A new type of super special vector space is constructed in chapter two of this book. Three new classes of super special codes namely, super special row code, super special column code and super special codes are introduced in chapter three. Applications of these codes are given in the final chapter.

  17. Super-resolution near field imaging device

    DEFF Research Database (Denmark)

    2014-01-01

    Super-resolution imaging device comprising at least a first and a second elongated coupling element, each having a first transverse dimension at a first end and a second transverse dimension at a second end and being adapted for guiding light between their respective first and second ends, each...

  18. Large amplitude oscillatory elongation flow

    DEFF Research Database (Denmark)

    Rasmussen, Henrik K.; Laillé, Philippe; Yu, Kaijia

    2008-01-01

    A filament stretching rheometer (FSR) was used for measuring the elongation flow with a large amplitude oscillative elongation imposed upon the flow. The large amplitude oscillation imposed upon the elongational flow as a function of the time t was defined as epsilon(t) =(epsilon) over dot(0)t + ...

  19. Super Factories

    Indian Academy of Sciences (India)

    D G Hitlin

    2006-11-01

    Heavy-flavor physics, in particular and physics results from the factories, currently provides strong constraints on models of physics beyond the Standard Model. A new generation of colliders, Super Factories, with 50 to 100 times the luminosity of existing colliders, can, in a dialog with LHC and ILC, provide unique clarification of new physics phenomena seen at those machines.

  20. The Super Patalan Numbers

    OpenAIRE

    Richardson, Thomas M.

    2014-01-01

    We introduce the super Patalan numbers, a generalization of the super Catalan numbers in the sense of Gessel, and prove a number of properties analagous to those of the super Catalan numbers. The super Patalan numbers generalize the super Catalan numbers similarly to how the Patalan numbers generalize the Catalan numbers.

  1. 双侧唇红矩形瓣前唇原长双侧唇裂修复术%Repair of the deformity of bilateral cleft lip with non-elongated cheiloplasty and rectangular mucomuscular complex flaps of double vermilion

    Institute of Scientific and Technical Information of China (English)

    贾志宇; 赵云转; 王维丽; 蒋崇槟; 屈鹏飞; 张英怀

    2009-01-01

    目的 介绍双侧唇红矩形瓣前唇原长双侧唇裂修复术的应用.方法 双侧唇裂患者29例,男性20例,女性9例.其中双侧完全裂15例,不完全裂11例,混合裂3例,均采用双侧唇红矩形瓣前唇原长法进行修复.首先采用传统的原长法原则修复唇白.修复唇红时,在两侧唇红设计形成包括黏膜和部分口轮匝肌的矩形瓣,并沿干湿唇交界线水平切开前唇,将两侧矩形瓣向下内旋转至前唇唇红对接缝合.缝合时口轮匝肌肌束的断端尽可能广阔而平整的接合,以恢复正常的环形结构.结果 所有患者的创口均Ⅰ期愈合,上唇高度宽度适中,唇珠明显,无口哨畸形.结论 该方法修复双侧唇裂,方法简单可靠,去除组织少,术后能获得较好的鼻唇外形,口唇功能较好,值得在临床推广.%Objective To introduce experiences with non-elongated cheiloplasty and rectangular mucomuscular complex flaps of double vermilion for repairing bilateral cleft lips. Methods 29 patients (20 males and 9 females) with bilateral cleft lips underwent operations of non-elongated cheiloplasty and rectangular mucomuscular complex flaps of double vermilion. There were 15 bilateral complete cleft lips, 11 bilateral incomplete cleft lips and 3 bilateral mixed cleft lips. The deformity of white lips was reconstructed with traditional non-elongated cheiloplasty. When repairing the vermilion, the rectangular mucomuscular complex flaps which included mucous membrane of vermilion and part of orbicularis oris in double vermilion were designed, and vermilion of fore lip was incised along boundary of wet lip and dry lip. Then rectangular mucomuscular complex flaps of double vermilion were rotated downward and inward to be sewn with fore lip. At the step, the end of orbicularis otis should be sewn widely and fitly in order to form a normal annular structure. Results The wounds of all the patients were healed at one stage. The height and width of patients' upper

  2. The Double-Strand Break Landscape of Meiotic Chromosomes Is Shaped by the Paf1 Transcription Elongation Complex in Saccharomyces cerevisiae.

    Science.gov (United States)

    Gothwal, Santosh K; Patel, Neem J; Colletti, Meaghan M; Sasanuma, Hiroyuki; Shinohara, Miki; Hochwagen, Andreas; Shinohara, Akira

    2016-02-01

    Histone modification is a critical determinant of the frequency and location of meiotic double-strand breaks (DSBs), and thus recombination. Set1-dependent histone H3K4 methylation and Dot1-dependent H3K79 methylation play important roles in this process in budding yeast. Given that the RNA polymerase II associated factor 1 complex, Paf1C, promotes both types of methylation, we addressed the role of the Paf1C component, Rtf1, in the regulation of meiotic DSB formation. Similar to a set1 mutation, disruption of RTF1 decreased the occurrence of DSBs in the genome. However, the rtf1 set1 double mutant exhibited a larger reduction in the levels of DSBs than either of the single mutants, indicating independent contributions of Rtf1 and Set1 to DSB formation. Importantly, the distribution of DSBs along chromosomes in the rtf1 mutant changed in a manner that was different from the distributions observed in both set1 and set1 dot1 mutants, including enhanced DSB formation at some DSB-cold regions that are occupied by nucleosomes in wild-type cells. These observations suggest that Rtf1, and by extension the Paf1C, modulate the genomic DSB landscape independently of H3K4 methylation.

  3. Extreme cervical elongation after sacrohysteropexy

    NARCIS (Netherlands)

    Vierhout, M.E.; Futterer, J.J.

    2013-01-01

    We present a case of extreme cervical elongation with a cervix of 12 cm after an unusual operation in which the uterine corpus was directly fixed to the promontory, and which became symptomatic after 8 years. The possible pathophysiology of cervical elongation is discussed. Diagnosing a case of seve

  4. 一种基于全局复合评价算法的Super Peer选择机制%Selection mechanism of Super Peers based on global complex evaluation algorithm

    Institute of Scientific and Technical Information of China (English)

    徐小龙; 王汝传

    2009-01-01

    提出一种基于全局复合评价算法的Super Peer选择机制,该机制以主客观相结合的科学依据从多方面自动选择P2P网络中稳定可靠、长期在线且积极提供服务的大量高性能Peer担当Super Peer职责,从而可以极大地扩充Super Peer的数量,使得全分布式结构化拓扑和半分布式拓扑结构可以在同一个P2P网络中有效地互补并存.全局复合评价算法综合采用在线活跃情况、任务完成能力和平均通信速率这3个指标来作为Super Peer的选择标准.构建了P2P仿真实验系统环境,验证所提出的算法和相应机制的可行性和实用价值.

  5. Combined self-learning based single-image super-resolution and dual-tree complex wavelet transform denoising for medical images

    Science.gov (United States)

    Yang, Guang; Ye, Xujiong; Slabaugh, Greg; Keegan, Jennifer; Mohiaddin, Raad; Firmin, David

    2016-03-01

    In this paper, we propose a novel self-learning based single-image super-resolution (SR) method, which is coupled with dual-tree complex wavelet transform (DTCWT) based denoising to better recover high-resolution (HR) medical images. Unlike previous methods, this self-learning based SR approach enables us to reconstruct HR medical images from a single low-resolution (LR) image without extra training on HR image datasets in advance. The relationships between the given image and its scaled down versions are modeled using support vector regression with sparse coding and dictionary learning, without explicitly assuming reoccurrence or self-similarity across image scales. In addition, we perform DTCWT based denoising to initialize the HR images at each scale instead of simple bicubic interpolation. We evaluate our method on a variety of medical images. Both quantitative and qualitative results show that the proposed approach outperforms bicubic interpolation and state-of-the-art single-image SR methods while effectively removing noise.

  6. Super-resolution complex amplitude reconstruction of nanostructured binary data using an interference microscope with pattern matching.

    Science.gov (United States)

    Ishikawa, Shinji; Hayasaki, Yoshio

    2013-07-29

    We propose a new method of optically reconstructing binary data formed by nanostructures with an elemental size several tens of nanometers smaller than the diffraction limit, implemented with an interference microscope and a complex-amplitude image pattern matching method. We examine the size dependency of the data reconstruction capacity using a light propagation simulation based on the finite-difference time-domain (FDTD) method and the Fourier spatial frequency filtering method. We demonstrated that the readable size of the binary nanostructure depends on the magnitude of noise.

  7. High-Resolution Imaging of Molecular Gas and Dust in the Antennae (NGC 4038/39) Super Giant Molecular Complexes

    CERN Document Server

    Wilson, C D; Madden, S C; Charmandaris, V

    2000-01-01

    We present new aperture synthesis CO maps of the Antennae (NGC 4038/39) obtained with the Caltech Millimeter Array. These sensitive images show molecular emission associated with the two nuclei and a partial ring of star formation to the west of NGC 4038, as well as revealing the large extent of the extra-nuclear region of star formation (the ``overlap region''), which dominates the CO emission from this system. The largest molecular complexes have masses of 3-6x10^8 M_sun, typically an order of magnitude larger than the largest structures seen to date in more quiescent galaxy disks. The extremely red luminous star clusters identified previously with HST are well-correlated with the CO emission, which supports the conclusion that they are highly embedded young objects rather than old globular clusters. There is an excellent correlation between the CO emission and the 15 micron emission seen with ISO, particularly for the brightest regions. The most massive complexes in the overlap region have similar [NeIII]/...

  8. Bromodomain and extra-terminal (BET) bromodomain inhibition activate transcription via transient release of positive transcription elongation factor b (P-TEFb) from 7SK small nuclear ribonucleoprotein.

    Science.gov (United States)

    Bartholomeeusen, Koen; Xiang, Yanhui; Fujinaga, Koh; Peterlin, B Matija

    2012-10-19

    By phosphorylating elongation factors and the C-terminal domain of RNA polymerase II, the positive transcription elongation factor b (P-TEFb) is the critical kinase for transcription elongation and co-transcriptional processing of eukaryotic genes. It exists in inactive small nuclear ribonucleoprotein (7SK snRNP) and active (free P-TEFb) complexes in cells. The P-TEFb equilibrium determines the state of cellular activation, proliferation, and differentiation. Free P-TEFb, which is required for growth, can be recruited to RNA polymerase II via transcription factors, BRD4, or the super elongation complex (SEC). UV light, various signaling cascades, transcriptional blockade, or compounds such as hexamethylene bisacetamide (HMBA), suberoylanilide hydroxamic acid (SAHA), and other histone deacetylase inhibitors lead to a rapid release of free P-TEFb, followed by its reassembly into the 7SK snRNP. As a consequence, transcription of HEXIM1, a critical 7SK snRNP subunit, and HIV is induced. In this study, we found that a bromodomain and extra-terminal (BET) bromodomain inhibitor, JQ1, which inhibits BRD4 by blocking its association with chromatin, also leads to the rapid release of free P-TEFb from the 7SK snRNP. Indeed, JQ1 transiently increased levels of free P-TEFb and BRD4·P-TEFb and SEC·P-TEFb complexes in cells. As a consequence, the levels of HEXIM1 and HIV proteins rose. Importantly, the knockdown of ELL2, a subunit of the SEC, blocked the ability of JQ1 to increase HIV transcription. Finally, the effects of JQ1 and HMBA or SAHA on the P-TEFb equilibrium were cooperative. We conclude that HMBA, SAHA, and JQ1 affect transcription elongation by a similar and convergent mechanism.

  9. A study of the super-abundant Bemisia tabaci (Gennadius) species complex (Hemiptera: Aleyrodidae) in cassava Mosaic disease pandemic areas in Tanzania

    DEFF Research Database (Denmark)

    Tajebe, Lensa Sefera

    and forcing some farmers to abandon the cultivation of the crop. The severe CMD pandemic is mainly characterized by high severity and incidence of the disease dominated by whitefly-borne infection and super-abundant populations of B. tabaci. All Bemisia tabaci individuals harbour a primary bacterial symbiont...... (Portiera aleyrodidarum) essential for their survival, and many also harbour non-essential secondary symbionts. In an attempt to understand the cause of the super-abundant populations, it was suggested that a distinct genotype cluster is associated with the pandemic, however, there was no definitive proof...... for this or other potential causes of super-abundance. Moreover, these super-abundant populations, that occur in pandemic areas, remain unstudied in terms of the endosymbiotic bacteria they harbour, their population structure, and the potential for gene flow and hybridization. Therefore, this research through...

  10. Super-resolution Phase Tomography

    KAUST Repository

    Depeursinge, Christian

    2013-04-21

    Digital Holographic Microscopy (DHM) yields reconstructed complex wavefields. It allows synthesizing the aperture of a virtual microscope up to 2π, offering super-resolution phase images. Live images of micro-organisms and neurons with resolution less than 100 nm are presented.

  11. Elongational dynamics of multiarm polystyrene

    DEFF Research Database (Denmark)

    Rasmussen, Henrik K.; Skov, Anne Ladegaard; Nielsen, Jens Kromann

    2009-01-01

    The startup of uni-axial elongational flow followed by stress relaxation and reversed bi-axial flow has been measured for a branched polystyrene melt with narrow molar mass distribution using the filament stretching rheometer. The branched polystyrene melt was a multiarm A(q)-C-C-A(q) pom-pom pol...

  12. Analysis on Dry Matter Production Characteristics of Super Hybrid Rice

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    Six middle-season indica hybrid rice combinations,including five super hybrid rice combinations with the high yield about 10.5 t/ha and a check hybrid rice combination Shanyou 63 with a yield potential about 9.5 t/ha,were used as materials to study the dry matter production characteristics.The super hybrid rice showed a high ability in dry matter production and accumulation and its yield enhanced with the increase of dry matter accumulation.The advantage period of dry matter production in the super hybrid rice was mainly at the middle and late growth stages compared with the check.The grain yield had no significant correlation with the dry matter accumulation before the elongation stage while had a significantly positive correlation with the dry matter accumulation from the elongation to maturity stages in super hybrid rice.There were more dry matter in vegetative organs at the heading stage in the super hybrid rice but its contribution to yield (apparent conversion percentage) was averagely 4.3 percent points lower than that in the check.For crop growth rate (CGR),the comparative advantage of super hybrid rice was at the middle and late stages,especially after flowering.Moreover,as the rising of leaf area index (LAI) and leaf area duration (LAD),CGR enhanced.The total LAD and the mean of LAD per day of super hybrid rice was about 14.79% and 10.31% higher than those of the check,respectively.The results indicate that the high yield of super hybrid rice mostly comes from the products of photosynthesis after heading,which is shown by the increased CGR at middle and later stages.It is suggested that LAD character might be used to better explain the advantage in the dry matter production of super hybrid rice than LAI.

  13. Hack's Law: Sinuosity, convexity, elongation

    Science.gov (United States)

    Willemin, James H.

    2000-11-01

    Hack's law, an empirical, power law relationship between drainage basin area and the length of the main stream channel, has long been taken to imply that drainage basins become more elongate (relatively longer and narrower) with increasing basin size. A study of the geometry of 38 basins from three distinct geomorphic settings shows that this geometric interpretation of Hack's law is only occasionally true: Even though Hack's power law relationship holds between basin area and main channel length, these basins do not necessarily become more elongate with increasing size. Rather, Hack's law is an expression of a balance between changes in basin shape and changes in channel planform geometry. For the basins in this study, changes in channel sinuosity play the most important role in this balance; changes in basin shape are far less regular. Local conditions appear to determine the partitioning of importance between changes in basin shape and channel sinuosity.

  14. Elongation Transducer For Tensile Tests

    Science.gov (United States)

    Roberts, Paul W.; Stokes, Thomas R.

    1994-01-01

    Extensometer transducer measures elongation of tensile-test specimen with negligible distortion of test results. Used in stress-versus-strain tests of small specimens of composite materials. Clamping stress distributed more evenly. Specimen clamped gently between jaw and facing surface of housing. Friction force of load points on conical tips onto specimen depends on compression of spring, adjusted by turning cover on housing. Limp, light nylon-insulated electrical leads impose minimal extraneous loads on measuring elements.

  15. Multiple DNA Interactions Contribute to the Initiation of Telomerase Elongation.

    Science.gov (United States)

    Karademir Andersson, Ahu; Gustafsson, Cecilia; Krishnankutty, Roopesh; Cohn, Marita

    2017-07-07

    Telomerase maintains telomere length and chromosome integrity by adding short tandem repeats of single-stranded DNA to the 3' ends, via reverse transcription of a defined template region of its RNA subunit. To further understand the telomerase elongation mechanism, we studied the primer utilization and extension activity of the telomerase from the budding yeast Naumovozyma castellii (Saccharomyces castellii), which displays a processive nucleotide and repeat addition polymerization. For the efficient initiation of canonical elongation, telomerase required 4-nt primer 3' end complementarity to the template RNA. This DNA-RNA hybrid formation was highly important for the stabilization of an initiation-competent telomerase-DNA complex. Anchor site interactions with the DNA provided additional stabilization to the complex. Our studies indicate three additional separate interactions along the length of the DNA primer, each providing different and distinct contributions to the initiation event. A sequence-independent anchor site interaction acts immediately adjacent to the base-pairing 3' end, indicating a protein anchor site positioned very close to the catalytic site. Two additional anchor regions further 5' on the DNA provide sequence-specific contributions to the initiation of elongation. Remarkably, a non-telomeric sequence in the distal 25- to 32-nt region negatively influences the initiation of telomerase elongation, suggesting an anchor site with a regulatory role in the telomerase elongation decision. Copyright © 2017 Elsevier Ltd. All rights reserved.

  16. Targeting Transcription Elongation Machinery for Breast Cancer Therapy

    Science.gov (United States)

    2016-05-01

    molecules. We have employed the CRISPR /Cas9 genome-editing tool to knock out the gene encoding the SEC component AFF4 or knock in a mutant cyclin T1 (AAG...for RNA Pol II. The potential role of a Super Enhancer will also be tested by knocking down the mediator complex in these breast cancer cells and

  17. Reversed planar elongation of soft polymeric networks

    DEFF Research Database (Denmark)

    Jensen, Mette Krog; Rasmussen, Henrik K.; Skov, Anne Ladegaard

    2011-01-01

    The newly developed planar elongation fixture, designed as an add-on to the filament stretch rheometer, is used to measure reversible large amplitude planar elongation on soft elastomers. The concept of this new fixture is to elongate an annulus, by keeping the perimeter constant. The deformation...

  18. Retention of transcription initiation factor sigma(70) in transcription elongation: Single-molecule analysis

    OpenAIRE

    Kapanidis, A. N.; Margeat, E; Laurence, T A; Doose, S.; Ho, S O; Mukhopadhyay, J.; Kortkhonjia, E; Mekler, V; Ebright, R H; S. Weiss

    2005-01-01

    We report a single-molecule assay that defines, simultaneously, the translocational position of a protein complex relative to DNA and the subunit stoichiometry of the complex. We applied the assay to define translocational positions and sigma(70) contents of bacterial transcription elongation complexes in vitro. The results confirm ensemble results indicating that a large fraction, similar to 70%-90%, of early elongation complexes retain sigma(70) and that a determinant for sigma(70) recognit...

  19. Quadratic elongation: A quantitative measure of distortion in coordination polyhedra

    Science.gov (United States)

    Robinson, Kelly F.; Gibbs, G.V.; Ribbe, P.H.

    1971-01-01

    Quadratic elongation and the variance of bond angles are linearly correlated for distorted octahedral and tetrahedral coordination complexes, both of which show variations in bond length and bond angle. The quadratic elonga tion is dimensionless, giving a quantitative measure of polyhedral distortion which is independent of the effective size of the polyhedron.

  20. FtsZ-Dependent Elongation of a Coccoid Bacterium

    NARCIS (Netherlands)

    Pereira, Ana R; Hsin, Jen; Król, Ewa; Tavares, Andreia C; Flores, Pierre; Hoiczyk, Egbert; Ng, Natalie; Dajkovic, Alex; Brun, Yves V; VanNieuwenhze, Michael S; Roemer, Terry; Carballido-Lopez, Rut; Scheffers, Dirk-Jan; Huang, Kerwyn Casey; Pinho, Mariana G

    2016-01-01

    UNLABELLED: A mechanistic understanding of the determination and maintenance of the simplest bacterial cell shape, a sphere, remains elusive compared with that of more complex shapes. Cocci seem to lack a dedicated elongation machinery, and a spherical shape has been considered an evolutionary dead-

  1. Calculus super review

    CERN Document Server

    2012-01-01

    Get all you need to know with Super Reviews! Each Super Review is packed with in-depth, student-friendly topic reviews that fully explain everything about the subject. The Calculus I Super Review includes a review of functions, limits, basic derivatives, the definite integral, combinations, and permutations. Take the Super Review quizzes to see how much you've learned - and where you need more study. Makes an excellent study aid and textbook companion. Great for self-study!DETAILS- From cover to cover, each in-depth topic review is easy-to-follow and easy-to-grasp - Perfect when preparing for

  2. Algebra & trigonometry super review

    CERN Document Server

    2012-01-01

    Get all you need to know with Super Reviews! Each Super Review is packed with in-depth, student-friendly topic reviews that fully explain everything about the subject. The Algebra and Trigonometry Super Review includes sets and set operations, number systems and fundamental algebraic laws and operations, exponents and radicals, polynomials and rational expressions, equations, linear equations and systems of linear equations, inequalities, relations and functions, quadratic equations, equations of higher order, ratios, proportions, and variations. Take the Super Review quizzes to see how much y

  3. Repeat-PPM Super-Symbol Synchronization

    Science.gov (United States)

    Connelly, J.

    2016-11-01

    To attain a wider range of data rates in pulse position modulation (PPM) schemes with constrained pulse durations, the sender can repeat a PPM symbol multiple times, forming a super-symbol. In addition to the slot and symbol synchronization typically required for PPM, the receiver must also properly align the noisy super-symbols. We present a low-complexity approximation of the maximum-likelihood method for performing super-symbol synchronization without use of synchronization sequences. We provide simulation results demonstrating performance advantage when PPM symbols are spread by a pseudo-noise sequence, as opposed to simply repeating. Additionally, the results suggest that this super-symbol synchronization technique requires signal levels below those required for reliable communication. This validates that the PPM spreading approach proposed to CCSDS can work properly as part of the overall scheme.

  4. Super Tomboy Style

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    Sparked by Super Girl, the androgynous look is in among Chinese youth On September 8, this year's top six contestants on the Super Girl television show, a singing contest for young women, stepped into the spotlight. Nearly none of them had long black hair or wore evening gowns, traditionally associated with beauty in China. Rather, they

  5. Getting up to speed with transcription elongation by RNA polymerase II

    Science.gov (United States)

    Jonkers, Iris; Lis, John T.

    2016-01-01

    Recent advances in sequencing techniques that measure nascent transcripts and that reveal the positioning of RNA polymerase II (Pol II) have shown that the pausing of Pol II in promoter-proximal regions and its release to initiate a phase of productive elongation are key steps in transcription regulation. Moreover, after the release of Pol II from the promoter-proximal region, elongation rates are highly dynamic throughout the transcription of a gene, and vary on a gene-by-gene basis. Interestingly, Pol II elongation rates affect co-transcriptional processes such as splicing, termination and genome stability. Increasing numbers of factors and regulatory mechanisms have been associated with the steps of transcription elongation by Pol II, revealing that elongation is a highly complex process. Elongation is thus now recognized as a key phase in the regulation of transcription by Pol II. PMID:25693130

  6. Nonlinear Super Integrable Couplings of Super Classical-Boussinesq Hierarchy

    Directory of Open Access Journals (Sweden)

    Xiuzhi Xing

    2014-01-01

    Full Text Available Nonlinear integrable couplings of super classical-Boussinesq hierarchy based upon an enlarged matrix Lie super algebra were constructed. Then, its super Hamiltonian structures were established by using super trace identity. As its reduction, nonlinear integrable couplings of the classical integrable hierarchy were obtained.

  7. The interaction between bacterial transcription factors and RNA polymerase during the transition from initiation to elongation.

    Science.gov (United States)

    Yang, Xiao; Lewis, Peter J

    2010-01-01

    There are three stages of transcription: initiation, elongation and termination, and traditionally there has been a clear distinction between the stages. The specificity factor sigma is completely released from bacterial RNA polymerase after initiation, and then recycled for another round of transcription. Elongation factors then associate with the polymerase followed by termination factors (where necessary). These factors dissociate prior to initiation of a new round of transcription. However, there is growing evidence suggesting that sigma factors can be retained in the elongation complex. The structure of bacterial RNAP in complex with an essential elongation factor NusA has recently been published, which suggested rather than competing for the major σ binding site, NusA binds to a discrete region on RNAP. A model was proposed to help explain the way in which both factors could be associated with RNAP during the transition from transcription initiation to elongation.

  8. Super-resolution

    DEFF Research Database (Denmark)

    Nasrollahi, Kamal; Moeslund, Thomas B.

    2014-01-01

    Super-resolution, the process of obtaining one or more high-resolution images from one or more low-resolution observations, has been a very attractive research topic over the last two decades. It has found practical applications in many real world problems in different fields, from satellite...... the contributions of different authors to the basic concepts of each group. Furthermore, common issues in super-resolution algorithms, such as imaging models and registration algorithms, optimization of the cost functions employed, dealing with color information, improvement factors, assessment of super...

  9. Uniaxial Elongational viscosity of bidisperse polystyrene melts

    DEFF Research Database (Denmark)

    Nielsen, Jens Kromann; Rasmussen, Henrik K.; Hassager, Ole

    2006-01-01

    The startup and steady uniaxial elongational viscosity have been measured for three bidisperse polystyrene (PS) melts, consisting of blends of monodisperse PS with molecular weights of 52 kg/mole or 103 kg/mole and 390 kg/mole. The bidisperse melts have a maximum in the steady elongational...

  10. Planar elongation of soft polymeric networks

    DEFF Research Database (Denmark)

    Jensen, Mette Krog; Hassager, Ole; Rasmussen, Henrik K.

    2010-01-01

    A new test fixture for the filament stretch rheometer (FSR) has been developed to measure planar elongation of soft polymeric networks with application towards pressure-sensitive adhesives (PSAs). The concept of this new geometry is to elongate a tube-like sample by keeping the perimeter constant...

  11. Uniaxial Elongational viscosity of bidisperse polystyrene melts

    DEFF Research Database (Denmark)

    Nielsen, Jens Kromann; Rasmussen, Henrik K.; Hassager, Ole

    2006-01-01

    The startup and steady uniaxial elongational viscosity have been measured for three bidisperse polystyrene (PS) melts, consisting of blends of monodisperse PS with molecular weights of 52 kg/mole or 103 kg/mole and 390 kg/mole. The bidisperse melts have a maximum in the steady elongational viscos...

  12. NETL Super Computer

    Data.gov (United States)

    Federal Laboratory Consortium — The NETL Super Computer was designed for performing engineering calculations that apply to fossil energy research. It is one of the world’s larger supercomputers,...

  13. Super-resolution

    DEFF Research Database (Denmark)

    Nasrollahi, Kamal; Moeslund, Thomas B.

    2014-01-01

    and aerial imaging to medical image processing, to facial image analysis, text image analysis, sign and number plates reading, and biometrics recognition, to name a few. This has resulted in many research papers, each developing a new super-resolution algorithm for a specific purpose. The current......Super-resolution, the process of obtaining one or more high-resolution images from one or more low-resolution observations, has been a very attractive research topic over the last two decades. It has found practical applications in many real world problems in different fields, from satellite...... the contributions of different authors to the basic concepts of each group. Furthermore, common issues in super-resolution algorithms, such as imaging models and registration algorithms, optimization of the cost functions employed, dealing with color information, improvement factors, assessment of super...

  14. ELONGATED ODONTOID PROCESS OF AXIS VERTEBRA

    Directory of Open Access Journals (Sweden)

    Prathap Kumar J,

    2014-09-01

    Full Text Available Introduction: Odontoid process is a bony projection of axis around which the atlas rotates. It measures 1 to 1.25 cms in length and projects upwards from the body of Axis. An elongated odontoid process may narrow the foramen magnum causing compressive neurological symptoms. It can cause cervical stiffness, serious restrictions of neck movement, and even a bone-derived torticollis. Observation: During routine osteology classes, we encountered an Axis vertebra with an elongated odontoid process. The measurements of the elongated odontoid process were taken using digital Vernier slide calipers. Conclusion: Elongated odontoid process can be mistaken for fracture of dens in radiological images; hence the knowledge of elongated odontoid process is useful for the radiologists, neurosurgeons and orthopaedicians for accurate diagnosis and treatment involving cranio-vertebral junctions.

  15. Super-Kamiokande

    Science.gov (United States)

    Magro, Lluís Martí

    2016-06-01

    The Super-Kamiokande experiment performs a large variety of studies, many of them in the neutrino sector. The archetypes are atmospheric neutrino (recently awarded with the Nobel prize for Mr. T. Kajita) and the solar neutrinos analyses. In these proceedings we report our latest results and present updates to indirect dark matter searches, our solar neutrino analysis and discuss the future upgrade of Super-Kamiokande by loading gadolinium into our ultra-pure water.

  16. The Super Girl Effect

    Institute of Scientific and Technical Information of China (English)

    WANG PEI

    2006-01-01

    @@ In recent years, Changsha,the capital city of Hunan Province, has become famous across China for its innovative TV channel, in particular the cultural phenomenon of the Super Girl talent show. And as far as culture goes, Hunan TV is merely a reflection of a renaissance happening in the city. Animation, music halls, drama festivals and a famous book market are just some of the city's cultural sectors that are benefiting from the fame and notoriety of the Super Girl show.

  17. The formation of super-rings

    CERN Document Server

    Tenorio-Tagle, G

    1980-01-01

    The author has calculated the collision of a small neutral cloud (surface density approximately 10/sup 19/ cm/sup -2/) with a constant density galactic disk. Through the collision, a large amount of energy is deposited in a small volume of the galaxy, resulting in a supersonic expansion of very hot (10/sup 6/-10/sup 7/K) gas into the Galaxy and out of the galactic disk. The expansion generates a large cavity (a super-ring) with physical characteristics (diameter, velocity of expansion, etc.) in agreement with the observations, and a large volume of hot low-density gas with properties similar to those of the observed coronal gas. (31 refs).

  18. Nonlinear Super Integrable Couplings of Super Dirac Hierarchy and Its Super Hamiltonian Structures

    Institute of Scientific and Technical Information of China (English)

    尤福财

    2012-01-01

    We construct nonlinear super integrable couplings of the super integrable Dirac hierarchy based on an enlarged matrix Lie superalgebra. Then its super Hamiltonian structure is furnished by super trace identity. As its reduction, we gain the nonlinear integrable couplings of the classical integrable Dirac hierarchy.

  19. FtsZ-Dependent Elongation of a Coccoid Bacterium

    Directory of Open Access Journals (Sweden)

    Ana R. Pereira

    2016-09-01

    Full Text Available A mechanistic understanding of the determination and maintenance of the simplest bacterial cell shape, a sphere, remains elusive compared with that of more complex shapes. Cocci seem to lack a dedicated elongation machinery, and a spherical shape has been considered an evolutionary dead-end morphology, as a transition from a spherical to a rod-like shape has never been observed in bacteria. Here we show that a Staphylococcus aureus mutant (M5 expressing the ftsZG193D allele exhibits elongated cells. Molecular dynamics simulations and in vitro studies indicate that FtsZG193D filaments are more twisted and shorter than wild-type filaments. In vivo, M5 cell wall deposition is initiated asymmetrically, only on one side of the cell, and progresses into a helical pattern rather than into a constricting ring as in wild-type cells. This helical pattern of wall insertion leads to elongation, as in rod-shaped cells. Thus, structural flexibility of FtsZ filaments can result in an FtsZ-dependent mechanism for generating elongated cells from cocci.

  20. The life and death of translation elongation factor 2

    DEFF Research Database (Denmark)

    Jørgensen, Rene; Merrill, A.R.; Andersen, Gregers Rom

    2006-01-01

    The eukaryotic elongation factor 2 (eEF2) occupies an essential role in protein synthesis where it catalyses the translocation of the two tRNAs and the mRNA after peptidyl transfer on the 80S ribosome. Recent crystal structures of eEF2 and the cryo-EM reconstruction of its 80S complex now provide...... diphthamide residue, which is ADP-ribosylated by diphtheria toxin from Corynebacterium diphtheriae and exotoxin A from Pseudomonas aeruginosa....

  1. Super-resolution imaging visualizes the eightfold symmetry of gp210 proteins around the nuclear pore complex and resolves the central channel with nanometer resolution

    NARCIS (Netherlands)

    Löschberger, A.; Van de Linde, S.; Debauvalle, M.C.; Rieger, B.; Heilemann, M.; Krohne, G.; Sauer, M.

    2012-01-01

    One of the most complex molecular machines of cells is the nuclear pore complex (NPC), which controls all trafficking of molecules in and out of the nucleus. Because of their importance for cellular processes such as gene expression and cytoskeleton organization, the structure of NPCs has been studi

  2. Deforming super Riemann surfaces with gravitinos and super Schottky groups

    Energy Technology Data Exchange (ETDEWEB)

    Playle, Sam [Dipartimento di Fisica, Università di Torino and INFN, Sezione di Torino,Via P. Giuria 1, I-10125 Torino (Italy)

    2016-12-12

    The (super) Schottky uniformization of compact (super) Riemann surfaces is briefly reviewed. Deformations of super Riemann surface by gravitinos and Beltrami parameters are recast in terms of super Schottky group cohomology. It is checked that the super Schottky group formula for the period matrix of a non-split surface matches its expression in terms of a gravitino and Beltrami parameter on a split surface. The relationship between (super) Schottky groups and the construction of surfaces by gluing pairs of punctures is discussed in an appendix.

  3. Venus - A Large Elongated Caldera 'Sacajawea Patera

    Science.gov (United States)

    1991-01-01

    This Magellan image reveals Sacajawea Patera, a large, elongate caldera located in Western Ishtar Terra on the smooth plateau of Lakshmi Planum. The image is centered at 64.5 degrees North latitude and 337 degrees East longitude. It is approximately 420 kilometers (252 miles) wide at the base. Sacajawea is a depression approximately 1-2 kilometers (0.6-1.2 miles) deep and 120 x 215 kilometers (74 x 133 miles) in diameter; it is elongate in a southwest-northeast direction. The depression is bounded by a zone of circumferential curvilinear structures interpreted to be graben and fault scarps. These structures are spaced 0.5-4 kilometers (0.3-2.5 miles) apart, are 0.6-4.0 kilometers (0.4-2.5 miles) in width and up to 100 kilometers (62 miles) in length. Extending up to approximately 140 kilometers (87 miles) in length from the southeast of the patera is a system of linear structures thought to represent a flanking rift zone along which the lateral injection and eruption of magma may have occurred. A shield edifice 12 kilometers (7 miles) in diameter with a prominent central pit lies along the trend of one of these features. The impact crater Zlata, approximately 6 kilometers (4 miles) in diameter is located within the zone of graben to the northwest of the patera. Few flow features are observed in association with Sacajawea, possibly due to age and state of degradation of the flows. Mottled bright deposits 4-20 kilometers (2.5-12 miles) in width are located near the periphery and in the center of the patera floor within local topographic lows. Diffuse patches of dark material approximately 40 kilometers (25 miles) in width are observed southwest of the patera, superposed on portions of the surrounding graben. The formation of Sacajawea is thought to be related to the drainage and collapse of a large magma chamber. Gravitational relaxation may have caused the resultant caldera to sag, producing the numerous faults and graben that circumscribe the patera. Regions of

  4. A review of penile elongation surgery

    Science.gov (United States)

    Gillis, Joshua

    2017-01-01

    Penile elongation surgery is less commonly performed in the public sector, but involves a collaborative approach between urology and plastic surgery. Congenital and acquired micropenis are the classic surgical indications for penile elongation surgery. The goal of intervention in these patients is to restore a functional penis size in order to allow normal standing micturition, enable satisfying sexual intercourse and improve patient quality of life. Many men seeking elongation actually have normal length penises, but perceive themselves to be small, a psychologic condition termed ‘penile dysmorphophobia’. This paper will review the anatomy and embryology of congenital micropenis and discuss both conservative and surgical management options for men seeking penile elongation therapy. PMID:28217452

  5. Increased damping of natural rubber stocks from prior elongation-retraction

    Science.gov (United States)

    Fitzgerald, Edwin R.

    1995-05-01

    The effects of elongation on the audiofrequency dynamic mechanical properties of a natural rubber (Hevea) gum stock have been described previously in terms of the elastic (J') and the viscous (J') components of a complex shear compliance, J* equals J' - iJ'. In this prior work emphasis was on the changes in compliance levels and the frequency dependencies of the elastic and viscous components at static elongations from 0 to 400%, and after retractions to elongations below 300%. At elongations above 300%, several large, sharp resonances appeared in the compliance-frequency plots coincident with the well known stretch-induced, oriented crystallinity above 300% elongation for the initially amorphous rubber at room temperatures. In the present work attention is on the loss tangent, J'/J', which governs vibration damping, and for which no data were given in the earlier report. After extensions to 400%, as described above, followed by retraction to 275%, for example, values of loss tangent were two or three times those found at any of the first elongations from 0 to 400%. Current measurements using an automated measurement system yield similar results. Additional information on the effect of time at an elongation and the elongation-retraction sequence on enhanced damping has also been gathered. In any case, it is evident that natural rubber gum stocks, ordinarily with low damping, when treated smartly can be changed to high damping materials at some audio frequencies.

  6. Mutual interdependence of splicing and transcription elongation.

    Science.gov (United States)

    Brzyżek, Grzegorz; Świeżewski, Szymon

    2015-01-01

    Transcription and splicing are intrinsically linked, as splicing needs a pre-mRNA substrate to commence. The more nuanced view is that the rate of transcription contributes to splicing regulation. On the other hand there is accumulating evidence that splicing has an active role in controlling transcription elongation by DNA-dependent RNA polymerase II (RNAP II). We briefly review those mechanisms and propose a unifying model where splicing controls transcription elongation to provide an optimal timing for successive rounds of splicing.

  7. Planar Elongation Measurements on Soft Elastomers

    DEFF Research Database (Denmark)

    Jensen, Mette Krog; Skov, Anne Ladegaard; Rasmussen, Henrik K.

    2009-01-01

    A new fixture to the filament stretch rheometer (FSR) has been developed to measure planar elongation of soft polymeric networks. To validate this new technique, soft polymeric networks of poly(propyleneoxide) (PPO) were investigated during deformation.......A new fixture to the filament stretch rheometer (FSR) has been developed to measure planar elongation of soft polymeric networks. To validate this new technique, soft polymeric networks of poly(propyleneoxide) (PPO) were investigated during deformation....

  8. Elongated Styloid Process - A Radiographic Study

    Directory of Open Access Journals (Sweden)

    Vajendra Joshi

    2007-01-01

    Full Text Available Eagle′s syndrome, also known as elongated styloid process syndrome, is a condition that may be the source of craniofacial and cervical pain. The styloid process is a slender bony projection arising from the lower surface of the petrous portion of the temporal bone. It has been estimated that between 2% to 28% of the general adult population has radiographic evidence of elongated styloid process. In adults, the mean radiographic length of the styloid process is 20 to 30 mm and its tip is located between the external and internal carotid arteries, just lateral to the tonsillar fossa. This study was done to evaluate the elongation of the styloid process and/or ligament ossification by using panoramic radiographs. Both ossification of stylohyoid and stylomandibular ligaments and truly elongated styloid process were defined as elongated styloid process. Elongated styloid processes should be kept in mind when the clinician is faced with oropharyngeal/ maxillary pain originating from impacted or unerupted third molars or dental caries.

  9. Visualization of large elongated DNA molecules.

    Science.gov (United States)

    Lee, Jinyong; Kim, Yongkyun; Lee, Seonghyun; Jo, Kyubong

    2015-09-01

    Long and linear DNA molecules are the mainstream single-molecule analytes for a variety of biochemical analysis within microfluidic devices, including functionalized surfaces and nanostructures. However, for biochemical analysis, large DNA molecules have to be unraveled, elongated, and visualized to obtain biochemical and genomic information. To date, elongated DNA molecules have been exploited in the development of a number of genome analysis systems as well as for the study of polymer physics due to the advantage of direct visualization of single DNA molecule. Moreover, each single DNA molecule provides individual information, which makes it useful for stochastic event analysis. Therefore, numerous studies of enzymatic random motions have been performed on a large elongated DNA molecule. In this review, we introduce mechanisms to elongate DNA molecules using microfluidics and nanostructures in the beginning. Secondly, we discuss how elongated DNA molecules have been utilized to obtain biochemical and genomic information by direct visualization of DNA molecules. Finally, we reviewed the approaches used to study the interaction of proteins and large DNA molecules. Although DNA-protein interactions have been investigated for many decades, it is noticeable that there have been significant achievements for the last five years. Therefore, we focus mainly on recent developments for monitoring enzymatic activity on large elongated DNA molecules.

  10. Accumulation of motile elongated micro-organisms in turbulence

    Science.gov (United States)

    Zhan, Caijuan; Sardina, Gaetano; Lushi, Enkeleida; Brandt, Luca

    2014-01-01

    We study the effect of turbulence on marine life by performing numerical simulations of motile microorganisms, modelled as prolate spheroids, in isotropic homogeneous turbulence. We show that the clustering and patchiness observed in laminar flows, linear shear and vortex flows, are significantly reduced in a three-dimensional turbulent flow mainly because of the complex topology; elongated micro-orgamisms show some level of clustering in the case of swimmers without any preferential alignment whereas spherical swimmers remain uniformly distributed. Micro-organisms with one preferential swimming direction (e.g. gyrotaxis) still show significant clustering if spherical in shape, whereas prolate swimmers remain more uniformly distributed. Due to their large sensitivity to the local shear, these elongated swimmers react slower to the action of vorticity and gravity and therefore do not have time to accumulate in a turbulent flow. These results show how purely hydrodynamic effects can alter the ecology of microorganisms that can vary their shape and their preferential orientation.

  11. Accumulation of motile elongated micro-organisms in turbulence

    CERN Document Server

    Zhan, Caijuan; Lushi, Enkeleida; Brandt, Luca

    2013-01-01

    We study the effect of turbulence on marine life by performing numerical simulations of motile microorganisms, modelled as prolate spheroids, in isotropic homogeneous turbulence. We show that the clustering and patchiness observed in laminar flows, linear shear and vortex flows, are significantly reduced in a three-dimensional turbulent flow mainly because of the complex topology; elongated micro-orgamisms show some level of clustering in the case of swimmers without any preferential alignment whereas spherical swimmers remain uniformly distributed. Micro-organisms with one preferential swimming direction (e.g. gyrotaxis) still show significant clustering if spherical in shape, whereas prolate swimmers remain more uniformly distributed. Due to their large sensitivity to the local shear, these elongated swimmers react slower to the action of vorticity and gravity and therefore do not have time to accumulate in a turbulent flow. These results show how purely hydrodynamic effects can alter the ecology of microor...

  12. Development of a PCR-RFLP method based on the transcription elongation factor 1-a gene to differentiate Fusarium graminearum from other species within the Fusarium graminearum species complex

    Science.gov (United States)

    Fusarium head blight (FHB) is a destructive disease of cereals crops worldwide and a major food safety concern due to grain contamination with trichothecenes and other mycotoxins. Fusarium graminearum, a member of the Fusarium graminearum species complex (FGSC) is the dominant FHB pathogen in many p...

  13. Evaporation of elongated droplets on chemically stripe-patterned surfaces

    NARCIS (Netherlands)

    Jansen, H.P.; Zandvliet, H.J.W.; Kooij, E.S.

    2015-01-01

    We investigate the evaporation of elongated droplets on chemically striped patterned surfaces. Variation of elongation is achieved by depositing droplets on surfaces with varying ratios of hydrophobic and hydrophilic stripe widths. Elongated droplets evaporate faster than more spherical droplets. Bo

  14. Raspberry Pi super cluster

    CERN Document Server

    Dennis, Andrew K

    2013-01-01

    This book follows a step-by-step, tutorial-based approach which will teach you how to develop your own super cluster using Raspberry Pi computers quickly and efficiently.Raspberry Pi Super Cluster is an introductory guide for those interested in experimenting with parallel computing at home. Aimed at Raspberry Pi enthusiasts, this book is a primer for getting your first cluster up and running.Basic knowledge of C or Java would be helpful but no prior knowledge of parallel computing is necessary.

  15. SuperQuant

    DEFF Research Database (Denmark)

    Gorshkov, Vladimir; Verano-Braga, Thiago; Kjeldsen, Frank

    2015-01-01

    SuperQuant is a quantitative proteomics data processing approach that uses complementary fragment ions to identify multiple co-isolated peptides in tandem mass spectra allowing for their quantification. This approach can be applied to any shotgun proteomics data set acquired with high mass accura...... of the same proteins were close to the values typical for other precursor ion-based quantification methods. The raw data is deposited to ProteomeXchange (PXD001907). The developed node is available for testing at https://github.com/caetera/SuperQuantNode....

  16. Application of super total station instrument technology in the complex topographic survey%超站仪技术在复杂地形测量中的应用研究

    Institute of Scientific and Technical Information of China (English)

    李国明; 李国庆; 吕健; 吴晓萍

    2011-01-01

    In recent years, due to the rapid development of infrastructure and the conduct of the 5. 12 post-disaster reconstruction in China, topographic measurements increased significantly. However, as many of the construction area of the terrain is more complicated, for measurements made new demands, in addition to improving the conventional measurement methods, more efficient e-quipment are also needed to provide technical support. In this paper, taking Xianxugou 1:500 post-earthquake Geological Disaster Engineering Projects in Jiuzhaigou County of Sichuan Province for example, it introduced the principle of super total station in topographic measurement Combined with the construction area, it discussed the implementation methods, notes, measuring result' s repeatability and reproducibility and so on were analyzed. Finally, a method of measuring in complex terrain was taken. Super total station had more advantage than common measurement instruments in complex topographical surveys. This method would have a significant impact on other surveys.%由于很多施工区域的地形较为复杂,对测量工作提出了新的要求,除改进常规测量方法外,同时需要更高效的仪器提供技术保障.本文以震后四川省九寨沟县鲜浒沟地质灾害工程1:500地形测绘项目为例,介绍了超站仪在地形测量中的应用原理,结合施工区,讨论了其实施方法、注意事项、对测量成果的重复性、复现性等问题进行了分析,提出了复杂地形测量的新方法.实践证明,超站仪在复杂地形测量工作中较常规测量仪器有较大的优势.

  17. Microscale Synthesis, Reactions, and (Super 1)H NMR Spectroscopic Investigations of Square Planar Macrocyclic, Tetramido-N Co(III) Complexes Relevant to Green Chemistry

    Science.gov (United States)

    Watson, Tanya T.; Uffelman, Erich S.; Lee, Daniel W., III; Doherty, Jonathan R.; Schulze, Carl; Burke, Amy L.; Bonnema, Kristen, R.

    2004-01-01

    The microscale preparation, characterization, and reactivity of a square planar Co(III) complex that has grown out of a program to introduce experiments of relevance to green chemistry into the undergraduate curriculum is presented. The given experiments illustrate the remarkable redox and aqueous acid-base stability that make the macrocycles very…

  18. Application of HydroGeoSphere to model the response to anthropogenic climate change of three-dimensional hydrological processes in the geologically, geothermally, and topographically complex Valles Caldera super volcano, New Mexico: Preliminary results

    Science.gov (United States)

    Wine, M.; Cadol, D. D.

    2014-12-01

    Anthropogenic climate change is expected to reduce streamflow in the southwestern USA due to reduction in precipitation and increases in evaporative demand. Understanding the effects of climate change in this region is particularly important for mountainous areas since these are primary sources of recharge in arid and semi-arid environments. Therefore we undertook to model effects of climate change on the hydrological processes in Valles Caldera (448 km2), located in the Jemez Mountains of northern New Mexico. In Valles Caldera modeling the surficial, hydrogeological, and geothermal processes that influence hydrologic fluxes each present challenges. The surficial dynamics of evaporative demand and snowmelt both serve to control recharge dynamics, but are complicated by the complex topography and spatiotemporal vegetation dynamics. Complex factors affecting evaporative demand include leaf area index, temperature, albedo, and radiation affected by topographic shading; all of these factors vary in space and time. Snowmelt processes interact with evaporative demand and geology to serve as an important control on streamflow generation, but modeling the effects of spatiotemporal snow distributions on streamflow generation remains a challenge. The complexity of Valles Caldera's geology—and its associated hydraulic properties—rivals that of its surficial hydrologic forcings. Hydrologically important geologic features that have formed in the Valles Caldera are three-dimensionally intricate and include a dense system of faults, alluvium, landslides, lake deposits, and features associated with the eruption and collapse of this super volcano. Coupling geothermally-driven convection to the hydrologic cycle in this still-active geothermal system presents yet an additional challenge in modeling Valles Caldera. Preliminary results from applying the three-dimensional distributed hydrologic finite element model HydroGeoSphere to a sub-catchment of Valles Caldera will be

  19. "Super Roman Pots"

    CERN Multimedia

    CERN PhotoLab

    1975-01-01

    Remotely controlled re-entrant vacuum vessels, with very thin (0.17 mm) central windows, that will be installed in each downstream arm of intersection I-8. Detectors for a coming physics experiment, placed inside these "Super Roman Pots", can be moved very close to the circulating ISR beams.

  20. A Super Roman Pot

    CERN Multimedia

    1975-01-01

    Remotely controlled re-entrant vacuum vessels, with very thin (0.17 mm) central windows, that were installed in each downstream arm of the ISR intersection I-8. Detectors placed inside these Super Roman Pots could be moved very close to the circulating ISR beams. (See Annual Report 1974 p. 110.)

  1. Single-Plane Magnetically Focused Elongated Small Field Proton Beams.

    Science.gov (United States)

    McAuley, Grant A; Slater, James M; Wroe, Andrew J

    2015-08-01

    We previously performed Monte Carlo simulations of magnetically focused proton beams shaped by a single quadrapole magnet and thereby created narrow elongated beams with superior dose delivery characteristics (compared to collimated beams) suitable for targets of similar geometry. The present study seeks to experimentally validate these simulations using a focusing magnet consisting of 24 segments of samarium cobalt permanent magnetic material adhered into a hollow cylinder. Proton beams with properties relevant to clinical radiosurgery applications were delivered through the magnet to a water tank containing a diode detector or radiochromic film. Dose profiles were analyzed and compared with analogous Monte Carlo simulations. The focused beams produced elongated beam spots with high elliptical symmetry, indicative of magnet quality. Experimental data showed good agreement with simulations, affirming the utility of Monte Carlo simulations as a tool to model the inherent complexity of a magnetic focusing system. Compared to target-matched unfocused simulations, focused beams showed larger peak to entrance ratios (26% to 38%) and focused simulations showed a two-fold increase in beam delivery efficiency. These advantages can be attributed to the magnetic acceleration of protons in the transverse plane that tends to counteract the particle outscatter that leads to degradation of peak to entrance performance in small field proton beams. Our results have important clinical implications and suggest rare earth focusing magnet assemblies are feasible and could reduce skin dose and beam number while delivering enhanced dose to narrow elongated targets (eg, in and around the spinal cord) in less time compared to collimated beams.

  2. NF-κB-repressing factor phosphorylation regulates transcription elongation via its interactions with 5'→3' exoribonuclease 2 and negative elongation factor.

    Science.gov (United States)

    Rother, Sascha; Bartels, Myriam; Schweda, Aike Torben; Resch, Klaus; Pallua, Norbert; Nourbakhsh, Mahtab

    2016-01-01

    NF-κB-repressing factor (NKRF) inhibits transcription elongation by binding to specific sequences in target promoters. Stimuli such as IL-1 have been shown to overcome this inhibitory action and enable the resumption of transcription elongation machinery by an unknown mechanism. Using mass spectrometry and in vitro phosphorylation analyses, we demonstrate that NKRF is phosphorylated within 3 different domains in unstimulated HeLa cells. Phosphoamino acid mapping and mutation analysis of NKRF further suggest that only Ser phosphorylation within aa 421-429 is regulated by IL-1 stimulation. In copurification studies, aa 421-429 is required for interactions between NKRF, 5'→3' exoribonuclease 2 (XRN2) and the negative elongation factor (NELF)-E in HeLa cells. Chromatin immunoprecipitation experiments further show that IL-1 stimulation leads to decrease in NKRF aa 421-429 phosphorylation and dissociation of NELF-E and XRN2 by concomitant resumption of transcription elongation of a synthetic reporter or the endogenous NKRF target gene, IL-8. Together, NKRF phosphorylation modulates promoter-proximal transcription elongation of NF-κB/NKRF-regulated genes via direct interactions with elongation complex in response to specific stimuli.

  3. Env-2dCD4 S60C complexes act as super immunogens and elicit potent, broadly neutralizing antibodies against clinically relevant human immunodeficiency virus type 1 (HIV-1).

    Science.gov (United States)

    Killick, Mark A; Grant, Michelle L; Cerutti, Nichole M; Capovilla, Alexio; Papathanasopoulos, Maria A

    2015-11-17

    The ability to induce a broadly neutralizing antibody (bNAb) response following vaccination is regarded as a crucial aspect in developing an effective vaccine against human immunodeficiency virus type 1 (HIV-1). The bNAbs target the HIV-1 envelope glycoprotein (Env) which is exposed on the virus surface, thereby preventing cell entry. To date, conventional vaccine approaches such as the use of Env-based immunogens have been unsuccessful. We expressed, purified, characterized and evaluated the immunogenicity of several unique HIV-1 subtype C Env immunogens in small animals. Here we report that vaccine immunogens based on Env liganded to a two domain CD4 variant, 2dCD4(S60C) are capable of consistently eliciting potent, broadly neutralizing antibody responses in New Zealand white rabbits against a panel of clinically relevant HIV-1 pseudoviruses. This was irrespective of the Env protein subtype and context. Importantly, depletion of the anti-CD4 antibodies appeared to abrogate the neutralization activity in the rabbit sera. Taken together, this data suggests that the Env-2dCD4(S60C) complexes described here are "super" immunogens, and potentially immunofocus antibody responses to a unique epitope spanning the 2dCD4(60C). Recent data from the two available anti-CD4 monoclonal antibodies, Ibalizumab and CD4-Ig (and bispecific variants thereof) have highlighted that the use of these broad and potent entry inhibitors could circumvent the need for a conventional vaccine targeting HIV-1. Overall, the ability of the unique Env-2dCD4(S60C) complexes to elicit potent bNAb responses has not been described previously, reinforcing that further investigation for their utility in preventing and controlling HIV-1/SIV infection is warranted.

  4. The life and death of translation elongation factor 2

    DEFF Research Database (Denmark)

    Jørgensen, Rene; Merrill, A.R.; Andersen, Gregers Rom

    2006-01-01

    The eukaryotic elongation factor 2 (eEF2) occupies an essential role in protein synthesis where it catalyses the translocation of the two tRNAs and the mRNA after peptidyl transfer on the 80S ribosome. Recent crystal structures of eEF2 and the cryo-EM reconstruction of its 80S complex now provide...... a substantial structural framework for dissecting the functional properties of this factor. The factor can be modified by either phosphorylation or ADP-ribosylation which results in cessation of translation. We review the structural and functional properties of eEF2 with particular emphasis on the unique...

  5. SuperSegger

    DEFF Research Database (Denmark)

    Stylianidou, Stella; Brennan, Connor; Nissen, Silas B

    2016-01-01

    -colonies with many cells, facilitating the analysis of cell-cycle dynamics in bacteria as well as cell-contact mediated phenomena. This package has a range of built-in capabilities for characterizing bacterial cells, including the identification of cell division events, mother, daughter, and neighboring cells......Many quantitative cell biology questions require fast yet reliable automated image segmentation to identify and link cells from frame-to-frame, and characterize the cell morphology and fluorescence. We present SuperSegger, an automated MATLAB-based image processing package well......-suited to quantitative analysis of high-throughput live-cell fluorescence microscopy of bacterial cells. SuperSegger incorporates machine-learning algorithms to optimize cellular boundaries and automated error resolution to reliably link cells from frame-to-frame. Unlike existing packages, it can reliably segment micro...

  6. NASA Super Pressure Balloon

    Science.gov (United States)

    Fairbrother, Debbie

    2017-01-01

    NASA is in the process of qualifying the mid-size Super Pressure Balloon (SPB) to provide constant density altitude flight for science investigations at polar and mid-latitudes. The status of the development of the 18.8 million cubic foot SPB capable of carrying one-tone of science to 110,000 feet, will be given. In addition, the operating considerations such as launch sites, flight safety considerations, and recovery will be discussed.

  7. Super-diversité

    NARCIS (Netherlands)

    Crul, M.R.J.; Schneider, J.; Lelie, F.

    2013-01-01

    Le concept de super-diversité, en cernant les conditions d'un scénario 'avenir optimiste, offre un nouvel éclairage au débat sur l'intégration. Nous sommes à la croisée des chemins. Cette étude comparative internationale montre qu'un avenir souriant se profile dans les villes qui donnent des chances

  8. Performing the Super Instrument

    DEFF Research Database (Denmark)

    Kallionpaa, Maria

    2016-01-01

    The genre of contemporary classical music has seen significant innovation and research related to new super, hyper, and hybrid instruments, which opens up a vast palette of expressive potential. An increasing number of composers, performers, instrument designers, engineers, and computer programmers...... provides the performer extensive virtuoso capabilities in terms of instrumental range, harmony, timbre, or spatial, textural, acoustic, technical, or technological qualities. The discussion will be illustrated by a composition case study involving augmented musical instrument electromagnetic resonator...

  9. Performing the Super Instrument

    DEFF Research Database (Denmark)

    Kallionpaa, Maria

    2016-01-01

    provides the performer extensive virtuoso capabilities in terms of instrumental range, harmony, timbre, or spatial, textural, acoustic, technical, or technological qualities. The discussion will be illustrated by a composition case study involving augmented musical instrument electromagnetic resonator......The genre of contemporary classical music has seen significant innovation and research related to new super, hyper, and hybrid instruments, which opens up a vast palette of expressive potential. An increasing number of composers, performers, instrument designers, engineers, and computer programmers...

  10. Are dopaminergic genes involved in a predisposition to pathological aggression? Hypothesizing the importance of "super normal controls" in psychiatricgenetic research of complex behavioral disorders.

    Science.gov (United States)

    Chen, Thomas J H; Blum, Kenneth; Mathews, Daniel; Fisher, Larry; Schnautz, Nancy; Braverman, Eric R; Schoolfield, John; Downs, Bernard W; Comings, David E

    2005-01-01

    We hypothesize that pathological aggression, a complex behavioral disorder, in adolescents may in part involve polymorphisms of the dopaminergic system. While a number of neurotransmitter systems must be involved, due to polygenic inheritance, one major pathway should involve the dopaminergic system. Advances in our knowledge of the neurobiology of aggression and violence have given rise to rational pharmacological treatments for these behaviors. The main biological systems that are known to be involved are certain reward neurotransmitters including: serotonin, opioid peptides, gamma-aminobutyric acid, and the catecholamines (dopamine and norepinephrine). It is our notion that pathological aggressive behavior is in part similar mechanistically to other forms of impulsive behaviors such as pathological gambling. By analogy to drug dependence, it has been speculated that the underlying pathology in pathological gambling is a reduction in the sensitivity of the reward system. While studying pathological gamblers and controls during a guessing game using functional Magnetic Resonance Imaging, Reuter et al. observed a reduction of ventral striatal and ventromedial prefrontal activation in the pathological gamblers that were negatively correlated with gambling severity. Subsequently, linking hypo activation of these areas to disease severity. A positive correlation of both the dopamine D2 receptor gene (DRD2) and the dopamine transporter gene (DAT1) polymorphisms were observed with pathological violence in adolescents in a blinded clinical trial. Thus, this and other cited work preliminary suggest a role for both the DRD2 and DAT genes in pathological aggressive behavior. We further hypothesize that follow-up gene research in this area, albeit premature, resulting in confirmation of positive correlations with dopaminergic polymorphisms, and utilizing highly screened controls (eliminating any addictive, compulsive and impulsive behaviors in both proband and family) may

  11. Characterising Super-Earths

    Directory of Open Access Journals (Sweden)

    Valencia D.

    2011-02-01

    Full Text Available The era of Super-Earths has formally begun with the detection of transiting low-mass exoplanets CoRoT-7b and GJ 1214b. In the path of characterising super-Earths, the first step is to infer their composition. While the discovery data for CoRoT-7b, in combination with the high atmospheric mass loss rate inferred from the high insolation, suggested that it was a rocky planet, the new proposed mass values have widened the possibilities. The combined mass range 1−10 M⊕ allows for a volatile-rich (and requires it if the mass is less than 4 M⊕ , an Earth-like or a super-Mercury-like composition. In contrast, the radius of GJ 1214b is too large to admit a solid composition, thus it necessarily to have a substantial gas layer. Some evidence suggests that within this gas layer H/He is a small but non-negligible component. These two planets are the first of many transiting low-mass exoplanets expected to be detected and they exemplify the limitations faced when inferring composition, which come from the degenerate character of the problem and the large error bars in the data.

  12. Super Fuzzy Matrices and Super Fuzzy Models for Social Scientists

    CERN Document Server

    Kandasamy, W B Vasantha; Amal, K

    2008-01-01

    This book introduces the concept of fuzzy super matrices and operations on them. This book will be highly useful to social scientists who wish to work with multi-expert models. Super fuzzy models using Fuzzy Cognitive Maps, Fuzzy Relational Maps, Bidirectional Associative Memories and Fuzzy Associative Memories are defined here. The authors introduce 13 multi-expert models using the notion of fuzzy supermatrices. These models are described with illustrative examples. This book has three chapters. In the first chaper, the basic concepts about super matrices and fuzzy super matrices are recalled. Chapter two introduces the notion of fuzzy super matrices adn their properties. The final chapter introduces many super fuzzy multi expert models.

  13. Interplay between DNA supercoiling and transcription elongation.

    Science.gov (United States)

    Ma, Jie; Wang, Michelle

    2014-01-01

    Transcription-coupled DNA supercoiling has been shown to be an important regulator of transcription that is broadly present in the cell. Here we review experimental work which shows that RNA polymerase is a powerful torsional motor that can alter DNA topology and structure, and DNA supercoiling in turn directly affects transcription elongation.

  14. Segmentation of elongated structures in medical images

    NARCIS (Netherlands)

    Staal, Jozef Johannes

    2004-01-01

    The research described in this thesis concerns the automatic detection, recognition and segmentation of elongated structures in medical images. For this purpose techniques have been developed to detect subdimensional pointsets (e.g. ridges, edges) in images of arbitrary dimension. These pointsets ar

  15. Strigolactones stimulate internode elongation independently of gibberellins.

    Science.gov (United States)

    de Saint Germain, Alexandre; Ligerot, Yasmine; Dun, Elizabeth A; Pillot, Jean-Paul; Ross, John J; Beveridge, Christine A; Rameau, Catherine

    2013-10-01

    Strigolactone (SL) mutants in diverse species show reduced stature in addition to their extensive branching. Here, we show that this dwarfism in pea (Pisum sativum) is not attributable to the strong branching of the mutants. The continuous supply of the synthetic SL GR24 via the root system using hydroponics can restore internode length of the SL-deficient rms1 mutant but not of the SL-response rms4 mutant, indicating that SLs stimulate internode elongation via RMS4. Cytological analysis of internode epidermal cells indicates that SLs control cell number but not cell length, suggesting that SL may affect stem elongation by stimulating cell division. Consequently, SLs can repress (in axillary buds) or promote (in the stem) cell division in a tissue-dependent manner. Because gibberellins (GAs) increase internode length by affecting both cell division and cell length, we tested if SLs stimulate internode elongation by affecting GA metabolism or signaling. Genetic analyses using SL-deficient and GA-deficient or DELLA-deficient double mutants, together with molecular and physiological approaches, suggest that SLs act independently from GAs to stimulate internode elongation.

  16. RNA Polymerase II Elongation at the Crossroads of Transcription and Alternative Splicing

    Directory of Open Access Journals (Sweden)

    Manuel de la Mata

    2011-01-01

    Full Text Available The elongation phase of transcription lies at the core of several simultaneous and coupled events leading to alternative splicing regulation. Although underestimated in the past, it is at this phase of the transcription cycle where complexes affecting the transcription machinery itself, chromatin structure, posttranscriptional gene regulation and pre-mRNA processing converge to regulate each other or simply to consolidate higher-order complexes and functions. This paper focuses on the multiple processes that take place during transcription elongation which ultimately regulate the outcome of alternative splicing decisions.

  17. Super insulating aerogel glazing

    DEFF Research Database (Denmark)

    Schultz, Jørgen Munthe; Jensen, Karsten Ingerslev; Kristiansen, Finn Harken

    2004-01-01

    Monolithic silica aerogel offers the possibility of combining super insulation and high solar energy transmittance, which has been the background for a previous and a current EU project on research and development of monolithic silica aerogel as transparent insulation in windows. Generally, windows...... form the weakest part of the thermal envelope with respect to heat loss coefficient, but on the other hand also play an important role for passive solar energy utilisation. For window orientations other than south, the net energy balance will be close to or below zero. However, the properties...

  18. Super insulating aerogel glazing

    DEFF Research Database (Denmark)

    Schultz, Jørgen Munthe; Jensen, Karsten Ingerslev; Kristiansen, Finn Harken

    2005-01-01

    This paper describes the application results of a previous and current EU-project on super insulating glazing based on monolithic silica aerogel. Prototypes measuring approx. 55´55 cm2 have been made with 15 mm evacuated aerogel between two layers of low-iron glass. Anti-reflective treatment...... of the glass and a heat-treatment of the aerogel increases the visible quality and the solar energy transmittance. A low-conductive rim seal solution with the required vacuum barrier properties has been developed along with a reliable assembly and evacuation process. The prototypes have a centre heat loss...

  19. Super-heptazethrene

    KAUST Repository

    Zeng, Wangdong

    2016-05-30

    The challenging synthesis of a laterally extended heptazethrene molecule, the super-heptazethrene derivative SHZ-CF3, is reported. This molecule was prepared using a strategy involving a multiple selective intramolecular Friedel–Crafts alkylation followed by oxidative dehydrogenation. Compound SHZ-CF3 exhibits an open-shell singlet diradical ground state with a much larger diradical character compared with the heptazethrene derivatives. An intermediate dibenzo-terrylene SHZ-2H was also obtained during the synthesis. This study provides a new synthetic method to access large-size quinoidal polycyclic hydrocarbons with unique physical properties.

  20. 3D super-resolution microscopy of bacterial division machinery

    Science.gov (United States)

    Vedyaykin, A. D.; Sabantsev, A. V.; Vishnyakov, I. E.; Morozova, N. E.; Polinovskaya, V. S.; Khodorkovskii, M. A.

    2016-08-01

    Super-resolution microscopy is a promising tool for the field of microbiology, as bacteria sizes are comparable to the resolution limit of light microscopy. Bacterial division machinery and FtsZ protein in particular attract much attention of scientists who use different super-resolution microscopy techniques, but most of the available data on FtsZ structures was obtained using two-dimensional (2D) super-resolution microscopy. Using 3D single-molecule localization microscopy (SMLM, namely dSTORM) to visualize FtsZ, we demonstrate that this approach allows more accurate interpretation of super-resolution images and provides new opportunities for the study of complex structures like bacterial divisome.

  1. Nursing Student Coaches for Emergency Department Super Utilizers.

    Science.gov (United States)

    Anderson, Della; Patch, Enedina; Oxandale, Brooke; Kincade, Amy; Gamber, Angie; Ohm, Ruth

    2017-01-01

    The Super Utilizer Project is a collaboration between an integrated health care organization and a baccalaureate school of nursing. The goal is to help the super utilizers access appropriate health care resources through the use of a student coach model. The student coaches provide clients with disease prevention and health promotion education and assistance specific to the clients' unique health care needs. The tenets of the theoretical frameworks of servant leadership, caring theory, and transtheoretical model of behavior change are applied throughout this project. First-year outcomes for the project were encouraging, with the total number of visits for 23 super utilizers to the emergency department decreasing from 710 annually to a projected 510 annually, and second-semester visits for 20 clients decreased from 634 to a projected 462. The students experience complex client care and collaboration with an interdisciplinary team reducing nonemergent emergency department super utilizer visits. [J Nurs Educ. 2017;56(1):27-30.]. Copyright 2017, SLACK Incorporated.

  2. Super-resolution imaging in glycoscience: New developments and challenges

    Directory of Open Access Journals (Sweden)

    Junling Chen

    2016-05-01

    Full Text Available Carbohydrates on cell surfaces play a crucial role in a wide variety of biological processes, including cell adhesion, recognition and signaling, viral and bacterial infection, inflammation and metastasis. However, owing to the large diversity and complexity of carbohydrate structure and nongenetically synthesis, glycoscience is the least understood field compared with genomics and proteomics. Although the structures and functions of carbohydrates have been investigated by various conventional analysis methods, the distribution and role of carbohydrates in cell membranes remain elusive. This review focuses on the developments and challenges of super-resolution imaging in glycoscience through introduction of imaging principle and the available fluorescent probes for super-resolution imaging, the labeling strategies of carbohydrates, and the recent applications of super-resolution imaging in glycoscience, which will promote the super-resolution imaging technology as a promising tool to provide new insights into the study of glycoscience.

  3. Vertically stabilized elongated cross-section tokamak

    Science.gov (United States)

    Sheffield, George V.

    1977-01-01

    This invention provides a vertically stabilized, non-circular (minor) cross-section, toroidal plasma column characterized by an external separatrix. To this end, a specific poloidal coil means is added outside a toroidal plasma column containing an endless plasma current in a tokamak to produce a rectangular cross-section plasma column along the equilibrium axis of the plasma column. By elongating the spacing between the poloidal coil means the plasma cross-section is vertically elongated, while maintaining vertical stability, efficiently to increase the poloidal flux in linear proportion to the plasma cross-section height to achieve a much greater plasma volume than could be achieved with the heretofore known round cross-section plasma columns. Also, vertical stability is enhanced over an elliptical cross-section plasma column, and poloidal magnetic divertors are achieved.

  4. Membrane tubulation by elongated and patchy nanoparticles

    CERN Document Server

    Raatz, Michael

    2016-01-01

    Advances in nanotechnology lead to an increasing interest in how nanoparticles interact with biomembranes. Nanoparticles are wrapped spontaneously by biomembranes if the adhesive interactions between the particles and membranes compensate for the cost of membrane bending. In the last years, the cooperative wrapping of spherical nanoparticles in membrane tubules has been observed in experiments and simulations. For spherical nanoparticles, the stability of the particle-filled membrane tubules strongly depends on the range of the adhesive particle-membrane interactions. In this article, we show via modeling and energy minimization that elongated and patchy particles are wrapped cooperatively in membrane tubules that are highly stable for all ranges of the particle-membrane interactions, compared to individual wrapping of the particles. The cooperative wrapping of linear chains of elongated or patchy particles in membrane tubules may thus provide an efficient route to induce membrane tubulation, or to store such...

  5. Translating cell polarity into tissue elongation

    OpenAIRE

    2011-01-01

    Planar cell polarity, the orientation of single-cell asymmetries within the plane of a multicellular tissue, is essential to generating the shape and dimensions of organs and organisms. Planar polarity systems align cell behavior with the body axes and orient the cellular processes that lead to tissue elongation. Using Drosophila as a model system, significant progress has been made toward understanding how planar polarity is generated by biochemical and mechanical signals. Recent studies usi...

  6. Constructing kinetic models to elucidate structural dynamics of a complete RNA polymerase II elongation cycle

    Science.gov (United States)

    Yu, Jin; Da, Lin-Tai; Huang, Xuhui

    2015-02-01

    The RNA polymerase II elongation is central in eukaryotic transcription. Although multiple intermediates of the elongation complex have been identified, the dynamical mechanisms remain elusive or controversial. Here we build a structure-based kinetic model of a full elongation cycle of polymerase II, taking into account transition rates and conformational changes characterized from both single molecule experimental studies and computational simulations at atomistic scale. Our model suggests a force-dependent slow transition detected in the single molecule experiments corresponds to an essential conformational change of a trigger loop (TL) opening prior to the polymerase translocation. The analyses on mutant study of E1103G and on potential sequence effects of the translocation substantiate this proposal. Our model also investigates another slow transition detected in the transcription elongation cycle which is independent of mechanical force. If this force-independent slow transition happens as the TL gradually closes upon NTP binding, the analyses indicate that the binding affinity of NTP to the polymerase has to be sufficiently high. Otherwise, one infers that the slow transition happens pre-catalytically but after the TL closing. Accordingly, accurate determination of intrinsic properties of NTP binding is demanded for an improved characterization of the polymerase elongation. Overall, the study provides a working model of the polymerase II elongation under a generic Brownian ratchet mechanism, with most essential structural transition and functional kinetics elucidated.

  7. Unilateral nephrectomy elongates primary cilia in the remaining kidney via reactive oxygen species.

    Science.gov (United States)

    Han, Sang Jun; Jang, Hee-Seong; Kim, Jee In; Lipschutz, Joshua H; Park, Kwon Moo

    2016-02-29

    The length of primary cilia is associated with normal cell and organ function. In the kidney, the change of functional cilia length/mass is associated with various diseases such as ischemia/reperfusion injury, polycystic kidney disease, and congenital solitary kidney. Here, we investigate whether renal mass reduction affects primary cilia length and function. To induce renal mass reduction, mice were subjected to unilateral nephrectomy (UNx). UNx increased kidney weight and superoxide formation in the remaining kidney. Primary cilia were elongated in proximal tubule cells, collecting duct cells and parietal cells of the remaining kidney. Mn(III) Tetrakis (1-methyl-4-pyridyl) porphyrin (MnTMPyP), an antioxidant, reduced superoxide formation in UNx-mice and prevented the elongation of primary cilia. UNx increased the expression of phosphorylated ERK, p21, and exocyst complex members Sec8 and Sec10, in the remaining kidney, and these increases were prevented by MnTMPyP. In MDCK, a kidney tubular epithelial cell line, cells, low concentrations of H2O2 treatment elongated primary cilia. This H2O2-induced elongation of primary cilia was also prevented by MnTMPyP treatment. Taken together, these data demonstrate that kidney compensation, induced by a reduction of renal mass, results in primary cilia elongation, and this elongation is associated with an increased production of reactive oxygen species (ROS).

  8. The curative effect observation of super adhesive bonding of light cured composite resin inlay in the repair of deciduous teeth Ⅱ complex cavities%超级黏接剂黏接光固化复合树脂嵌体在修复乳牙Ⅱ类复面洞型的疗效观察

    Institute of Scientific and Technical Information of China (English)

    辜赵娜

    2015-01-01

    目的:观察超级黏接剂黏接材料黏接复合树脂嵌体在修复乳牙Ⅱ类洞型的临床疗效。方法:收治乳牙Ⅱ类洞型患者18例,采用超级黏接剂黏接材料黏接复合树脂嵌体进行修复治疗,观察临床效果。结果:经过随访观察,用超级黏接剂黏接材料黏接光固化复合树脂嵌体在口腔无脱落,嵌体边缘继发龋发生率4.8%。结论:使用超级黏接剂材料黏接光固化复合树脂嵌体具有很好防止脱落和防止继发龋的效果。%Objective:To explore the curative effect observation of super adhesive bonding of light cured composite resin inlay in the repair of deciduous teeth Ⅱ complex cavities.Methods:18 patients with deciduous teeth Ⅱ complex cavities were selected. They were treated by super adhesive bonding of light cured composite resin inlay.We observed the clinical effect.Results:After follow-up observation,with super adhesive bonding of light cured composite resin inlay,there was no shedding in oral,and secondary caries incidence at inlay edge was 4.8%.Conclusion:Using super adhesive bonding of light cured composite resin inlay was good to prevent the shedding and prevent the incidence of secondary caries.

  9. Transcription elongation and tissue-specific somatic CAG instability.

    Directory of Open Access Journals (Sweden)

    Agathi-Vasiliki Goula

    Full Text Available The expansion of CAG/CTG repeats is responsible for many diseases, including Huntington's disease (HD and myotonic dystrophy 1. CAG/CTG expansions are unstable in selective somatic tissues, which accelerates disease progression. The mechanisms underlying repeat instability are complex, and it remains unclear whether chromatin structure and/or transcription contribute to somatic CAG/CTG instability in vivo. To address these issues, we investigated the relationship between CAG instability, chromatin structure, and transcription at the HD locus using the R6/1 and R6/2 HD transgenic mouse lines. These mice express a similar transgene, albeit integrated at a different site, and recapitulate HD tissue-specific instability. We show that instability rates are increased in R6/2 tissues as compared to R6/1 matched-samples. High transgene expression levels and chromatin accessibility correlated with the increased CAG instability of R6/2 mice. Transgene mRNA and H3K4 trimethylation at the HD locus were increased, whereas H3K9 dimethylation was reduced in R6/2 tissues relative to R6/1 matched-tissues. However, the levels of transgene expression and these specific histone marks were similar in the striatum and cerebellum, two tissues showing very different CAG instability levels, irrespective of mouse line. Interestingly, the levels of elongating RNA Pol II at the HD locus, but not the initiating form of RNA Pol II, were tissue-specific and correlated with CAG instability levels. Similarly, H3K36 trimethylation, a mark associated with transcription elongation, was specifically increased at the HD locus in the striatum and not in the cerebellum. Together, our data support the view that transcription modulates somatic CAG instability in vivo. More specifically, our results suggest for the first time that transcription elongation is regulated in a tissue-dependent manner, contributing to tissue-selective CAG instability.

  10. Quantitative super-resolution microscopy

    NARCIS (Netherlands)

    Harkes, Rolf

    2016-01-01

    Super-Resolution Microscopy is an optical fluorescence technique. In this thesis we focus on single molecule super-resolution, where the position of single molecules is determined. Typically these molecules can be localized with a 10 to 30nm precision. This technique is applied in four different s

  11. Transcriptional elongation factor ENL phosphorylated by ATM recruits polycomb and switches off transcription for DSB repair.

    Science.gov (United States)

    Ui, Ayako; Nagaura, Yuko; Yasui, Akira

    2015-05-07

    Transcription is repressed if a DNA double-strand break (DSB) is introduced in close proximity to a transcriptional activation site at least in part by H2A-ubiquitination. While ATM signaling is involved, how it controls H2A-ubiquitination remains unclear. Here, we identify that, in response to DSBs, a transcriptional elongation factor, ENL (MLLT1), is phosphorylated by ATM at conserved SQ sites. This phosphorylation increases the interaction between ENL and the E3-ubiquitin-ligase complex of Polycomb Repressive Complex 1 (PRC1) via BMI1. This interaction promotes enrichment of PRC1 at transcription elongation sites near DSBs to ubiquitinate H2A leading to transcriptional repression. ENL SQ sites and BMI1 are necessary for KU70 accumulation at DSBs near active transcription sites and cellular resistance to DSBs. Our data suggest that ATM-dependent phosphorylation of ENL functions as switch from elongation to Polycomb-mediated repression to preserve genome integrity.

  12. Super-telomeres in transformed human fibroblasts.

    Science.gov (United States)

    Chiodi, Ilaria; Belgiovine, Cristina; Zongaro, Samantha; Ricotti, Roberta; Horard, Beatrice; Lossani, Andrea; Focher, Federico; Gilson, Eric; Giulotto, Elena; Mondello, Chiara

    2013-08-01

    Telomere length maintenance is critical for organisms' long-term survival and cancer cell proliferation. Telomeres are kept within species-specific length ranges by the interplay between telomerase activity and telomeric chromatin organization. In this paper, we exploited telomerase immortalized human fibroblasts (cen3tel) that gradually underwent neoplastic transformation during culture propagation to study telomere composition and length regulation during the transformation process. Just after telomerase catalytic subunit (hTERT) expression, cen3tel telomeres shortened despite the presence of telomerase activity. At a later stage and concomitantly with transformation, cells started elongating telomeres, which reached a mean length greater than 100kb in about 900 population doublings. Super-telomeres were stable and compatible with cell growth and tumorigenesis. Telomere extension was associated with increasing levels of telomerase activity that were linked to the deregulation of endogenous telomerase RNA (hTERC) and exogenous telomerase reverse transcriptase (hTERT) expression. Notably, the increase in hTERC levels paralleled the increase in telomerase activity, suggesting that this subunit plays a role in regulating enzyme activity. Telomeres ranging in length between 10 and more than 100kb were maintained in an extendible state although TRF1 and TRF2 binding increased with telomere length. Super-telomeres neither influenced subtelomeric region global methylation nor the expression of the subtelomeric gene FRG1, attesting the lack of a clear-cut relationship between telomere length, subtelomeric DNA methylation and expression in human cells. The cellular levels of the telomeric proteins hTERT, TRF1, TRF2 and Hsp90 rose with transformation and were independent of telomere length, pointing to a role of these proteins in tumorigenesis.

  13. Structural basis for transcription elongation by bacterial RNA polymerase.

    Science.gov (United States)

    Vassylyev, Dmitry G; Vassylyeva, Marina N; Perederina, Anna; Tahirov, Tahir H; Artsimovitch, Irina

    2007-07-12

    The RNA polymerase elongation complex (EC) is both highly stable and processive, rapidly extending RNA chains for thousands of nucleotides. Understanding the mechanisms of elongation and its regulation requires detailed information about the structural organization of the EC. Here we report the 2.5-A resolution structure of the Thermus thermophilus EC; the structure reveals the post-translocated intermediate with the DNA template in the active site available for pairing with the substrate. DNA strand separation occurs one position downstream of the active site, implying that only one substrate at a time can specifically bind to the EC. The upstream edge of the RNA/DNA hybrid stacks on the beta'-subunit 'lid' loop, whereas the first displaced RNA base is trapped within a protein pocket, suggesting a mechanism for RNA displacement. The RNA is threaded through the RNA exit channel, where it adopts a conformation mimicking that of a single strand within a double helix, providing insight into a mechanism for hairpin-dependent pausing and termination.

  14. Elongational viscosity of monodisperse and bidisperse polystyrene melts

    DEFF Research Database (Denmark)

    Nielsen, Jens Kromann; Rasmussen, Henrik K.; Hassager, Ole

    2006-01-01

    The start-up and steady uniaxial elongational viscosity have been measured for two monodisperse polystyrene melts with molecular weights of 52 and 103 kg/mole, and for three bidisperse polystyrene melts. The monodisperse melts show a maximum in the steady elongational viscosity vs. the elongation...

  15. Super insulating aerogel glazing

    DEFF Research Database (Denmark)

    Schultz, Jørgen Munthe; Jensen, Karsten Ingerslev; Kristiansen, Finn Harken

    2004-01-01

    Monolithic silica aerogel offers the possibility of combining super insulation and high solar energy transmittance, which has been the background for a previous and a current EU project on research and development of monolithic silica aerogel as transparent insulation in windows. Generally, windows...... form the weakest part of the thermal envelope with respect to heat loss coefficient, but on the other hand also play an important role for passive solar energy utilisation. For window orientations other than south, the net energy balance will be close to or below zero. However, the properties...... of aerogel glazing will allow for a positive net energy gain even for north facing vertical windows in a Danish climate during the heating season. This means that high quality daylight can be obtained even with additional energy gain. On behalf of the partners of the two EU projects, results related...

  16. Mapping Escherichia coli elongation factor Tu residues involved in binding of aminoacyl-tRNA

    DEFF Research Database (Denmark)

    Wiborg, Ove; Andersen, C; Knudsen, Charlotte Rohde

    1996-01-01

    were characterized with respect to thermal and chemical stability, GTPase activity, tRNA affinity, and activity in an in vitro translation assay. Most conspicuously tRNA affinities were reduced for all mutants. The results verify our structural analysis of elongation factor Tu in complex with aminoacyl...

  17. Xinjiang Girl World Super Model

    Institute of Scientific and Technical Information of China (English)

    1999-01-01

    Leading Chinese model Yue Mei won thetitle of World Super Model at the ’98 WorldSuper Model Competition held in FranceSeptember 6 - 17. Yue, a university studentfrom the Xinjiang Uygur AutonomousRegion, had won the top title at ’98 ChinaSuper Model Competition held in Beijingone month earier.After that, she underwentone month’s professional modeling trainingwith the New Silk Road ModelingManagement Company before setting off forthe world competition. In France, Yueimpressed the judges with her strikingfeatures, and display of oriental elegance and

  18. SuperB Progress Reports Accelerator

    CERN Document Server

    Biagini, Maria Enrica; Boscolo, M; Buonomo, B; Demma, T; Drago, A; Esposito, M; Guiducci, S; Mazzitelli, G; Pellegrino, L; Preger, M A; Raimondi, P; Ricci, R; Rotundo, U; Sanelli, C; Serio, M; Stella, A; Tomassini, S; Zobov, M; Bertsche, K; Brachman, A; Cai, Y; Chao, A; Chesnut, R; Donald, M.H; Field, C; Fisher, A; Kharakh, D; Krasnykh, A; Moffeit, K; Nosochkov, Y; Pivi, M; Seeman, J; Sullivan, M.K; Weathersby, S; Weidemann, A; Weisend, J; Wienands, U; Wittmer, W; Woods, M; Yocky, G; Bogomiagkov, A; Koop, I; Levichev, E; Nikitin, S; Okunev, I; Piminov, P; Sinyatkin, S; Shatilov, D; Vobly, P; Bosi, F; Liuzzo, S; Paoloni, E; Bonis, J; Chehab, R; Le Meur, G; Lepercq, P; Letellier-Cohen, F; Mercier, B; Poirier, F; Prevost, C; Rimbault, C; Touze, F; Variola, A; Bolzon, B; Brunetti, L; Jeremie, A; Baylac, M; Bourrion, O; De Conto, J M; Gomez, Y; Meot, F; Monseu, N; Tourres, D; Vescovi, C; Chanci, A; Napoly, O; Barber, D P; Bettoni, S; Quatraro, D

    2010-01-01

    This report details the present status of the Accelerator design for the SuperB Project. It is one of four separate progress reports that, taken collectively, describe progress made on the SuperB Project since the publication of the SuperB Conceptual Design Report in 2007 and the Proceedings of SuperB Workshop VI in Valencia in 2008.

  19. SuperB Progress Report: Detector

    Energy Technology Data Exchange (ETDEWEB)

    Grauges, E.; /Barcelona U., ECM; Donvito, G.; Spinoso, V.; /INFN, Bari /Bari U.; Manghisoni, M.; Re, V.; Traversi, G.; /INFN, Pavia /Bergamo U., Ingengneria Dept.; Eigen, G.; Fehlker, D.; Helleve, L.; /Bergen U.; Carbone, A.; Di Sipio, R.; Gabrielli, A.; Galli, D.; Giorgi, F.; Marconi, U.; Perazzini, S.; Sbarra, C.; Vagnoni, V.; Valentinetti, S.; Villa, M.; Zoccoli, A.; /INFN, Bologna /Bologna U. /Caltech /Carleton U. /Cincinnati U. /INFN, CNAF /INFN, Ferrara /Ferrara U. /UC, Irvine /Taras Shevchenko U. /Orsay, LAL /LBL, Berkeley /UC, Berkeley /Frascati /INFN, Legnaro /Orsay, IPN /Maryland U. /McGill U. /INFN, Milan /Milan U. /INFN, Naples /Naples U. /Novosibirsk, IYF /INFN, Padua /Padua U. /INFN, Pavia /Pavia U. /INFN, Perugia /Perugia U. /INFN, Perugia /Caltech /INFN, Pisa /Pisa U. /Pisa, Scuola Normale Superiore /PNL, Richland /Queen Mary, U. of London /Rutherford /INFN, Rome /Rome U. /INFN, Rome2 /Rome U.,Tor Vergata /INFN, Rome3 /Rome III U. /SLAC /Tel Aviv U. /INFN, Turin /Turin U. /INFN, Padua /Trento U. /INFN, Trieste /Trieste U. /TRIUMF /British Columbia U. /Montreal U. /Victoria U.

    2012-02-14

    This report describes the present status of the detector design for SuperB. It is one of four separate progress reports that, taken collectively, describe progress made on the SuperB Project since the publication of the SuperB Conceptual Design Report in 2007 and the Proceedings of SuperB Workshop VI in Valencia in 2008.

  20. Super-multiplex vibrational imaging

    Science.gov (United States)

    Wei, Lu; Chen, Zhixing; Shi, Lixue; Long, Rong; Anzalone, Andrew V.; Zhang, Luyuan; Hu, Fanghao; Yuste, Rafael; Cornish, Virginia W.; Min, Wei

    2017-04-01

    potential of this 24-colour (super-multiplex) optical imaging approach for elucidating intricate interactions in complex biological systems.

  1. What's So Super about Superfoods?

    Science.gov (United States)

    ... with meals. The Skinny on Common Super Foods Salmon is a fatty fish that’s low in saturated ... soy nuts are high in polyunsaturated fat, fiber, vitamins and minerals but low in saturated fat. They ...

  2. Super Ministries,Better Administration

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    @@ Chinese lawmakers on March 15th endorsed a State Counci l proposal for institutional overhaul of the tentral government,which involves the establishment of"super ministries"concerning energy,transport,industry and environmental protection.

  3. Crystal structure of elongation factor 4 bound to a clockwise ratcheted ribosome

    Energy Technology Data Exchange (ETDEWEB)

    Gagnon, M. G.; Lin, J.; Bulkley, D.; Steitz, T. A.

    2014-08-08

    Elongation factor 4 (EF4/LepA) is a highly conserved guanosine triphosphatase translation factor. It was shown to promote back-translocation of tRNAs on posttranslocational ribosome complexes and to compete with elongation factor G for interaction with pretranslocational ribosomes, inhibiting the elongation phase of protein synthesis. Here, we report a crystal structure of EF4–guanosine diphosphate bound to the Thermus thermophilus ribosome with a P-site tRNA at 2.9 angstroms resolution. The C-terminal domain of EF4 reaches into the peptidyl transferase center and interacts with the acceptor stem of the peptidyl-tRNA in the P site. The ribosome is in an unusual state of ratcheting with the 30S subunit rotated clockwise relative to the 50S subunit, resulting in a remodeled decoding center. The structure is consistent with EF4 functioning either as a back-translocase or a ribosome sequester.

  4. Dissection of transcription factor TFIIF functional domains required for initiation and elongation.

    Science.gov (United States)

    Tan, S; Conaway, R C; Conaway, J W

    1995-06-20

    TFIIF is unique among the general transcription factors because of its ability to control the activity of RNA polymerase II at both the initiation and elongation stages of transcription. Mammalian TFIIF, a heterodimer of approximately 30-kDa (RAP30) and approximately 70-kDa (RAP74) subunits, assists TFIIB in recruiting RNA polymerase II into the preinitiation complex and activates the overall rate of RNA chain elongation by suppressing transient pausing by polymerase at many sites on DNA templates. A major objective of efforts to understand how TFIIF regulates transcription has been to establish the relationship between its initiation and elongation activities. Here we establish this relationship by demonstrating that TFIIF transcriptional activities are mediated by separable functional domains. To accomplish this, we sought and identified distinct classes of RAP30 mutations that selectively block TFIIF activity in transcription initiation and elongation. We propose that (i) TFIIF initiation activity is mediated at least in part by RAP30 C-terminal sequences that include a cryptic DNA-binding domain similar to conserved region 4 of bacterial sigma factors and (ii) TFIIF elongation activity is mediated in part by RAP30 sequences located immediately upstream of the C terminus in a region proposed to bind RNA polymerase II and by additional sequences located in the RAP30 N terminus.

  5. Complexity

    CERN Document Server

    Gershenson, Carlos

    2011-01-01

    The term complexity derives etymologically from the Latin plexus, which means interwoven. Intuitively, this implies that something complex is composed by elements that are difficult to separate. This difficulty arises from the relevant interactions that take place between components. This lack of separability is at odds with the classical scientific method - which has been used since the times of Galileo, Newton, Descartes, and Laplace - and has also influenced philosophy and engineering. In recent decades, the scientific study of complexity and complex systems has proposed a paradigm shift in science and philosophy, proposing novel methods that take into account relevant interactions.

  6. What are super-enhancers?

    Science.gov (United States)

    Pott, Sebastian; Lieb, Jason D

    2015-01-01

    The term 'super-enhancer' has been used to describe groups of putative enhancers in close genomic proximity with unusually high levels of Mediator binding, as measured by chromatin immunoprecipitation and sequencing (ChIP-seq). Here we review the identification and composition of super-enhancers, describe links between super-enhancers, gene regulation and disease, and discuss the functional significance of enhancer clustering. We also provide our perspective regarding the proposition that super-enhancers are a regulatory entity conceptually distinct from what was known before the introduction of the term. Our opinion is that there is not yet strong evidence that super-enhancers are a novel paradigm in gene regulation and that use of the term in this context is not currently justified. However, the term likely identifies strong enhancers that exhibit behaviors consistent with previous models and concepts of transcriptional regulation. In this respect, the super-enhancer definition is useful in identifying regulatory elements likely to control genes important for cell type specification.

  7. Holography based super resolution

    Science.gov (United States)

    Hussain, Anwar; Mudassar, Asloob A.

    2012-05-01

    This paper describes the simulation of a simple technique of superresolution based on holographic imaging in spectral domain. The input beam assembly containing 25 optical fibers with different orientations and positions is placed to illuminate the object in the 4f optical system. The position and orientation of each fiber is calculated with respect to the central fiber in the array. The positions and orientations of the fibers are related to the shift of object spectrum at aperture plane. During the imaging process each fiber is operated once in the whole procedure to illuminate the input object transparency which gives shift to the object spectrum in the spectral domain. This shift of the spectrum is equal to the integral multiple of the pass band aperture width. During the operation of single fiber (ON-state) all other fibers are in OFF-state at that time. The hologram recorded by each fiber at the CCD plane is stored in computer memory. At the end of illumination process total 25 holograms are recorded by the whole fiber array and by applying some post processing and specific algorithm single super resolved image is obtained. The superresolved image is five times better than the band-limited image. The work is demonstrated using computer simulation only.

  8. Complex

    African Journals Online (AJOL)

    CLEMENT O BEWAJI

    Schiff bases and their complex compounds have been studied for their .... establishing coordination of the N–(2 – hydroxybenzyl) - L - α - valine Schiff base ..... (1967); “Spectrophotometric Identification of Organic Compounds”, Willey, New.

  9. High temperature promotes auxin-mediated hypocotyl elongation in Arabidopsis

    OpenAIRE

    Gray, William M; Östin, Anders; Sandberg, Göran; Romano, Charles P.; Estelle, Mark

    1998-01-01

    Physiological studies with excised stem segments have implicated the plant hormone indole-3-acetic acid (IAA or auxin) in the regulation of cell elongation. Supporting evidence from intact plants has been somewhat more difficult to obtain, however. Here, we report the identification and characterization of an auxin-mediated cell elongation growth response in Arabidopsis thaliana. When grown in the light at high temperature (29°C), Arabidopsis seedlings exhibit dramatic hypocotyl elongation co...

  10. Analysis of Percent Elongation for Ductile Metal in Uniaxial Tension

    Institute of Scientific and Technical Information of China (English)

    WANG Xue-bin; YANG Mei; JIANG Jian

    2005-01-01

    Percent elongation of ductile metal in uniaxial tension due to non-homogeneity was analyzed based on gradient-dependent plasticity. Three assumptions are used to get the analytical solution of percent elongation: one is static equilibrium condition in axial direction; another is that plastic volumetric strain is zero in necking zone;the other is that the diameter in unloading zone remains constant after strain localization is initiated. The strain gradient term was introduced into the yield function of classical plastic mechanics to obtain the analytical solution of distributed plastic strain. Integrating the plastic strain and considering the influence of necking on plastic elongation, a one-dimensional analytical solution of percent elongation was proposed. The analytical solution shows that the percent elongation is inversely proportional to the gauge length, and the solution is formally similar to earlier empirical formula proposed by Barba. Comparisons of existing experimental results and present analytical solutions for relation between load and total elongation and for relation between percent elongation and gauge lengthwere carried out and the new mechanical model for percent elongation was verified. Moreover, higher ductility,toughness and heterogeneity can cause much larger percentage elongation, which coincides with usual viewpoints.

  11. The Super-B Project Accelerator Status

    Energy Technology Data Exchange (ETDEWEB)

    Biagini, M.E.; Alesini, D.; Boni, R.; Boscolo, M.; Demma, T.; Drago, A.; Esposito, M.; Guiducci, S.; Marcellini, F.; Mazzitelli, G.; Preger, M.; Raimondi, P.; Sanelli, C.; Serio, M.; Stecchi, A.; Stella, A.; Tomassini, S.; Zobov, M.; /Frascati; Bertsche, K.; Brachmann, A.; Cai, Y.; /SLAC /Novosibirsk, IYF /Annecy, LAPP /LPSC, Grenoble /Orsay, LAL /Saclay /Pisa U. /CERN

    2011-08-17

    The SuperB project is an international effort aiming at building in Italy a very high luminosity e{sup +}e{sup -} (10{sup 36} cm{sup -2} sec{sup -1}) asymmetric collider at the Y(4S) energy in the CM. The accelerator design has been extensively studied and changed during the past year. The present design, based on the new collision scheme, with large Piwinski angle and the use of 'crab waist' sextupoles already successfully tested at the DA{Phi}NE {Phi}-Factory at LNF Frascati, provides larger flexibility, better dynamic aperture and spin manipulation sections in the Low Energy Ring (LER) for longitudinal polarization of the electron beam at the Interaction Point (IP). The Interaction Region (IR) has been further optimized in terms of apertures and reduced backgrounds in the detector. The injector complex design has been also updated. A summary of the project status will be presented in this paper. The SuperB collider can reach a peak luminosity of 10{sup 36} cm{sup -2} sec{sup -1} with beam currents and bunch lengths similar to those of the past and present e{sup +}e{sup -} Factories, through the use of smaller emittances and new scheme of crossing angle collision. The beams are stored in two rings at 6.7 GeV (HER) and 4.2 GeV (LER). Unique features of the project are the polarization of the electron beam in the LER and the possibility to decrease the energies for running at the {tau}/charm threshold. The option to reuse the PEP-II B-Factory (SLAC) hardware will allow reducing costs. The SuperB facility will require a big complex of civil infrastructure. The main construction, which will house the final part of the LINAC, the injection lines, the damping rings, and the storage rings, will be mainly underground. Two sites have been considered: the campus of Tor Vergata University near Frascati, and the INFN Frascati Laboratory. No decision has been made yet. A footprint of the possible SuperB layout on the LNF area is shown in Fig. 1.

  12. Super-resolution optical telescopes with local light diffraction shrinkage

    Science.gov (United States)

    Wang, Changtao; Tang, Dongliang; Wang, Yanqin; Zhao, Zeyu; Wang, Jiong; Pu, Mingbo; Zhang, Yudong; Yan, Wei; Gao, Ping; Luo, Xiangang

    2015-12-01

    Suffering from giant size of objective lenses and infeasible manipulations of distant targets, telescopes could not seek helps from present super-resolution imaging, such as scanning near-field optical microscopy, perfect lens and stimulated emission depletion microscopy. In this paper, local light diffraction shrinkage associated with optical super-oscillatory phenomenon is proposed for real-time and optically restoring super-resolution imaging information in a telescope system. It is found that fine target features concealed in diffraction-limited optical images of a telescope could be observed in a small local field of view, benefiting from a relayed metasurface-based super-oscillatory imaging optics in which some local Fourier components beyond the cut-off frequency of telescope could be restored. As experimental examples, a minimal resolution to 0.55 of Rayleigh criterion is obtained, and imaging complex targets and large targets by superimposing multiple local fields of views are demonstrated as well. This investigation provides an access for real-time, incoherent and super-resolution telescopes without the manipulation of distant targets. More importantly, it gives counterintuitive evidence to the common knowledge that relayed optics could not deliver more imaging details than objective systems.

  13. Electrically tuned super-capacitors

    CERN Document Server

    Chowdhury, Tazima S

    2015-01-01

    Fast charging and discharging of large amounts of electrical energy make super-capacitors ideal for short-term energy storage [1-5]. In its simplest form, the super-capacitor is an electrolytic capacitor made of an anode and a cathode immersed in an electrolyte. As for an ordinary capacitor, minimizing the charge separation distance and increasing the electrode area increase capacitance. In super-capacitors, charge separation is of nano-meter scale at each of the electrode interface (the Helmholtz double layer). Making the electrodes porous increases their effective surface area [6-8]. A separating layer between the anode and the cathode electrodes is used to minimize unintentional electrical discharge (Figure 1). Here we show how to increase the capacitance of super-capacitors by more than 45 percent when modifying the otherwise passive separator layer into an active diode-like structure. Active control of super-capacitors may increase their efficiency during charge and discharge cycles. Controlling ion flow...

  14. Quantization of super Teichmueller spaces

    Energy Technology Data Exchange (ETDEWEB)

    Aghaei, Nezhla

    2016-08-15

    The quantization of the Teichmueller spaces of Riemann surfaces has found important applications to conformal field theory and N=2 supersymmetric gauge theories. We construct a quantization of the Teichmueller spaces of super Riemann surfaces, using coordinates associated to the ideal triangulations of super Riemann surfaces. A new feature is the non-trivial dependence on the choice of a spin structure which can be encoded combinatorially in a certain refinement of the ideal triangulation. We construct a projective unitary representation of the groupoid of changes of refined ideal triangulations. Therefore, we demonstrate that the dependence of the resulting quantum theory on the choice of a triangulation is inessential. In the quantum Teichmueller theory, it was observed that the key object defining the Teichmueller theory has a close relation to the representation theory of the Borel half of U{sub q}(sl(2)). In our research we observed that the role of U{sub q}(sl(2)) is taken by quantum superalgebra U{sub q}(osp(1 vertical stroke 2)). A Borel half of U{sub q}(osp(1 vertical stroke 2)) is the super quantum plane. The canonical element of the Heisenberg double of the quantum super plane is evaluated in certain infinite dimensional representations on L{sup 2}(R) x C{sup 1} {sup vertical} {sup stroke} {sup 1} and compared to the flip operator from the Teichmueller theory of super Riemann surfaces.

  15. Super-Virasoro anomaly, super-Weyl anomaly and the super-Liouville action for 2D supergravity

    CERN Document Server

    Fujiwara, T; Suzuki, T; Fujiwara, Takanori; Igarashi, Hiroshi; Suzuki, Tadao

    1996-01-01

    The relation between super-Virasoro anomaly and super-Weyl anomaly in N=1 NSR superstring coupled with 2D supergravity is investigated from canonical theoretical view point. The WZW action canceling the super-Virasoro anomaly is explicitly constructed. It is super-Weyl invariant but nonlocal functional of 2D supergravity. The nonlocality can be remedied by the super-Liouvlle action, which in turn recovers the super-Weyl anomaly. The final gravitational effective action turns out to be local but noncovariant super-Liouville action, describing the dynamical behavior of the super-Liouville fields. The BRST invariance of this approach is examined in the superconformal gauge and in the light-cone gauge.

  16. The Super-Kamiokande Experiment

    CERN Document Server

    Walter, C W

    2008-01-01

    Super-Kamiokande is a 50 kiloton water Cherenkov detector located at the Kamioka Observatory of the Institute for Cosmic Ray Research, University of Tokyo. It was designed to study neutrino oscillations and carry out searches for the decay of the nucleon. The Super-Kamiokande experiment began in 1996 and in the ensuing decade of running has produced extremely important results in the fields of atmospheric and solar neutrino oscillations, along with setting stringent limits on the decay of the nucleon and the existence of dark matter and astrophysical sources of neutrinos. Perhaps most crucially, Super-Kamiokande for the first time definitively showed that neutrinos have mass and undergo flavor oscillations. This chapter will summarize the published scientific output of the experiment with a particular emphasis on the atmospheric neutrino results.

  17. Microsphere Super-resolution Imaging

    CERN Document Server

    Wang, Zengbo

    2015-01-01

    Recently, it was discovered that microsphere can generate super-resolution focusing beyond diffraction limit. This has led to the development of an exciting super-resolution imaging technique -microsphere nanoscopy- that features a record resolution of 50 nm under white lights. Different samples have been directly imaged in high resolution and real time without labelling, including both non-biological (nano devices, structures and materials) and biological (subcellular details, viruses) samples. This chapter reviews the technique, which covers its background, fundamentals, experiments, mechanisms as well as the future outlook.

  18. Interactive Super Mario Bros Evolution

    DEFF Research Database (Denmark)

    Sørensen, Patrikk D.; Olsen, Jeppeh M.; Risi, Sebastian

    2016-01-01

    to encourage the evolution of desired behaviors. In this paper, we show how casual users can create controllers for \\emph{Super Mario Bros} through an interactive evolutionary computation (IEC) approach, without prior domain or programming knowledge. By iteratively selecting Super Mario behaviors from a set...... of candidates, users are able to guide evolution towards a variety of different behaviors, which would be difficult with an automated approach. Additionally, the user-evolved controllers perform similarly well as controllers evolved with a traditional fitness-based approach when comparing distance traveled...

  19. Quantisation of super Teichmueller theory

    Energy Technology Data Exchange (ETDEWEB)

    Aghaei, Nezhla [DESY Hamburg (Germany). Theory Group; Hamburg Univ. (Germany). Dept. of Mathematics; Pawelkiewicz, Michal; Techner, Joerg [DESY Hamburg (Germany). Theory Group

    2015-12-15

    We construct a quantisation of the Teichmueller spaces of super Riemann surfaces using coordinates associated to ideal triangulations of super Riemann surfaces. A new feature is the non-trivial dependence on the choice of a spin structure which can be encoded combinatorially in a certain refinement of the ideal triangulation. By constructing a projective unitary representation of the groupoid of changes of refined ideal triangulations we demonstrate that the dependence of the resulting quantum theory on the choice of a triangulation is inessential.

  20. Quantisation of super Teichmueller theory

    CERN Document Server

    Aghaei, Nezhla; Teschner, Joerg

    2015-01-01

    We construct a quantisation of the Teichmueller spaces of super Riemann surfaces using coordinates associated to ideal triangulations of super Riemann surfaces. A new feature is the non-trivial dependence on the choice of a spin structure which can be encoded combinatorially in a certain refinement of the ideal triangulation. By constructing a projective unitary representation of the groupoid of changes of refined ideal triangulations we demonstrate that the dependence of the resulting quantum theory on the choice of a triangulation is inessential.

  1. The construction of orthodox super rpp semigroups

    Institute of Scientific and Technical Information of China (English)

    HE Yong; GUO Yuqi; Kar Ping Shum

    2004-01-01

    We define orthodox super rpp semigroups and study their semilattice decompositions. Standard representation theorem of orthodox super rpp semigroups whose subband of idempotents is in the varieties of bands described by an identity with at most three variables are obtained.

  2. An elongation method for large systems toward bio-systems.

    Science.gov (United States)

    Aoki, Yuriko; Gu, Feng Long

    2012-06-07

    The elongation method, proposed in the early 1990s, originally for theoretical synthesis of aperiodic polymers, has been reviewed. The details of derivation of the localization scheme adopted by the elongation method are described along with the elongation processes. The reliability and efficiency of the elongation method have been proven by applying it to various models of bio-systems, such as gramicidin A, collagen, DNA, etc. By means of orbital shift, the elongation method has been successfully applied to delocalized π-conjugated systems. The so-called orbital shift works in such a way that during the elongation process, some strongly delocalized frozen orbitals are assigned as active orbitals and joined with the interaction of the attacking monomer. By this treatment, it has been demonstrated that the total energies and non-linear optical properties determined by the elongation method are more accurate even for bio-systems and delocalized systems like fused porphyrin wires. The elongation method has been further developed for treating any three-dimensional (3D) systems and its applicability is confirmed by applying it to entangled insulin models whose terminal is capped by both neutral and zwitterionic sequences.

  3. Elongational viscosity of narrow molar mass distribution polystyrene

    DEFF Research Database (Denmark)

    Bach, Anders; Almdal, Kristoffer; Rasmussen, Henrik Koblitz

    2003-01-01

    Transient and steady elongational viscosity has been measured for two narrow molar mass distribution polystyrene melts of molar masses 200 000 and 390 000 by means of a filament stretching rheometer. Total Hencky strains of about five have been obtained. The transient elongational viscosity rises...

  4. Halogenated auxins affect microtubules and root elongation in Lactuca sativa

    Science.gov (United States)

    Zhang, N.; Hasenstein, K. H.

    2000-01-01

    We studied the effect of 4,4,4-trifluoro-3-(indole-3-)butyric acid (TFIBA), a recently described root growth stimulator, and 5,6-dichloro-indole-3-acetic acid (DCIAA) on growth and microtubule (MT) organization in roots of Lactuca sativa L. DCIAA and indole-3-butyric acid (IBA) inhibited root elongation and depolymerized MTs in the cortex of the elongation zone, inhibited the elongation of stele cells, and promoted xylem maturation. Both auxins caused the plane of cell division to shift from anticlinal to periclinal. In contrast, TFIBA (100 micromolar) promoted elongation of primary roots by 40% and stimulated the elongation of lateral roots, even in the presence of IBA, the microtubular inhibitors oryzalin and taxol, or the auxin transport inhibitor naphthylphthalamic acid. However, TFIBA inhibited the formation of lateral root primordia. Immunostaining showed that TFIBA stabilized MTs orientation perpendicular to the root axis, doubled the cortical cell length, but delayed xylem maturation. The data indicate that the auxin-induced inhibition of elongation and swelling of roots results from reoriented phragmoplasts, the destabilization of MTs in elongating cells, and promotion of vessel formation. In contrast, TFIBA induced promotion of root elongation by enhancing cell length, prolonging transverse MT orientation, delaying cell and xylem maturation.

  5. Halogenated auxins affect microtubules and root elongation in Lactuca sativa

    Science.gov (United States)

    Zhang, N.; Hasenstein, K. H.

    2000-01-01

    We studied the effect of 4,4,4-trifluoro-3-(indole-3-)butyric acid (TFIBA), a recently described root growth stimulator, and 5,6-dichloro-indole-3-acetic acid (DCIAA) on growth and microtubule (MT) organization in roots of Lactuca sativa L. DCIAA and indole-3-butyric acid (IBA) inhibited root elongation and depolymerized MTs in the cortex of the elongation zone, inhibited the elongation of stele cells, and promoted xylem maturation. Both auxins caused the plane of cell division to shift from anticlinal to periclinal. In contrast, TFIBA (100 micromolar) promoted elongation of primary roots by 40% and stimulated the elongation of lateral roots, even in the presence of IBA, the microtubular inhibitors oryzalin and taxol, or the auxin transport inhibitor naphthylphthalamic acid. However, TFIBA inhibited the formation of lateral root primordia. Immunostaining showed that TFIBA stabilized MTs orientation perpendicular to the root axis, doubled the cortical cell length, but delayed xylem maturation. The data indicate that the auxin-induced inhibition of elongation and swelling of roots results from reoriented phragmoplasts, the destabilization of MTs in elongating cells, and promotion of vessel formation. In contrast, TFIBA induced promotion of root elongation by enhancing cell length, prolonging transverse MT orientation, delaying cell and xylem maturation.

  6. Isolated Horner Syndrome From an Elongated Styloid Process (Eagle Syndrome).

    Science.gov (United States)

    Chang, Caitlin A; Lin, Tony; Fung, Kevin; Sharma, Manas; Fraser, J Alexander

    2015-12-01

    Eagle syndrome occurs when an elongated styloid process causes otolaryngological or neurological symptoms or signs. We report a patient who had an isolated asymptomatic Horner syndrome that resulted from a pinned internal carotid artery being dynamically injured by an elongated styloid process during chiropractic neck manipulation. There was no evidence of arterial dissection.

  7. The Birth of a Super Star Cluster: NGC 5253

    CERN Document Server

    Turner, J L; Turner, Jean L.; Beck, Sara C.

    2004-01-01

    We present images of the 7mm free-free emission from the radio "supernebula" in NGC 5253 made with the Very Large Array and the Pie Town link. The images reveal structure in the nebula, which has a <~ 1 pc (~50 mas radius) core requiring the excitation of 1200 O7 stars. The nebula is elongated, with an arc of emission curving to the northeast and to the south. The total ionizing flux within the central 1.2" (~20 pc) is 7 x 10^52 s^-1, corresponding to 7000 O7 stars. We propose that the radio source is coincident with a small, very red near-infrared cluster and apparently linked to a larger, optical source some 10 pc away on the sky. We speculate on the causes of this structure and what it might tell us about the birth of the embedded young super star cluster.

  8. Eukaryotic elongation factor 2 kinase regulates the cold stress response by slowing translation elongation.

    Science.gov (United States)

    Knight, John R P; Bastide, Amandine; Roobol, Anne; Roobol, Jo; Jackson, Thomas J; Utami, Wahyu; Barrett, David A; Smales, C Mark; Willis, Anne E

    2015-01-15

    Cells respond to external stress conditions by controlling gene expression, a process which occurs rapidly via post-transcriptional regulation at the level of protein synthesis. Global control of translation is mediated by modification of translation factors to allow reprogramming of the translatome and synthesis of specific proteins that are required for stress protection or initiation of apoptosis. In the present study, we have investigated how global protein synthesis rates are regulated upon mild cooling. We demonstrate that although there are changes to the factors that control initiation, including phosphorylation of eukaryotic translation initiation factor 2 (eIF2) on the α-subunit, the reduction in the global translation rate is mediated by regulation of elongation via phosphorylation of eukaryotic elongation factor 2 (eEF2) by its specific kinase, eEF2K (eukaryotic elongation factor 2 kinase). The AMP/ATP ratio increases following cooling, consistent with a reduction in metabolic rates, giving rise to activation of AMPK (5'-AMP-activated protein kinase), which is upstream of eEF2K. However, our data show that the major trigger for activation of eEF2K upon mild cooling is the release of Ca2+ ions from the endoplasmic reticulum (ER) and, importantly, that it is possible to restore protein synthesis rates in cooled cells by inhibition of this pathway at multiple points. As cooling has both therapeutic and industrial applications, our data provide important new insights into how the cellular responses to this stress are regulated, opening up new possibilities to modulate these responses for medical or industrial use at physiological or cooler temperatures.

  9. (R)-β-lysine-modified elongation factor P functions in translation elongation

    DEFF Research Database (Denmark)

    Bullwinkle, Tammy J; Zou, S Betty; Rajkovic, Andrei

    2013-01-01

    Post-translational modification of bacterial elongation factor P (EF-P) with (R)-β-lysine at a conserved lysine residue activates the protein in vivo and increases puromycin reactivity of the ribosome in vitro. The additional hydroxylation of EF-P at the same lysine residue by the YfcM protein has......-(β)-lysyl-EF-P showed 30% increased puromycin reactivity but no differences in dipeptide synthesis rates when compared with the β-lysylated form. Unlike disruption of the other genes required for EF-P modification, deletion of yfcM had no phenotypic consequences in Salmonella. Taken together, our findings indicate...

  10. The Drosophila egg chamber-a new spin on how tissues elongate.

    Science.gov (United States)

    Horne-Badovinac, Sally

    2014-10-01

    During development, tissues undergo complex cellular rearrangements and changes in shape that produce a diversity of body plans and the functional organs therein. The Drosophila egg chamber has emerged as an exciting and highly tractable model in which to investigate novel mechanisms driving the elongation of tissues. Egg chambers are multicellular assemblies within flies' ovaries that will each give rise to a single egg. Although initially spherical, these simple organ-like structures lengthen as they grow. This transformation depends on an unusual form of planar polarity in the egg chamber's outer epithelial layer, in which arrays of linear actin bundles and fibril-like structures in the basement membrane both align perpendicular to the axis of elongation. The resulting circumferential arrangement of structural molecules is then thought to act as a "molecular corset" that directionally biases growth of the egg chamber. I will explore four fundamental questions about this system: (1) How is the circumferential pattern generated in the follicular epithelium? (2) What is the physical nature of the corset? (3) How does a corset-type mechanism lead to the cellular rearrangements necessary for the elongation of tissues? and (4) To what extent are the cellular mechanisms controlling egg chamber elongation conserved in other systems? For each topic, I will present insights gleaned from the recent literature and highlight fertile areas for future investigation.

  11. Super Rice Breeding in China

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    @@I. Demand for super high yield rice in China   Rice is one of the main staple food in China. The performance of rice sector in production and yield had been very impressive in the last four decades. However, rice production and yield has stagnated since 1990.

  12. Super Girls Still Center Stage

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    The TV singing contest continues to draw a devoted audience, but will its impact on Chinese culture fall away like a shooting star? Ask any teenage girl in China to name the finalists of last year's Super Girl show and chances are she will instantly come up with the three big names.She'll probable

  13. Analysis of Forensic Super Timelines

    Science.gov (United States)

    2012-06-14

    BIB .1  vii List of Figures Figure Page...Hacker disconnects from User’s system  User clicks off Screen Saver  User closes Solitaire program  User logs off system BIB .1...analysis- tapestry_33836. BIB .2 Guðjónsson, K. (2010). Mastering the super timeline with log2timeline. SANS Gold Paper accepted June 29,2010

  14. One-dimensional super Calabi-Yau manifolds and their mirrors

    Science.gov (United States)

    Noja, S.; Cacciatori, S. L.; Piazza, F. Dalla; Marrani, A.; Re, R.

    2017-04-01

    We apply a definition of generalised super Calabi-Yau variety (SCY) to supermanifolds of complex dimension one. One of our results is that there are two SCY's having reduced manifold equal to P^1, namely the projective super space P^{.1|2} and the weighted projective super space W{P}_{(2)}^{.1|1} . Then we compute the corresponding sheaf cohomology of superforms, showing that the cohomology with picture number one is infinite dimensional, while the de Rham cohomology, which is what matters from a physical point of view, remains finite dimensional. Moreover, we provide the complete real and holomorphic de Rham cohomology for generic projective super spaces {P}^{.n|m} . We also determine the automorphism groups: these always match the dimension of the projective super group with the only exception of {P}^{.1|2} , whose automorphism group turns out to be larger than the projective super group. By considering the cohomology of the super tangent sheaf, we compute the deformations of {P}^{.1|m} , discovering that the presence of a fermionic structure allows for deformations even if the reduced manifold is rigid. Finally, we show that {P}^{.1|2} is self-mirror, whereas W{P}_{(2)}^{.1|1} has a zero dimensional mirror. Also, the mirror map for {P}^{.1|2} naturally endows it with a structure of N = 2 super Riemann surface.

  15. Negative elongation factor controls energy homeostasis in cardiomyocytes.

    Science.gov (United States)

    Pan, Haihui; Qin, Kunhua; Guo, Zhanyong; Ma, Yonggang; April, Craig; Gao, Xiaoli; Andrews, Thomas G; Bokov, Alex; Zhang, Jianhua; Chen, Yidong; Weintraub, Susan T; Fan, Jian-Bing; Wang, Degeng; Hu, Yanfen; Aune, Gregory J; Lindsey, Merry L; Li, Rong

    2014-04-10

    Negative elongation factor (NELF) is known to enforce promoter-proximal pausing of RNA polymerase II (Pol II), a pervasive phenomenon observed across multicellular genomes. However, the physiological impact of NELF on tissue homeostasis remains unclear. Here, we show that whole-body conditional deletion of the B subunit of NELF (NELF-B) in adult mice results in cardiomyopathy and impaired response to cardiac stress. Tissue-specific knockout of NELF-B confirms its cell-autonomous function in cardiomyocytes. NELF directly supports transcription of those genes encoding rate-limiting enzymes in fatty acid oxidation (FAO) and the tricarboxylic acid (TCA) cycle. NELF also shares extensively transcriptional target genes with peroxisome proliferator-activated receptor α (PPARα), a master regulator of energy metabolism in the myocardium. Mechanistically, NELF helps stabilize the transcription initiation complex at the metabolism-related genes. Our findings strongly indicate that NELF is part of the PPARα-mediated transcription regulatory network that maintains metabolic homeostasis in cardiomyocytes.

  16. The Impact of Aminoglycosides on the Dynamics of Translation Elongation

    Directory of Open Access Journals (Sweden)

    Albert Tsai

    2013-02-01

    Full Text Available Inferring antibiotic mechanisms on translation through static structures has been challenging, as biological systems are highly dynamic. Dynamic single-molecule methods are also limited to few simultaneously measurable parameters. We have circumvented these limitations with a multifaceted approach to investigate three structurally distinct aminoglycosides that bind to the aminoacyl-transfer RNA site (A site in the prokaryotic 30S ribosomal subunit: apramycin, paromomycin, and gentamicin. Using several single-molecule fluorescence measurements combined with structural and biochemical techniques, we observed distinct changes to translational dynamics for each aminoglycoside. While all three drugs effectively inhibit translation elongation, their actions are structurally and mechanistically distinct. Apramycin does not displace A1492 and A1493 at the decoding center, as demonstrated by a solution nuclear magnetic resonance structure, causing only limited miscoding; instead, it primarily blocks translocation. Paromomycin and gentamicin, which displace A1492 and A1493, cause significant miscoding, block intersubunit rotation, and inhibit translocation. Our results show the power of combined dynamics, structural, and biochemical approaches to elucidate the complex mechanisms underlying translation and its inhibition.

  17. Nanoscale Spatial Organization of Prokaryotic Cells Studied by Super-Resolution Optical Microscopy

    Science.gov (United States)

    McEvoy, Andrea Lynn

    now see individual proteins inside of large complexes or observe structures with ten times the resolution of conventional imaging. These techniques are known as super-resolution microscopes. In this dissertation, I use super-resolution microscopes to understand how a model microbe, Escherichia coli, assembles complex protein structures. I focus on two spatially organized systems, the chemotaxis network and the cell division machinery. These assembly mechanisms could be general mechanisms for protein assembly in all organisms. I also characterize new fluorescent probes for use in multiple super-resolution imaging modalities and discuss the practicalities of using different super-resolution microscopes. The chemotaxis network in E. coli is the best understood signal transduction network in biology. Chemotaxis receptors cluster into complexes of thousands of proteins located at the cell poles and are used to move bacteria towards favorable stimuli in the environment. In these dense clusters, the receptors can bind each other and communicate to filter out noise and amplify weak signals. It is surprising that chemotaxis receptors are spatially segregated and the mechanism for polar localization of these complexes remains unclear. Using data from PALM images, we develop a model to understand how bacteria organize their receptors into large clusters. The model, stochastic cluster nucleation, is surprising in that is generates micron-scale periodic patterns without the need for accessory proteins to provide scaffolding or active transport. This model may be a general mechanism that cells utilize to organize small and large complexes of proteins. During cell division, E. coli must elongate, replicate its DNA and position its components properly prior to binary fission. Prior to septum formation, a ubiquitous protein called FtsZ, assembles into a ring at mid-cell (Z-ring) which constricts during cell division and recruits the remaining proteins necessary for cytokinesis. Though

  18. The Super-B project accelerator status

    CERN Document Server

    Biagini, M.E.; Boni, R; Boscolo, M; Demma, T; Drago, A; Esposito, M; Guiducci, S; Marcellini, F; Mazzitelli, G; Preger, M; Raimondi, P; Sanelli, C; Serio, M; Stecchi, A; Stella, A; Tomassini, S; Zobov, M; Bertsche, K; Brachmann, A; Cai, Y; Chao, A; DeLira, A; Donald, M; Fisher, A; Kharakh, D; Krasnykh, A; Li, N; MacFarlane, D; Nosochkov, Y; Novokhatski, A; Pivi, M.; Seeman, J; Sullivan, M; Wienands, U; Weisend, J; Wittmer, W; Koop, I; Levichev, E; Nikitin, S; Piminov, P; Sinyatkin, S; Shatilov, D; Bolzon, B; Brunetti, L; Jeremie, A; Baylac, M; DeConto, J M; Gomez, Y; Meot, F; Monseu, N; Tourres, D; Bonis, J.; Chehab, R; Le Meur, G; Mercier, B; Poirier, F; Prevost, C; Rimbault, C; Touze, F; Variola, A; Chance, A; Napoly, O; Bosi, F; Liuzzo, S; Paoloni, E; Bettoni, S

    2010-01-01

    The SuperB project is an international effort aiming at building in Italy a very high luminosity e+e- (1036 cm-2 sec-1) asymmetric collider at the Y(4S) energy in the cm. The accelerator design has been extensively studied and changed during the past year. The present design, based on the new collision scheme, with large Piwinski angle and the use of “crab waist” sextupoles already successfully tested at the DANE -Factory at LNF Frascati, provides larger flexibility, better dynamic aperture and spin manipulation sections in the Low Energy Ring (LER) for longitudinal polarization of the electron beam at the Interaction Point (IP). The Interaction Region (IR) has been further optimized in terms of apertures and reduced backgrounds in the detector. The injector complex design has been also updated. A summary of the project status will be presented in this paper

  19. 有限内固定结合铰链式超关节外固定架治疗肱骨远端复杂骨折%Limited internal fixation combined with super-articular external fixator for complex distal humeral fractures

    Institute of Scientific and Technical Information of China (English)

    郭亚洲; 徐辉; 郑均华; 万昌涛; 钱苏林; 曾舸

    2012-01-01

    Objective To evaluate the application of limited internal fixation combined with hinged super - articular external fixator for complex distal humeral fractures( CDHF ). Methods Twelve cases of CDHF were treated with limited internal fixation combined with hinged super - articular externnal fixator, and the results were analyzed. Results All 12 patients were followed up for a mean duration of 7 months( range 4 ~ 15 months ). According to the Morrey scoring system,results were excellent in 7 cases, good in 3 , fair in 2, and the effective rate was 83. 3% . All cases of fracture healed without severe complication such as infection,limited flection or extension of elbow joint,cubitus varus and nerve injury. Conclusion Limited internal fixation combined with hinged super - articular external fixator in treatment of complex distal humeral fractures can promote early rehabilitation and improve the recovery of elbow function, which is an effective treatment for CDHF.%目的 总结有限内固定结合铰链式超关节外固定架治疗肱骨远端复杂骨折的效果.方法 对12例肱骨远端复杂骨折采用有限内固定结合铰链式超关节外固定架固定进行治疗.结果 12 例全部获得随访,随访时间平均7个月(4~15个月),根据Morrey指定评估指数评价,优7例,良3例,可2例.优良率83.3%.无感染、关节僵硬、肘内翻畸形、神经损伤等严重并发症发生.结论 有限内固定结合铰链式超关节外固定架治疗能早期进行关节活动,可明显恢复关节功能,是一种良好的治疗肱骨远端复杂骨折的方法.

  20. Benchmarking of Proton Transport in Super Monte Carlo Simulation Program

    Science.gov (United States)

    Wang, Yongfeng; Li, Gui; Song, Jing; Zheng, Huaqing; Sun, Guangyao; Hao, Lijuan; Wu, Yican

    2014-06-01

    The Monte Carlo (MC) method has been traditionally applied in nuclear design and analysis due to its capability of dealing with complicated geometries and multi-dimensional physics problems as well as obtaining accurate results. The Super Monte Carlo Simulation Program (SuperMC) is developed by FDS Team in China for fusion, fission, and other nuclear applications. The simulations of radiation transport, isotope burn-up, material activation, radiation dose, and biology damage could be performed using SuperMC. Complicated geometries and the whole physical process of various types of particles in broad energy scale can be well handled. Bi-directional automatic conversion between general CAD models and full-formed input files of SuperMC is supported by MCAM, which is a CAD/image-based automatic modeling program for neutronics and radiation transport simulation. Mixed visualization of dynamical 3D dataset and geometry model is supported by RVIS, which is a nuclear radiation virtual simulation and assessment system. Continuous-energy cross section data from hybrid evaluated nuclear data library HENDL are utilized to support simulation. Neutronic fixed source and critical design parameters calculates for reactors of complex geometry and material distribution based on the transport of neutron and photon have been achieved in our former version of SuperMC. Recently, the proton transport has also been intergrated in SuperMC in the energy region up to 10 GeV. The physical processes considered for proton transport include electromagnetic processes and hadronic processes. The electromagnetic processes include ionization, multiple scattering, bremsstrahlung, and pair production processes. Public evaluated data from HENDL are used in some electromagnetic processes. In hadronic physics, the Bertini intra-nuclear cascade model with exitons, preequilibrium model, nucleus explosion model, fission model, and evaporation model are incorporated to treat the intermediate energy nuclear

  1. Super-translations and super-rotations at the horizon

    CERN Document Server

    Donnay, Laura; Gonzalez, Hernan A; Pino, Miguel

    2015-01-01

    We show that the asymptotic symmetries close to non-extremal black hole horizons are generated by an extension of super-translations. This group is generated by a semi-direct sum of Virasoro and abelian currents. The charges associated to the asymptotic Killing symmetries satisfy the same algebra. When considering the special case of the stationary black hole, the zero mode charges correspond to the angular momentum and the entropy at the horizon.

  2. 基于行为博弈的特大型工程项目复杂风险组合性均衡评价%Balance Evaluation for Complex Risk Compositionality of Super-large Engineering Projects Based on Behavior Game Theory

    Institute of Scientific and Technical Information of China (English)

    高武; 洪开荣

    2013-01-01

    基于行为博弈理论构建了特大型工程项目复杂风险组合性均衡评价模型。在项目风险评价中,不仅要综合考虑风险发生的可能性和价值影响,还应嵌入项目关联主体的价值偏好和动态博弈因素,从而使项目复杂风险评价具有更为合理的主体行为基础。首先从博弈视角分析了特大型工程项目复杂风险评价的特殊性,其次运用模糊层次法、行为实验方法设计指标体系和参数,最后对模型进行算例分析,得出项目分类风险和组合性风险指数。%Based on Behavior Game Theory, this paper establishes a balance model for evaluation of the complex risk of super-large en-gineering projects. In the project risk evaluation, we should not only think about the probability and valuable influences of risks, but also value preference and dynamic game factors of the item-associated subject, making the evaluation of the complex risk of projects have more rational behavioral base. Firstly, it analyzes the particularity of risk evaluation for super-large engineering projects from the perspective of game. Secondly, it designs index system and parameters by fuzzy AHP and behavioral experimental approaches. Thirdly, it makes a calculation example analysis to obtain indexes of classification risk and compositionality risk.

  3. Electrohydrodynamic behavior of water droplets on a horizontal super hydrophobic surface and its self-cleaning application

    Science.gov (United States)

    Li, Jian; Wei, Yuan; Huang, Zhengyong; Wang, Feipeng; Yan, Xinzhu; Wu, Zhuolin

    2017-05-01

    Moisture is a significant factor that affects the insulation performance of outdoor high-voltage insulators in power systems. Accumulation of water droplets on insulators causes severe problems such as flashover of insulators and power outage. In this study, we develop a method to fabricate a micro/nano hierarchical super hydrophobic surface. The as-prepared super hydrophobic surface exhibits a water contact angle (WCA) of 160.4 ± 2°, slide angle (SA) less than 1° and surface free energy (SFE) of 5.99 mJ/m2. We investigated the electrohydropdynamic behavior of water droplet on a horizontal super hydrophobic surface compared with hydrophobic RTV silicone rubber surface which was widely used as anti-pollution coating or shed material of composite insulator. Results show that water droplet tended to a self-propelled motion on the super hydrophobic surface while it tended to elongate and break up on the RTV surface. The micro/nano hierarchical surface structure and chemical components with low surface free energy of the super hydrophobic surface jointly contributed to the reduction of skin fraction drag and subsequently made it possible for the motion of water droplet driven by electric field. Furthermore, the self-propelled motion of water droplets could also sweep away contaminations along its moving trace, which provides super hydrophobic surface a promising anti-pollution prospect in power systems.

  4. 伦敦SuperDesign展

    Institute of Scientific and Technical Information of China (English)

    柚子

    2011-01-01

    近日,英国伦敦Super Design展在伦敦Wakefield大街的The Dairy展厅如期举行。本次展览展出了来自包括知名设计师和新兴设计师的特别定制的工作室作品:到如今已经是第五个年头的伦敦Super Deslgn展,力图强发展,展出形式别出心裁、独树一帜,从一个崭新.活跃的角度集展示当代艺术。

  5. Super-stable Poissonian structures

    Science.gov (United States)

    Eliazar, Iddo

    2012-10-01

    In this paper we characterize classes of Poisson processes whose statistical structures are super-stable. We consider a flow generated by a one-dimensional ordinary differential equation, and an ensemble of particles ‘surfing’ the flow. The particles start from random initial positions, and are propagated along the flow by stochastic ‘wave processes’ with general statistics and general cross correlations. Setting the initial positions to be Poisson processes, we characterize the classes of Poisson processes that render the particles’ positions—at all times, and invariantly with respect to the wave processes—statistically identical to their initial positions. These Poisson processes are termed ‘super-stable’ and facilitate the generalization of the notion of stationary distributions far beyond the realm of Markov dynamics.

  6. Super-Kamiokande atmospheric neutrinos

    Energy Technology Data Exchange (ETDEWEB)

    Moriyama, S. [Kamioka Observatory, Institute for Cosmic Ray Research, University of Tokyo, Higashi Mozumi, Hida city, Gifu prefecture (Japan)

    2005-08-15

    Results on atmospheric neutrino analysis at Super-Kamiokande I is presented. The whole data set of atmospheric neutrino sample in Super-Kamiokande I is consistently explained with an assumption of pure {nu}{sub {mu}}-{nu}{sub {tau}} oscillations. The allowed range of parameters is 1.5x10{sup -3}<{delta}m{sup 2}<3.4x10{sup -3} eV{sup 2} and sin{sup 2}2{theta}>0.92 at 90% C.L. In the oscillation analysis, we improved the treatment of systematic errors so that they can be considered as independent. This makes possible to find which systematic errors have larger effect on the analysis results. Some sensitivity studies under several assumptions of improvements in systematic errors are presented.

  7. Amyloid-like fibril elongation follows michaelis-menten kinetics

    National Research Council Canada - National Science Library

    Milto, Katazyna; Botyriute, Akvile; Smirnovas, Vytautas

    2013-01-01

    ... are. We obtained experimental data on insulin amyloid-like fibril elongation at the conditions where other processes which may impact kinetics of fibril formation are minor and fitted it using Michaelis-Menten equation...

  8. Amyloid-like fibril elongation follows michaelis-menten kinetics.

    Science.gov (United States)

    Milto, Katazyna; Botyriute, Akvile; Smirnovas, Vytautas

    2013-01-01

    A number of proteins can aggregate into amyloid-like fibrils. It was noted that fibril elongation has similarities to an enzymatic reaction, where monomers or oligomers would play a role of substrate and nuclei/fibrils would play a role of enzyme. The question is how similar these processes really are. We obtained experimental data on insulin amyloid-like fibril elongation at the conditions where other processes which may impact kinetics of fibril formation are minor and fitted it using Michaelis-Menten equation. The correlation of the fit is very good and repeatable. It speaks in favour of enzyme-like model of fibril elongation. In addition, obtained [Formula: see text] and [Formula: see text] values at different conditions may help in better understanding influence of environmental factors on the process of fibril elongation.

  9. Screening for Rice Germplasms with Specially-Elongated Mesocotyl

    Institute of Scientific and Technical Information of China (English)

    WU Ming-guo; ZHANG Guang-heng; LIN Jian-rong; CHENG Shi-hua

    2005-01-01

    The lengths of mesocotyl in the seedlings of 84 lowland rice varieties and 12 upland rice varieties were measured following the treatments of daylight and darkness during germination. The elongation of mesocotyl in the varieties tested was inhibited under daylight condition, and the mesocotyl of all the varieties elongated variably under darkness condition. The elongated lengths of the mesocotyl in upland rice, ranging from 0.36 cm to 1.61 cm with an average of 0.81 cm, was obviously longer than those in lowland rice, ranging from 0.12 cm to 1.56 cm with an average of 0.42 cm. Among 14 rice varieties with over 1 cm of mesocotyl length, five belonged to upland rice, and nine to lowland rice. The possible utilization of the elongated-mesocotyl rice germplasm in varietal improvement, direct-seeded planting and seed purity testing were discussed.

  10. ELONGATED STYLOID PROCESS: A REPORT OF TWO CADAVERIC CASES

    Directory of Open Access Journals (Sweden)

    Komala Nanjundaiah

    2014-06-01

    Full Text Available Introduction: Styloid process is a part of temporal bone. It measures 2 to 3 cms in length and lies antero-medial to the mastoid process. An elongated styloid process can compress the vital vessels and nerves close to it. This can lead to pain, foreign body sensation in the pharyngeal region and can also cause dysphagia. Observation: During routine dissection, we encountered elongated styloid process in two cadavers. In one it was unilateral and in another it was bilateral. The measurements of the elongated styloid process were taken using digital Vernier slide calipers. Conclusion: The awareness of the embryological cause and the clinical implications of an elongated styloid process are important for accurate diagnosis and treatment

  11. The Era of Super Capitalism

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    The world has entered the "super capitalism" era when one third of its economic activities are controlled by less than 3 percent of global financial capital. This year,a global economic recession,triggered by the U.S. subprime mortgage crisis,seems unavoidable. To tackle international financial problems,Tao Dong,Chief Economist for Asia at Credit Suisse First Boston in Hong Kong,shared his insights with China Business Journal. Excerpts follow.

  12. The elongation factor Spt4/5 regulates RNA polymerase II transcription through the nucleosome

    Science.gov (United States)

    Crickard, John B.; Lee, Jaehyoun; Lee, Tae-Hee

    2017-01-01

    Abstract RNA polymerase II (RNAPII) passes through the nucleosome in a coordinated manner, generating several intermediate nucleosomal states as it breaks and then reforms histone–DNA contacts ahead of and behind it, respectively. Several studies have defined transcription-induced nucleosome intermediates using only RNA Polymerase. However, RNAPII is decorated with elongation factors as it transcribes the genome. One such factor, Spt4/5, becomes an integral component of the elongation complex, making direct contact with the ‘jaws’ of RNAPII and nucleic acids in the transcription scaffold. We have characterized the effect of incorporating Spt4/5 into the elongation complex on transcription through the 601R nucleosome. Spt4/5 suppressed RNAPII pausing at the major H3/H4-induced arrest point, resulting in downstream re-positioning of RNAPII further into the nucleosome. Using a novel single molecule FRET system, we found that Spt4/5 affected the kinetics of DNA re-wrapping and stabilized a nucleosomal intermediate with partially unwrapped DNA behind RNAPII. Comparison of nucleosomes of different sequence polarities suggest that the strength of the DNA–histone interactions behind RNAPII specifies the Spt4/5 requirement. We propose that Spt4/5 may be important to coordinate the mechanical movement of RNAPII through the nucleosome with co-transcriptional chromatin modifications during transcription, which is affected by the strength of histone–DNA interactions. PMID:28379497

  13. Observation of improved ohmic confinement in highly elongated TCV discharges

    Energy Technology Data Exchange (ETDEWEB)

    Nieswand, C.; Hofmann, F.; Behn, R.; Furno, I.; Moret, J.M.; Pietrzyk, Z.A.; Pochelon, A.; Reimerdes, H.; Weisen, H. [Ecole Polytechnique Federale, Lausanne (Switzerland). Centre de Recherche en Physique des Plasma (CRPP)

    1997-06-01

    The primary goals of the TCV tokamak are to produce plasmas with high elongation and to investigate confinement behaviour for a variety of plasma shapes. A spontaneous transition to an improved ohmic confinement regime has recently been observed in moderately and highly elongated discharges limited by the central column. The observed features are similar to those observed in ASDEX (IOC regime). (author) 5 tab., 5 refs.

  14. BEWARE OF...SUPER GLUES!!

    CERN Multimedia

    2006-01-01

    What happened? A number of accidents have occurred with the use of 'Super Glues'. Some individuals have suffered injuries - severe irritation, or skin bonded together - through getting glue on their face and in their eyes. What are the hazards associated with glues? 'Super Glues' (i.e. cyanoacrylates): Are harmful if swallowed and are chemical irritants to the eyes, respiratory system and skin. Present the risk of polymerization (hardening) leading to skin damage. Be careful ! 'Super Glues' can bond to skin and eyes in seconds. Note: Other glues, resins and hardeners are also chemicals and as such can cause serious damage to the skin, eyes, respiratory or digestive tract. (For example: some components can be toxic, harmful, corrosive, sensitizing agents, etc.). How to prevent accidents in the future? Read the Material Safety Data Sheet (MSDS) for all of the glues you work with. Check the label on the container to find out which of the materials you work with are hazardous. Wear the right Per...

  15. Super-Eccentric Migrating Jupiters

    CERN Document Server

    Socrates, Aristotle; Dong, Subo; Tremaine, Scott

    2011-01-01

    An important class of formation theories for hot Jupiters involves the excitation of extreme orbital eccentricity (e=0.99 or even larger) followed by tidal dissipation at periastron passage that eventually circularizes the planetary orbit at a period less than 10 days. In a steady state, this mechanism requires the existence of a significant population of super-eccentric (e>0.9) migrating Jupiters with long orbital periods and periastron distances of only a few stellar radii. For these super-eccentric planets, the periastron is fixed due to conservation of orbital angular momentum and the energy dissipated per orbit is constant, implying that the rate of change in semi-major axis a is \\dot a \\propto a^0.5 and consequently the number distribution satisfies dN/dlog a\\propto a^0.5. If this formation process produces most hot Jupiters, Kepler should detect several super-eccentric migrating progenitors of hot Jupiters, allowing for a test of high-eccentricity migration scenarios.

  16. SUPER-ECCENTRIC MIGRATING JUPITERS

    Energy Technology Data Exchange (ETDEWEB)

    Socrates, Aristotle; Katz, Boaz; Dong Subo; Tremaine, Scott [Institute for Advanced Study, Princeton, NJ 08540 (United States)

    2012-05-10

    An important class of formation theories for hot Jupiters involves the excitation of extreme orbital eccentricity (e = 0.99 or even larger) followed by tidal dissipation at periastron passage that eventually circularizes the planetary orbit at a period less than 10 days. In a steady state, this mechanism requires the existence of a significant population of super-eccentric (e > 0.9) migrating Jupiters with long orbital periods and periastron distances of only a few stellar radii. For these super-eccentric planets, the periastron is fixed due to conservation of orbital angular momentum and the energy dissipated per orbit is constant, implying that the rate of change in semi-major axis a is a-dot {proportional_to}a{sup 1/2} and consequently the number distribution satisfies dN/d log a{proportional_to}a{sup 1/2}. If this formation process produces most hot Jupiters, Kepler should detect several super-eccentric migrating progenitors of hot Jupiters, allowing for a test of high-eccentricity migration scenarios.

  17. Is Cervical Elongation Associated with Pelvic Organ Prolapse?

    Science.gov (United States)

    Berger, Mitchell B.; Ramanah, Rajeev; Guire, Kenneth E.; DeLancey, John O. L.

    2012-01-01

    Introduction and Hypothesis It is commonly believed that pelvic organ prolapse is associated with cervical elongation. However, cervical lengths have not been formally compared between women with prolapse and those with normal support. Methods Cervix and uterine corpus lengths were measured on magnetic resonance images in a case-control study of 51 women with prolapse and 46 women with normal support determined by pelvic organ prolapse (POP) quantification (POP-Q) examination. Group matching ensured similar demographics in both groups. Ranges for normal cervical lengths were determined from the values in the control group in order to evaluate for cervical elongation amongst women with prolapse. Results The cervix is 36.4% (8.6 mm) longer in women with prolapse than in women with normal pelvic support (p uterine descent (POP-Q point C). Approximately 40% of women with prolapse have cervical elongation. 57% of cervical elongation in prolapse can be explained by a logistic-regression based model including POP-Q point C, body mass index and menopausal status. Conclusion Cervical elongation is found in one-third of women with pelvic organ prolapse, with the extent of elongation increasing with greater degrees of uterine descent. PMID:22527546

  18. Effect of Nascent Peptide Steric Bulk on Elongation Kinetics in the Ribosome Exit Tunnel.

    Science.gov (United States)

    Po, Pengse; Delaney, Erin; Gamper, Howard; Szantai-Kis, D Miklos; Speight, Lee; Tu, LiWei; Kosolapov, Andrey; Petersson, E James; Hou, Ya-Ming; Deutsch, Carol

    2017-06-16

    All proteins are synthesized by the ribosome, a macromolecular complex that accomplishes the life-sustaining tasks of faithfully decoding mRNA and catalyzing peptide bond formation at the peptidyl transferase center (PTC). The ribosome has evolved an exit tunnel to host the elongating new peptide, protect it from proteolytic digestion, and guide its emergence. It is here that the nascent chain begins to fold. This folding process depends on the rate of translation at the PTC. We report here that besides PTC events, translation kinetics depend on steric constraints on nascent peptide side chains and that confined movements of cramped side chains within and through the tunnel fine-tune elongation rates. Copyright © 2017 Elsevier Ltd. All rights reserved.

  19. SPO73 and SPO71 Function Cooperatively in Prospore Membrane Elongation During Sporulation in Saccharomyces cerevisiae.

    Science.gov (United States)

    Parodi, Emily M; Roesner, Joseph M; Huang, Linda S

    2015-01-01

    In the yeast Saccharomyces cerevisiae, cells undergoing sporulation form prospore membranes to surround their meiotic nuclei. The prospore membranes ultimately become the plasma membranes of the new cells. The putative phospholipase Spo1 and the tandem Pleckstrin Homology domain protein Spo71 have previously been shown to be required for prospore membrane development, along with the constitutively expressed Vps13 involved in vacuolar sorting. Here, we utilize genetic analysis, and find that SPO73 is required for proper prospore membrane shape and, like SPO71, is necessary for prospore membrane elongation. Additionally, similar to SPO71, loss of SPO73 partially suppresses spo1Δ. Spo73 localizes to prospore membranes and complexes with Spo71. We also find that phosphatidylserine localizes to the prospore membrane. Our results suggest a model where SPO71 and SPO73 act in opposition to SPO1 to form and elongate prospore membranes, while VPS13 plays a distinct role in prospore membrane development.

  20. SPO73 and SPO71 Function Cooperatively in Prospore Membrane Elongation During Sporulation in Saccharomyces cerevisiae.

    Directory of Open Access Journals (Sweden)

    Emily M Parodi

    Full Text Available In the yeast Saccharomyces cerevisiae, cells undergoing sporulation form prospore membranes to surround their meiotic nuclei. The prospore membranes ultimately become the plasma membranes of the new cells. The putative phospholipase Spo1 and the tandem Pleckstrin Homology domain protein Spo71 have previously been shown to be required for prospore membrane development, along with the constitutively expressed Vps13 involved in vacuolar sorting. Here, we utilize genetic analysis, and find that SPO73 is required for proper prospore membrane shape and, like SPO71, is necessary for prospore membrane elongation. Additionally, similar to SPO71, loss of SPO73 partially suppresses spo1Δ. Spo73 localizes to prospore membranes and complexes with Spo71. We also find that phosphatidylserine localizes to the prospore membrane. Our results suggest a model where SPO71 and SPO73 act in opposition to SPO1 to form and elongate prospore membranes, while VPS13 plays a distinct role in prospore membrane development.

  1. The transcription elongation factor Bur1-Bur2 interacts with replication protein A and maintains genome stability during replication stress

    DEFF Research Database (Denmark)

    Clausing, Emanuel; Mayer, Andreas; Chanarat, Sittinan

    2010-01-01

    foci. Interestingly, the DNA damage sensitivity of an rfa1 mutant was suppressed by bur1 mutation, further underscoring a functional link between these two protein complexes. The transcription elongation factor Bur1-Bur2 interacts with RPA and maintains genome integrity during DNA replication stress....

  2. Properties, structure and creep resistance of austenitic steel Super 304H

    Energy Technology Data Exchange (ETDEWEB)

    Zielinski, Adam; Dobrzanski, Janusz; Purzynska, Hanna [Institute for Ferrous Metallurgy, Gliwice (Poland); Golanski, Grzegorz [Czestochowa Univ. of Technology (Poland). Inst. of Materials Engineering

    2015-07-01

    This paper presents selected material characteristics of Super 304H austenitic steel used for elements of boilers with super- and ultra-critical steam parameters. In particular, abridged and long-term creep tests with and without elongation measurement during testing and investigations of microstructural changes due to long-term impact of temperature and stress were carried out. The practical aspect of the use of creep test and structure investigation results in forecasting the durability of materials operating under creep conditions was presented. The characteristics of steels with regard to creep tests and structure investigations developed in this paper are used for estimation of changes in functional properties of the material of elements operating under creep conditions.

  3. Observation of fiber ultrastructure of Ligon lintless mutant in upland cotton during fiber elongation

    Institute of Scientific and Technical Information of China (English)

    CHENG Chaohua; WANG Xuede; NI Xiyuan

    2005-01-01

    Lintless mutant is a super-short fiber mutant in upland cotton only 4-8 mm in fiber length and also named Ligon cotton controlled by one dominant gene Li1. Fiber ultrastructure of the mutant (Li1) and its wild type (li1) in situ and in vitro was observed under an electron microscope to understand its cytological characteristics during the fiber cell elongation. The results showed that the mutant fiber in situ had thinner cytoplasm, more small vacuoles, less mitochondria, Golgi apparatus and endoplasmic reticula, and there were more starch granules which were free or packed in the amyloplast beside the cell wall than that of wild type. It was indicated that scarcity of functional organelles and disability of transformation from starch to sugar might be associated with the fact that the mutant fiber cell was aborted too early to elongate into normal length. Mutant ovule in some media containing GA3 could produce a kind of huge callus that grew faster than normal ovules. The callus was covered with many white, loose, and semitransparent fiber-like cells that apt to get off from ovule. These fiber-like cells were multicellular fibers generated by cell division and had black dots just like pigment glands in the stem and leaf of cotton. There were lots of micro-tubes beside cytoplasm membrane of the multicellular fiber, which were thought to be primary preparation for second wall deposition of multicellular fiber. It was indicated that GA3 might induce the expression of gene(s) that kept inactive in the field condition and then stimulate the original fiber cell in vitro to undergo division again.

  4. Watching the Birth of Super Star Clusters

    CERN Document Server

    Turner, J L; Turner, Jean L.; Beck, Sara C.

    2003-01-01

    Subarcsecond infrared and radio observations yield important information about the formation of super star clusters from their surrounding gas. We discuss the general properties of ionized and molecular gas near young, forming SSCs, as illustrated by the prototypical young forming super star cluster nebula in the dwarf galaxy, NGC 5253. This super star cluster appears to have a gravitationally bound nebula. The lack of molecular gas suggests a very high star formation efficiency, consistent with the formation of a large, bound star cluster.

  5. Gdown1 Associates Efficiently with RNA Polymerase II after Promoter Clearance and Displaces TFIIF during Transcript Elongation

    Science.gov (United States)

    DeLaney, Elizabeth

    2016-01-01

    Pausing during the earliest stage of transcript elongation by RNA polymerase II (Pol II) is a nearly universal control point in metazoan gene expression. The substoichiometric Pol II subunit Gdown1 facilitates promoter proximal pausing in vitro in extract-based transcription reactions, out-competes the initiation/elongation factor TFIIF for binding to free Pol II and co-localizes with paused Pol II in vivo. However, we have shown that Gdown1 cannot functionally associate with the Pol II preinitiation complex (PIC), which contains TFIIF. In the present study, we determined at what point after initiation Gdown1 can associate with Pol II and how rapidly this competition with TFIIF occurs. We show that, as with the PIC, Gdown1 cannot functionally load into open complexes or complexes engaged in abortive synthesis of very short RNAs. Gdown1 can load into early elongation complexes (EECs) with 5–9 nt RNAs, but efficient association with EECs does not take place until the point at which the upstream segment of the long initial transcription bubble reanneals. Tests of EECs assembled on a series of promoter variants confirm that this bubble collapse transition, and not transcript length, modulates Gdown1 functional affinity. Gdown1 displaces TFIIF effectively from all complexes downstream of the collapse transition, but this displacement is surprisingly slow: complete loss of TFIIF stimulation of elongation requires 5 min of incubation with Gdown1. The relatively slow functional loading of Gdown1 in the presence of TFIIF suggests that Gdown1 works in promoter-proximal pausing by locking in the paused state after elongation is already antagonized by other factors, including DSIF, NELF and possibly the first downstream nucleosome. PMID:27716820

  6. 3-D In Vitro Acoustic Super-Resolution and Super-Resolved Velocity Mapping Using Microbubbles.

    Science.gov (United States)

    Christensen-Jeffries, Kirsten; Brown, Jemma; Aljabar, Paul; Tang, Mengxing; Dunsby, Christopher; Eckersley, Robert J

    2017-07-31

    Standard clinical ultrasound (US) imaging frequencies are unable to resolve microvascular structures due to the fundamental diffraction limit of US waves. Recent demonstrations of 2D super-resolution both in vitro and in vivo have demonstrated that fine vascular structures can be visualized using acoustic single bubble localization. Visualization of more complex and disordered 3D vasculature, such as that of a tumor, requires an acquisition strategy which can additionally localize bubbles in the elevational plane with high precision in order to generate super-resolution in all three dimensions. Furthermore, a particular challenge lies in the need to provide this level of visualization with minimal acquisition time. In this work, we develop a fast, coherent US imaging tool for microbubble localization in 3D using a pair of US transducers positioned at 90°. This allowed detection of point scatterer signals in 3 dimensions with average precisions equal to 1.9 µm in axial and elevational planes, and 11 µm in the lateral plane, compared to the diffraction limited point spread function full widths at half maximum of 488 µm, 1188 µm and 953 µm of the original imaging system with a single transducer. Visualization and velocity mapping of 3D in vitro structures was demonstrated far beyond the diffraction limit. The capability to measure the complete flow pattern of blood vessels associated with disease at depth would ultimately enable analysis of in vivo microvascular morphology, blood flow dynamics and occlusions resulting from disease states.

  7. Two-Component Super AKNS Equations and Their Finite-Dimensional Integrable Super Hamiltonian System

    OpenAIRE

    Jing Yu; Jingwei Han

    2014-01-01

    Starting from a matrix Lie superalgebra, two-component super AKNS system is constructed. By making use of monononlinearization technique of Lax pairs, we find that the obtained two-component super AKNS system is a finite-dimensional integrable super Hamiltonian system. And its Lax representation and $r$ -matrix are also given in this paper.

  8. Two-Component Super AKNS Equations and Their Finite-Dimensional Integrable Super Hamiltonian System

    Directory of Open Access Journals (Sweden)

    Jing Yu

    2014-01-01

    Full Text Available Starting from a matrix Lie superalgebra, two-component super AKNS system is constructed. By making use of monononlinearization technique of Lax pairs, we find that the obtained two-component super AKNS system is a finite-dimensional integrable super Hamiltonian system. And its Lax representation and r-matrix are also given in this paper.

  9. Slip-activated surface creep with room-temperature super-elongation in metallic nanocrystals

    Energy Technology Data Exchange (ETDEWEB)

    Zhong, Li; Sansoz, Frederic; He, Yang; Wang, Chongmin; Zhang, Ze; Mao, Scott X.

    2016-11-28

    Atom diffusion assisted by surfaces or interfaces (e.g. Coble creep) has been known to be the origin of large creep rates and superplastic softening in nanosized crystals at low temperature. By contrast, source-limited crystal slip in defect-free nanostructures engenders important strengths, but also premature plastic instability and low ductility. Here, using in-situ transmission electron microscopy, we report a slip-activated surface creep mechanism that suppresses the tendency towards plastic instability without compromising the strength, resulting in ultra-large room-temperature plasticity in face-centered-cubic silver nanocrystals. This phenomenon is shown experimentally and theoretically to prevail over a material-dependent range of diameters where surface dislocation nucleation becomes a stimulus to diffusional creep. This work provides new fundamental insight into coupled diffusive-displacive deformation mechanisms maximizing ductility and strength simultaneously in nanoscale materials.

  10. The Potyviral P3 Protein Targets Eukaryotic Elongation Factor 1A to Promote the Unfolded Protein Response and Viral Pathogenesis.

    Science.gov (United States)

    Luan, Hexiang; Shine, M B; Cui, Xiaoyan; Chen, Xin; Ma, Na; Kachroo, Pradeep; Zhi, Haijan; Kachroo, Aardra

    2016-09-01

    The biochemical function of the potyviral P3 protein is not known, although it is known to regulate virus replication, movement, and pathogenesis. We show that P3, the putative virulence determinant of soybean mosaic virus (SMV), targets a component of the translation elongation complex in soybean. Eukaryotic elongation factor 1A (eEF1A), a well-known host factor in viral pathogenesis, is essential for SMV virulence and the associated unfolded protein response (UPR). Silencing GmEF1A inhibits accumulation of SMV and another ER-associated virus in soybean. Conversely, endoplasmic reticulum (ER) stress-inducing chemicals promote SMV accumulation in wild-type, but not GmEF1A-knockdown, plants. Knockdown of genes encoding the eEF1B isoform, which is important for eEF1A function in translation elongation, has similar effects on UPR and SMV resistance, suggesting a link to translation elongation. P3 and GmEF1A promote each other's nuclear localization, similar to the nuclear-cytoplasmic transport of eEF1A by the Human immunodeficiency virus 1 Nef protein. Our results suggest that P3 targets host elongation factors resulting in UPR, which in turn facilitates SMV replication and place eEF1A upstream of BiP in the ER stress response during pathogen infection.

  11. A double-ratchet mechanism of transcription elongation and its control

    Science.gov (United States)

    Ruckenstein, Andrei

    2005-03-01

    Transcription, the process by which the genetic information encoded in DNA is transferred into RNA, is the first step in gene expression and it is the step at which most regulation occurs. A detailed understanding of the structural and mechanistic aspects of each step of transcription (initiation, elongation, termination and regulation) is one of the holy grails of biology. Here we characterize the motion of RNA polymerase (RNAP), the multi-subunit molecular motor that carries out the transcription process, during the elongation stage. We argue that during elongation RNAP moves by a complex Brownian ratchet mechanism in which the translocation along DNA and the binding of nucleotides into RNAP's catalytic center are coupled to a fluctuating internal degree of freedom associated with a protein sub-unit (the F-bridge) of RNAP. More precisely, the model is defined by a set of kinetic equations^ describing the competition for the catalytic site between an incoming nucleotide, the 3'-end of RNA, and the F-bridge which in its bent conformation blocks the active center. An important aspect of the model is the incorporation of the three ``active'' processes describing (i) the ejection of bound nucleotides from the active center through steric clashes with either the F-bridge in its bent conformation or with the 3'-end of RNA; and (ii) the forward translocation induced by bending of the F-bridge pushing against the 3'-end of RNA. The ``active'' processes do not imply a ``power stroke'' mechanism since the energy driving them is purely thermal. Indeed the model displays a route by which the system uses thermal fluctuations to control the rate, processivity and fidelity of transcription already before the irreversible chemical incorporation step. Moreover, the model qualitatively explains many aspects of both bio-chemicalootnotetextBar-Nahum, G., Epshtein, V., Ruckenstein, A.E., Rafikov, R., Mustaev, A., and Nudler, E. A ratchet mechanism of transcription elongation and its

  12. Amphiregulin Antibody and Reduction of Axial Elongation in Experimental Myopia

    Directory of Open Access Journals (Sweden)

    Wen Jun Jiang

    2017-03-01

    Full Text Available To examine the mechanism of ocular axial elongation in myopia, guinea pigs (age: 2–3 weeks which either underwent unilateral or bilateral lens-induced myopization (group 1 or which were primarily myopic at baseline (group 2 received unilateral intraocular injections of amphiregulin antibody (doses: 5, 10, or 15 μg three times in intervals of 9 days. A third group of emmetropic guinea pigs got intraocular unilateral injections of amphiregulin (doses: 0.25, 0.50 or 1.00 ng, respectively. In each group, the contralateral eyes received intraocular injections of Ringer's solution. In intra-animal inter-eye comparison and intra-eye follow-up comparison in groups 1 and 2, the study eyes as compared to the contralateral eyes showed a dose-dependent reduction in axial elongation. In group 3, study eyes and control eyes did not differ significantly in axial elongation. Immunohistochemistry revealed amphiregulin labelling at the retinal pigment epithelium in eyes with lens-induced myopization and Ringer's solution injection, but not in eyes with amphiregulin antibody injection. Intraocular injections of amphiregulin-antibody led to a reduction of lens-induced axial myopic elongation and of the physiological eye enlargement in young guinea pigs. In contrast, intraocularly injected amphiregulin in a dose of ≤1 ng did not show a significant effect. Amphiregulin may be one of several essential molecular factors for axial elongation.

  13. Highlights from Super-Kamiokande

    Science.gov (United States)

    Okumura, Kimihiro

    2016-11-01

    Recent results from Super-Kamiokande experiment are reviewed in this paper; Neutrino mass hierarchy and CP violation in the lepton sector are investigated via νμ → νe oscillation of the atmospheric neutrinos. The event rate, correlation with solar activity, energy spectrum of the solar neutrinos are measured via electron elastic scattering interactions. Neutrino emission from the WIMP annihilation at the center of the Sun are searched in the GeV energy regions. New project, SK-Gd project, to enhance anti-neutrino identification capability, has been approved inside the collaboration group.

  14. Highlights from Super-Kamiokande

    Directory of Open Access Journals (Sweden)

    Okumura Kimihiro

    2016-01-01

    Full Text Available Recent results from Super-Kamiokande experiment are reviewed in this paper; Neutrino mass hierarchy and CP violation in the lepton sector are investigated via νμ → νe oscillation of the atmospheric neutrinos. The event rate, correlation with solar activity, energy spectrum of the solar neutrinos are measured via electron elastic scattering interactions. Neutrino emission from the WIMP annihilation at the center of the Sun are searched in the GeV energy regions. New project, SK-Gd project, to enhance anti-neutrino identification capability, has been approved inside the collaboration group.

  15. Super-resolution microscopy of the synaptic active zone

    Directory of Open Access Journals (Sweden)

    Nadine eEhmann

    2015-01-01

    Full Text Available Brain function relies on accurate information transfer at chemical synapses. At the presynaptic active zone (AZ a variety of specialised proteins are assembled to complex architectures, which set the basis for speed, precision and plasticity of synaptic transmission.Calcium (Ca2+ channels are pivotal for the initiation of excitation-secretion coupling and, correspondingly, capture a central position at the AZ. Combining quantitative functional studies with modelling approaches has provided predictions of channel properties, numbers and even positions on the nanometre scale. However, elucidating the nanoscopic organisation of the surrounding protein network requires direct ultrastructural access. Without this information, knowledge of molecular synaptic structure-function relationships remains incomplete. Recently, super-resolution microscopy techniques have begun to enter the neurosciences. These approaches combine high spatial resolution with the molecular specificity of fluorescence microscopy. Here, we discuss how super-resolution microscopy can be used to obtain information on the organisation of AZ proteins.

  16. Odd Deformations of Super Riemann Surfaces: $\\mathcal N = 1$

    CERN Document Server

    Bettadapura, Kowshik

    2016-01-01

    In this article we study odd deformations of an $\\mathcal N =1$ super Riemann surface. We begin with odd, infinitesimal deformations with the objective being to describe the Kodaira-Spencer map for them and explore the consequences of the vanishing thereof. Our intent is to relate the deformation theory of a super Riemann surface with the obstruction theory of the deformation (itself to be thought of as a complex supermanifold). Illustrations are provided in low genus. Subsequently, we investigate deformations of higher order with a view to further understand this relation between obstruction theory and deformation theory. By way of motivation, a detailed study of odd, second order deformations is presented, leading naturally to a question on the characterisation odd deformations of any order.

  17. Investigation of Fano resonances induced by higher order plasmon modes on a circular nano-disk with an elongated cavity

    KAUST Repository

    Amin, Muhammad Ruhul

    2012-08-10

    In this paper, a planar metallic nanostructure design, which supports two distinct Fano resonances in its extinction cross-section spectrum under normally incident and linearly polarized electromagnetic field, is proposed. The proposed design involves a circular disk embedding an elongated cavity; shifting and rotating the cavity break the symmetry of the structure with respect to the incident field and induce higher order plasmon modes. As a result, Fano resonances are generated in the visible spectrum due to the destructive interference between the sub-radiant higher order modes and super-radiant the dipolar mode. The Fano resonances can be tuned by varying the cavity\\'s width and the rotation angle. An RLC circuit, which is mathematically equivalent to a mass-spring oscillator, is proposed to model the optical response of the nanostructure design.

  18. Prevention and Treatment of Postoperative Complications of the Penile Elongation

    Institute of Scientific and Technical Information of China (English)

    余墨声; 陕声国; 赵月强; 吴晓蔚; 周立纯; 龙道畴

    2003-01-01

    Summary: To explore the cauls of the postoperative complications of the penile elongation and themeasures to prevent them in order to raise the success rate of the penile elongation. 1 000 patientswho had received the penile elongation were reviewed and analyzed for the causes of postoperativecomplications, and the measures of prevention and treatment were discussed. Our results showedthat, of the 1 000 cases, 64 had the postoperative complications, including 20 cases of edema of pre-puce, 15 cases of flap necrosis, 12 hematoma, 9 infections, and 8 cases of fat and clumsy penis. It isconcluded that correct operative manipulation, strict aseptic measures and necessary postoperativecare and management could avoid or reduce the postoperative complications. When complications hap-pened, a satisfactory result can be achieved with timely and correct treatment in the majority of thepatients.

  19. Bilateral elongated mandibular coronoid process in an Anatolian skull

    Science.gov (United States)

    Çorumlu, Ufuk; Demir, Mehmet Tevfik; Pirzirenli, Mennan Ece

    2016-01-01

    Elongation or hyperplasia of coronoid process of mandible is rare condition characterized by abnormal bone development which cause malocclusion and the limited mouth opening. In this study, in an Anatolian skull, a case of bilateral elongation of mandibular coronoid process was presented. Levandoski panographic analysis was performed on the panoramic radiographie to determine the hyperplasia of the coronoid process. The right condylar process was exactly hyperplastic. The measurements of Kr-Go/Cd-Go were 95.10 mm/79.03 mm on right side and 97.53 mm/87.80 mm on left side. The ratio of Kr-Go/Cd-Go on the right side was 1.20. Elongated coronoid process is one of the factors cause mandibular hypomobility, it as reported here might lead to limited mouth opening. The knowledge of this variation or abnormality can be useful for the radiologist and surgeons and prevent misdiagnosis. PMID:27722017

  20. Tokamak elongation: how much is too much? II Numerical results

    CERN Document Server

    Lee, Jungpyo; Freidberg, Jeffrey P

    2015-01-01

    The analytic theory presented in Paper I is converted into a form convenient for numerical analysis. A fast and accurate code has been written using this numerical formulation. The results are presented by first defining a reference set of physical parameters based on experimental data from high performance discharges. Numerically obtained scaling relations of maximum achievable elongation versus inverse aspect ratio are obtained for various values of poloidal beta, wall radius and feedback capability parameter in ranges near the reference values. It is also shown that each value of maximum elongation occurs at a corresponding value of optimized triangularity, whose scaling is also determined as a function of inverse aspect ratio. The results show that the theoretical predictions of maximum elongation are slightly higher than experimental observations for high performance discharges as measured by high average pressure. The theoretical optimized triangularity values are noticeably lower. We suggest that the e...

  1. Auxin activates the plasma membrane H+-ATPase by phosphorylation during hypocotyl elongation in Arabidopsis.

    Science.gov (United States)

    Takahashi, Koji; Hayashi, Ken-ichiro; Kinoshita, Toshinori

    2012-06-01

    The phytohormone auxin is a major regulator of diverse aspects of plant growth and development. The ubiquitin-ligase complex SCF(TIR1/AFB) (for Skp1-Cul1-F-box protein), which includes the TRANSPORT INHIBITOR RESPONSE1/AUXIN SIGNALING F-BOX (TIR1/AFB) auxin receptor family, has recently been demonstrated to be critical for auxin-mediated transcriptional regulation. Early-phase auxin-induced hypocotyl elongation, on the other hand, has long been explained by the acid-growth theory, for which proton extrusion by the plasma membrane H(+)-ATPase is a functional prerequisite. However, the mechanism by which auxin mediates H(+)-ATPase activation has yet to be elucidated. Here, we present direct evidence for H(+)-ATPase activation in etiolated hypocotyls of Arabidopsis (Arabidopsis thaliana) by auxin through phosphorylation of the penultimate threonine during early-phase hypocotyl elongation. Application of the natural auxin indole-3-acetic acid (IAA) to endogenous auxin-depleted hypocotyl sections induced phosphorylation of the penultimate threonine of the H(+)-ATPase and increased H(+)-ATPase activity without altering the amount of the enzyme. Changes in both the phosphorylation level of H(+)-ATPase and IAA-induced elongation were similarly concentration dependent. Furthermore, IAA-induced H(+)-ATPase phosphorylation occurred in a tir1-1 afb2-3 double mutant, which is severely defective in auxin-mediated transcriptional regulation. In addition, α-(phenylethyl-2-one)-IAA, the auxin antagonist specific for the nuclear auxin receptor TIR1/AFBs, had no effect on IAA-induced H(+)-ATPase phosphorylation. These results suggest that the TIR1/AFB auxin receptor family is not involved in auxin-induced H(+)-ATPase phosphorylation. Our results define the activation mechanism of H(+)-ATPase by auxin during early-phase hypocotyl elongation; this is the long-sought-after mechanism that is central to the acid-growth theory.

  2. Active repression by RARγ signaling is required for vertebrate axial elongation.

    Science.gov (United States)

    Janesick, Amanda; Nguyen, Tuyen T L; Aisaki, Ken-ichi; Igarashi, Katsuhide; Kitajima, Satoshi; Chandraratna, Roshantha A S; Kanno, Jun; Blumberg, Bruce

    2014-06-01

    Retinoic acid receptor gamma 2 (RARγ2) is the major RAR isoform expressed throughout the caudal axial progenitor domain in vertebrates. During a microarray screen to identify RAR targets, we identified a subset of genes that pattern caudal structures or promote axial elongation and are upregulated by increased RAR-mediated repression. Previous studies have suggested that RAR is present in the caudal domain, but is quiescent until its activation in late stage embryos terminates axial elongation. By contrast, we show here that RARγ2 is engaged in all stages of axial elongation, not solely as a terminator of axial growth. In the absence of RA, RARγ2 represses transcriptional activity in vivo and maintains the pool of caudal progenitor cells and presomitic mesoderm. In the presence of RA, RARγ2 serves as an activator, facilitating somite differentiation. Treatment with an RARγ-selective inverse agonist (NRX205099) or overexpression of dominant-negative RARγ increases the expression of posterior Hox genes and that of marker genes for presomitic mesoderm and the chordoneural hinge. Conversely, when RAR-mediated repression is reduced by overexpressing a dominant-negative co-repressor (c-SMRT), a constitutively active RAR (VP16-RARγ2), or by treatment with an RARγ-selective agonist (NRX204647), expression of caudal genes is diminished and extension of the body axis is prematurely terminated. Hence, gene repression mediated by the unliganded RARγ2-co-repressor complex constitutes a novel mechanism to regulate and facilitate the correct expression levels and spatial restriction of key genes that maintain the caudal progenitor pool during axial elongation in Xenopus embryos.

  3. Performance improvement of super-resolving pupil filters via combination with nonlinear saturable absorption films

    Science.gov (United States)

    Zha, Yikun; Wei, Jingsong; Gan, Fuxi

    2013-04-01

    With the continuous development of the field of information technology, there has been a demand for recording mark size of optical data storage, optical imaging resolving power, and characteristic linewidth of photolithography to reach nanoscale. However, it is very difficult to realize the goal due to the optical diffraction limit restrictions. Much interest has focused on the study of optical far-field super-resolution spot by using pupil filters. However, common concerns have continued to plague super-resolving pupil filters based on either scalar diffraction theory or vector diffraction theory. These concerns include the fact that the side lobe becomes non-negligible when the central lobe is squeezed to a certain extent. Moreover, it is difficult to reduce the super-resolving spot to nanoscale. In this work, we proposed a novel method to combine the super-resolving pupil filters with nonlinear saturable absorption thin films to reduce the central spot size to nanoscale, lower the intensity ratio of side lobe to central lobe, and elongate the depth of focus or tunable tolerance distance between the super-resolving spot and sample. The simulated results indicate that by using the three-zone annular binary phase filter as the super-resolving pupil filter and Sb2Te3 as the nonlinear saturable absorption thin films, the central spot size can be reduced to nanoscale, the side lobe intensity is squeezed to about 10% of the central lobe intensity, and the tunable tolerance distance between the super-resolving spot and the sample is about two times that of the depth of focus of the diffraction limited spot at the incident laser wavelength of 405 nm and the numerical aperture of focusing lens of 0.95. The combination of the super-resolving pupil filters with the nonlinear saturable absorption thin films is very useful for nano-optical data storage, maskless nanolithography, and nano-optical imaging. It is also easy to use in actual applications because of the operation

  4. Optical trapping with Super-Gaussian beams

    CSIR Research Space (South Africa)

    McLaren, M

    2013-04-01

    Full Text Available We outline the possibility of optical trapping and tweezing with Super-Gaussian beam profiles. We show that the trapping strength can be tuned continuously by adjusting the order of a Super-Gaussian beam, approaching that of a perfect Gaussian...

  5. Tetrahedral Units: For Dodecahedral Super-Structures

    CERN Document Server

    Ortiz, Y; Liebman, J F

    2016-01-01

    Different novel organic-chemical possibilities for tetrahedral building units are considered, with attention to their utility in constructing different super-structures. As a representative construction we consider the use of sets of 20 such identical tetrahedral units to form a super-dodecahedron.

  6. dbSUPER: a database of super-enhancers in mouse and human genome.

    Science.gov (United States)

    Khan, Aziz; Zhang, Xuegong

    2016-01-04

    Super-enhancers are clusters of transcriptional enhancers that drive cell-type-specific gene expression and are crucial to cell identity. Many disease-associated sequence variations are enriched in super-enhancer regions of disease-relevant cell types. Thus, super-enhancers can be used as potential biomarkers for disease diagnosis and therapeutics. Current studies have identified super-enhancers in more than 100 cell types and demonstrated their functional importance. However, a centralized resource to integrate all these findings is not currently available. We developed dbSUPER (http://bioinfo.au.tsinghua.edu.cn/dbsuper/), the first integrated and interactive database of super-enhancers, with the primary goal of providing a resource for assistance in further studies related to transcriptional control of cell identity and disease. dbSUPER provides a responsive and user-friendly web interface to facilitate efficient and comprehensive search and browsing. The data can be easily sent to Galaxy instances, GREAT and Cistrome web-servers for downstream analysis, and can also be visualized in the UCSC genome browser where custom tracks can be added automatically. The data can be downloaded and exported in variety of formats. Furthermore, dbSUPER lists genes associated with super-enhancers and also links to external databases such as GeneCards, UniProt and Entrez. dbSUPER also provides an overlap analysis tool to annotate user-defined regions. We believe dbSUPER is a valuable resource for the biology and genetic research communities.

  7. Viscosity overshoot in the start-up of uniaxial elongation of low density polyethylene melts

    DEFF Research Database (Denmark)

    Rasmussen, Henrik K.; Nielsen, Jens Kromann; Bach, Anders

    2005-01-01

    The transient uniaxial elongational viscosity of BASF Lupolen 1840D and 3020D melts has been measured on a filament stretch rheometer up to Hencky strains of 6-7. The elongational viscosity of both melts was measured at 130 degrees C within a broad range of elongational rates. At high elongation ...

  8. Ending Aging in Super Glassy Polymer Membranes

    Energy Technology Data Exchange (ETDEWEB)

    Lau, CH; Nguyen, PT; Hill, MR; Thornton, AW; Konstas, K; Doherty, CM; Mulder, RJ; Bourgeois, L; Liu, ACY; Sprouster, DJ; Sullivan, JP; Bastow, TJ; Hill, AJ; Gin, DL; Noble, RD

    2014-04-16

    Aging in super glassy polymers such as poly(trimethylsilylpropyne) (PTMSP), poly(4-methyl-2-pentyne) (PMP), and polymers with intrinsic microporosity (PIM-1) reduces gas permeabilities and limits their application as gas-separation membranes. While super glassy polymers are initially very porous, and ultra-permeable, they quickly pack into a denser phase becoming less porous and permeable. This age-old problem has been solved by adding an ultraporous additive that maintains the low density, porous, initial stage of super glassy polymers through absorbing a portion of the polymer chains within its pores thereby holding the chains in their open position. This result is the first time that aging in super glassy polymers is inhibited whilst maintaining enhanced CO2 permeability for one year and improving CO2/N-2 selectivity. This approach could allow super glassy polymers to be revisited for commercial application in gas separations.

  9. Bilateral elongated styloid process: Its anatomical, embryological and clinical implications

    Directory of Open Access Journals (Sweden)

    Bagoji Ishwar B, Hadimani Gavishiddappa A, Patil Balasaheb G, Bannur Balappa M,Ambadasu B

    2013-04-01

    Full Text Available The styloid process is a slender, elongated, cylindrical bony projection from temporal bone. It normally varies in length from 2 cm to 3 cm. During a routine demonstration of skull for MBBS students we found the bilateral elongated styloid process in dry human skull. The length of elongation measured on the right and left side was 6.0 & 5.9 cms respectively. Such abnormal elongation of the styloid process may cause compression on a number of vital vessels and nerves related to it, producing inflammatory changes that include continuous chronic pain in the pharyngeal region. Mechanical stresses stretching the second brachial arch during fetal development probably induce variable involvement of Reichert’s cartilage in morphogenesis of the styloid process. It is important that clinicians especially dentists and otolaryngologists are aware of the natural variations of the styloid process and do not consider the styloid process with a length of 30 mm as an abnormality or as an anomaly.

  10. Ubiquitylation and degradation of elongating RNA polymerase II

    DEFF Research Database (Denmark)

    Wilson, Marcus D; Harreman, Michelle; Svejstrup, Jesper Q

    2013-01-01

    During its journey across a gene, RNA polymerase II has to contend with a number of obstacles to its progression, including nucleosomes, DNA-binding proteins, DNA damage, and sequences that are intrinsically difficult to transcribe. Not surprisingly, a large number of elongation factors have evol....... In this review, we describe the mechanisms and factors responsible for the last resort mechanism of transcriptional elongation. This article is part of a Special Issue entitled: RNA polymerase II Transcript Elongation.......During its journey across a gene, RNA polymerase II has to contend with a number of obstacles to its progression, including nucleosomes, DNA-binding proteins, DNA damage, and sequences that are intrinsically difficult to transcribe. Not surprisingly, a large number of elongation factors have...... evolved to ensure that transcription stalling or arrest does not occur. If, however, the polymerase cannot be restarted, it becomes poly-ubiquitylated and degraded by the proteasome. This process is highly regulated, ensuring that only RNAPII molecules that cannot otherwise be salvaged are degraded...

  11. One-step purification of E. coli elongation factor Tu

    DEFF Research Database (Denmark)

    Knudsen, Charlotte Rohde; Clark, Brian F. C.; Degn, B

    1993-01-01

    The tuf A gene, encoding the E. coli elongation factor Tu, was cloned in the pGEX gene fusion system. Upon expression EF-Tu is fused to glutathione-S-transferase serving as a purification handle with affinity for glutathione immobilised on agarose. This allows purification of EF-Tu in a one...

  12. Osteogenetic changes in elongated styloid processes of Eagle syndrome patients.

    Science.gov (United States)

    Kim, Soung Min; Seo, Mi Hyun; Myoung, Hoon; Choi, Jin Young; Kim, Yeon Sook; Lee, Suk Keun

    2014-07-01

    Abnormal elongation of the styloid process, or Eagle syndrome, can be painful, and is associated with differential diagnoses including cranio-facial malformations and vasculo-neurological disturbances. The precise molecular mechanism leading to styloid process elongation is unknown. In this study, elongated styloid processes with periosteal fibrous ligament tissue were obtained from three patients with Eagle syndrome and examined by immunohistochemical methods using different antisera. In all cases, marked bony deposition was found at the apex of the styloid process. The osteogenetic proteins, such as osteonectin, osteocalcin, BMP-2, BMP-4, and RANKL were strongly positive by immunohistochemistry in both the ligament fibers and the periosteal membrane attached to the styloid process apex. Staining for protective proteins, HO-1, HSP-70, and HSP-90 was also positive. These results suggest that styloid process elongation is related to increased expression of osteogenetic and protective proteins. Therefore, we propose that Eagle syndrome results from a protective response to increased tensile stress in the ligament attached to the styloid process, which could also signal osteogenetic protein expression in the periosteal fibrous tissue.

  13. Longitudinal domain wall formation in elongated assemblies of ferromagnetic nanoparticles

    DEFF Research Database (Denmark)

    Varón, Miriam; Beleggia, Marco; Jordanovic, Jelena

    2015-01-01

    Through evaporation of dense colloids of ferromagnetic ~13 nm ε-Co particles onto carbon substrates, anisotropic magnetic dipolar interactions can support formation of elongated particle structures with aggregate thicknesses of 100-400 nm and lengths of up to some hundred microns. Lorenz microsco...

  14. Comparative Proteomic Analysis of the Fiber Elongating Process in Cotton

    Institute of Scientific and Technical Information of China (English)

    LIU Jin-yuan; YANG Yi-wei; BIAN Shao-min

    2008-01-01

    @@ A comparative proteomic analysis was performed to explore the mechanism of cell elongation in developing cotton fibers.The temporal changes of global proteomes at five representative development stages (5~25 days post-anthesis [DPA]) were examined using 2-D electrophoresis.

  15. CLOSED FORM OF THE STEERED ELONGATED HERMITE-GAUSS WAVELETS

    NARCIS (Netherlands)

    Papari, Giuseppe; Campisi, Patrizio; Petkov, Nicolai

    2010-01-01

    We provide a closed form, both in the spatial and in the frequency domain, of a family of wavelets which arise from steering elongated Hermite-Gauss filters. These wavelets have interesting mathematical properties, as they form new dyadic families of eigenfunctions of the 2D Fourier transform, and

  16. Molecular landscape of cotton fiber in early elongation

    Science.gov (United States)

    Cotton fibers are the dominant source of natural fibers used in the textile industry and contribute significantly to the world economy. Adverse environmental conditions negatively affect fiber characteristics, especially when the fibers are in the elongation phase of development. Improvement in the...

  17. Relationship between elongation and porosity for high porosity metal materials

    Institute of Scientific and Technical Information of China (English)

    1999-01-01

    A simplified model was proposed targeting at the isotropic high porosity metal materials with well-distributed structure. From the model the mathematical relationship between elongation and porosity was deduced for those materials, and the relationship formula was derived generally for actual high porosity metals at last, whose validity is supported by the representative experiment on a nickel foam prepared by electrodeposition.

  18. One-step purification of E. coli elongation factor Tu

    DEFF Research Database (Denmark)

    Knudsen, Charlotte Rohde; Clark, Brian F. C.; Degn, B

    1993-01-01

    The tuf A gene, encoding the E. coli elongation factor Tu, was cloned in the pGEX gene fusion system. Upon expression EF-Tu is fused to glutathione-S-transferase serving as a purification handle with affinity for glutathione immobilised on agarose. This allows purification of EF-Tu in a one...

  19. Binary asteroid population. 3. Secondary rotations and elongations

    Science.gov (United States)

    Pravec, P.; Scheirich, P.; Kušnirák, P.; Hornoch, K.; Galád, A.; Naidu, S. P.; Pray, D. P.; Világi, J.; Gajdoš, Š.; Kornoš, L.; Krugly, Yu. N.; Cooney, W. R.; Gross, J.; Terrell, D.; Gaftonyuk, N.; Pollock, J.; Husárik, M.; Chiorny, V.; Stephens, R. D.; Durkee, R.; Reddy, V.; Dyvig, R.; Vraštil, J.; Žižka, J.; Mottola, S.; Hellmich, S.; Oey, J.; Benishek, V.; Kryszczyńska, A.; Higgins, D.; Ries, J.; Marchis, F.; Baek, M.; Macomber, B.; Inasaridze, R.; Kvaratskhelia, O.; Ayvazian, V.; Rumyantsev, V.; Masi, G.; Colas, F.; Lecacheux, J.; Montaigut, R.; Leroy, A.; Brown, P.; Krzeminski, Z.; Molotov, I.; Reichart, D.; Haislip, J.; LaCluyze, A.

    2016-03-01

    We collected data on rotations and elongations of 46 secondaries of binary and triple systems among near-Earth, Mars-crossing and small main belt asteroids. 24 were found or are strongly suspected to be synchronous (in 1:1 spin-orbit resonance), and the other 22, generally on more distant and/or eccentric orbits, were found or are suggested to have asynchronous rotations. For 18 of the synchronous secondaries, we constrained their librational angles, finding that their long axes pointed to within 20° of the primary on most epochs. The observed anti-correlation of secondary synchroneity with orbital eccentricity and the limited librational angles agree with the theories by Ćuk and Nesvorný (Ćuk, M., Nesvorný, D. [2010]. Icarus 207, 732-743) and Naidu and Margot (Naidu, S.P., Margot, J.-L. [2015]. Astron. J. 149, 80). A reason for the asynchronous secondaries being on wider orbits than synchronous ones may be longer tidal circularization time scales at larger semi-major axes. The asynchronous secondaries show relatively fast spins; their rotation periods are typically VH, the secondary rotations are single-periodic with no signs of chaotic rotation and their periods are constant on timescales from weeks to years. The secondary equatorial elongations show an upper limit of a2 /b2 ∼ 1.5 . The lack of synchronous secondaries with greater elongations appears consistent, considering uncertainties of the axis ratio estimates, with the theory by Ćuk and Nesvorný that predicts large regions of chaotic rotation in the phase space for a2 /b2 ≳√{ 2 } . Alternatively, secondaries may not form or stay very elongated in gravitational (tidal) field of the primary. It could be due to the secondary fission mechanism suggested by Jacobson and Scheeres (Jacobson, S.A., Scheeres, D.J. [2011]. Icarus 214, 161-178), as its efficiency is correlated with the secondary elongation. Sharma (Sharma, I. [2014]. Icarus 229, 278-294) found that rubble-pile satellites with a2 /b2 ≲ 1

  20. Characterization of microstructure and texture across dissimilar super duplex/austenitic stainless steel weldment joint by super duplex filler metal

    Energy Technology Data Exchange (ETDEWEB)

    Eghlimi, Abbas, E-mail: a.eghlimi@ma.iut.ac.ir [Department of Materials Engineering, Isfahan University of Technology, Isfahan 84156-83111 (Iran, Islamic Republic of); Shamanian, Morteza [Department of Materials Engineering, Isfahan University of Technology, Isfahan 84156-83111 (Iran, Islamic Republic of); Eskandarian, Masoomeh [Department of Materials Engineering, Shiraz University, Shiraz 71348-51154 (Iran, Islamic Republic of); Zabolian, Azam [Department of Natural Resources, Isfahan University of Technology, Isfahan 84156-83111 (Iran, Islamic Republic of); Szpunar, Jerzy A. [Department of Mechanical Engineering, University of Saskatchewan, Saskatoon SK S7N 5A9 (Canada)

    2015-08-15

    In the present paper, microstructural changes across an as-welded dissimilar austenitic/duplex stainless steel couple welded by a super duplex stainless steel filler metal using gas tungsten arc welding process is characterized with optical microscopy and electron back-scattered diffraction techniques. Accordingly, variations of microstructure, texture, and grain boundary character distribution of base metals, heat affected zones, and weld metal were investigated. The results showed that the weld metal, which was composed of Widmanstätten austenite side-plates and allotriomorphic grain boundary austenite morphologies, had the weakest texture and was dominated by low angle boundaries. The welding process increased the ferrite content but decreased the texture intensity at the heat affected zone of the super duplex stainless steel base metal. In addition, through partial ferritization, it changed the morphology of elongated grains of the rolled microstructure to twinned partially transformed austenite plateaus scattered between ferrite textured colonies. However, the texture of the austenitic stainless steel heat affected zone was strengthened via encouraging recrystallization and formation of annealing twins. At both interfaces, an increase in the special character coincident site lattice boundaries of the primary phase as well as a strong texture with <100> orientation, mainly of Goss component, was observed. - Graphical abstract: Display Omitted - Highlights: • Weld metal showed local orientation at microscale but random texture at macroscale. • Intensification of <100> orientated grains was observed adjacent to the fusion lines. • The austenite texture was weaker than that of the ferrite in all duplex regions. • Welding caused twinned partially transformed austenites to form at SDSS HAZ. • At both interfaces, the ratio of special CSL boundaries of the primary phase increased.

  1. Towards a Mathematical Theory of Super-Resolution

    CERN Document Server

    Candes, Emmanuel

    2012-01-01

    This paper develops a mathematical theory of super-resolution. Broadly speaking, super-resolution is the problem of recovering the fine details of an object---the high end of its spectrum---from coarse scale information only---from samples at the low end of the spectrum. Suppose we have many point sources at unknown locations in $[0,1]$ and with unknown complex-valued amplitudes. We only observe Fourier samples of this object up until a frequency cut-off $f_c$. We show that one can super-resolve these point sources with infinite precision---i.e. recover the exact locations and amplitudes---by solving a simple convex program. This holds provided that the distance between sources is at least $2/f_c$. This result extends to higher dimensions and other models. In one dimension for instance, it is possible to recover a piecewise smooth function by resolving the discontinuity points with infinite precision as well. We also show that the theory and methods are robust to noise. In particular, we develop some theoreti...

  2. Adenylate cyclase regulates elongation of mammalian primary cilia

    Energy Technology Data Exchange (ETDEWEB)

    Ou, Young; Ruan, Yibing; Cheng, Min; Moser, Joanna J. [Department of Biochemistry and Molecular Biology, Faculty of Medicine, University of Calgary, 3330 Hospital Drive NW, Calgary, Alberta, T2N 4N1 (Canada); Rattner, Jerome B. [Department of Cell Biology and Anatomy, Faculty of Medicine, University of Calgary, 3330 Hospital Drive NW, Calgary, Alberta, T2N 4N1 (Canada); Hoorn, Frans A. van der, E-mail: fvdhoorn@ucalgary.ca [Department of Biochemistry and Molecular Biology, Faculty of Medicine, University of Calgary, 3330 Hospital Drive NW, Calgary, Alberta, T2N 4N1 (Canada)

    2009-10-01

    The primary cilium is a non-motile microtubule-based structure that shares many similarities with the structures of flagella and motile cilia. It is well known that the length of flagella is under stringent control, but it is not known whether this is true for primary cilia. In this study, we found that the length of primary cilia in fibroblast-like synoviocytes, either in log phase culture or in quiescent state, was confined within a range. However, when lithium was added to the culture to a final concentration of 100 mM, primary cilia of synoviocytes grew beyond this range, elongating to a length that was on average approximately 3 times the length of untreated cilia. Lithium is a drug approved for treating bipolar disorder. We dissected the molecular targets of this drug, and observed that inhibition of adenylate cyclase III (ACIII) by specific inhibitors mimicked the effects of lithium on primary cilium elongation. Inhibition of GSK-3{beta} by four different inhibitors did not induce primary cilia elongation. ACIII was found in primary cilia of a variety of cell types, and lithium treatment of these cell types led to their cilium elongation. Further, we demonstrate that different cell types displayed distinct sensitivities to the lithium treatment. However, in all cases examined primary cilia elongated as a result of lithium treatment. In particular, two neuronal cell types, rat PC-12 adrenal medulla cells and human astrocytes, developed long primary cilia when lithium was used at or close to the therapeutic relevant concentration (1-2 mM). These results suggest that the length of primary cilia is controlled, at least in part, by the ACIII-cAMP signaling pathway.

  3. 复杂空气分离类成套装备超大型化与低能耗化的关键科学问题立项报告%Key Scientific Problem of Super-large and Low Energy of Complex Air Separation Equipment

    Institute of Scientific and Technical Information of China (English)

    谭建荣

    2016-01-01

    Focusing on the key technique problems of super-large complex air separation equipment with low energy consumption which is a necessity of steel, petrochemical, and thermal power industry in China, several basic scientific questions are explored, "complex large-scale mixed flow interface gradient formation law driven by low energy consumption”,“super-large multi-set multivariable field coupling and decoupling principle", "key sets life balance design and stable operation theory with high reliability" etc. Six topics are set up centered on these three key scientific questions, interface formation laws of large-scale mixed flow and unsteady flow, dynamics nonlinear coupling mechanism of large equipment, multivariable and multi-set correlation design theory under complicated conditions, multi-sets synchronization stability and life balance principle, key sets high-strength component quality-ensured manufacturing, super-large complex air separation equipment performance test, simulation, and integration. The research of this project clarified the affection of super-large complex air separation equipment large-scale mixed flow to the mechanism of gas heat and mass transfer, revealed the poly-phase fluid unsteady flow alternating mechanism and energy migration law in equipment, illuminated dynamics nonlinear coupling mechanism of large equipment under complicated conditions, established the equipment inter-set multi-variable multi-parameter performance analysis and process design theory, uncovered air separation equipment key set and unit high reliability and long duration mechanism, proposed key set and unit large-scale structure life balance design and quality-ensured manufacturing method, thus providing the scientific basis for next generation air separation equipment theoretical breakthrough.%针对我国大型钢铁、大型石化、大型火电等重大工程必需的复杂空气分离类成套装备超大型化与低能耗化的关键技术难题,探索解

  4. SuperB Progress Report for Physics

    Energy Technology Data Exchange (ETDEWEB)

    O' Leary, B.; /Aachen, Tech. Hochsch.; Matias, J.; Ramon, M.; /Barcelona, IFAE; Pous, E.; /Barcelona U.; De Fazio, F.; Palano, A.; /INFN, Bari; Eigen, G.; /Bergen U.; Asgeirsson, D.; /British Columbia U.; Cheng, C.H.; Chivukula, A.; Echenard, B.; Hitlin, D.G.; Porter, F.; Rakitin, A.; /Caltech; Heinemeyer, S.; /Cantabria Inst. of Phys.; McElrath, B.; /CERN; Andreassen, R.; Meadows, B.; Sokoloff, M.; /Cincinnati U.; Blanke, M.; /Cornell U., Phys. Dept.; Lesiak, T.; /Cracow, INP /DESY /Zurich, ETH /INFN, Ferrara /Frascati /INFN, Genoa /Glasgow U. /Indiana U. /Mainz U., Inst. Phys. /Karlsruhe, Inst. Technol. /KEK, Tsukuba /LBL, Berkeley /UC, Berkeley /Lisbon, IST /Ljubljana U. /Madrid, Autonoma U. /Maryland U. /MIT /INFN, Milan /McGill U. /Munich, Tech. U. /Notre Dame U. /PNL, Richland /INFN, Padua /Paris U., VI-VII /Orsay, LAL /Orsay, LPT /INFN, Pavia /INFN, Perugia /INFN, Pisa /Queen Mary, U. of London /Regensburg U. /Republica U., Montevideo /Frascati /INFN, Rome /INFN, Rome /INFN, Rome /Rutherford /Sassari U. /Siegen U. /SLAC /Southern Methodist U. /Tel Aviv U. /Tohoku U. /INFN, Turin /INFN, Trieste /Uppsala U. /Valencia U., IFIC /Victoria U. /Wayne State U. /Wisconsin U., Madison

    2012-02-14

    SuperB is a high luminosity e{sup +}e{sup -} collider that will be able to indirectly probe new physics at energy scales far beyond the reach of any man made accelerator planned or in existence. Just as detailed understanding of the Standard Model of particle physics was developed from stringent constraints imposed by flavour changing processes between quarks, the detailed structure of any new physics is severely constrained by flavour processes. In order to elucidate this structure it is necessary to perform a number of complementary studies of a set of golden channels. With these measurements in hand, the pattern of deviations from the Standard Model behavior can be used as a test of the structure of new physics. If new physics is found at the LHC, then the many golden measurements from SuperB will help decode the subtle nature of the new physics. However if no new particles are found at the LHC, SuperB will be able to search for new physics at energy scales up to 10-100 TeV. In either scenario, flavour physics measurements that can be made at SuperB play a pivotal role in understanding the nature of physics beyond the Standard Model. Examples for using the interplay between measurements to discriminate New Physics models are discussed in this document. SuperB is a Super Flavour Factory, in addition to studying large samples of B{sub u,d,s}, D and {tau} decays, SuperB has a broad physics programme that includes spectroscopy both in terms of the Standard Model and exotica, and precision measurements of sin{sup 2} {theta}{sub W}. In addition to performing CP violation measurements at the {Upsilon}(4S) and {phi}(3770), SuperB will test CPT in these systems, and lepton universality in a number of different processes. The multitude of rare decay measurements possible at SuperB can be used to constrain scenarios of physics beyond the Standard Model. In terms of other precision tests of the Standard Model, this experiment will be able to perform precision over

  5. The superB silicon vertex tracker

    Energy Technology Data Exchange (ETDEWEB)

    Rizzo, G., E-mail: giuliana.rizzo@pi.infn.i [INFN-Pisa and Universita di Pisa (Italy); Avanzini, C.; Batignani, G.; Bettarini, S.; Bosi, F.; Calderini, G.; Ceccanti, M.; Cenci, R.; Cervelli, A.; Crescioli, F.; Dell' Orso, M.; Forti, F.; Giannetti, P.; Giorgi, M.A. [INFN-Pisa and Universita di Pisa (Italy); Lusiani, A. [Scuola Normale Superiore and INFN-Pisa (Italy); Gregucci, S.; Mammini, P.; Marchiori, G.; Massa, M.; Morsani, F. [INFN-Pisa and Universita di Pisa (Italy)

    2010-05-21

    The SuperB asymmetric e{sup +}-e{sup -} collider has been designed to deliver a luminosity greater than 10{sup 36}cm{sup -2}s{sup -1} with moderate beam currents. Comparing to current B-Factories, the reduced center of mass boost of the SuperB machine requires improved vertex resolution to allow precision measurements sensitive to New Physics. We present the conceptual design of the silicon vertex tracker (SVT) for the SuperB detector with the present status of the R and D on the different options under study for its innermost Layer0.

  6. N=2 Super - $W_{3}$ Algebra and N=2 Super Boussinesq Equations

    CERN Document Server

    Ivanov, E; Malik, R P

    1995-01-01

    We study classical $N=2$ super-$W_3$ algebra and its interplay with $N=2$ supersymmetric extensions of the Boussinesq equation in the framework of the nonlinear realization method and the inverse Higgs - covariant reduction approach. These techniques have been previously applied by us in the bosonic $W_3$ case to give a new geometric interpretation of the Boussinesq hierarchy. Here we deduce the most general $N=2$ super Boussinesq equation and two kinds of the modified $N=2$ super Boussinesq equations, as well as the super Miura maps relating these systems to each other, by applying the covariant reduction to certain coset manifolds of linear $N=2$ super-$W_3^{\\infty}$ symmetry associated with $N=2$ super-$W_3$. We discuss the integrability properties of the equations obtained and their correspondence with the formulation based on the notion of the second hamiltonian structure.

  7. Mcm10 regulates DNA replication elongation by stimulating the CMG replicative helicase

    Science.gov (United States)

    Lõoke, Marko; Maloney, Michael F.; Bell, Stephen P.

    2017-01-01

    Activation of the Mcm2–7 replicative DNA helicase is the committed step in eukaryotic DNA replication initiation. Although Mcm2–7 activation requires binding of the helicase-activating proteins Cdc45 and GINS (forming the CMG complex), an additional protein, Mcm10, drives initial origin DNA unwinding by an unknown mechanism. We show that Mcm10 binds a conserved motif located between the oligonucleotide/oligosaccharide fold (OB-fold) and A subdomain of Mcm2. Although buried in the interface between these domains in Mcm2–7 structures, mutations predicted to separate the domains and expose this motif restore growth to conditional-lethal MCM10 mutant cells. We found that, in addition to stimulating initial DNA unwinding, Mcm10 stabilizes Cdc45 and GINS association with Mcm2–7 and stimulates replication elongation in vivo and in vitro. Furthermore, we identified a lethal allele of MCM10 that stimulates initial DNA unwinding but is defective in replication elongation and CMG binding. Our findings expand the roles of Mcm10 during DNA replication and suggest a new model for Mcm10 function as an activator of the CMG complex throughout DNA replication. PMID:28270517

  8. Transition zone cells reach G2 phase before initiating elongation in maize root apex

    Directory of Open Access Journals (Sweden)

    M. Victoria Alarcón

    2017-06-01

    Full Text Available Root elongation requires cell divisions in the meristematic zone and cell elongation in the elongation zone. The boundary between dividing and elongating cells is called the transition zone. In the meristem zone, initial cells are continuously dividing, but on the basal side of the meristem cells exit the meristem through the transition zone and enter in the elongation zone, where they stop division and rapidly elongate. Throughout this journey cells are accompanied by changes in cell cycle progression. Flow cytometry analysis showed that meristematic cells are in cycle, but exit when they enter the elongation zone. In addition, the percentage of cells in G2 phase (4C strongly increased from the meristem to the elongation zone. However, we did not observe remarkable changes in the percentage of cells in cell cycle phases along the entire elongation zone. These results suggest that meristematic cells in maize root apex stop the cell cycle in G2 phase after leaving the meristem.

  9. Interaction of Eukaryote Initiator Methionyl-tRNA with the Eukaryote Equivalent of Bacterial Elongation Factor T and Guanosine Triphosphate

    Science.gov (United States)

    Richter, Dietmar; Lipmann, Fritz; Tarragó, Adela; Allende, Jorge E.

    1971-01-01

    The initiator tRNA, methionyl-tRNAiMet, of yeast and wheat germ forms relatively unstable ternary complexes with their corresponding elongation factors T and GTP. Such complexes can be demonstrated only with fast separation techniques such as Sephadex G-50 and Millipore filtration, but not with the slow Sephadex G-100 method, although both techniques yield stable ternary complexes with all other aminoacyl-tRNAs, including the internal Met-tRNAmMet. To bind yeast-initiating Met-tRNAiMet to ribosomes, initiation factors present in a ribosomal wash fraction from yeast are needed. PMID:5288767

  10. Head morphology of the duckbill eel, Hoplunnis punctata (Regan, 1915; Nettastomatidae: Anguilliformes) in relation to jaw elongation.

    Science.gov (United States)

    Eagderi, Soheil; Adriaens, Dominique

    2010-05-01

    Hoplunnis punctata, a member of the Anguilliformes, is a long-snouted eel that lives in benthic habitats of the continental shelf of tropical waters. The purpose of this study was to examine the skull morphology of this little known nettastomatid and to understand the changes associated with jaw elongation as well as the implications of jaw elongation on the feeding apparatus. We present a detailed description of the cranial osteology and myology of H. punctata and how these characters differ from Conger conger (Congrinae: Congridae), a representative with moderate jaw length, and Heteroconger hassi (Heterocongrinae: Congridae), a representative with a short jaw. Shape comparison shows a caudal displacement of the hyomandibula, quadrate-mandibular articulation and opercle-hyomandibular joint, decrease in the depth of the neurocranium, and increase in the distance between the anterior suspensorial facet and the posterior end of the orbit in H. punctata as a result of jaw elongation. These characteristics along with its immobile, long maxillary and well-developed adductor mandibulae muscle complex suggest that food may be obtained by powerful biting. Jaw elongation potentially affects the functioning of the feeding apparatus in H. punctata by providing more space for the olfactory rosette, increasing biting speed and reducing drag during prey capture. (c) 2010 Elsevier GmbH. All rights reserved.

  11. Thermodynamic Modeling of Variations in the Rate of RNA Chain Elongation of E. coli rrn Operons

    Science.gov (United States)

    Fange, David; Mellenius, Harriet; Dennis, Patrick P.; Ehrenberg, Måns

    2014-01-01

    Previous electron-microscopic imaging has shown high RNA polymerase occupation densities in the 16S and 23S encoding regions and low occupation densities in the noncoding leader, spacer, and trailer regions of the rRNA (rrn) operons in E. coli. This indicates slower transcript elongation within the coding regions and faster elongation within the noncoding regions of the operon. Inactivation of four of the seven rrn operons increases the transcript initiation frequency at the promoters of the three intact operons and reduces the time for RNA polymerase to traverse the operon. We have used the DNA sequence-dependent standard free energy variation of the transcription complex to model the experimentally observed changes in the elongation rate along the rrnB operon. We also model the stimulation of the average transcription rate over the whole operon by increasing rate of transcript initiation. Monte Carlo simulations, taking into account initiation of transcription, translocation, and backward and forward tracking of RNA polymerase, partially reproduce the observed transcript elongation rate variations along the rrn operon and fully account for the increased average rate in response to increased frequency of transcript initiation. PMID:24411237

  12. Axial Super-resolution Evanescent Wave Tomography

    CERN Document Server

    Pendharker, Sarang; Newman, Ward; Ogg, Stephen; Nazemifard, Neda; Jacob, Zubin

    2016-01-01

    Optical tomographic reconstruction of a 3D nanoscale specimen is hindered by the axial diffraction limit, which is 2-3 times worse than the focal plane resolution. We propose and experimentally demonstrate an axial super-resolution evanescent wave tomography (AxSET) method that enables the use of regular evanescent wave microscopes like Total Internal Reflection Fluorescence Microscope (TIRF) beyond surface imaging, and achieve tomographic reconstruction with axial super-resolution. Our proposed method based on Fourier reconstruction achieves axial super-resolution by extracting information from multiple sets of three-dimensional fluorescence images when the sample is illuminated by an evanescent wave. We propose a procedure to extract super-resolution features from the incremental penetration of an evanescent wave and support our theory by 1D (along the optical axis) and 3D simulations. We validate our claims by experimentally demonstrating tomographic reconstruction of microtubules in HeLa cells with an axi...

  13. Mutant versions of the S. cerevisiae transcription elongation factor Spt16 define regions of Spt16 that functionally interact with histone H3.

    Directory of Open Access Journals (Sweden)

    Catherine N Myers

    Full Text Available In eukaryotic cells, the highly conserved FACT (FAcilitates Chromatin Transcription complex plays important roles in several chromatin-based processes including transcription initiation and elongation. During transcription elongation, the FACT complex interacts directly with nucleosomes to facilitate histone removal upon RNA polymerase II (Pol II passage and assists in the reconstitution of nucleosomes following Pol II passage. Although the contribution of the FACT complex to the process of transcription elongation has been well established, the mechanisms that govern interactions between FACT and chromatin still remain to be fully elucidated. Using the budding yeast Saccharomyces cerevisiae as a model system, we provide evidence that the middle domain of the FACT subunit Spt16--the Spt16-M domain--is involved in functional interactions with histone H3. Our results show that the Spt16-M domain plays a role in the prevention of cryptic intragenic transcription during transcription elongation and also suggest that the Spt16-M domain has a function in regulating dissociation of Spt16 from chromatin at the end of the transcription process. We also provide evidence for a role for the extreme carboxy terminus of Spt16 in functional interactions with histone H3. Taken together, our studies point to previously undescribed roles for the Spt16 M-domain and extreme carboxy terminus in regulating interactions between Spt16 and chromatin during the process of transcription elongation.

  14. Biochemical Pathways That Are Important for Cotton Fiber Cell Elongation

    Institute of Scientific and Technical Information of China (English)

    ZHU YU-xian

    2008-01-01

    @@ The regulatory mechanism that controls the sustained cotton fiber cell elongation is gradually being elucidated by coupling genome-wide transcriptome profiling with systematic biochemical and physiological studies.Very long chain fatty acids (VLCFA),H2O2,and several types of plant hormones including ethylene,gibberellin,and brassinolide have been reported to be involved in this process.Here we first identified by proteomic analysis a cotton cytosolic APX1 (GhAPX1) that was specifically accumulated during cotton fiber elongation.GhAPX1 expression was up-regulated in response to cellular H2O2 and ethylene,and it was involved in modulating the stead-state level of H2O2.

  15. Methanofullerene elongated nanostructure formation for enhanced organic solar cells

    Energy Technology Data Exchange (ETDEWEB)

    Reyes-Reyes, M. [Instituto de Investigacion en Comunicacion Optica, Universidad Autonoma de San Luis Potosi, Alvaro Obregon 64, San Luis Potosi (Mexico)], E-mail: reyesm@cactus.iico.uaslp.mx; Lopez-Sandoval, R. [Instituto Potosino de Investigacion Cientifica y Tecnologica, Camino a la presa San Jose 2055, CP 78216. San Luis Potosi (Mexico); Arenas-Alatorre, J. [Instituto de Fisica, UNAM, Apartado Postal 20-364, 01000, Mexico, D.F. (Mexico); Garibay-Alonso, R. [Instituto Potosino de Investigacion Cientifica y Tecnologica, Camino a la presa San Jose 2055, CP 78216. San Luis Potosi (Mexico); Carroll, D.L. [Center for Nanotechnology and Molecular Materials, Department of Physics. Wake Forest University, Winston-Salem NC 27109 (United States); Lastras-Martinez, A. [Instituto de Investigacion en Comunicacion Optica, Universidad Autonoma de San Luis Potosi, Alvaro Obregon 64, San Luis Potosi (Mexico)

    2007-11-01

    Using transmission electron microscopy (TEM) and Z-contrast imaging we have demonstrated elongated nanostructure formation of fullerene derivative [6,6]-phenyl-C61-butyric acid methyl ester (PCBM) within an organic host through annealing. The annealing provides an enhanced mobility of the PCBM molecules and, with good initial dispersion, allows for the formation of exaggerated grain growth within the polymer host. We have assembled these nanostructures within the regioregular conjugated polymer poly(3-hexylthiophene) (P3HT). This PCBM elongated nanostructure formation maybe responsible for the very high efficiencies observed, at very low loadings of PCBM (1:0.6, polymer to PCBM), in annealed photovoltaics. Moreover, our high resolution TEM and electron energy loss spectroscopy studies clearly show that the PCBM crystals remain crystalline and are unaffected by the 200-keV electron beam.

  16. New Insights on Plant Cell Elongation: A Role for Acetylcholine

    Directory of Open Access Journals (Sweden)

    Gian-Pietro Di Sansebastiano

    2014-03-01

    Full Text Available We investigated the effect of auxin and acetylcholine on the expression of the tomato expansin gene LeEXPA2, a specific expansin gene expressed in elongating tomato hypocotyl segments. Since auxin interferes with clathrin-mediated endocytosis, in order to regulate cellular and developmental responses we produced protoplasts from tomato elongating hypocotyls and followed the endocytotic marker, FM4-64, internalization in response to treatments. Tomato protoplasts were observed during auxin and acetylcholine treatments after transient expression of chimerical markers of volume-control related compartments such as vacuoles. Here we describe the contribution of auxin and acetylcholine to LeEXPA2 expression regulation and we support the hypothesis that a possible subcellular target of acetylcholine signal is the vesicular transport, shedding some light on the characterization of this small molecule as local mediator in the plant physiological response.

  17. Efficient fidelity control by stepwise nucleotide selection in polymerase elongation

    CERN Document Server

    Yu, Jin

    2014-01-01

    Polymerases select nucleotides before incorporating them for chemical synthesis during gene replication or transcription. How the selection proceeds stepwise efficiently to achieve sufficiently high fidelity and speed is essential for polymerase function. We examined step-by-step selections that have conformational transition rates tuned one at time in the polymerase elongation cycle, with a controlled differentiation free energy at each checkpoint. The elongation is sustained at non-equilibrium steady state with constant free energy input and heat dissipation. It is found that error reduction capability does not improve for selection checkpoints down the reaction path. Hence, it is essential to select early to achieve an efficient fidelity control. In particular, for two consecutive selections that reject the wrong substrate back and inhibit it forward from a same kinetic state, the same error rates are obtained at the same free energy differentiation. The initial screening is indispensible for maintaining t...

  18. Tidally Induced Elongation and Alignments of Galaxy Clusters

    CERN Document Server

    Salvador-Solé, E; Salvador-Sole, Eduard; Solanes, Jose M.

    1993-01-01

    We show that tidal interaction among galaxy clusters can account for their observed alignments and very marked elongation and, consequently, that these characteristics of clusters are actually consistent with them being formed in hierarchical clustering. The well-established distribution of projected axial ratios of clusters with richness class $R\\ge 0$ is recovered very satisfactorily by means of a simple model with no free parameters. The main perturbers are relatively rich ($R\\ge 1$) single clusters and/or groups of clusters (superclusters) of a wider richness class ($R\\ge 0$) located within a distance of about 65 $h^{-1}$ Mpc from the perturbed cluster. This makes the proposed scheme be also consistent with all reported alignment effects involving clusters. We find that this tidal interaction is typically in the saturate regime (\\ie the maximum elongation allowed for systems in equilibrium is reached), which explains the very similar intrinsic axial ratio shown by all clusters. Tides would therefore play ...

  19. Influence of lead on auxin-induced cell elongation

    Directory of Open Access Journals (Sweden)

    Marek Burzyński

    2014-01-01

    Full Text Available The influence of lead chloride on plant tissue growth is described. Lead reduced elongation of etiolated wheat coleoptile segments, green pea epicotyl fragments and etiolated and green sunflower hypocotyls. Green tissues were more susceptible to lead than etiolated ones. PbCl2 in a 10-4 M concentration significantly reduced plastic and elastic extensibility of the wheat coleoptile cell walls and diminished the hydration of sunflower hypocotyl segments. Auxin (indolyl-3-acetic acid - IAA applied in concentration optimal for growth of the particular tissues partly attenuated the inhibitory action of lead on elongation, plastic and elastic extensibility and water absorption. Auxin applied in supraoptimal concentrations did not abolish the inhibitory action of lead on tissue growth.

  20. Electrostatics in the ribosomal tunnel modulate chain elongation rates.

    Science.gov (United States)

    Lu, Jianli; Deutsch, Carol

    2008-12-05

    Electrostatic potentials along the ribosomal exit tunnel are nonuniform and negative. The significance of electrostatics in the tunnel remains relatively uninvestigated, yet they are likely to play a role in translation and secondary folding of nascent peptides. To probe the role of nascent peptide charges in ribosome function, we used a molecular tape measure that was engineered to contain different numbers of charged amino acids localized to known regions of the tunnel and measured chain elongation rates. Positively charged arginine or lysine sequences produce transient arrest (pausing) before the nascent peptide is fully elongated. The rate of conversion from transiently arrested to full-length nascent peptide is faster for peptides containing neutral or negatively charged residues than for those containing positively charged residues. We provide experimental evidence that extraribosomal mechanisms do not account for this charge-specific pausing. We conclude that pausing is due to charge-specific interactions between the tunnel and the nascent peptide.

  1. Brownian Dynamics Simulation of Microstructures and Elongational Viscosities of Micellar Surfactant Solution

    Institute of Scientific and Technical Information of China (English)

    WEI Jin-Jia; KAWAGUCHI Yasuo; YU Bo; LI Feng-Chen

    2008-01-01

    @@ Brownian dynamics simulation is conducted for a dilute surfactant solution under a steady uniaxial elongational flow.A new inter-cluster potential is used for the interaction among surfactant micelles to determine the micellar network structures in the surfactant solution.The micellar network is successfully simulated.It is formed at low elongation rates and destroyed by high elongation rates.The computed elongational viscosities show elongation-thinning characteristics.The relationship between the elongational viscosities and the microstructure of the surfactant solution is revealed.

  2. Mirror-enhanced super-resolution microscopy

    OpenAIRE

    2016-01-01

    Axial excitation confinement beyond the diffraction limit is crucial to the development of next-generation, super-resolution microscopy. STimulated Emission Depletion (STED) nanoscopy offers lateral super-resolution using a donut-beam depletion, but its axial resolution is still over 500 nm. Total internal reflection fluorescence microscopy is widely used for single-molecule localization, but its ability to detect molecules is limited to within the evanescent field of ~ 100 nm from the cell a...

  3. Characterization of Enzymes Involved in Fatty Acid Elongation

    Science.gov (United States)

    2007-04-11

    dihydroxyacetone reductase involved in phosphatidic acid biosynthesis [111]. Therefore, altered glycerophospholipid metabolism, along with reduced...in Mammals Increases with Muscle n-6 Polyunsaturated Fatty Acid Content. PLoS ONE, 2006. 1: p. e65. 143. Cole, G.M., Lim, G.P., Yang, F., Teter, B...2007 Title of Dissertation: "Characterization of Enzymes Involved in Fatty Acid Elongation" APPROVAL SHEET Ernest Maynard, P .D. Department of

  4. A Note on Elongations of Summable QTAG-Modules

    Directory of Open Access Journals (Sweden)

    Alveera Mehdi

    2013-01-01

    Full Text Available A right module M over an associative ring with unity is a QTAG-module if every finitely generated submodule of any homomorphic image of M is a direct sum of uniserial modules. In this paper we find a suitable condition under which a special ω-elongation of a summable QTAG-module by a ω+k-projective QTAG-module is also a summable QTAG-module.

  5. Mechanism of gibberellin-dependent stem elongation in peas

    Science.gov (United States)

    Cosgrove, D. J.; Sovonick-Dunford, S. A.

    1989-01-01

    Stem elongation in peas (Pisum sativum L.) is under partial control by gibberellins, yet the mechanism of such control is uncertain. In this study, we examined the cellular and physical properties that govern stem elongation, to determine how gibberellins influence pea stem growth. Stem elongation of etiolated seedlings was retarded with uniconozol, a gibberellin synthesis inhibitor, and the growth retardation was reversed by exogenous gibberellin. Using the pressure probe and vapor pressure osmometry, we found little effect of uniconozol and gibberellin on cell turgor pressure or osmotic pressure. In contrast, these treatments had major effects on in vivo stress relaxation, measured by turgor relaxation and pressure-block techniques. Uniconozol-treated plants exhibited reduced wall relaxation (both initial rate and total amount). The results show that growth retardation is effected via a reduction in the wall yield coefficient and an increase in the yield threshold. These effects were largely reversed by exogenous gibberellin. When we measured the mechanical characteristics of the wall by stress/strain (Instron) analysis, we found only minor effects of uniconozol and gibberellin on the plastic compliance. This observation indicates that these agents did not alter wall expansion through effects on the mechanical (viscoelastic) properties of the wall. Our results suggest that wall expansion in peas is better viewed as a chemorheological, rather than a viscoelastic, process.

  6. Analysis of cracking potential and micro-elongation of linerboard

    Directory of Open Access Journals (Sweden)

    Supattra Panthai

    2016-11-01

    Full Text Available Folding cracks of linerboards in relation to their micro-elongation and the forming conditions were studied using an industrial linerboard machine with a top former. The experiments consisted of the study of various forming conditions by manipulating the jet/wire speed ratio to produce linerboard with differences in fiber structures that were related to the cracked and uncracked products. The results showed that changes to the jet/wire speed ratio of about 0.01–0.02 to improve the tested folding endurance in the machine direction potentially produced folding cracks in the linerboard, which indicated an ambiguous interpretation of the foldability tests. The delaminated cracked layers were found to have a high folding endurance and tensile strength, while the decrease in the micro-elongation formulated in this study was found to be related to cracking. A lower micro-elongation of about 350–500 μm/N·g was found in a range of products with folding cracks.

  7. Telomerase efficiently elongates highly transcribing telomeres in human cancer cells.

    Directory of Open Access Journals (Sweden)

    Benjamin O Farnung

    Full Text Available RNA polymerase II transcribes the physical ends of linear eukaryotic chromosomes into a variety of long non-coding RNA molecules including telomeric repeat-containing RNA (TERRA. Since TERRA discovery, advances have been made in the characterization of TERRA biogenesis and regulation; on the contrary its associated functions remain elusive. Most of the biological roles so far proposed for TERRA are indeed based on in vitro experiments carried out using short TERRA-like RNA oligonucleotides. In particular, it has been suggested that TERRA inhibits telomerase activity. We have exploited two alternative cellular systems to test whether TERRA and/or telomere transcription influence telomerase-mediated telomere elongation in human cancer cells. In cells lacking the two DNA methyltransferases DNMT1 and DNMT3b, TERRA transcription and steady-state levels are greatly increased while telomerase is able to elongate telomeres normally. Similarly, telomerase can efficiently elongate transgenic inducible telomeres whose transcription has been experimentally augmented. Our data challenge the current hypothesis that TERRA functions as a general inhibitor of telomerase and suggest that telomere length homeostasis is maintained independently of TERRA and telomere transcription.

  8. Rad51 recombinase prevents Mre11 nuclease-dependent degradation and excessive PrimPol-mediated elongation of nascent DNA after UV irradiation.

    Science.gov (United States)

    Vallerga, María Belén; Mansilla, Sabrina F; Federico, María Belén; Bertolin, Agustina P; Gottifredi, Vanesa

    2015-12-01

    After UV irradiation, DNA polymerases specialized in translesion DNA synthesis (TLS) aid DNA replication. However, it is unclear whether other mechanisms also facilitate the elongation of UV-damaged DNA. We wondered if Rad51 recombinase (Rad51), a factor that escorts replication forks, aids replication across UV lesions. We found that depletion of Rad51 impairs S-phase progression and increases cell death after UV irradiation. Interestingly, Rad51 and the TLS polymerase polη modulate the elongation of nascent DNA in different ways, suggesting that DNA elongation after UV irradiation does not exclusively rely on TLS events. In particular, Rad51 protects the DNA synthesized immediately before UV irradiation from degradation and avoids excessive elongation of nascent DNA after UV irradiation. In Rad51-depleted samples, the degradation of DNA was limited to the first minutes after UV irradiation and required the exonuclease activity of the double strand break repair nuclease (Mre11). The persistent dysregulation of nascent DNA elongation after Rad51 knockdown required Mre11, but not its exonuclease activity, and PrimPol, a DNA polymerase with primase activity. By showing a crucial contribution of Rad51 to the synthesis of nascent DNA, our results reveal an unanticipated complexity in the regulation of DNA elongation across UV-damaged templates.

  9. SuperHILAC Upgrade Project

    Energy Technology Data Exchange (ETDEWEB)

    Feinberg, B.; Brown, I.G.

    1986-06-01

    A high current MEtal Vapor Vacuum Arc (MEVVA) ion source is to be installed in the third injector (Abel) at the SuperHILAC, representing the first accelerator use of this novel ion source. The MEVVA source has produced over 1 A of uranium in all charge states, with typically more than 100 electrical mA (emA) of U/sup 5 +/. A substantial fraction of this high current, heavy ion beam must be successfully transported to the entrance of the Wideroe linac to approach the 10 emA space-charge output limit of the Wideroe. Calculations show that up to 50 emA of U/sup 5 +/ can be transported through the present high voltage column. A bouncer will be added to the Cockcroft-Walton supply to handle the increased beam current. The Low Energy Beam Transport line vacuum will be improved to reduce charge exchange, and the phase matching between the 23 MHz Wideroe and the 70 MHz Alvarez linacs will be improved by the addition of two 70 HMz bunchers. The installation of the MEVVA source along with the modifications described above are expected to result in a five-fold increase in beam delivered to Bevatron experiments, increasing the extracted uranium beam to 5 x 10/sup 7/ ions/pulse.

  10. Super-B Project Overview

    Energy Technology Data Exchange (ETDEWEB)

    Biagini, M.E.; Boni, R.; Boscolo, M.; Demma, T.; Drago, A.; Guiducci, S.; Raimondi, P.; Tomassini, S.; Zobov, M.; /Frascati; Bertsche, K.; Donald, M.; Nosochkov, Y.; Novokhatski, A.; Seeman, J.; Sullivan, M.; Yocky, G.; Wienands, U.; Wittmer, W.; /SLAC; Koop, I.; Levichev, E.; Nikitin, S.; /Novosibirsk, IYF /KEK, Tsukuba /Pisa U. /CERN

    2010-08-26

    The SuperB project aims at the construction of an asymmetric very high luminosity B-Factory on the Frascati/Tor Vergata (Italy) area, providing a uniquely sensitive probe of New Physics in the flavour sector of the Standard Model. The luminosity goal of 10{sup 36} cm{sup -2} s{sup -1} can be reached with a new collision scheme with 'large Piwinski angle' (LPA) and the use of 'crab waist sextupoles' (CW). A LPA&CW Interaction Region (IR) has been successfully tested at the DA{Phi}NE {Phi}-Factory at LNF-Frascati in 2008. The LPA&CW scheme, together with very low {beta}*, will allow for operation with relatively low beam currents and reasonable bunch length, comparable to those of PEP-II and KEKB. In the High Energy Ring (HER), two spin rotators will bring longitudinally polarized beams into collision at the IP. The lattice has been designed with a very low intrinsic emittance and is quite compact, less than 2 km long. The tight focusing requires the final doublet quadrupoles to be very close to the IP and very compact. A Conceptual Design Report was published in March 2007, and beam dynamics and collective effects R&D studies are in progress in order to publish a Technical Design Report by the end of 2010.

  11. SUPER-B LATTICE STUDIES

    Energy Technology Data Exchange (ETDEWEB)

    Biagini, M.E.; Raimondi, P.; /Frascati; Piminov, P.; Sinyatkin, S.; /Novosibirsk, IYF; Nosochkov, Y.; Wittmer, W.; /SLAC

    2010-08-25

    The SuperB asymmetric e{sup +}e{sup -} collider is designed for 10{sup 36} cm{sup -2} s{sup -1} luminosity and beam energies of 6.7 and 4.18 GeV for e{sup +} and e{sup -} respectively. The High and Low Energy Rings (HER and LER) have one Interaction Point (IP) with 66 mrad crossing angle. The 1258 m rings fit to the INFN-LNF site at Frascati. The ring emittance is minimized for the high luminosity. The Final Focus (FF) chromaticity correction is optimized for maximum transverse acceptance and energy bandwidth. Included Crab Waist sextupoles suppress betatron resonances induced in the collisions with a large Piwinski angle. The LER Spin Rotator sections provide longitudinally polarized electron beam at the IP. The lattice is flexible for tuning the machine parameters and compatible with reusing the PEP-II magnets, RF cavities and other components. Details of the lattice design are presented.

  12. Studies of the Super VELO

    CERN Document Server

    AUTHOR|(CDS)2156302

    2016-01-01

    The Super VELO is the Run 5 upgrade of the VeloPix detector of the LHCb experiment. Its most challenging task is to cope with a luminosity increase of the factor 10. This study examines the potential physics performance of a detector based on the VeloPix design at high luminosity conditions. It is found that an unmodified VeloPix detector shows poor performance when exposed to 10x design luminosity, most gravely high ghost rates of 40 %. When applying basic assumptions about material changes such as cutting the silicon thickness by half and removing the RF foil, the ghost rate drops by 20 %. When using thin silicon and re-optimizing the tracking algorithm, the ghost rate can even be reduced by 60 %. Applying the additional modification of a pixel area size four times smaller, the ghost rate drops by 88 % and the IP resolution improves. Finally, in a dream scenario with thin silicon, smaller pixels and no RF foil, big gains in resolution and a ghost rate of less than 4 % can be achieved.

  13. Super continuum generation at 800 nm in highly nonlinear photonic crystal fibers with normal dispersion

    DEFF Research Database (Denmark)

    Hansen, Kim Per; Larsen, Jacob Juul; Jensen, Jacob Riis

    2001-01-01

    More than 90 nm broad self-phase modulation (SPM) induced pulses have been created from both 25 and 50 fs pulses in just 12.5 cm of fiber. The broadening is more than 2.5 times that observed in standard SMF. SPM broadening in PCFs has several advantages over more complex super continuum generation...

  14. Molecular engineered super-nanodevices: smart and safe delivery of potent drugs into tumors.

    Science.gov (United States)

    Ding, Mingming; Li, Jiehua; He, Xueling; Song, Nijia; Tan, Hong; Zhang, Yi; Zhou, Lijuan; Gu, Qun; Deng, Hua; Fu, Qiang

    2012-07-17

    A super-nanodevice engineered at molecular level integrates various desired properties in a smart and coordinated way, and can "switch on" or "turn off" certain functionalities as required. Importantly, it can break through complex physiological barriers, and then precisely ferry potent toxic triptolide into tumor cells in vivo, thus significantly maximizing the therapeutic efficacy and reducing the drug toxicity.

  15. Grain Size Dependence of Uniform Elongation in Single-Phase FCC/BCC Metals

    Science.gov (United States)

    Liu, Haiting; Shen, Yao; Ma, Jiawei; Zheng, Pengfei; Zhang, Lei

    2016-09-01

    We studied the dependence of uniform elongation on grain size in the range of submicron to millimeter for single-phase FCC/BCC metals by reviewing recent experimental results and applying crystal plasticity finite element method simulation. In the order of increasing grain size, uniform elongation can be divided into three stages, namely low elongation stage, nearly constant elongation stage, and decreased elongation with large scatters stage. Low elongation stage features a dramatic increase near the critical grain size at the end of the stage, which is primarily attributed to the emergence of dislocation cell size transition from ultrafine to mid-size grain. Other factors can be neglected due to their negligible influence on overall variation trend. In nearly constant elongation stage, uniform elongation remains unchanged at a high level in general. As grain size keeps growing, uniform elongation starts decreasing and becomes scattered upon a certain grain size, indicating the initiation of decreased elongation with large scatters stage. It is shown that the increase is not linear or smooth but rather sharp at the end of low elongation stage, leading to a wider range in nearly constant elongation stage. The grain size dependence of uniform elongation can serve as a guiding principle for designing small uniaxial tensile specimens for mechanical testing, where size effect matters in most cases.

  16. Mechanical roles of apical constriction, cell elongation, and cell migration during neural tube formation in Xenopus.

    Science.gov (United States)

    Inoue, Yasuhiro; Suzuki, Makoto; Watanabe, Tadashi; Yasue, Naoko; Tateo, Itsuki; Adachi, Taiji; Ueno, Naoto

    2016-12-01

    Neural tube closure is an important and necessary process during the development of the central nervous system. The formation of the neural tube structure from a flat sheet of neural epithelium requires several cell morphogenetic events and tissue dynamics to account for the mechanics of tissue deformation. Cell elongation changes cuboidal cells into columnar cells, and apical constriction then causes them to adopt apically narrow, wedge-like shapes. In addition, the neural plate in Xenopus is stratified, and the non-neural cells in the deep layer (deep cells) pull the overlying superficial cells, eventually bringing the two layers of cells to the midline. Thus, neural tube closure appears to be a complex event in which these three physical events are considered to play key mechanical roles. To test whether these three physical events are mechanically sufficient to drive neural tube formation, we employed a three-dimensional vertex model and used it to simulate the process of neural tube closure. The results suggest that apical constriction cued the bending of the neural plate by pursing the circumference of the apical surface of the neural cells. Neural cell elongation in concert with apical constriction further narrowed the apical surface of the cells and drove the rapid folding of the neural plate, but was insufficient for complete neural tube closure. Migration of the deep cells provided the additional tissue deformation necessary for closure. To validate the model, apical constriction and cell elongation were inhibited in Xenopus laevis embryos. The resulting cell and tissue shapes resembled the corresponding simulation results.

  17. SuperB Progress Report for Accelerator

    Energy Technology Data Exchange (ETDEWEB)

    Biagini, M.E.; Boni, R.; Boscolo, M.; Buonomo, B.; Demma, T.; Drago, A.; Esposito, M.; Guiducci, S.; Mazzitelli, G.; Pellegrino, L.; Preger, M.A.; Raimondi, P.; Ricci, R.; Rotundo, U.; Sanelli, C.; Serio, M.; Stella, A.; Tomassini, S.; Zobov, M.; /Frascati; Bertsche, K.; Brachman, A.; /SLAC /Novosibirsk, IYF /INFN, Pisa /Pisa U. /Orsay, LAL /Annecy, LAPP /LPSC, Grenoble /IRFU, SPP, Saclay /DESY /Cockroft Inst. Accel. Sci. Tech. /U. Liverpool /CERN

    2012-02-14

    This report details the progress made in by the SuperB Project in the area of the Collider since the publication of the SuperB Conceptual Design Report in 2007 and the Proceedings of SuperB Workshop VI in Valencia in 2008. With this document we propose a new electron positron colliding beam accelerator to be built in Italy to study flavor physics in the B-meson system at an energy of 10 GeV in the center-of-mass. This facility is called a high luminosity B-factory with a project name 'SuperB'. This project builds on a long history of successful e+e- colliders built around the world, as illustrated in Figure 1.1. The key advances in the design of this accelerator come from recent successes at the DAFNE collider at INFN in Frascati, Italy, at PEP-II at SLAC in California, USA, and at KEKB at KEK in Tsukuba Japan, and from new concepts in beam manipulation at the interaction region (IP) called 'crab waist'. This new collider comprises of two colliding beam rings, one at 4.2 GeV and one at 6.7 GeV, a common interaction region, a new injection system at full beam energies, and one of the two beams longitudinally polarized at the IP. Most of the new accelerator techniques needed for this collider have been achieved at other recently completed accelerators including the new PETRA-3 light source at DESY in Hamburg (Germany) and the upgraded DAFNE collider at the INFN laboratory at Frascati (Italy), or during design studies of CLIC or the International Linear Collider (ILC). The project is to be designed and constructed by a worldwide collaboration of accelerator and engineering staff along with ties to industry. To save significant construction costs, many components from the PEP-II collider at SLAC will be recycled and used in this new accelerator. The interaction region will be designed in collaboration with the particle physics detector to guarantee successful mutual use. The accelerator collaboration will consist of several groups at present

  18. BolA inhibits cell elongation and regulates MreB expression levels.

    Science.gov (United States)

    Freire, Patrick; Moreira, Ricardo Neves; Arraiano, Cecília Maria

    2009-02-06

    The morphogene bolA is a general stress response gene in Escherichia coli that induces a round morphology when overexpressed. Results presented in this report show that increased BolA levels can inhibit cell elongation mechanisms. MreB polymerization is crucial for the bacterial cell cytoskeleton, and this protein is essential for the maintenance of a cellular rod shape. In this report, we demonstrate that bolA overexpression affects the architecture of MreB filaments. An increase in BolA leads to a significant reduction in MreB protein levels and mreB transcripts. BolA affects the mreBCD operon in vivo at the level of transcription. Furthermore, our results show that BolA is a new transcriptional repressor of MreB. The alterations in cell morphology induced by bolA seem to be mediated by a complex pathway that integrates PBP5, PBP6, MreB, and probably other regulators of cell morphology/elongation.

  19. Cooperative RNA polymerase molecules behavior on a stochastic sequence-dependent model for transcription elongation.

    Directory of Open Access Journals (Sweden)

    Pedro Rafael Costa

    Full Text Available The transcription process is crucial to life and the enzyme RNA polymerase (RNAP is the major component of the transcription machinery. The development of single-molecule techniques, such as magnetic and optical tweezers, atomic-force microscopy and single-molecule fluorescence, increased our understanding of the transcription process and complements traditional biochemical studies. Based on these studies, theoretical models have been proposed to explain and predict the kinetics of the RNAP during the polymerization, highlighting the results achieved by models based on the thermodynamic stability of the transcription elongation complex. However, experiments showed that if more than one RNAP initiates from the same promoter, the transcription behavior slightly changes and new phenomenona are observed. We proposed and implemented a theoretical model that considers collisions between RNAPs and predicts their cooperative behavior during multi-round transcription generalizing the Bai et al. stochastic sequence-dependent model. In our approach, collisions between elongating enzymes modify their transcription rate values. We performed the simulations in Mathematica® and compared the results of the single and the multiple-molecule transcription with experimental results and other theoretical models. Our multi-round approach can recover several expected behaviors, showing that the transcription process for the studied sequences can be accelerated up to 48% when collisions are allowed: the dwell times on pause sites are reduced as well as the distance that the RNAPs backtracked from backtracking sites.

  20. IGF-1 Induces GHRH Neuronal Axon Elongation during Early Postnatal Life in Mice

    Science.gov (United States)

    Clemessy, Maud; Heurtier, Victor; Ledent, Tatiana; Robinson, Iain C.; Mollard, Patrice; Epelbaum, Jacques; Meaney, Michael J.; Garel, Sonia; Le Bouc, Yves; Kappeler, Laurent

    2017-01-01

    Nutrition during the perinatal period programs body growth. Growth hormone (GH) secretion from the pituitary regulates body growth and is controlled by Growth Hormone Releasing Hormone (GHRH) neurons located in the arcuate nucleus of the hypothalamus. We observed that dietary restriction during the early postnatal period (i.e. lactation) in mice influences postnatal growth by permanently altering the development of the somatotropic axis in the pituitary gland. This alteration may be due to a lack of GHRH signaling during this critical developmental period. Indeed, underfed pups showed decreased insulin-like growth factor I (IGF-I) plasma levels, which are associated with lower innervation of the median eminence by GHRH axons at 10 days of age relative to normally fed pups. IGF-I preferentially stimulated axon elongation of GHRH neurons in in vitro arcuate explant cultures from 7 day-old normally fed pups. This IGF-I stimulating effect was selective since other arcuate neurons visualized concomitantly by neurofilament labeling, or AgRP immunochemistry, did not significantly respond to IGF-I stimulation. Moreover, GHRH neurons in explants from age-matched underfed pups lost the capacity to respond to IGF-I stimulation. Molecular analyses indicated that nutritional restriction was associated with impaired activation of AKT. These results highlight a role for IGF-I in axon elongation that appears to be cell selective and participates in the complex cellular mechanisms that link underfeeding during the early postnatal period with programming of the growth trajectory. PMID:28076448

  1. Elongation distribution between tension leveler and temper mill for pickling line 2030 in Baosteel

    Institute of Scientific and Technical Information of China (English)

    LIU Xiancui; SU Lanhai; LI Zhongfu; FU Zhilin; ZHANG Qingdong; HE Chun

    2007-01-01

    Research into plate elongation distribution between the tension leveler and temper mill for pickling line 2030 at Baosteel is conducted.The study,which involved performance testing of mechanics,is designed at different elongation distributions and analyzed from many aspects.Finally,the optimal elongation of the tension leveler and temper mill is given.

  2. SuperLFV: An SLHA tool for lepton flavor violating observables in supersymmetric models

    CERN Document Server

    Murakami, Brandon

    2013-01-01

    We introduce SuperLFV, a numerical tool for calculating low-energy LFV observables in the context of the minimal supersymmetric standard model (MSSM). As the Large Hadron Collider and MEG, a dedicated mu -> e gamma experiment, are presently acquiring data, there is need for tools that provide rapid discrimination of models that exhibit lepton flavor violation (LFV). SuperLFV accepts an SLHA-compliant spectrum file that contains the MSSM couplings and masses with complex phases at the supersymmetry breaking scale. In this manner, SuperLFV is compatible with but divorced from existing SLHA spectrum calculators that provides the low energy spectrum. Hence, input spectra are not confined to the LFV sources provided by established SLHA spectrum calculators. Input spectra may be generated by personal code or by hand, allowing for arbitrary models not supported by existing spectrum calculators.

  3. The transcriptional regulator Aire binds to and activates super-enhancers.

    Science.gov (United States)

    Bansal, Kushagra; Yoshida, Hideyuki; Benoist, Christophe; Mathis, Diane

    2017-03-01

    Aire is a transcription factor that controls T cell tolerance by inducing the expression of a large repertoire of genes specifically in thymic stromal cells. It interacts with scores of protein partners of diverse functional classes. We found that Aire and some of its partners, notably those implicated in the DNA-damage response, preferentially localized to and activated long chromatin stretches that were overloaded with transcriptional regulators, known as super-enhancers. We also identified topoisomerase 1 as a cardinal Aire partner that colocalized on super-enhancers and was required for the interaction of Aire with all of its other associates. We propose a model that entails looping of super-enhancers to efficiently deliver Aire-containing complexes to local and distal transcriptional start sites.

  4. Identification and super-resolution imaging of ligand-activated receptor dimers in live cells

    CERN Document Server

    Winckler, Pascale; Giannone, Gregory; De Giorgi, Francesca; Ichas, François; Sibarita, Jean-Baptiste; Lounis, Brahim; Cognet, Laurent

    2013-01-01

    Molecular interactions are key to many chemical and biological processes like protein function. In many signaling processes they occur in sub-cellular areas displaying nanoscale organizations and involving molecular assemblies. The nanometric dimensions and the dynamic nature of the interactions make their investigations complex in live cells. While super-resolution fluorescence microscopies offer live-cell molecular imaging with sub-wavelength resolutions, they lack specificity for distinguishing interacting molecule populations. Here we combine super-resolution microscopy and single-molecule F\\"orster Resonance Energy Transfer (FRET) to identify dimers of receptors induced by ligand binding and provide super-resolved images of their membrane distribution in live cells. By developing a two-color universal-Point-Accumulation-In-the-Nanoscale-Topography (uPAINT) method, dimers of epidermal growth factor receptors (EGFR) activated by EGF are studied at ultra-high densities, revealing preferential cell-edge sub-...

  5. Magnetic Resonance Super-resolution Imaging Measurement with Dictionary-optimized Sparse Learning

    Science.gov (United States)

    Li, Jun-Bao; Liu, Jing; Pan, Jeng-Shyang; Yao, Hongxun

    2017-06-01

    Magnetic Resonance Super-resolution Imaging Measurement (MRIM) is an effective way of measuring materials. MRIM has wide applications in physics, chemistry, biology, geology, medical and material science, especially in medical diagnosis. It is feasible to improve the resolution of MR imaging through increasing radiation intensity, but the high radiation intensity and the longtime of magnetic field harm the human body. Thus, in the practical applications the resolution of hardware imaging reaches the limitation of resolution. Software-based super-resolution technology is effective to improve the resolution of image. This work proposes a framework of dictionary-optimized sparse learning based MR super-resolution method. The framework is to solve the problem of sample selection for dictionary learning of sparse reconstruction. The textural complexity-based image quality representation is proposed to choose the optimal samples for dictionary learning. Comprehensive experiments show that the dictionary-optimized sparse learning improves the performance of sparse representation.

  6. Super-Resolution Scanning Laser Microscopy Based on Virtually Structured Detection.

    Science.gov (United States)

    Zhi, Yanan; Wang, Benquan; Yao, Xincheng

    2015-01-01

    Light microscopy plays a key role in biological studies and medical diagnosis. The spatial resolution of conventional optical microscopes is limited to approximately half the wavelength of the illumination light as a result of the diffraction limit. Several approaches-including confocal microscopy, stimulated emission depletion microscopy, stochastic optical reconstruction microscopy, photoactivated localization microscopy, and structured illumination microscopy-have been established to achieve super-resolution imaging. However, none of these methods is suitable for the super-resolution ophthalmoscopy of retinal structures because of laser safety issues and inevitable eye movements. We recently experimentally validated virtually structured detection (VSD) as an alternative strategy to extend the diffraction limit. Without the complexity of structured illumination, VSD provides an easy, low-cost, and phase artifact-free strategy to achieve super-resolution in scanning laser microscopy. In this article we summarize the basic principles of the VSD method, review our demonstrated single-point and line-scan super-resolution systems, and discuss both technical challenges and the potential of VSD-based instrumentation for super-resolution ophthalmoscopy of the retina.

  7. Fruiting branch K+ level affects cotton fibre elongation through osmoregulation

    Directory of Open Access Journals (Sweden)

    Jiashuo eYang

    2016-01-01

    Full Text Available Potassium (K deficiency in cotton plants results in reduced fibre length. As one of the primary osmotica, K+ contributes to an increase in cell turgor pressure during fibre elongation. Therefore, it is hypothesized that fibre length is affected by K deficiency through an osmotic pathway, so in 2012 and 2013, an experiment was conducted to test this hypothesis by imposing three potassium supply regimes (0, 125, 250 kg K ha-1 on a low-K-sensitive cultivar, Siza 3, and a low-K-tolerant cultivar, Simian 3. We found that fibres were longer in the later season bolls than in the earlier ones in cotton plants grown under normal growth conditions, but later season bolls showed a greater sensitivity to low-K stress, especially the low-K sensitive genotype. We also found that the maximum velocity of fibre elongation (Vmax is the parameter that best reflects the change in fibre elongation under K deficiency. This parameter mostly depends on cell turgor, so the content of the osmotically active solutes was analysed accordingly. Statistical analysis showed that K+ was the major osmotic factor affecting fibre length, and malate was likely facilitating K+ accumulation into fibres, which enabled the low-K-tolerant genotype to cope with low-K stress. Moreover, the low-K-tolerant genotype tended to have greater K+ absorptive capacities in the upper fruiting branches. Based on our findings, we suggest a fertilization scheme for Gossypium hirsutum that adds extra potash fertilizer or distributes it during the development of late season bolls to mitigate K deficiency in the second half of the growth season and to enhance fibre length in late season bolls.

  8. Axial super-resolution evanescent wave tomography.

    Science.gov (United States)

    Pendharker, Sarang; Shende, Swapnali; Newman, Ward; Ogg, Stephen; Nazemifard, Neda; Jacob, Zubin

    2016-12-01

    Optical tomographic reconstruction of a three-dimensional (3D) nanoscale specimen is hindered by the axial diffraction limit, which is 2-3 times worse than the focal plane resolution. We propose and experimentally demonstrate an axial super-resolution evanescent wave tomography method that enables the use of regular evanescent wave microscopes like the total internal reflection fluorescence microscope beyond surface imaging and achieve a tomographic reconstruction with axial super-resolution. Our proposed method based on Fourier reconstruction achieves axial super-resolution by extracting information from multiple sets of 3D fluorescence images when the sample is illuminated by an evanescent wave. We propose a procedure to extract super-resolution features from the incremental penetration of an evanescent wave and support our theory by one-dimensional (along the optical axis) and 3D simulations. We validate our claims by experimentally demonstrating tomographic reconstruction of microtubules in HeLa cells with an axial resolution of ∼130  nm. Our method does not require any additional optical components or sample preparation. The proposed method can be combined with focal plane super-resolution techniques like stochastic optical reconstruction microscopy and can also be adapted for THz and microwave near-field tomography.

  9. Axial super-resolution evanescent wave tomography

    Science.gov (United States)

    Pendharker, Sarang; Shende, Swapnali; Newman, Ward; Ogg, Stephen; Nazemifard, Neda; Jacob, Zubin

    2016-12-01

    Optical tomographic reconstruction of a 3D nanoscale specimen is hindered by the axial diffraction limit, which is 2-3 times worse than the focal plane resolution. We propose and experimentally demonstrate an axial super-resolution evanescent wave tomography (AxSET) method that enables the use of regular evanescent wave microscopes like Total Internal Reflection Fluorescence Microscope (TIRF) beyond surface imaging, and achieve tomographic reconstruction with axial super-resolution. Our proposed method based on Fourier reconstruction achieves axial super-resolution by extracting information from multiple sets of three-dimensional fluorescence images when the sample is illuminated by an evanescent wave. We propose a procedure to extract super-resolution features from the incremental penetration of an evanescent wave and support our theory by 1D (along the optical axis) and 3D simulations. We validate our claims by experimentally demonstrating tomographic reconstruction of microtubules in HeLa cells with an axial resolution of $\\sim$130 nm. Our method does not require any additional optical components or sample preparation. The proposed method can be combined with focal plane super-resolution techniques like STORM and can also be adapted for THz and microwave near-field tomography.

  10. Precursor for elongation factor Tu from Escherichia coli.

    OpenAIRE

    1986-01-01

    The tufA gene, one of two genes in Escherichia coli encoding elongation factor Tu (EF-Tu), was cloned into a ColE1-derived plasmid downstream of the lac promoter-operator. In cells carrying this plasmid, the synthesis of EF-Tu was increased four- to fivefold upon the addition of isopropyl-beta-D-thiogalactopyranoside (an inducer of the lac promoter). This condition led to the synthesis of a novel protein, called pTu, which comigrated with EF-Tu on a sodium dodecyl sulfate-polyacrylamide gel b...

  11. Targeting Transcription Elongation Machinery for Breast Cancer Therapy

    Science.gov (United States)

    2017-05-01

    INVESTIGATOR:    Kunxin  Luo CONTRACTING  ORGANIZATION:   University  of  California,  Berkeley REPORT  DATE:  May 2017   TYPE  OF  REPORT:    Annual...NUMBER A ND  ADDRESS(ES) University of California, Berkeley Berkeley, CA 94704 9. SPONSORING  /  MONITORING  AGENCY  NAME(S)  AND  ADDRESS(ES) 10...direct role for the P-TEFb transcription elongation machinery in breast cancer progression. However, in addition to residing in the 7SK snRNP

  12. Stability and energy confinement of highly elongated plasmas in TCV

    Energy Technology Data Exchange (ETDEWEB)

    Hofmann, F.; Behn, R.; Dutch, M.J.; Martin, Y.; Moret, J.M.; Nieswand, C.; Pietrzyk, Z.A.; Reimerdes, H.; Ward, D.J. [Ecole Polytechnique Federale, Lausanne (Switzerland). Centre de Recherche en Physique des Plasma (CRPP)

    1997-06-01

    One of the principal aims of TCV is the creation and active stabilization of highly elongated plasmas, {kappa}{>=}3. This implies high growth rates of axisymmetric modes and a very low stability margin. To stabilize such modes, TCV is equipped with a vertical position control system using a combination of slow coils outside the vacuum vessel (response time {approx_equal}1 ms) and a fast coil inside the vessel (response time {approx_equal}0.2 ms). The fast coil became operational in August 1996 and this paper describes the first experiments using both fast and slow coils for vertical stabilization. (author) 4 figs., 8 refs.

  13. The acoustical significance of age-dependent ear elongation

    DEFF Research Database (Denmark)

    Christensen, Flemming

    2015-01-01

    Elderly people, especially some old men, appear to have very large ears. This paper presents an investigation on the acoustic significance of the age dependent ear elongation. HRTFs and ear lengths were measured for two groups of young and old people. The older groups had larger ears on average......, corresponding to what is reported in the literature. For female ears, virtually no acoustical effect was found. For male ears directional dependent effects in the range up to 5 dB on average was found for certain directions and frequencies. Implications on age dependent hearing loss (presbycusis...

  14. Tandem Oligonucleotide Probe Annealing and Elongation To Discriminate Viral Sequence

    DEFF Research Database (Denmark)

    Taskova, Maria; Uhd, Jesper; Miotke, Laura

    2017-01-01

    followed by click assembly and analysis of the read sequence by various techniques. As we demonstrate in this paper, using our new approach, a viral RNA sequence can be detected in less than 2 h without the need for cDNA synthesis or any other enzymatic reactions and with a sensitivity of ... opportunities in transcriptome analysis, virology, and other fields. Herein, we report for the first time a "click" chemistry approach to oligonucleotide probe elongation as a novel approach to specifically detect a viral sequence. We hybridized a library of short, terminally labeled probes to Ebola virus RNA...

  15. Time Dependent and Steady Uni-axial Elongational Viscosity

    DEFF Research Database (Denmark)

    Nielsen, Jens K.; Rasmussen, Henrik Koblitz; Hassager, Ole

    2005-01-01

    Here we present measurements of transient and steady uni-axial elongational viscosity, using the Filament Stretching Rheometer1 or FSR1 (see Fig. 1) of the following melts: Four narrow MMD polystyrene (PS) samples with weight-average molar mass Mw in the range of 50k to 390k. Three different bi......-disperse samples, mixed from the narrow MMD PS. Two low-density polyethylene (LDPE) melts (Lupolen 1840D and 3020D). A steady-state viscosity was kept for 1-2.5 Hencky strain units in all measurements....

  16. Using mechanical force to probe the mechanism of pausing and arrest during continuous elongation by Escherichia coli RNA polymerase

    Science.gov (United States)

    Forde, Nancy R.; Izhaky, David; Woodcock, Glenna R.; Wuite, Gijs J. L.; Bustamante, Carlos

    2002-09-01

    Escherichia coli RNA polymerase translocates along the DNA discontinuously during the elongation phase of transcription, spending proportionally more time at some template positions, known as pause and arrest sites, than at others. Current models of elongation suggest that the enzyme backtracks at these locations, but the dynamics are unresolved. Here, we study the role of lateral displacement in pausing and arrest by applying force to individually transcribing molecules. We find that an assisting mechanical force does not alter the translocation rate of the enzyme, but does reduce the efficiency of both pausing and arrest. Moreover, arrested molecules cannot be rescued by force, suggesting that arrest occurs by a bipartite mechanism: the enzyme backtracks along the DNA followed by a conformational change of the ternary complex (RNA polymerase, DNA and transcript), which cannot be reversed mechanically.

  17. ATLAS FTK a – very complex – custom super computer

    CERN Document Server

    Kimura, Naoki; The ATLAS collaboration

    2016-01-01

    In the ever increasing pile-up LHC environment advanced techniques of analyzing the data are implemented in order to increase the rate of relevant physics processes with respect to background processes. The Fast TracKer (FTK) is a track finding implementation at hardware level that is designed to deliver full-scan tracks with PT above 1GeV to the ATLAS trigger system for every L1 accept (at a maximum rate of 100kHz). In order to achieve this performance a highly parallel system was designed and now it is under installation in ATLAS. In the beginning of 2016 it will provide tracks for the trigger system in a region covering the central part of the ATLAS detector, and during the year it's coverage will be extended to the full detector coverage. The system relies on matching hits coming from the silicon tracking detectors against 1 billion patterns stored in specially designed ASICS chips (Associative memory - AM06). In a first stage coarse resolution hits are matched against the patterns and the accepted hits u...

  18. Assessing resolution in super-resolution imaging.

    Science.gov (United States)

    Demmerle, Justin; Wegel, Eva; Schermelleh, Lothar; Dobbie, Ian M

    2015-10-15

    Resolution is a central concept in all imaging fields, and particularly in optical microscopy, but it can be easily misinterpreted. The mathematical definition of optical resolution was codified by Abbe, and practically defined by the Rayleigh Criterion in the late 19th century. The limit of conventional resolution was also achieved in this period, and it was thought that fundamental constraints of physics prevented further increases in resolution. With the recent development of a range of super-resolution techniques, it is necessary to revisit the concept of optical resolution. Fundamental differences in super-resolution modalities mean that resolution is not a directly transferrable metric between techniques. This article considers the issues in resolution raised by these new technologies, and presents approaches for comparing resolution between different super-resolution methods.

  19. Architectural Engineering to Super-Light Structures

    DEFF Research Database (Denmark)

    Castberg, Niels Andreas

    with architectural engineering as a starting point. The thesis is based on a two stringed hypothesis: Architectural engineering gives rise to better architecture and Super-Light Structures support and enables a static, challenging architecture. The aim of the thesis is to clarify architectural engineering's impact...... on the work process between architects and engineers in the design development. Using architectural engineering, Super-Light Structures are examined in an architectural context, and it is explained how digital tools can support architectural engineering and design of Super-Light Structures. The experiences...... to be subjects of examination for this thesis. The research results show that architectural engineering has a significant impact on a design process. The projects illustrate that simple explanations, underpinned by visualisations of the challenges between shape versus structure, often creates a shared...

  20. ZEITLUPE positively regulates hypocotyl elongation at warm temperature under light in Arabidopsis thaliana.

    Science.gov (United States)

    Miyazaki, Yuji; Takase, Tomoyuki; Kiyosue, Tomohiro

    2015-01-01

    Hypocotyl cell elongation has been studied as a model to understand how cellular expansion contributes to plant organ growth. Hypocotyl elongation is affected by multiple environmental factors, including light quantity and light quality. Red light inhibits hypocotyl growth via the phytochrome signaling pathways. Proteins of the flavin-binding KELCH repeat F-box 1 / LOV KELCH protein 2 / ZEITLUPE family are positive regulators of hypocotyl elongation under red light in Arabidopsis. These proteins were suggested to reduce phytochrome-mediated inhibition of hypocotyl elongation. Here, we show that ZEITLUPE also functions as a positive regulator in warmth-induced hypocotyl elongation under light in Arabidopsis.

  1. Breeding Super-Earths and Birthing Super-Puffs in Transitional Disks

    CERN Document Server

    Lee, Eve J

    2015-01-01

    The riddle posed by super-Earths (1-4$R_\\oplus$, 2-20$M_\\oplus$) is that they are not Jupiters: their core masses are large enough to trigger runaway gas accretion, yet somehow super-Earths accreted atmospheres that weigh only a few percent of their total mass. We show that this puzzle is solved if super-Earths formed late, as the last vestiges of their parent gas disks were about to clear. This scenario would seem to present fine-tuning problems, but we show that there are none. Ambient gas densities can span many (up to 9) orders of magnitude, and super-Earths can still robustly emerge after $\\sim$0.1-1 Myr with percent-by-weight atmospheres. Super-Earth cores are naturally bred in gas-poor environments where gas dynamical friction has weakened sufficiently to allow constituent protocores to merge. So little gas is present at the time of core assembly that cores hardly migrate by disk torques: formation of super-Earths can be in situ. The picture --- that close-in super-Earths form in a gas-poor (but not ga...

  2. Bone scintigraphy in the treatment planning for hemimandibular elongation; Die Skelettszintigraphie bei der Therapieplanung der hemimandibulaeren Elongation

    Energy Technology Data Exchange (ETDEWEB)

    Kerscher, A. [Kiel Univ. (Germany). Klinik fuer Mund-, Kiefer- und Gesichtschirurgie; Fleiner, B. [Kiel Univ. (Germany). Klinik fuer Mund-, Kiefer- und Gesichtschirurgie; Bohuslaviski, K.H. [Kiel Univ. (Germany). Klinik fuer Nuklearmedizin; Clausen, M. [Kiel Univ. (Germany). Klinik fuer Nuklearmedizin

    1995-06-01

    Hemimandibular elongation is characterized by unilateral continuous growth of the mandibular ramus and condyle. Skeletal scintigraphy is indicated for the assessment of prospective growth. When growth has ceased a correcting osteotomy may be performed. In the case of severe active growth and fast progressive facial asymmetry the growth centre should be removed surgically by condylectomy. 21 patients with facial asymmetry and/or laterognathia underwent skeletal scintigraphy. 19 patients showed symmetrical or nearly symmetrical nuclear uptake. In 11 cases a correcting osteotomy was performed without any relapse. 2 patients showed markedly unilateral increased nuclear uptake. One of them underwent condylectomy and showed a stable result 3 years postoperatively. The other patient underwent a correcting osteotomy with subsequent recurrence of laterognathia. By visualization of the pathophysiological process skeletal scintigraphy yields information for treatment planning in hemimandibular elongation. (orig.) [Deutsch] Die hemimandibulaere Elongation zeichnet sich durch ein einseitig ueberschiessendes Wachstum im Bereich des Raums und Condylus mandibulae aus. Zur Beurteilung des noch zu erwartenden Wachstums ist die Skelettszintigraphie indiziert. Bei abgeschlossenem Wachstum kann eine Umstellungsosteotomie erfolgen. Bei rasch progredienter Gesichtsasymmetrie und deutlich aktivem Wachstum sollte die Wachstumszone durch Kondylektomie operativ entfernt werden. In 21 Faellen mit Gesichtsasymmetrie und/oder Laterognathie fuehrten wir eine Skelettszintigraphie durch. 19 Patienten zeigten eine seitengleiche oder gering differente Nuklidbelegung. In 11 Faellen erfolgte eine Umstellungsosteotomie. Alle Faelle waren rezidivfrei. Zwei Patienten zeigten eine deutlich einseitige Nuklidmehrbelegung. Eine Patientin erhielt eine Kondylektomie und ist drei Jahre postoperativ rezidivfrei. Der andere Patient erhielt nur eine Umstellungsosteotomie. Die Laterognathie rezidivierte. Durch die

  3. Maintenance of Transcription-Translation Coupling by Elongation Factor P

    Directory of Open Access Journals (Sweden)

    Sara Elgamal

    2016-09-01

    Full Text Available Under conditions of tight coupling between translation and transcription, the ribosome enables synthesis of full-length mRNAs by preventing both formation of intrinsic terminator hairpins and loading of the transcription termination factor Rho. While previous studies have focused on transcription factors, we investigated the role of Escherichia coli elongation factor P (EF-P, an elongation factor required for efficient translation of mRNAs containing consecutive proline codons, in maintaining coupled translation and transcription. In the absence of EF-P, the presence of Rho utilization (rut sites led to an ~30-fold decrease in translation of polyproline-encoding mRNAs. Coexpression of the Rho inhibitor Psu fully restored translation. EF-P was also shown to inhibit premature termination during synthesis and translation of mRNAs encoding intrinsic terminators. The effects of EF-P loss on expression of polyproline mRNAs were augmented by a substitution in RNA polymerase that accelerates transcription. Analyses of previously reported ribosome profiling and global proteomic data identified several candidate gene clusters where EF-P could act to prevent premature transcription termination. In vivo probing allowed detection of some predicted premature termination products in the absence of EF-P. Our findings support a model in which EF-P maintains coupling of translation and transcription by decreasing ribosome stalling at polyproline motifs. Other regulators that facilitate ribosome translocation through roadblocks to prevent premature transcription termination upon uncoupling remain to be identified.

  4. Device for measuring hole elongation in a bolted joint

    Science.gov (United States)

    Wichorek, Gregory R. (Inventor)

    1987-01-01

    A device to determine the operable failure mode of mechanically fastened lightweight composite joints by measuring the hole elongation of a bolted joint is disclosed. The double-lap joint test apparatus comprises a stud, a test specimen having a hole, two load transfer plates, and linear displacement measuring instruments. The test specimen is sandwiched between the two load transfer plates and clamped together with the stud. Spacer washers are placed between the test specimen and each load transfer plate to provide a known, controllable area for the determination of clamping forces around the hole of the specimen attributable to bolt torque. The spacer washers also provide a gap for the mounting of reference angles on each side of the test specimen. Under tensile loading, elongation of the hole of the test specimen causes the stud to move away from the reference angles. This displacement is measured by the voltage output of two linear displacement measuring instruments that are attached to the stud and remain in contact with the reference angles throughout the tensile loading. The present invention obviates previous problems in obtaining specimen deformation measurements by monitoring the reference angles to the test specimen and the linear displacement measuring instruments to the stud.

  5. Initiation and elongation of lateral roots in Lactuca sativa

    Science.gov (United States)

    Zhang, N.; Hasenstein, K. H.

    1999-01-01

    Lactuca sativa cv. Baijianye seedlings do not normally produce lateral roots, but removal of the root tip or application of auxin, especially indole-butyric acid, triggered the formation of lateral roots. Primordia initiated within 9 h and were fully developed after 24 h by activating the pericycle cells opposite the xylem pole. The pericycle cells divided asymmetrically into short and long cells. The short cells divided further to form primordia. The effect of root tip removal and auxin application was reversed by 6-benzylaminopurine at concentrations >10(-8) M. The cytokinin oxidase inhibitor N1-(2chloro4pyridyl)-N2-phenylurea also suppressed auxin-induced lateral rooting. The elongation of primary roots was promoted by L-alpha-(2-aminoethoxyvinyl) glycine and silver ions, but only the latter enhanced elongation of lateral roots. The data indicate that the induction of lateral roots is controlled by basipetally moving cytokinin and acropetally moving auxin. Lateral roots appear to not produce ethylene.

  6. Mode-converted ultrasonic scattering in polycrystals with elongated grains.

    Science.gov (United States)

    Arguelles, Andrea P; Kube, Christopher M; Hu, Ping; Turner, Joseph A

    2016-09-01

    Elastic wave scattering is used to study polycrystalline media for a wide range of applications. Received signals, which include scattering from the randomly oriented grains comprising the polycrystal, contain information from which useful microstructural parameters may often be inferred. Recently, a mode-converted diffuse ultrasonic scattering model was developed for evaluating the scattered response of a transverse wave from an incident longitudinal wave in a polycrystalline medium containing equiaxed single-phase grains with cubic elastic symmetry. In this article, that theoretical mode-converted scattering model is modified to account for grain elongation within the sample. The model shows the dependence on scattering angle relative to the grain axis orientation. Experimental measurements were performed on a sample of 7475-T7351 aluminum using a pitch-catch transducer configuration. The results show that the mode-converted scattering can be used to determine the dimensions of the elongated grains. The average grain shape determined from the experimental measurements is compared with dimensions extracted from electron backscatter diffraction, an electron imaging technique. The results suggest that mode-converted diffuse ultrasonic scattering has the potential to quantify detailed information about grain microstructure.

  7. Initiation and elongation of lateral roots in Lactuca sativa

    Science.gov (United States)

    Zhang, N.; Hasenstein, K. H.

    1999-01-01

    Lactuca sativa cv. Baijianye seedlings do not normally produce lateral roots, but removal of the root tip or application of auxin, especially indole-butyric acid, triggered the formation of lateral roots. Primordia initiated within 9 h and were fully developed after 24 h by activating the pericycle cells opposite the xylem pole. The pericycle cells divided asymmetrically into short and long cells. The short cells divided further to form primordia. The effect of root tip removal and auxin application was reversed by 6-benzylaminopurine at concentrations >10(-8) M. The cytokinin oxidase inhibitor N1-(2chloro4pyridyl)-N2-phenylurea also suppressed auxin-induced lateral rooting. The elongation of primary roots was promoted by L-alpha-(2-aminoethoxyvinyl) glycine and silver ions, but only the latter enhanced elongation of lateral roots. The data indicate that the induction of lateral roots is controlled by basipetally moving cytokinin and acropetally moving auxin. Lateral roots appear to not produce ethylene.

  8. Effects of ethylene on root elongation in barley and rice

    Energy Technology Data Exchange (ETDEWEB)

    John, A.; Hall, M.A.; Crossett, R.N.

    1972-01-01

    Experiments were performed to determine the effects of rice and barley to growth inhibition by ethylene. The mechanism of growth inhibition was investigated at the cellular level and a detailed comparison was made between the responses of the two species. The following measurements were made on intact plants in short (up to 200 minutes), medium (up to 3 days) or long (up to 10 days) experiments: the rate of extension growth of main root axes; the final cell length and number of elongating cells produced; and the extensibility of the apical growing region. Results indicate that the effects of ethylene on the elongation of roots of rice and barley plants are different. In barley there is a rapid inhibition of root extension which persists with prolonged exposure to the gas but with little effect on the production of growing cells. However, rice roots exhibit no rapid growth inhibition response, but a reduction does occur after prolonged exposure. Low concentrations promote extension rice roots. The inhibition of root growth is reflected in a reduced extensibility of the apical growing region.

  9. Maintenance of Transcription-Translation Coupling by Elongation Factor P

    Science.gov (United States)

    Elgamal, Sara

    2016-01-01

    ABSTRACT Under conditions of tight coupling between translation and transcription, the ribosome enables synthesis of full-length mRNAs by preventing both formation of intrinsic terminator hairpins and loading of the transcription termination factor Rho. While previous studies have focused on transcription factors, we investigated the role of Escherichia coli elongation factor P (EF-P), an elongation factor required for efficient translation of mRNAs containing consecutive proline codons, in maintaining coupled translation and transcription. In the absence of EF-P, the presence of Rho utilization (rut) sites led to an ~30-fold decrease in translation of polyproline-encoding mRNAs. Coexpression of the Rho inhibitor Psu fully restored translation. EF-P was also shown to inhibit premature termination during synthesis and translation of mRNAs encoding intrinsic terminators. The effects of EF-P loss on expression of polyproline mRNAs were augmented by a substitution in RNA polymerase that accelerates transcription. Analyses of previously reported ribosome profiling and global proteomic data identified several candidate gene clusters where EF-P could act to prevent premature transcription termination. In vivo probing allowed detection of some predicted premature termination products in the absence of EF-P. Our findings support a model in which EF-P maintains coupling of translation and transcription by decreasing ribosome stalling at polyproline motifs. Other regulators that facilitate ribosome translocation through roadblocks to prevent premature transcription termination upon uncoupling remain to be identified. PMID:27624127

  10. Treatment of 41 Cases of Prostate Hyperplasia by Elongated Needle

    Institute of Scientific and Technical Information of China (English)

    WANG Zi-chen; WANG Zhan-ping; ZHANG Bing

    2006-01-01

    观察针药结合治疗前列腺增生症的疗效.采用芒针深刺秩边、中极穴和自备中药保留灌肠后,选曲骨配中、下穴接中药离子导入仪.41例患者总有效率为92.7%.芒针与中药离子导入能缓解前列腺增生的临床症状,提高患者的生活质量.%To observe the therapeutic effect of acupuncture plus medicament in the treatment of prostatic hyperplasia, Zhibian (BL 54) and Zhongji (CV 3) were deeply punctured with elongated needles and enema was applied with self-prepared medicinal herbs. Then Qugu (CV2),Zhongliao(BL 33) and Xialiao(BL 34) were selected and connected with a herbal Ion Introduction Apparatus. The total effective rate was 92.4% in 41 cases. Elongated needle and herbal ion introduction can relieve the clinical symptoms of prostatic hyperplasia and improve the patients' life quality.

  11. Axial elongation following prolonged near work in myopes and emmetropes.

    Science.gov (United States)

    Woodman, Emily C; Read, Scott A; Collins, Michael J; Hegarty, Katherine J; Priddle, Scott B; Smith, Josephine M; Perro, Judd V

    2011-05-01

    To investigate the influence of a period of sustained near work upon axial length in groups of emmetropes (EMM) and myopes. Forty young adult subjects (20 myopes and 20 emmetropes) were recruited for the study. Myopes were further classified as early onset (EOM), late onset (LOM), stable (SM) or progressing (PM) subgroups. Axial length was measured with the IOLMaster instrument before, immediately after and then again 10 min after a continuous 30 min near task of 5 D accommodation demand. Measures of distance objective refraction were also collected. Significant changes in axial length were observed immediately following the near task. EOM axial length elongated on average by 0.027±0.021 mm, LOM by 0.014±0.020 mm, EMM by 0.010±0.015 mm, PM by 0.031±0.022 mm and SM by 0.014±0.018 mm. At the conclusion of the 10 min regression period, axial length measures were not significantly different from baseline values. Axial elongation was observed following a prolonged near task. Both EOM and PM groups showed increases in axial length that were significantly greater than emmetropes.

  12. Molecular mechanism of viomycin inhibition of peptide elongation in bacteria.

    Science.gov (United States)

    Holm, Mikael; Borg, Anneli; Ehrenberg, Måns; Sanyal, Suparna

    2016-01-26

    Viomycin is a tuberactinomycin antibiotic essential for treating multidrug-resistant tuberculosis. It inhibits bacterial protein synthesis by blocking elongation factor G (EF-G) catalyzed translocation of messenger RNA on the ribosome. Here we have clarified the molecular aspects of viomycin inhibition of the elongating ribosome using pre-steady-state kinetics. We found that the probability of ribosome inhibition by viomycin depends on competition between viomycin and EF-G for binding to the pretranslocation ribosome, and that stable viomycin binding requires an A-site bound tRNA. Once bound, viomycin stalls the ribosome in a pretranslocation state for a minimum of ∼ 45 s. This stalling time increases linearly with viomycin concentration. Viomycin inhibition also promotes futile cycles of GTP hydrolysis by EF-G. Finally, we have constructed a kinetic model for viomycin inhibition of EF-G catalyzed translocation, allowing for testable predictions of tuberactinomycin action in vivo and facilitating in-depth understanding of resistance development against this important class of antibiotics.

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

    Science.gov (United States)

    Kellis, Eleftherios; Patsika, Glykeria; Karagiannidis, Evaggelos

    2013-12-01

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

  14. Identification of Elongated Primary Cilia with Impaired Mechanotransduction in Idiopathic Scoliosis Patients

    Science.gov (United States)

    Oliazadeh, Niaz; Gorman, Kristen F.; Eveleigh, Robert; Bourque, Guillaume; Moreau, Alain

    2017-01-01

    The primary cilium is an outward projecting antenna-like organelle with an important role in bone mechanotransduction. The capacity to sense mechanical stimuli can affect important cellular and molecular aspects of bone tissue. Idiopathic scoliosis (IS) is a complex pediatric disease of unknown cause, defined by abnormal spinal curvatures. We demonstrate significant elongation of primary cilia in IS patient bone cells. In response to mechanical stimulation, these IS cells differentially express osteogenic factors, mechanosensitive genes, and signaling genes. Considering that numerous ciliary genes are associated with a scoliosis phenotype, among ciliopathies and knockout animal models, we expected IS patients to have an accumulation of rare variants in ciliary genes. Instead, our SKAT-O analysis of whole exomes showed an enrichment among IS patients for rare variants in genes with a role in cellular mechanotransduction. Our data indicates defective cilia in IS bone cells, which may be linked to heterogeneous gene variants pertaining to cellular mechanotransduction. PMID:28290481

  15. Role of elongator subunit Elp3 in Drosophila melanogaster larval development and immunity

    DEFF Research Database (Denmark)

    Walker, Jane; Kwon, So Yeon; Badenhorst, Paul

    2011-01-01

    The Elongator complex has been implicated in several cellular processes, including gene expression and tRNA modification. We investigated the biological importance of the Elp3 gene in Drosophila melanogaster. Deletion of Elp3 results in larval lethality at the pupal stage. During early development......, larval growth is dramatically impaired, with progression to the third instar delayed for ~24 hr, and pupariation occurring only at day 14 after egg laying. Melanotic nodules appear after 4 days. Microarray analysis shows that stress response genes are induced and ecdysone-induced transcription factors...... are severely repressed in the mutant. Interestingly, the phenotypes of Elp3 flies are similar to those of flies lacking the domino gene, encoding a SWI/SNF-like ATP-dependent chromatin-remodeling enzyme. Indeed, the gene expression profiles of these mutants are also remarkably similar. Together, these data...

  16. Characterization of inner membrane protein YciB in Escherichia coli: YciB interacts with cell elongation and division proteins.

    Science.gov (United States)

    Li, Gaochi; Badaluddin, Noor Afiza; Kitakawa, Madoka

    2015-11-01

    The function of inner membrane protein YciB in Escherichia coli has not been identified. In this study, the membrane topology of the protein that contains five transmembrane domains was clarified. YciB was found to interact with various proteins involved in cell elongation and cell division using a bacterial two-hybrid system. It was also found that the deletion mutant of yciB is susceptible to the low osmolarity. These observations together with previous reports indicate that YciB is involved in synthesis of the cell envelope by interacting with cell elongation and cell division complexes.

  17. KML Super Overlay to WMS Translator

    Science.gov (United States)

    Plesea, Lucian

    2007-01-01

    This translator is a server-based application that automatically generates KML super overlay configuration files required by Google Earth for map data access via the Open Geospatial Consortium WMS (Web Map Service) standard. The translator uses a set of URL parameters that mirror the WMS parameters as much as possible, and it also can generate a super overlay subdivision of any given area that is only loaded when needed, enabling very large areas of coverage at very high resolutions. It can make almost any dataset available as a WMS service visible and usable in any KML application, without the need to reformat the data.

  18. Super-resolution optical microscopy: multiple choices.

    Science.gov (United States)

    Huang, Bo

    2010-02-01

    The recent invention of super-resolution optical microscopy enables the visualization of fine features in biological samples with unprecedented clarity. It creates numerous opportunities in biology because vast amount of previously obscured subcellular processes now can be directly observed. Rapid development in this field in the past two years offers many imaging modalities that address different needs but they also complicates the choice of the 'perfect' method for answering a specific question. Here I will briefly describe the principles of super-resolution optical microscopy techniques and then focus on comparing their characteristics in various aspects of practical applications.

  19. Super resolution of images and video

    CERN Document Server

    Katsaggelos, Aggelos K

    2007-01-01

    This book focuses on the super resolution of images and video. The authors' use of the term super resolution (SR) is used to describe the process of obtaining a high resolution (HR) image, or a sequence of HR images, from a set of low resolution (LR) observations. This process has also been referred to in the literature as resolution enhancement (RE). SR has been applied primarily to spatial and temporal RE, but also to hyperspectral image enhancement. This book concentrates on motion based spatial RE, although the authors also describe motion free and hyperspectral image SR problems. Also exa

  20. Super-Laplacians and their symmetries

    Science.gov (United States)

    Howe, P. S.; Lindström, U.

    2017-05-01

    A super-Laplacian is a set of differential operators in superspace whose highestdimensional component is given by the spacetime Laplacian. Symmetries of super-Laplacians are given by linear differential operators of arbitrary finite degree and are determined by superconformal Killing tensors. We investigate these in flat superspaces. The differential operators determining the symmetries give rise to algebras which can be identified in many cases with the tensor algebras of the relevant superconformal Lie algebras modulo certain ideals. They have applications to Higher Spin theories.

  1. New method for making super-plastic glasses

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    @@ It was a long-cherished dream for materials scientists to find a nearly ideal metallic alloy with high strength and super-plasticity concurrently as a super-material both extremely strong and exceptionally hard for human use.

  2. Second invariant for two-dimensional classical super systems

    Indian Academy of Sciences (India)

    S C Mishra; Roshan Lal; Veena Mishra

    2003-10-01

    Construction of superpotentials for two-dimensional classical super systems (for ≥ 2) is carried out. Some interesting potentials have been studied in their super form and also their integrability.

  3. An integrable generalization of the super AKNS hierarchy and its bi-Hamiltonian formulation

    Science.gov (United States)

    Yu, Jing; Ma, Wen-Xiu; Han, Jingwei; Chen, Shouting

    2017-02-01

    Based on a Lie super-algebra B(0, 1), an integrable generalization of the super AKNS iso-spectral problem is introduced and its corresponding generalized super AKNS hierarchy is generated. By making use of the super-trace identity (or the super variational identity), the resulting super soliton hierarchy can be put into a super bi-Hamiltonian form. A generalized super AKNS soliton hierarchy with self-consistent sources is also presented.

  4. Explosive Super-eruptions: Problems and Prejudices

    Science.gov (United States)

    Self, S.

    2010-12-01

    A super-eruption is defined as one with a magma yield > 10^15 kg (magnitude (M) 8). The term has mainly been applied to large-scale, caldera and ignimbrite-forming explosive eruptions, but it can be applied to all eruptions that released > 10^15 kg of magma. For effusive volcanism, evidence suggests that individual eruptions of this size ( > ~ 370 km^3 of typical basalt or > 450 km^3 of rhyolite flood lava) arise only during periods of LIP formation. The super-eruption concept raises interesting questions about genesis and storage of magmas that feed these vast events. Deposits of major explosive eruptions are Plinian fallout, ignimbrite sheets, and co-ignimbrite ash fall. Based on earlier suggestions and evidence, widespread outflow ignimbrite (O), co-ignimbrite ash (A), and inter-caldera ignimbrite (I) are all major components of the total super-eruption deposit and may tend towards being subequal. In super-eruption deposits, the reported volume of vent-derived Plinian eruption column fallout is often a minor component of the total volume, yet in several cases (Oruanui, Taupo, 26 ka ago, M 8.1; Bishop Tuff, 760 ka, M 8.2; Bandelier (Otowi) Tuff, 1.6 Ma, M8) it is now recognized that vent-derived columns persisted for most of the eruption. Thus, distally, the ash-fall derived from co-ignimbrite ash clouds may be mixed with contemporaneous fallout from a vertical column. Some major ignimbrites have no reported associated Plinian deposit; the huge Young Toba Tuff (YTT, 74 ka, M 8.8) is a significant example. However, the very widespread Toba ash-fall deposit constitutes ~ 40 % of the total mass of magma erupted and is presumed to be co-ignimbrite. Timing of the onset of column collapse probably controls whether a recognizable Plinian deposit is laid down. All super-eruptions probably produce extensive fallout deposits, and this is generally of vent-derived and pyroclastic-flow-derived origin. Establishing the relationships between large-scale ignimbrites and their

  5. On super edge-graceful trees of diameter four

    CERN Document Server

    Krop, E; Raridan, C

    2011-01-01

    In "On the super edge graceful trees of even orders," Chung, Lee, Gao, and Schaffer posed the following problem: Characterize trees of diameter 4 which are super edge-graceful. In this paper, we provide super edge-graceful labelings for all caterpillars and even size lobsters of diameter 4 which permit such labelings. We also provide super edge-graceful labelings for several families of odd size lobsters of diameter 4.

  6. 超级蒙特卡罗核计算仿真软件系统SuperMC%Super Monte Carlo Simulation Program for Nuclear and Radiation Process:SuperMC

    Institute of Scientific and Technical Information of China (English)

    吴宜灿; 孙光耀; 吴斌; 杨琪; 陈朝斌; 党同强; 方菱; 裴曦; 王芳; 汪进; 蒋洁琼; 宋婧; 汪建业; 赵柱民; FDS团队; 胡丽琴; 龙鹏程; 何桃; 程梦云; 郑华庆; 郝丽娟; 俞盛朋

    2016-01-01

    Monte Carlo method has distinct advantages in simulating complicated nuclear systems. However,great challenges to current MC methods and codes prevent its application in engineering proj ects, such as difficulties in the accurate modeling of complex geometries and material distribution,slow convergence of calculation,prompt and effective analysis of massive data. Super Monte Carlo Simulation Program for Nuclear and Radiation Process (SuperMC)is designed to perform the comprehensive neutronics calculation,taking the radiation transport as the core and including the depletion,radiation source term/dose/biohazard,material activation and transmutation,etc. It supports the multi-physics coupling calculation including thermo-hydraulics,structural mechanics,chemistry,biology,etc. Key techniques including automatic and accurate modeling,high efficient calculation,4D visualization were developed and more than 2000 international benchmark models and experiments were used to verify and validate SuperMC. SuperMC has been widely used in reactor engineering proj ects and etc. In this paper,the overview of SuperMC development was introduced.%蒙特卡罗方法对于复杂核系统的模拟具有明显优势,然而在实际工程应用中存在巨大的挑战,如复杂结构与材料分布精准建模难度大、计算收敛速度慢、海量数据难以及时有效分析等。超级蒙特卡罗核计算仿真软件系统 SuperMC设计为支持以辐射输运为核心,包含燃耗、辐射源项/剂量/生物危害、材料活化与嬗变等的综合中子学计算,支持热工水力学、结构力学、化学、生物学等多物理耦合模拟。 SuperMC目前已发展了精准建模、高效计算、四维可视化等关键技术,通过2000余个国际基准模型及实验的验证与确认,在反应堆工程等方面获得广泛应用,本文对其发展概况进行介绍。

  7. Modes of action of ADP-ribosylated elongation factor 2 in inhibiting the polypeptide elongation cycle: a modeling study.

    Directory of Open Access Journals (Sweden)

    Kevin C Chen

    Full Text Available Despite the fact that ADP-ribosylation of eukaryotic elongation factor 2 (EF2 leads to inhibition of protein synthesis, the mechanism by which ADP-ribosylated EF2 (ADPR•EF2 causes this inhibition remains controversial. Here, we applied modeling approaches to investigate the consequences of various modes of ADPR•EF2 inhibitory actions on the two coupled processes, the polypeptide chain elongation and ADP-ribosylation of EF2. Modeling of experimental data indicates that ADPR•EF2 fully blocks the late-phase translocation of tRNAs; but the impairment in the translocation upstream process, mainly the GTP-dependent factor binding with the pretranslocation ribosome and/or the guanine nucleotide exchange in EF2, is responsible for the overall inhibition kinetics. The reduced ADPR•EF2-ribosome association spares the ribosome to bind and shield native EF2 against toxin attack, thereby deferring the inhibition of protein synthesis inhibition and inactivation of EF2. Minimum association with the ribosome also keeps ADPR•EF2 in an accessible state for toxins to catalyze the reverse reaction when nicotinamide becomes available. Our work underscores the importance of unveiling the interactions between ADPR•EF2 and the ribosome, and argues against that toxins inhibit protein synthesis through converting native EF2 to a competitive inhibitor to actively disable the ribosome.

  8. Super-Virtual Refraction Interferometric Redatuming: Enhancing the Refracted Energy

    KAUST Repository

    Aldawood, Ali

    2012-02-26

    onshore seismic data processing. Refraction tomography is becoming a common way to estimate an accurate near surface velocity model. One of the problems with refraction tomography is the low signal to noise ration in far offset data. To improve, we propose using super-virtual refraction interferometry to enhance the weak energy at far offsets. We use Interferometric Green\\'s functions to redatum sources by cross-correlating two traces recorded at receiver stations, A and B, from a source at location W. The result is a redatumed trace with a virtual source at A and a receiver at B, which can also be obtained by correlating two traces recorded at A and B from different shots. Stacking them would enhance the signal-to-noise ratio of this "virtual" trace. We next augment redatuming with convolution and stacking. The trace recorded at B from a virtual source at A is convolved with the original trace recorded at A from a source at W. The result is a "super-virtual" trace at B in the far-offset from a source at W. Stacking N traces gives a vN-improvement. We applied our method to noisy synthetic and field data recorded over a complex near-surface and we could pick more traces at far offsets. It was possible to accommodate more picks resulting in a better subsurface coverage

  9. Super pixel density based clustering automatic image classification method

    Science.gov (United States)

    Xu, Mingxing; Zhang, Chuan; Zhang, Tianxu

    2015-12-01

    The image classification is an important means of image segmentation and data mining, how to achieve rapid automated image classification has been the focus of research. In this paper, based on the super pixel density of cluster centers algorithm for automatic image classification and identify outlier. The use of the image pixel location coordinates and gray value computing density and distance, to achieve automatic image classification and outlier extraction. Due to the increased pixel dramatically increase the computational complexity, consider the method of ultra-pixel image preprocessing, divided into a small number of super-pixel sub-blocks after the density and distance calculations, while the design of a normalized density and distance discrimination law, to achieve automatic classification and clustering center selection, whereby the image automatically classify and identify outlier. After a lot of experiments, our method does not require human intervention, can automatically categorize images computing speed than the density clustering algorithm, the image can be effectively automated classification and outlier extraction.

  10. The structure of the super-W∞(λ) algebra

    NARCIS (Netherlands)

    Bergshoeff, E.; Wit, B. de; Vasiliev, M.

    1991-01-01

    We give a comprehensive treatment of the super-W∞(λ) algebra, an extension of the super-Virasoro algebra that contains generators of spin s ≥ ½. The parameter λ defines the embedding of the Virasoro subalgebra. We describe how to obtain the super-W∞(λ) algebra from the associative algebra of

  11. Super-renormalizable or finite Lee-Wick quantum gravity

    Science.gov (United States)

    Modesto, Leonardo

    2016-08-01

    We propose a class of multidimensional higher derivative theories of gravity without extra real degrees of freedom besides the graviton field. The propagator shows up the usual real graviton pole in k2 = 0 and extra complex conjugates poles that do not contribute to the absorptive part of the physical scattering amplitudes. Indeed, they may consistently be excluded from the asymptotic observable states of the theory making use of the Lee-Wick and Cutkosky, Landshoff, Olive and Polkinghorne prescription for the construction of a unitary S-matrix. Therefore, the spectrum consists of the graviton and short lived elementary unstable particles that we named ;anti-gravitons; because of their repulsive contribution to the gravitational potential at short distance. However, another interpretation of the complex conjugate pairs is proposed based on the Calmet's suggestion, i.e. they could be understood as black hole precursors long established in the classical theory. Since the theory is CPT invariant, the conjugate complex of the micro black hole precursor can be interpreted as a white hole precursor consistently with the 't Hooft complementarity principle. It is proved that the quantum theory is super-renormalizable in even dimension, i.e. only a finite number of divergent diagrams survive, and finite in odd dimension. Furthermore, turning on a local potential of the Riemann tensor we can make the theory finite in any dimension. The singularity-free Newtonian gravitational potential is explicitly computed for a range of higher derivative theories. Finally, we propose a new super-renormalizable or finite Lee-Wick standard model of particle physics.

  12. Super-renormalizable or finite Lee–Wick quantum gravity

    Directory of Open Access Journals (Sweden)

    Leonardo Modesto

    2016-08-01

    Full Text Available We propose a class of multidimensional higher derivative theories of gravity without extra real degrees of freedom besides the graviton field. The propagator shows up the usual real graviton pole in k2=0 and extra complex conjugates poles that do not contribute to the absorptive part of the physical scattering amplitudes. Indeed, they may consistently be excluded from the asymptotic observable states of the theory making use of the Lee–Wick and Cutkosky, Landshoff, Olive and Polkinghorne prescription for the construction of a unitary S-matrix. Therefore, the spectrum consists of the graviton and short lived elementary unstable particles that we named “anti-gravitons” because of their repulsive contribution to the gravitational potential at short distance. However, another interpretation of the complex conjugate pairs is proposed based on the Calmet's suggestion, i.e. they could be understood as black hole precursors long established in the classical theory. Since the theory is CPT invariant, the conjugate complex of the micro black hole precursor can be interpreted as a white hole precursor consistently with the 't Hooft complementarity principle. It is proved that the quantum theory is super-renormalizable in even dimension, i.e. only a finite number of divergent diagrams survive, and finite in odd dimension. Furthermore, turning on a local potential of the Riemann tensor we can make the theory finite in any dimension. The singularity-free Newtonian gravitational potential is explicitly computed for a range of higher derivative theories. Finally, we propose a new super-renormalizable or finite Lee–Wick standard model of particle physics.

  13. Super ready: how a regional approach to Super Bowl EMS paid off.

    Science.gov (United States)

    Clancy, Terry; Cortacans, Henry P

    2014-07-01

    The Super Bowl and its associated activities represent one of the largest special events in the world. Super Bowl XLVIII was geographically unique because the NFL's and Super Bowl Host Committee's activities, venues and events encompassed two states and fell across numerous jurisdictions within six counties (Bergen, Hudson, Morris, Essex, Middlesex, and Manhattan).This Super Bowl was the first to do this. EMS was one of the largest operational components during this event. Last and most important, it is the people and relationships that make any planning initiative and event a success. Sit down and have a cup a coffee with your colleagues, partners and neighbors in and out of state to discuss your planning initiatives. Do it early-it will make your efforts less painful should an event of this magnitude come to a city near you!

  14. Acoustic Design of Super-light Structures

    DEFF Research Database (Denmark)

    Christensen, Jacob Ellehauge; Hertz, Kristian Dahl; Brunskog, Jonas

    aggregate (leca) along with a newly developed technology called pearl-chain reinforcement, which is a system for post-tensioning. Here, it is shown how to combine these technologies within a precast super-light slab element, while honoring the requirements of a holistic design. Acoustic experiments...

  15. Folded shapes with Super-Light Structures

    DEFF Research Database (Denmark)

    Castberg, Niels Andreas; Hertz, Kristian Dahl

    2012-01-01

    The use of folded shapes in structures has become more common, but it still costs problems because of construction issues and bending moments. The present paper deals with how the newly patented structural concept Super-Light structures (SLS) can be used to create folded shapes. SLS gives lighter...

  16. Single Image Super Resolution via Sparse Reconstruction

    NARCIS (Netherlands)

    Kruithof, M.C.; Eekeren, A.W.M. van; Dijk, J.; Schutte, K.

    2012-01-01

    High resolution sensors are required for recognition purposes. Low resolution sensors, however, are still widely used. Software can be used to increase the resolution of such sensors. One way of increasing the resolution of the images produced is using multi-frame super resolution algorithms. Limita

  17. Conformal anomaly of super Wilson loop

    Energy Technology Data Exchange (ETDEWEB)

    Belitsky, A.V., E-mail: andrei.belitsky@asu.edu [Department of Physics, Arizona State University, Tempe, AZ 85287-1504 (United States)

    2012-09-11

    Classically supersymmetric Wilson loop on a null polygonal contour possesses all symmetries required to match it onto non-MHV amplitudes in maximally supersymmetric Yang-Mills theory. However, to define it quantum mechanically, one is forced to regularize it since perturbative loop diagrams are not well defined due to presence of ultraviolet divergences stemming from integration in the vicinity of the cusps. A regularization that is adopted by practitioners by allowing one to use spinor helicity formalism, on the one hand, and systematically go to higher orders of perturbation theory is based on a version of dimensional regularization, known as Four-Dimensional Helicity scheme. Recently it was demonstrated that its use for the super Wilson loop at one loop breaks both conformal symmetry and Poincare supersymmetry. Presently, we exhibit the origin for these effects and demonstrate how one can undo this breaking. The phenomenon is alike the one emerging in renormalization group mixing of conformal operators in conformal theories when one uses dimensional regularization. The rotation matrix to the diagonal basis is found by means of computing the anomaly in the Ward identity for the conformal boost. Presently, we apply this ideology to the super Wilson loop. We compute the one-loop conformal anomaly for the super Wilson loop and find that the anomaly depends on its Grassmann coordinates. By subtracting this anomalous contribution from the super Wilson loop we restore its interpretation as a dual description for reduced non-MHV amplitudes which are expressed in terms of superconformal invariants.

  18. Super-Kamiokande worth full restoration

    CERN Multimedia

    Mishima, I

    2002-01-01

    While prospects are good that the SuperKamiokande facility will be partially repaired after an accident last November, the government has yet to confirm whether it will spend the estimated 2.5 billion yen needed for a full-scale restoration (1 page).

  19. Structural optimization of super-repellent surfaces

    DEFF Research Database (Denmark)

    Cavalli, Andrea; Bøggild, Peter; Okkels, Fridolin

    2013-01-01

    Micro-patterning is an effective way to achieve surfaces with extreme liquid repellency. This technique does not rely on chemical coatings and is therefore a promising concept for application in food processing and bio-compatibile coatings. This super-repellent behaviour is obtained by suspending...

  20. Facile preparation of super durable superhydrophobic materials.

    Science.gov (United States)

    Wu, Lei; Zhang, Junping; Li, Bucheng; Fan, Ling; Li, Lingxiao; Wang, Aiqin

    2014-10-15

    The low stability, complicated and expensive fabrication procedures seriously hinder practical applications of superhydrophobic materials. Here we report an extremely simple method for preparing super durable superhydrophobic materials, e.g., textiles and sponges, by dip coating in fluoropolymers (FPs). The morphology, surface chemical composition, mechanical, chemical and environmental stabilities of the superhydrophobic textiles were investigated. The results show how simple the preparation of super durable superhydrophobic textiles can be! The superhydrophobic textiles outperform their natural counterparts and most of the state-of-the-art synthetic superhydrophobic materials in stability. The intensive mechanical abrasion, long time immersion in various liquids and repeated washing have no obvious influence on the superhydrophobicity. Water drops are spherical in shape on the samples and could easily roll off after these harsh stability tests. In addition, this simple dip coating approach is applicable to various synthetic and natural textiles and can be easily scaled up. Furthermore, the results prove that a two-tier roughness is helpful but not essential with regard to the creation of super durable superhydrophobic textiles. The combination of microscale roughness of textiles and materials with very low surface tension is enough to form super durable superhydrophobic textiles. According to the same procedure, superhydrophobic polyurethane sponges can be prepared, which show high oil absorbency, oil/water separation efficiency and stability. Copyright © 2014 Elsevier Inc. All rights reserved.

  1. Pavement behaviour under the super single tyre

    CSIR Research Space (South Africa)

    Viljoen, AW

    1982-06-01

    Full Text Available Pavement behaviour under the super single tyre (SST) was investigated and compared with that under a conventional dual tyre (CDT). Contact areas and contact pressures over a range of loading conditions were measured and compared. Two approaches were...

  2. Typhoon effects on super-tall buildings

    Science.gov (United States)

    Li, Q. S.; Xiao, Y. Q.; Wu, J. R.; Fu, J. Y.; Li, Z. N.

    2008-06-01

    Full-scale measurement is considered to be the most reliable method for evaluating wind effects on buildings and structures. This paper presents selected results of wind characteristics and structural responses measured from four super-tall buildings, The Center (350 m high, 79 floors) in Hong Kong, Di Wang Tower (384 m high, 78 floors) in Shenzhen, CITIC Plaza Tower (391 m high, 80 floors) in Guangzhou and Jin Mao Building (421 m high, 88 floors) in Shanghai, during the passages of three typhoons. The field data such as wind speed, wind direction and acceleration responses, etc., were continuously measured from the super-tall buildings during the typhoons. Detailed analysis of the field data was conducted to investigate the characteristics of typhoon-generated wind and wind-induced vibrations of these super-tall buildings under typhoon conditions. The dynamic characteristics of the tall buildings were determined from the field measurements and comparisons with those calculated from the finite element (FE) models of the structures were made. Furthermore, the full-scale measurements were compared with wind tunnel results to evaluate the accuracy of the model test results and the adequacy of the techniques used in the wind tunnel tests. The results presented in this paper are expected to be of considerable interest and of use to researchers and professionals involved in designing super-tall buildings.

  3. Searching for Frozen Super Earth via Microlensing

    Science.gov (United States)

    Batista, V.; Beaulieu, J. P.; Cassan, A.; Coutures, C.; Donatowicz, J.; Fouqué, P.; Kubas, D.; Marquette, J. B.

    2009-04-01

    Microlensing planet hunt is a unique method to probe efficiently for frozen Super Earth orbiting the most common stars of our galaxy. It is nicely complementing the parameter space probed by very high accuracy radial velocity measurements and future space based detections of low mass transiting planets. In order to maximize the planet catch, the microlensing community is engaged in a total cooperation among the different groups (OGLE, MicroFUN, MOA, PLANET/RoboNET) by making the real time data available, and mutual informing/reporting about modeling efforts. Eight planets have been published so far by combinations of the different groups, 4 Jovian analogues, one Neptune and two Super Earth. Given the microlensing detection efficiency, it suggests that these Neptunes/Super Earths may be quite common. Using networks of dedicated 1-2m class telescopes, the microlensing community has entered a new phase of planet discoveries, and will be able to provide constraints on the abundance of frozen Super-Earths in the near future. Statistics about Mars to Earth mass planets, extending to the habitable zone will be achieved with space based wide field imagers (EUCLID) at the horizon 2017.

  4. Folded shapes with Super-Light Structures

    DEFF Research Database (Denmark)

    Castberg, Niels Andreas; Hertz, Kristian Dahl

    2012-01-01

    The use of folded shapes in structures has become more common, but it still costs problems because of construction issues and bending moments. The present paper deals with how the newly patented structural concept Super-Light structures (SLS) can be used to create folded shapes. SLS gives lighter...

  5. Advantages of super-light structures

    DEFF Research Database (Denmark)

    Hertz, Kristian Dahl

    2009-01-01

    Super-light structures with pearl-chain reinforcement is a new revolutionary technology that opens possibilities of building load-bearing structures much cheaper and with several other advantages compared to traditional constructions of concrete and steel. Some benefits are: 1 Half price or less. 2...

  6. BREEDING SUPER-EARTHS AND BIRTHING SUPER-PUFFS IN TRANSITIONAL DISKS

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Eve J.; Chiang, Eugene, E-mail: evelee@berkeley.edu, E-mail: echiang@astro.berkeley.edu [Department of Astronomy, University of California Berkeley, Berkeley, CA 94720-3411 (United States)

    2016-02-01

    The riddle posed by super-Earths (1–4R{sub ⊕}, 2–20M{sub ⊕}) is that they are not Jupiters: their core masses are large enough to trigger runaway gas accretion, yet somehow super-Earths accreted atmospheres that weigh only a few percent of their total mass. We show that this puzzle is solved if super-Earths formed late, as the last vestiges of their parent gas disks were about to clear. This scenario would seem to present fine-tuning problems, but we show that there are none. Ambient gas densities can span many (in one case up to 9) orders of magnitude, and super-Earths can still robustly emerge after ∼0.1–1 Myr with percent-by-weight atmospheres. Super-Earth cores are naturally bred in gas-poor environments where gas dynamical friction has weakened sufficiently to allow constituent protocores to gravitationally stir one another and merge. So little gas is present at the time of core assembly that cores hardly migrate by disk torques: formation of super-Earths can be in situ. The basic picture—that close-in super-Earths form in a gas-poor (but not gas-empty) inner disk, fed continuously by gas that bleeds inward from a more massive outer disk—recalls the largely evacuated but still accreting inner cavities of transitional protoplanetary disks. We also address the inverse problem presented by super-puffs: an uncommon class of short-period planets seemingly too voluminous for their small masses (4–10R{sub ⊕}, 2–6M{sub ⊕}). Super-puffs most easily acquire their thick atmospheres as dust-free, rapidly cooling worlds outside ∼1 AU where nebular gas is colder, less dense, and therefore less opaque. Unlike super-Earths, which can form in situ, super-puffs probably migrated in to their current orbits; they are expected to form the outer links of mean-motion resonant chains, and to exhibit greater water content. We close by confronting observations and itemizing remaining questions.

  7. SuperB A High-Luminosity Asymmetric $e^+ e^-$ Super Flavour Factory : Conceptual Design Report

    CERN Document Server

    Bona, M.; Grauges Pous, E.; Colangelo, P.; De Fazio, F.; Palano, A.; Manghisoni, M.; Re, V.; Traversi, G.; Eigen, G.; Venturini, M.; Soni, N.; Bruschi, M.; De Castro, S.; Faccioli, P.; Gabrieli, A.; Giacobbe, B.; Semprini Cesare, N.; Spighi, R.; Villa, M.; Zoccoli, A.; Hearty, C.; McKenna, J.; Soni, A.; Khan, A.; Barniakov, A.Y.; Barniakov, M.Y.; Blinov, V.E.; Druzhinin, V.P.; Golubev, V.B.; Kononov, S.A.; Koop, I.A.; Kravchenko, E.A.; Levichev, E.B.; Nikitin, S.A.; Onuchin, A.P.; Piminov, P.A.; Serednyakov, S.I.; Shatilov, D.N.; Skovpen, Y.I.; Solodov, E.A.; Cheng, C.H.; Echenard, B.; Fang, F.; Hitlin, D.J.; Porter, F.C.; Asner, D.M.; Pham, T.N.; Fleischer, R.; Giudice, G.F.; Hurth, T.; Mangano, M.; Mancinelli, G.; Meadows, B.T.; Schwartz, A.J.; Sokoloff, M.D.; Soffer, A.; Beard, C.D.; Haas, T.; Mankel, R.; Hiller, G.; Ball, P.; Pappagallo, M.; Pennington, M.R.; Gradl, W.; Playfer, S.; Abada, A.; Becirevic, D.; Descotes-Genon, S.; Pene, O.; Andreotti, D.; Andreotti, M.; Bettoni, D.; Bozzi, C.; Calabresi, R.; Cecchi, A.; Cibinetto, G.; Franchini, P.; Luppi, E.; Negrini, M.; Petrella, A.; Piemontese, L.; Prencipe, E.; Santoro, V.; Stancari, G.; Anulli, F.; Baldini-Ferroli, R.; Biagini, M.E.; Boscolo, M.; Calcaterra, A.; Drago, A.; Finocchiaro, G.; Guiducci, S.; Isidori, G.; Pacetti, S.; Patteri, P.; Peruzzi, I.M.; Piccolo, M.; Preger, M.A.; Raimondi, P.; Rama, M.; Vaccarezza, C.; Zallo, A.; Zobov, M.; De Sangro, R.; Buzzo, A.; Lo Vetere, M.; Macri, M.; Monge, M.R.; Passaggio, S.; Patrignani, C.; Robutti, E.; Tosi, S.; Matias, J.; Panduro Vazquez, W.; Borzumati, F.; Eyges, V.; Prell, S.A.; Pedlar, T.K.; Korpar, S.; Pestonik, R.; Staric, M.; Neubert, M.; Denig, A.G.; Nierste, U.; Agoh, T.; Ohmi, K.; Ohnishi, Y.; Fry, J.R.; Touramanis, C.; Wolski, A.; Golob, B.; Krizan, P.; Flaecher, H.; Bevan, A.J.; Di Lodovico, F.; George, K.A.; Barlow, R.; Lafferty, G.; Jawahery, A.; Roberts, D.A.; Simi, G.; Patel, P.M.; Robertson, S.H.; Lazzaro, A.; Palombo, F.; Kaidalov, A.; Buras, A.J.; Tarantino, C.; Buchalla, G.; Sanda, A.I.; D'Ambrosio, G.; Ricciardi, G.; Bigi, I.; Jessop, C.P.; Losecco, J.M.; Honscheid, K.; Arnaud, N.; Chehab, R.; Fedala, Y.; Polci, F.; Roudeau, P.; Sordini, V.; Soskov, V.; Stocchi, A.; Variola, A.; Vivoli, A.; Wormser, G.; Zomer, F.; Bertolin, A.; Brugnera, R.; Gagliardi, N.; Gaz, A.; Margoni, M.; Morandin, M.; Posocco, M.; Rotondo, M.; Simonetto, F.; Stroili, R.; Bonneaud, G.R.; Lombardo, V.; Calderini, G.; Ratti, L.; Speziali, V.; Biasini, M.; Covarelli, R.; Manoni, E.; Servoli, L.; Angelini, C.; Batignani, G.; Bettarini, S.; Bosi, F.; Carpinelli, M.; Cenci, R.; Cervelli, A.; Dell'Orso, M.; Forti, F.; Giannetti, P.; Giorgi, M.; Lusiani, A.; Marchiori, G.; Massa, M.; Mazur, M.A.; Morsani, F.; Neri, N.; Paoloni, E.; Raffaelli, F.; Rizzo, G.; Walsh, J.; Braun, V.; Lenz, A.; Adams, G.S.; Danko, I.Z.; Baracchini, E.; Bellini, F.; Cavoto, G.; D'Orazio, A.; Del Re, D.; Di Marco, E.; Faccini, R.; Ferrarotto, F.; Gaspero, Mario; Jackson, P.; Martinelli, G.; Mazzoni, M.A.; Morganti, Silvio; Piredda, G.; Renga, F.; Silvestrini, L.; Voena, C.; Catani, L.; Di Ciaccio, A.; Messi, R.; Santovetti, E.; Satta, A.; Ciuchini, M.; Lubicz, V.; Wilson, F.F.; Godang, R.; Chen, X.; Liu, H.; Park, W.; Purohit, M.; Trivedi, A.; White, R.M.; Wilson, J.R.; Allen, M.T.; Aston, D.; Bartoldus, R.; Brodsky, S.J.; Cai, Y.; Coleman, J.; Convery, M.R.; DeBarger, S.; Dingfelder, J.C.; Dubois-Felsmann, G.P.; Ecklund, S.; Fisher, A.S.; Haller, G.; Heifets, S.A.; Kaminski, J.; Kelsey, M.H.; Kocian, M.L.; Leith, D.W.G.S.; Li, N.; Luitz, S.; Luth, V.; MacFarlane, D.; Messner, R.; Muller, D.R.; Nosochkov, Y.; Novokhatski, A.; Pivi, M.; Ratcliff, B.N.; Roodman, A.; Schwiening, J.; Seeman, J.; Snyder, A.; Sullivan, M.; Va'Vra, J.; Wienands, U.; Wisniewski, W.; Stoeck, H.; Cheng, H.Y.; Li, H.N.; Keum, Y.Y.; Gronau, M.; Grossman, Y.; Bianchi, F.; Gamba, D.; Gambino, P.; Marchetto, F.; Menichetti, Ezio A.; Mussa, R.; Pelliccioni, M.; Dalla Betta, G.F.; Bomben, M.; Bosisio, L.; Cartaro, C.; Lanceri, L.; Vitale, L.; Azzolini, V.; Bernabeu, J.; Lopez-March, N.; Martinez-Vidal, F.; Milanes, D.A.; Oyanguren, A.; Paradisi, P.; Pich, A.; Sanchis-Lozano, M.A.; Kowalewski, Robert V.; Roney, J.M.; Back, J.J.; Gershon, T.J.; Harrison, P.F.; Latham, T.E.; Mohanty, G.B.; Petrov, A.A.; Pierini, M.; INFN

    2007-01-01

    The physics objectives of SuperB, an asymmetric electron-positron collider with a luminosity above 10^36/cm^2/s are described, together with the conceptual design of a novel low emittance design that achieves this performance with wallplug power comparable to that of the current B Factories, and an upgraded detector capable of doing the physics in the SuperB environment.

  8. Properties of Super-Poisson Processes and Super-Random Walks with Spatially Dependent Branching Rates

    Institute of Scientific and Technical Information of China (English)

    Yan Xia REN

    2008-01-01

    The global supports of super-Poisson processes and super-random walks with a branching mechanism ψ(z)=z2 and constant branching rate are known to be noncompact. It turns out that, for any spatially dependent branching rate, this property remains true. However, the asymptotic extinction property for these two kinds of superprocesses depends on the decay rate of the branching-rate function at infinity.

  9. Computationally efficient image restoration and super-resolution algorithns for real-time implementation

    Science.gov (United States)

    Sundareshan, Malur K.

    2002-07-01

    Computational complexity is a major impediment to the real- time implementation of image restoration and super- resolution algorithms. Although powerful restoration algorithms have been developed within the last few years utilizing sophisticated mathematical machinery (based on statistical optimization and convex set theory), these algorithms are typically iterative in nature and require enough number of iterations to be executed to achieve desired resolution gains in order to meaningfully perform detection and recognition tasks in practice. Additionally, recent technological breakthroughs have facilitated novel sensor designs (focal plane arrays, for instance) that make it possible to capture mega-pixel imagery data at video frame rates. A major challenge in the processing of these large format images is to complete the execution of the image processing steps within the frame capture times and to keep up with the output rate of the sensor so that all data captured by the sensor can be efficiently utilized. Consequently, development of novel methods that facilitate real-time implementation of image restoration and super- resolution algorithms is of significant practical interest and will be the primary focus of this paper. The key to designing computationally efficient processing schemes lies in strategically introducing appropriate pre-processing and post-processing steps together with the super-resolution iterations in order to tailor optimized overall processing sequences for imagery data of specific formats. Three distinct methods for tailoring a pre-processing filter and integrating it with the super-resolution processing steps will be outlined in this paper. These methods consist of a Region-of-Interest (ROI) extraction scheme, a background- detail separation procedure, and a scene-derived information extraction step for implementing a set-theoretic restoration of the image that is less demanding in computation compared to the super-resolution iterations. A

  10. Activation of 5-HT7 receptor stimulates neurite elongation through mTOR, Cdc42 and actin filaments dynamics.

    Science.gov (United States)

    Speranza, Luisa; Giuliano, Teresa; Volpicelli, Floriana; De Stefano, M Egle; Lombardi, Loredana; Chambery, Angela; Lacivita, Enza; Leopoldo, Marcello; Bellenchi, Gian C; di Porzio, Umberto; Crispino, Marianna; Perrone-Capano, Carla

    2015-01-01

    Recent studies have indicated that the serotonin receptor subtype 7 (5-HT7R) plays a crucial role in shaping neuronal morphology during embryonic and early postnatal life. Here we show that pharmacological stimulation of 5-HT7R using a highly selective agonist, LP-211, enhances neurite outgrowth in neuronal primary cultures from the cortex, hippocampus and striatal complex of embryonic mouse brain, through multiple signal transduction pathways. All these signaling systems, involving mTOR, the Rho GTPase Cdc42, Cdk5, and ERK, are known to converge on the reorganization of cytoskeletal proteins that subserve neurite outgrowth. Indeed, our data indicate that neurite elongation stimulated by 5-HT7R is modulated by drugs affecting actin polymerization. In addition, we show, by 2D Western blot analyses, that treatment of neuronal cultures with LP-211 alters the expression profile of cofilin, an actin binding protein involved in microfilaments dynamics. Furthermore, by using microfluidic chambers that physically separate axons from the soma and dendrites, we demonstrate that agonist-dependent activation of 5-HT7R stimulates axonal elongation. Our results identify for the first time several signal transduction pathways, activated by stimulation of 5-HT7R, that converge to promote cytoskeleton reorganization and consequent modulation of axonal elongation. Therefore, the activation of 5-HT7R might represent one of the key elements regulating CNS connectivity and plasticity during development.

  11. Activation of 5-HT7 receptor stimulates neurite elongation through mTOR, Cdc42 and actin filaments dynamics

    Directory of Open Access Journals (Sweden)

    Luisa eSperanza

    2015-03-01

    Full Text Available Recent studies have indicated that the serotonin receptor subtype 7 (5-HT7R plays a crucial role in shaping neuronal morphology during embryonic and early postnatal life. Here we show that pharmacological stimulation of 5-HT7R using a highly selective agonist, LP-211, enhances neurite outgrowth in neuronal primary cultures from the cortex, hippocampus and striatal complex of embryonic mouse brain, through multiple signal transduction pathways. All these signaling systems, involving mTOR, the Rho GTPase Cdc42, Cdk5 and ERK, are known to converge on the reorganization of cytoskeletal proteins that subserve neurite outgrowth. Indeed, our data indicate that neurite elongation stimulated by 5-HT7R is modulated by drugs affecting actin polymerization.In addition, we show, by 2D western blot analyses, that treatment of neuronal cultures with LP-211 alters the expression profile of cofilin, an actin binding protein involved in microfilaments dynamics. Furthermore, by using microfluidic chambers that physically separate axons from the soma and dendrites, we demonstrate that agonist-dependent activation of 5-HT7R stimulates axonal elongation. Our results identify for the first time several signal transduction pathways, activated by stimulation of 5-HT7R, that converge to promote cytoskeleton reorganization and consequent modulation of axonal elongation. Therefore, the activation of 5-HT7R might represent one of the key elements regulating CNS connectivity and plasticity during development.

  12. ECERIFERUM2-LIKE proteins have unique biochemical and physiological functions in very-long-chain fatty acid elongation.

    Science.gov (United States)

    Haslam, Tegan M; Haslam, Richard; Thoraval, Didier; Pascal, Stéphanie; Delude, Camille; Domergue, Frédéric; Fernández, Aurora Mañas; Beaudoin, Frédéric; Napier, Johnathan A; Kunst, Ljerka; Joubès, Jérôme

    2015-03-01

    The extension of very-long-chain fatty acids (VLCFAs) for the synthesis of specialized apoplastic lipids requires unique biochemical machinery. Condensing enzymes catalyze the first reaction in fatty acid elongation and determine the chain length of fatty acids accepted and produced by the fatty acid elongation complex. Although necessary for the elongation of all VLCFAs, known condensing enzymes cannot efficiently synthesize VLCFAs longer than 28 carbons, despite the prevalence of C28 to C34 acyl lipids in cuticular wax and the pollen coat. The eceriferum2 (cer2) mutant of Arabidopsis (Arabidopsis thaliana) was previously shown to have a specific deficiency in cuticular waxes longer than 28 carbons, and heterologous expression of CER2 in yeast (Saccharomyces cerevisiae) demonstrated that it can modify the acyl chain length produced by a condensing enzyme from 28 to 30 carbon atoms. Here, we report the physiological functions and biochemical specificities of the CER2 homologs CER2-LIKE1 and CER2-LIKE2 by mutant analysis and heterologous expression in yeast. We demonstrate that all three CER2-LIKEs function with the same small subset of condensing enzymes, and that they have different effects on the substrate specificity of the same condensing enzyme. Finally, we show that the changes in acyl chain length caused by each CER2-LIKE protein are of substantial importance for cuticle formation and pollen coat function.

  13. Effects of Transcription Elongation Rate and Xrn2 Exonuclease Activity on RNA Polymerase II Termination Suggest Widespread Kinetic Competition.

    Science.gov (United States)

    Fong, Nova; Brannan, Kristopher; Erickson, Benjamin; Kim, Hyunmin; Cortazar, Michael A; Sheridan, Ryan M; Nguyen, Tram; Karp, Shai; Bentley, David L

    2015-10-15

    The torpedo model of transcription termination asserts that the exonuclease Xrn2 attacks the 5'PO4-end exposed by nascent RNA cleavage and chases down the RNA polymerase. We tested this mechanism using a dominant-negative human Xrn2 mutant and found that it delayed termination genome-wide. Xrn2 nuclease inactivation caused strong termination defects downstream of most poly(A) sites and modest delays at some histone and U snRNA genes, suggesting that the torpedo mechanism is not limited to poly(A) site-dependent termination. A central untested feature of the torpedo model is that there is kinetic competition between the exonuclease and the pol II elongation complex. Using pol II rate mutants, we found that slow transcription robustly shifts termination upstream, and fast elongation extends the zone of termination further downstream. These results suggest that kinetic competition between elongating pol II and the Xrn2 exonuclease is integral to termination of transcription on most human genes. Copyright © 2015 Elsevier Inc. All rights reserved.

  14. Intermediate electrostatic field for the generalized elongation method.

    Science.gov (United States)

    Liu, Kai; Korchowiec, Jacek; Aoki, Yuriko

    2015-05-18

    An intermediate electrostatic field is introduced to improve the accuracy of fragment-based quantum-chemical computational methods by including long-range polarizations of biomolecules. The point charge distribution of the intermediate field is generated by a charge sensitivity analysis that is parameterized for five different population analyses, namely, atoms-in-molecules, Hirshfeld, Mulliken, natural orbital, and Voronoi population analysis. Two model systems are chosen to demonstrate the performance of the generalized elongation method (ELG) combined with the intermediate electrostatic field. The calculations are performed for the STO-3G, 6-31G, and 6-31G(d) basis sets and compared with reference Hartree-Fock calculations. It is shown that the error in the total energy is reduced by one order of magnitude, independently of the population analyses used. This demonstrates the importance of long-range polarization in electronic-structure calculations by fragmentation techniques.

  15. Elongation factor-2: a useful gene for arthropod phylogenetics.

    Science.gov (United States)

    Regier, J C; Shultz, J W

    2001-07-01

    Robust resolution of controversial higher-level groupings within Arthropoda requires additional sources of characters. Toward this end, elongation factor-2 sequences (1899 nucleotides) were generated from 17 arthropod taxa (5 chelicerates, 6 crustaceans, 3 hexapods, 3 myriapods) plus an onychophoran and a tardigrade as outgroups. Likelihood and parsimony analyses of nucleotide and amino acid data sets consistently recovered Myriapoda and major chelicerate groups with high bootstrap support. Crustacea + Hexapoda (= Pancrustacea) was recovered with moderate support, whereas the conflicting group Myriapoda + Hexapoda (= Atelocerata) was never recovered and bootstrap values were always protein-encoding, nuclear gene (in addition to RNA polymerase II) to support Pancrustacea over Atelocerata. Atelocerata is widely cited in morphology-based analyses, and the discrepancy between results derived from molecular and morphological data deserves greater attention.

  16. Gibberellins accumulate in the elongating endodermal cells of Arabidopsis root.

    Science.gov (United States)

    Shani, Eilon; Weinstain, Roy; Zhang, Yi; Castillejo, Cristina; Kaiserli, Eirini; Chory, Joanne; Tsien, Roger Y; Estelle, Mark

    2013-03-19

    Plant hormones are small-molecule signaling compounds that are collectively involved in all aspects of plant growth and development. Unlike animals, plants actively regulate the spatial distribution of several of their hormones. For example, auxin transport results in the formation of auxin maxima that have a key role in developmental patterning. However, the spatial distribution of the other plant hormones, including gibberellic acid (GA), is largely unknown. To address this, we generated two bioactive fluorescent GA compounds and studied their distribution in Arabidopsis thaliana roots. The labeled GAs specifically accumulated in the endodermal cells of the root elongation zone. Pharmacological studies, along with examination of mutants affected in endodermal specification, indicate that GA accumulation is an active and highly regulated process. Our results strongly suggest the presence of an active GA transport mechanism that would represent an additional level of GA regulation.

  17. TREATMENT OF 18 CASES OF TRIGEMINAL NEURALGIA WITH ELONGATED NEEDLE

    Institute of Scientific and Technical Information of China (English)

    李建兰; 阎巍; 岳仍丽

    2004-01-01

    In this paper, a total of 18 cases of primary trigeminal neuralgia were treated with elongated needle. Of the 18 cases, 5 were male and 15 female, ranging in age from 27 to 58 years and in disease duration from 3 days to 8 years. Main acupoints used were Taiyang (EX-HN 5) to Xiaguan (ST 7, for penetration needling), Xiajiache, Fengchi (GB 20), Yanglingquan (GB 34) and Taichong (LR 3). The treatment was given once daily, with 12 sessions being a therapeutic course. After 2 courses of treatment, of the 18 cases, 10 cases were cured, 7 experienced improvement in pain and one failed in the treatment, with an effective rate of 94.4%. The key point for treating trigeminal neuralgia is applying penetrative needling from EX-HN 5 to ST 7 to achieve ideal needling sensations.

  18. Natural oscillations of a gas in an elongated combustion chamber

    Science.gov (United States)

    Nesterov, S. V.; Akulenko, L. D.; Baydulov, V. G.

    2017-02-01

    For the analysis of the frequencies and shapes of the natural oscillations of a gas in an elongated rectilinear combustion chamber, this chamber can be treated as a kind of an organ pipe that has the following specific features: 1. the chamber has an inlet and outlet nozzles; 2. a gas mixture burns in the combustion chamber; 3. the combustion materials flow out from the outlet nozzle; 4. the gas flows in such a way that its velocity in the larger part (closer to the outlet nozzle) of the chamber exceeds the speed of sound (Mach number M > 1). There are only separate domains (one or several), where M < 1. The excitation of the natural oscillations of the gas and an increase in the amplitude of such oscillations can lead to instability of the combustion process [1].

  19. Centrosome splitting during nuclear elongation in the Drosophila embryo.

    Science.gov (United States)

    Callaini, G; Anselmi, F

    1988-10-01

    In the early Drosophila embryo, nuclear elongation occurs during cellularization of the syncytial blastoderm. This process is closely related to the presence of microtubular bundles forming a basket-like structure surrounding the nuclei. In immunofluorescence observations with antibodies against alpha-tubulin, the microtubules appear to radiate from two bright foci widely separated from each other. We used electron microscopy to show that these foci are true centrosomes constituted by daughter and parent centrioles orthogonally disposed and surrounded by pericentriolar electrondense material. The centrosomes may be observed in the apical region of the blastoderm cells from the beginning of cellularization until the reestablishment of the first postblastodermic mitosis, when they organize the spindle poles. Until this time the dimensions of the procentrioles remain unchanged. The significance of these results is discussed in relation to the known behavior of centrioles in the cell cycle.

  20. Experimental and Theoretical Investigations of Phonation Threshold Pressure as a Function of Vocal Fold Elongation

    Science.gov (United States)

    Tao, Chao; Regner, Michael F.; Zhang, Yu; Jiang, Jack J.

    2014-01-01

    Summary The relationship between the vocal fold elongation and the phonation threshold pressure (PTP) was experimentally and theoretically investigated. The PTP values of seventeen excised canine larynges with 0% to 15% bilateral vocal fold elongations in 5% elongation steps were measured using an excised larynx phonation system. It was found that twelve larynges exhibited a monotonic relationship between PTP and elongation; in these larynges, the 0% elongation condition had the lowest PTP. Five larynges exhibited a PTP minimum at 5% elongation. To provide a theoretical explanation of these phenomena, a two-mass model was modified to simulate vibration of the elongated vocal folds. Two pairs of longitudinal springs were used to represent the longitudinal elastin in the vocal folds. This model showed that when the vocal folds were elongated, the increased longitudinal tension would increase the PTP value and the increased vocal fold length would decrease the PTP value. The antagonistic effects contributed by these two factors were found to be able to cause either a monotonic or a non-monotonic relationship between PTP and elongation, which were consistent with experimental observations. Because PTP describes the ease of phonation, this study suggests that there may exist a nonzero optimal vocal fold elongation for the greatest ease for phonation in some larynges. PMID:25530744

  1. Elongational rheology and cohesive fracture of photo-oxidated LDPE

    Energy Technology Data Exchange (ETDEWEB)

    Rolón-Garrido, Víctor H., E-mail: victor.h.rolongarrido@tu-berlin.de; Wagner, Manfred H. [Chair of Polymer Engineering/Polymer Physics, Berlin Institute of Technology (TU Berlin), Fasanenstrasse 90, D-10623 Berlin (Germany)

    2014-01-15

    It was found recently that low-density polyethylene (LDPE) samples with different degrees of photo-oxidation represent an interesting system to study the transition from ductile to cohesive fracture and the aspects of the cohesive rupture in elongational flow. Sheets of LDPE were subjected to photo-oxidation in the presence of air using a xenon lamp to irradiate the samples for times between 1 day and 6 weeks. Characterisation methods included Fourier transform infrared spectroscopy, solvent extraction method, and rheology in shear and uniaxial extensional flows. Linear viscoelasticity was increasingly affected by increasing photo-oxidation due to crosslinking of LDPE, as corroborated by the carbonyl index, acid and aldehydes groups, and gel fraction. The molecular stress function model was used to quantify the experimental data, and the nonlinear model parameter β was found to be correlated with the gel content. The uniaxial data showed that the transition from ductile to cohesive fracture was shifted to lower elongational rates, the higher the gel content was. From 2 weeks photo-oxidation onwards, cohesive rupture occurred at every strain rate investigated. The true strain and true stress at cohesive fracture as well as the energy density applied to the sample up to fracture were analyzed. At low gel content, rupture was mainly determined by the melt fraction while at high gel content, rupture occurred predominantly in the gel structure. The strain at break was found to be independent of strain rate, contrary to the stress at break and the energy density. Thus, the true strain and not the stress at break or the energy density was found to be the relevant physical quantity to describe cohesive fracture behavior of photo-oxidated LDPE. The equilibrium modulus of the gel structures was correlated with the true strain at rupture. The stiffer the gel structure, the lower was the deformation tolerated before the sample breaks.

  2. Tracing primordial protein evolution through structurally guided stepwise segment elongation.

    Science.gov (United States)

    Watanabe, Hideki; Yamasaki, Kazuhiko; Honda, Shinya

    2014-02-07

    The understanding of how primordial proteins emerged has been a fundamental and longstanding issue in biology and biochemistry. For a better understanding of primordial protein evolution, we synthesized an artificial protein on the basis of an evolutionary hypothesis, segment-based elongation starting from an autonomously foldable short peptide. A 10-residue protein, chignolin, the smallest foldable polypeptide ever reported, was used as a structural support to facilitate higher structural organization and gain-of-function in the development of an artificial protein. Repetitive cycles of segment elongation and subsequent phage display selection successfully produced a 25-residue protein, termed AF.2A1, with nanomolar affinity against the Fc region of immunoglobulin G. AF.2A1 shows exquisite molecular recognition ability such that it can distinguish conformational differences of the same molecule. The structure determined by NMR measurements demonstrated that AF.2A1 forms a globular protein-like conformation with the chignolin-derived β-hairpin and a tryptophan-mediated hydrophobic core. Using sequence analysis and a mutation study, we discovered that the structural organization and gain-of-function emerged from the vicinity of the chignolin segment, revealing that the structural support served as the core in both structural and functional development. Here, we propose an evolutionary model for primordial proteins in which a foldable segment serves as the evolving core to facilitate structural and functional evolution. This study provides insights into primordial protein evolution and also presents a novel methodology for designing small sized proteins useful for industrial and pharmaceutical applications.

  3. Dendrosomatic Sonic Hedgehog Signaling in Hippocampal Neurons Regulates Axon Elongation

    Science.gov (United States)

    Petralia, Ronald S.; Ott, Carolyn; Wang, Ya-Xian; Lippincott-Schwartz, Jennifer; Mattson, Mark P.

    2015-01-01

    The presence of Sonic Hedgehog (Shh) and its signaling components in the neurons of the hippocampus raises a question about what role the Shh signaling pathway may play in these neurons. We show here that activation of the Shh signaling pathway stimulates axon elongation in rat hippocampal neurons. This Shh-induced effect depends on the pathway transducer Smoothened (Smo) and the transcription factor Gli1. The axon itself does not respond directly to Shh; instead, the Shh signal transduction originates from the somatodendritic region of the neurons and occurs in neurons with and without detectable primary cilia. Upon Shh stimulation, Smo localization to dendrites increases significantly. Shh pathway activation results in increased levels of profilin1 (Pfn1), an actin-binding protein. Mutations in Pfn1's actin-binding sites or reduction of Pfn1 eliminate the Shh-induced axon elongation. These findings indicate that Shh can regulate axon growth, which may be critical for development of hippocampal neurons. SIGNIFICANCE STATEMENT Although numerous signaling mechanisms have been identified that act directly on axons to regulate their outgrowth, it is not known whether signals transduced in dendrites may also affect axon outgrowth. We describe here a transcellular signaling pathway in embryonic hippocampal neurons in which activation of Sonic Hedgehog (Shh) receptors in dendrites stimulates axon growth. The pathway involves the dendritic-membrane-associated Shh signal transducer Smoothened (Smo) and the transcription factor Gli, which induces the expression of the gene encoding the actin-binding protein profilin 1. Our findings suggest scenarios in which stimulation of Shh in dendrites results in accelerated outgrowth of the axon, which therefore reaches its presumptive postsynaptic target cell more quickly. By this mechanism, Shh may play critical roles in the development of hippocampal neuronal circuits. PMID:26658865

  4. A generalized super AKNS hierarchy associated with Lie superalgebra sl(2|1) and its super bi-Hamiltonian structure

    Science.gov (United States)

    Han, Jingwei; Yu, Jing

    2017-03-01

    Starting from a 3 × 3 matrix-valued spectral problem associated with a Lie superalgebra sl(2|1), a generalized super Ablowitz-Kaup-Newell-Segur (AKNS) hierarchy is derived. The resulting super AKNS hierarchy has a super bi-Hamiltonian structure by the supertrace identity.

  5. Super SI燃烧方式试验研究%Super SI Combustion Mode

    Institute of Scientific and Technical Information of China (English)

    沈义涛; 吕世亮; 尹琪; 杨嘉林; 高卫民

    2011-01-01

    The super spark ignition (Super SI) combustion mode, which was the ignition combustion of lean mixture at the temperature of close spontaneous combustion, was researched and its combustion characteristic and feasibility were analyzed.The results indicate that the increase of intake temperature can reduce the cyclic variation of Pmi obviously, shorten the combustion duration and extend the lean limit of SI combustion under the condition of lean mixture. Accordingly, Super SI combustion has the advantages of high thermal efficiency and controllable combustion process.%研究了Super Spark Ignition(Super SI)燃烧方式,即稀薄混合气在近自燃温度状态下点燃燃烧,分析了这种燃烧方式的可行性和燃烧特性.研究结果表明,混合气稀薄时提高发动机的进气温度可显著降低平均指示压力(pmi)的循环波动,缩短燃烧持续期,拓展点燃燃烧的稀薄极限;Super SI燃烧方式具有热效率高、燃烧过程可控的优点.

  6. The 2015 super-resolution microscopy roadmap

    Science.gov (United States)

    Hell, Stefan W.; Sahl, Steffen J.; Bates, Mark; Zhuang, Xiaowei; Heintzmann, Rainer; Booth, Martin J.; Bewersdorf, Joerg; Shtengel, Gleb; Hess, Harald; Tinnefeld, Philip; Honigmann, Alf; Jakobs, Stefan; Testa, Ilaria; Cognet, Laurent; Lounis, Brahim; Ewers, Helge; Davis, Simon J.; Eggeling, Christian; Klenerman, David; Willig, Katrin I.; Vicidomini, Giuseppe; Castello, Marco; Diaspro, Alberto; Cordes, Thorben

    2015-11-01

    Far-field optical microscopy using focused light is an important tool in a number of scientific disciplines including chemical, (bio)physical and biomedical research, particularly with respect to the study of living cells and organisms. Unfortunately, the applicability of the optical microscope is limited, since the diffraction of light imposes limitations on the spatial resolution of the image. Consequently the details of, for example, cellular protein distributions, can be visualized only to a certain extent. Fortunately, recent years have witnessed the development of ‘super-resolution’ far-field optical microscopy (nanoscopy) techniques such as stimulated emission depletion (STED), ground state depletion (GSD), reversible saturated optical (fluorescence) transitions (RESOLFT), photoactivation localization microscopy (PALM), stochastic optical reconstruction microscopy (STORM), structured illumination microscopy (SIM) or saturated structured illumination microscopy (SSIM), all in one way or another addressing the problem of the limited spatial resolution of far-field optical microscopy. While SIM achieves a two-fold improvement in spatial resolution compared to conventional optical microscopy, STED, RESOLFT, PALM/STORM, or SSIM have all gone beyond, pushing the limits of optical image resolution to the nanometer scale. Consequently, all super-resolution techniques open new avenues of biomedical research. Because the field is so young, the potential capabilities of different super-resolution microscopy approaches have yet to be fully explored, and uncertainties remain when considering the best choice of methodology. Thus, even for experts, the road to the future is sometimes shrouded in mist. The super-resolution optical microscopy roadmap of Journal of Physics D: Applied Physics addresses this need for clarity. It provides guidance to the outstanding questions through a collection of short review articles from experts in the field, giving a thorough

  7. The Effects of Microgravity on Seated Height (Spinal Elongation)

    Science.gov (United States)

    Young, K. S.; Rajulu, S.

    2011-01-01

    ABSTRACT Many physiological factors, such as spinal elongation, fluid shifts, bone atrophy, and muscle loss, occur during an exposure to a microgravity environment. Spinal elongation is just one of the factors that can also affect the safety and performance of a crewmember while in space. Spinal elongation occurs due to the lack of gravity/compression on the spinal column. This allows for the straightening of the natural spinal curve. There is a possible fluid shift in the inter-vertebral disks that may also result in changes in height. This study aims at collecting the overall change in seated height for crewmembers exposed to a microgravity environment. During previous Programs, Apollo-Soyuz Test Project (ASTP) and Skylab, spinal elongation data was collected from a small number of subjects in a standing posture but were limited in scope. Data from these studies indicated a quick increase in stature during the first few days of weightlessness, after which stature growth reached a plateau resulting in up to a 3% increase of the original measurement [1-5]. However, this data was collected only for crewmembers in standing posture and not in a seated posture. Seated height may have a different effect than standing height due to a change in posture as well as due to a compounded effect of wearing restraints and a potential compression of the gluteal area. Seated height was deemed as a critical measurement in the design of the Constellation Program s (CxP) Crew Exploration Vehicle (CEV), called Orion which is now the point-of-departure vehicle for the Multi-Purpose Crew Vehicle (MPCV) Program; therefore a better understanding of the effects of microgravity on seated height is necessary. Potential changes in seated height that may not have impacted crew accommodation in previous Programs will have significant effects on crew accommodation due to the layout of seats in the Orion.. The current and existing configuration is such that the four crewmembers are stacked two by

  8. The Solution Construction of Heterotic Super-Liouville Model

    Institute of Scientific and Technical Information of China (English)

    YANG Zhan-Ying; ZHEN Yi

    2001-01-01

    We investigate the heterotic super-Liouville model on the base of the basic Lie super-algebra Osp(1|2).Using the super extension of Leznov-Saveliev analysis and Drinfeld Sokolov linear system, we construct the explicit solution of the heterotic super-Liouville system in component form. We also show that the solutions are local and periodic by calculating the exchange relation of the solution. Finally starting from the action of heterotic super-Liou ville model, we obtain the conserved current and conserved charge which possessed the BR ST properties.

  9. Exploring the formation of focal adhesions on patterned surfaces using super-resolution imaging.

    Science.gov (United States)

    Chien, Fan-Ching; Kuo, Chiung Wen; Yang, Zong-Han; Chueh, Di-Yen; Chen, Peilin

    2011-10-17

    The formation of focal adhesions on various sizes of fibronectin patterns, ranging from 200 μm to 250 nm, was systematically investigated by total internal reflection fluorescence microscopy and super-resolution imaging. It was found that cells adhered to and spread on these micro/nanopatterns, forming focal adhesions. On a micrometer scale the shape of the focal adhesions was elongated. However, on the nanometer scale, the shape of focal adhesions became dotlike. To further explore the distribution of focal adhesion proteins formed on surfaces, a localization-based super-resolution imaging technique was employed in order to determine the position and density of vinculin proteins. A characteristic distance of 50 nm was found between vinculin molecules in the focal adhesions, which did not depend on the size of the fibronectin nanopatterns. This distance was found to be crucial for the formation of focal adhesions. In addition, the density of vinculin at the focal adhesions formed on the nanopatterns increased as the pattern size decreased. The density of the protein was found to be 425 ± 247, 584 ± 302, and 703 ± 305 proteins μm(-2) on the 600, 400, and 250 nm fibronectin patterns respectively. Whereas 226 ± 77 proteins μm(-2) was measured for the matured focal adhesions on homogeneous fibronectin coated substrates. The increase in vinculin density implies that an increase in mechanical load was applied to the focal adhesions formed on the smaller nanopatterns.

  10. Transcriptome Sequencing and Analysis for Culm Elongation of the World's Largest Bamboo (Dendrocalamus sinicus.

    Directory of Open Access Journals (Sweden)

    Kai Cui

    Full Text Available Dendrocalamus sinicus is the world's largest bamboo species with strong woody culms, and known for its fast-growing culms. As an economic bamboo species, it was popularized for multi-functional applications including furniture, construction, and industrial paper pulp. To comprehensively elucidate the molecular processes involved in its culm elongation, Illumina paired-end sequencing was conducted. About 65.08 million high-quality reads were produced, and assembled into 81,744 unigenes with an average length of 723 bp. A total of 64,338 (79% unigenes were annotated for their functions, of which, 56,587 were annotated in the NCBI non-redundant protein database and 35,262 were annotated in the Swiss-Prot database. Also, 42,508 and 21,009 annotated unigenes were allocated to gene ontology (GO categories and clusters of orthologous groups (COG, respectively. By searching against the Kyoto Encyclopedia of Genes and Genomes Pathway database (KEGG, 33,920 unigenes were assigned to 128 KEGG pathways. Meanwhile, 8,553 simple sequence repeats (SSRs and 81,534 single-nucleotide polymorphism (SNPs were identified, respectively. Additionally, 388 transcripts encoding lignin biosynthesis were detected, among which, 27 transcripts encoding Shikimate O-hydroxycinnamoyltransferase (HCT specifically expressed in D. sinicus when compared to other bamboo species and rice. The phylogenetic relationship between D. sinicus and other plants was analyzed, suggesting functional diversity of HCT unigenes in D. sinicus. We conjectured that HCT might lead to the high lignin content and giant culm. Given that the leaves are not yet formed and culm is covered with sheaths during culm elongation, the existence of photosynthesis of bamboo culm is usually neglected. Surprisedly, 109 transcripts encoding photosynthesis were identified, including photosystem I and II, cytochrome b6/f complex, photosynthetic electron transport and F-type ATPase, and 24 transcripts were characterized

  11. Transcriptome Sequencing and Analysis for Culm Elongation of the World's Largest Bamboo (Dendrocalamus sinicus).

    Science.gov (United States)

    Cui, Kai; Wang, Haiying; Liao, Shengxi; Tang, Qi; Li, Li; Cui, Yongzhong; He, Yuan

    2016-01-01

    Dendrocalamus sinicus is the world's largest bamboo species with strong woody culms, and known for its fast-growing culms. As an economic bamboo species, it was popularized for multi-functional applications including furniture, construction, and industrial paper pulp. To comprehensively elucidate the molecular processes involved in its culm elongation, Illumina paired-end sequencing was conducted. About 65.08 million high-quality reads were produced, and assembled into 81,744 unigenes with an average length of 723 bp. A total of 64,338 (79%) unigenes were annotated for their functions, of which, 56,587 were annotated in the NCBI non-redundant protein database and 35,262 were annotated in the Swiss-Prot database. Also, 42,508 and 21,009 annotated unigenes were allocated to gene ontology (GO) categories and clusters of orthologous groups (COG), respectively. By searching against the Kyoto Encyclopedia of Genes and Genomes Pathway database (KEGG), 33,920 unigenes were assigned to 128 KEGG pathways. Meanwhile, 8,553 simple sequence repeats (SSRs) and 81,534 single-nucleotide polymorphism (SNPs) were identified, respectively. Additionally, 388 transcripts encoding lignin biosynthesis were detected, among which, 27 transcripts encoding Shikimate O-hydroxycinnamoyltransferase (HCT) specifically expressed in D. sinicus when compared to other bamboo species and rice. The phylogenetic relationship between D. sinicus and other plants was analyzed, suggesting functional diversity of HCT unigenes in D. sinicus. We conjectured that HCT might lead to the high lignin content and giant culm. Given that the leaves are not yet formed and culm is covered with sheaths during culm elongation, the existence of photosynthesis of bamboo culm is usually neglected. Surprisedly, 109 transcripts encoding photosynthesis were identified, including photosystem I and II, cytochrome b6/f complex, photosynthetic electron transport and F-type ATPase, and 24 transcripts were characterized as antenna

  12. Transcriptome Sequencing and Analysis for Culm Elongation of the World’s Largest Bamboo (Dendrocalamus sinicus)

    Science.gov (United States)

    Cui, Kai; Wang, Haiying; Liao, Shengxi; Tang, Qi; Li, Li; Cui, Yongzhong; He, Yuan

    2016-01-01

    Dendrocalamus sinicus is the world’s largest bamboo species with strong woody culms, and known for its fast-growing culms. As an economic bamboo species, it was popularized for multi-functional applications including furniture, construction, and industrial paper pulp. To comprehensively elucidate the molecular processes involved in its culm elongation, Illumina paired-end sequencing was conducted. About 65.08 million high-quality reads were produced, and assembled into 81,744 unigenes with an average length of 723 bp. A total of 64,338 (79%) unigenes were annotated for their functions, of which, 56,587 were annotated in the NCBI non-redundant protein database and 35,262 were annotated in the Swiss-Prot database. Also, 42,508 and 21,009 annotated unigenes were allocated to gene ontology (GO) categories and clusters of orthologous groups (COG), respectively. By searching against the Kyoto Encyclopedia of Genes and Genomes Pathway database (KEGG), 33,920 unigenes were assigned to 128 KEGG pathways. Meanwhile, 8,553 simple sequence repeats (SSRs) and 81,534 single-nucleotide polymorphism (SNPs) were identified, respectively. Additionally, 388 transcripts encoding lignin biosynthesis were detected, among which, 27 transcripts encoding Shikimate O-hydroxycinnamoyltransferase (HCT) specifically expressed in D. sinicus when compared to other bamboo species and rice. The phylogenetic relationship between D. sinicus and other plants was analyzed, suggesting functional diversity of HCT unigenes in D. sinicus. We conjectured that HCT might lead to the high lignin content and giant culm. Given that the leaves are not yet formed and culm is covered with sheaths during culm elongation, the existence of photosynthesis of bamboo culm is usually neglected. Surprisedly, 109 transcripts encoding photosynthesis were identified, including photosystem I and II, cytochrome b6/f complex, photosynthetic electron transport and F-type ATPase, and 24 transcripts were characterized as antenna

  13. Coculture of elongated neuron axon with poly (D, L-lactide-co-glycolide) biomembrane in vitro

    Institute of Scientific and Technical Information of China (English)

    程飚; 陈峥嵘

    2004-01-01

    Objective: To elongate human nerve axon in culture and search for suitable support matrices for peripheral nervous system transplantation.Methods: Human embryo cortical neuronal cells,seeded on poly ( D, L-lactide-co-glycolide ) ( PLGA )membrane scaffolds, were elongated with a self-made neuro-axon extending device. The growth and morphological changes of neuron axons were observed to measure axolemmal permeability after elongation.Neurofilament protein was stained by immunohistochemical technique.Results: Human embryo neuron axon could be elongated and cultured on the PLGA membrane and retain their normal form and function.Conclusions: Three dimensional scaffolds with elongated neuron axon have the basic characteristics of artificial nerves, indicating a fundemental theory of nerve repair with elongated neuron axon.

  14. Super-resolution microscopy of the synaptic active zone.

    Science.gov (United States)

    Ehmann, Nadine; Sauer, Markus; Kittel, Robert J

    2015-01-01

    Brain function relies on accurate information transfer at chemical synapses. At the presynaptic active zone (AZ) a variety of specialized proteins are assembled to complex architectures, which set the basis for speed, precision and plasticity of synaptic transmission. Calcium channels are pivotal for the initiation of excitation-secretion coupling and, correspondingly, capture a central position at the AZ. Combining quantitative functional studies with modeling approaches has provided predictions of channel properties, numbers and even positions on the nanometer scale. However, elucidating the nanoscopic organization of the surrounding protein network requires direct ultrastructural access. Without this information, knowledge of molecular synaptic structure-function relationships remains incomplete. Recently, super-resolution microscopy (SRM) techniques have begun to enter the neurosciences. These approaches combine high spatial resolution with the molecular specificity of fluorescence microscopy. Here, we discuss how SRM can be used to obtain information on the organization of AZ proteins.

  15. HST Super Lightweight Interchangeable Carrier (SLIC) Static Test

    Science.gov (United States)

    Chambers, William V.

    2008-01-01

    The HST Super Light Weight Interchangeable Carrier Static Test program calls for a total of 15 load cases with an average of 9 simultaneous push/pull locations per load case. This testing program represents the most complex static test ever attempted at Goddard Space Flight Center. Many unique multi-pull fixtures were designed to apply the simultaneous loading. Additionally, a total of 600 channels of data required processing for each loadcase. A total of 1100 separate strain gages were installed on SLIC. A team of 15 trained technicians were needed to apply test loads via mechanical hand pumps for several load cases. All 15 load cases were successfully conducted within 15 weeks. The ManTech team successfully tested all SLIC 1200 interface clips to the required testing loads. Several unique designs were needed to address testing challenges as loadline interference, Payload Safety, payload flexibility and opposing load applications.

  16. Mmp25β facilitates elongation of sensory neurons during zebrafish development.

    Science.gov (United States)

    Crawford, Bryan D; Po, Michelle D; Saranyan, Pillai V; Forsberg, Daniel; Schulz, Richard; Pilgrim, Dave B

    2014-10-01

    Matrix metalloproteinases (MMPs) are a large and complex family of zinc-dependent endoproteinases widely recognized for their roles in remodeling the extracellular matrix (ECM) during embryonic development, wound healing, and tissue homeostasis. Their misregulation is central to many pathologies, and they have therefore been the focus of biomedical research for decades. These proteases have also recently emerged as mediators of neural development and synaptic plasticity in vertebrates, however, understanding of the mechanistic basis of these roles and the molecular identities of the MMPs involved remains far from complete. We have identified a zebrafish orthologue of mmp25 (a.k.a. leukolysin; MT6-MMP), a membrane-type, furin-activated MMP associated with leukocytes and invasive carcinomas, but which we find is expressed by a subset of the sensory neurons during normal embryonic development. We detect high levels of Mmp25β expression in the trigeminal, craniofacial, and posterior lateral line ganglia in the hindbrain, and in Rohon-Beard cells in the dorsal neural tube during the first 48 h of embryonic development. Knockdown of Mmp25β expression with morpholino oligonucleotides results in larvae that are uncoordinated and insensitive to touch, and which exhibit defects in the development of sensory neural structures. Using in vivo zymography, we observe that Mmp25β morphant embryos show reduced Type IV collagen degradation in regions of the head traversed by elongating axons emanating from the trigeminal ganglion, suggesting that Mmp25β may play a pivotal role in mediating ECM remodeling in the vicinity of these elongating axons.

  17. Offspring's leukocyte telomere length, paternal age, and telomere elongation in sperm.

    Directory of Open Access Journals (Sweden)

    Masayuki Kimura

    2008-02-01

    Full Text Available Leukocyte telomere length (LTL is a complex genetic trait. It shortens with age and is associated with a host of aging-related disorders. Recent studies have observed that offspring of older fathers have longer LTLs. We explored the relation between paternal age and offspring's LTLs in 4 different cohorts. Moreover, we examined the potential cause of the paternal age on offspring's LTL by delineating telomere parameters in sperm donors. We measured LTL by Southern blots in Caucasian men and women (n=3365, aged 18-94 years, from the Offspring of the Framingham Heart Study (Framingham Offspring, the NHLBI Family Heart Study (NHLBI-Heart, the Longitudinal Study of Aging Danish Twins (Danish Twins, and the UK Adult Twin Registry (UK Twins. Using Southern blots, Q-FISH, and flow-FISH, we also measured telomere parameters in sperm from 46 young (50 years donors. Paternal age had an independent effect, expressed by a longer LTL in males of the Framingham Offspring and Danish Twins, males and females of the NHLBI-Heart, and females of UK Twins. For every additional year of paternal age, LTL in offspring increased at a magnitude ranging from half to more than twice of the annual attrition in LTL with age. Moreover, sperm telomere length analyses were compatible with the emergence in older men of a subset of sperm with elongated telomeres. Paternal age exerts a considerable effect on the offspring's LTL, a phenomenon which might relate to telomere elongation in sperm from older men. The implications of this effect deserve detailed study.

  18. Elongation, proliferation & migration differentiate endothelial cell phenotypes and determine capillary sprouting

    Directory of Open Access Journals (Sweden)

    Popel Aleksander S

    2009-01-01

    Full Text Available Abstract Background Angiogenesis, the growth of capillaries from preexisting blood vessels, has been extensively studied experimentally over the past thirty years. Molecular insights from these studies have lead to therapies for cancer, macular degeneration and ischemia. In parallel, mathematical models of angiogenesis have helped characterize a broader view of capillary network formation and have suggested new directions for experimental pursuit. We developed a computational model that bridges the gap between these two perspectives, and addresses a remaining question in angiogenic sprouting: how do the processes of endothelial cell elongation, migration and proliferation contribute to vessel formation? Results We present a multiscale systems model that closely simulates the mechanisms underlying sprouting at the onset of angiogenesis. Designed by agent-based programming, the model uses logical rules to guide the behavior of individual endothelial cells and segments of cells. The activation, proliferation, and movement of these cells lead to capillary growth in three dimensions. By this means, a novel capillary network emerges out of combinatorially complex interactions of single cells. Rules and parameter ranges are based on literature data on endothelial cell behavior in vitro. The model is designed generally, and will subsequently be applied to represent species-specific, tissue-specific in vitro and in vivo conditions. Initial results predict tip cell activation, stalk cell development and sprout formation as a function of local vascular endothelial growth factor concentrations and the Delta-like 4 Notch ligand, as it might occur in a three-dimensional in vitro setting. Results demonstrate the differential effects of ligand concentrations, cell movement and proliferation on sprouting and directional persistence. Conclusion This systems biology model offers a paradigm closely related to biological phenomena and highlights previously

  19. N=1 supersymmetry and super quantum electrodynamic in Atiyah-Ward space-time

    Energy Technology Data Exchange (ETDEWEB)

    Andrade, M.A. de; Cima, O.M. Del; Magalhaes, M.N.P.

    1994-12-01

    The supersymmetric gauge invariant action for the massive Abelian N=1 super-QED{sub 2+2} in the Atiyah-Ward space-time (D=2+2) is formulated. The questions concerning the scheme of the gauge invariance in D=2+2 by means of gauging the massive N=1 super-QED{sub 2+2} are investigated. It is studied how to ensure the gauge invariance at the expenses of the introduction of a complex vector superfield. It is discussed the Wess-Zumino gauge and thereupon we conclude that in this gauge, only the imaginary part of the complex vector field, B{sub {mu}}, gauges a U(1)-symmetry, whereas its real part gauges a Weyl symmetry. It is build up the gauge invariant massive term by introducing four scalar superfields: a pair of chiral and a pair of anti-chiral superfields; the supermultiplets of each pair have opposite U (1)-changes. It is carried out a dimensional reduction a la Scherk of the massive N=1 super-QED{sub 2+2} action from D=2+2 to D=1+2. Truncations are needed in order to suppress unphysical modes and one ends up with a parity-preserving N=1 super QED{sub 1+2} (rather than N=2) in D=1+2 which spectrum is free from tachyons and ghosts at tree-level. Finally it is show that the N=1 super-QED{sub 1+2} obtained is the supersymmetry version of the {sub {phi}3} QED. (author). 27 refs.

  20. Making a Short Story Long: Regulation of P-TEFb and HIV-1 Transcriptional Elongation in CD4+ T Lymphocytes and Macrophages

    Directory of Open Access Journals (Sweden)

    Andrew P. Rice

    2012-06-01

    Full Text Available Productive transcription of the integrated HIV-1 provirus is restricted by cellular factors that inhibit RNA polymerase II elongation. The viral Tat protein overcomes this by recruiting a general elongation factor, P-TEFb, to the TAR RNA element that forms at the 5’ end of nascent viral transcripts. P-TEFb exists in multiple complexes in cells, and its core consists of a kinase, Cdk9, and a regulatory subunit, either Cyclin T1 or Cyclin T2. Tat binds directly to Cyclin T1 and thereby targets the Cyclin T1/P-TEFb complex that phosphorylates the CTD of RNA polymerase II and the negative factors that inhibit elongation, resulting in efficient transcriptional elongation. P-TEFb is tightly regulated in cells infected by HIV-1—CD4+ T lymphocytes and monocytes/macrophages. A number of mechanisms have been identified that inhibit P-TEFb in resting CD4+ T lymphocytes and monocytes, including miRNAs that repress Cyclin T1 protein expression and dephosphorylation of residue Thr186 in the Cdk9 T-loop. These repressive mechanisms are overcome upon T cell activation and macrophage differentiation when the permissivity for HIV-1 replication is greatly increased. This review will summarize what is currently known about mechanisms that regulate P-TEFb and how this regulation impacts HIV-1 replication and latency.

  1. Micro- and Nanoscale Capacitors that Incorporate an Array of Conductive Elements Having Elongated Bodies

    Science.gov (United States)

    Manohara, Harish (Inventor); Del Castillo, Linda Y. (Inventor); Mojarradi, Mohammed M. (Inventor)

    2016-01-01

    Systems and methods in accordance with embodiments of the invention implement micro- and nanoscale capacitors that incorporate a conductive element that conforms to the shape of an array elongated bodies. In one embodiment, a capacitor that incorporates a conductive element that conforms to the shape of an array of elongated bodies includes: a first conductive element that conforms to the shape of an array of elongated bodies; a second conductive element that conforms to the shape of an array of elongated bodies; and a dielectric material disposed in between the first conductive element and the second conductive element, and thereby physically separates them.

  2. Engineering of methionine chain elongation part of glucoraphanin pathway in E. coli

    DEFF Research Database (Denmark)

    Mirza, Nadia Muhammad Akram; Crocoll, Christoph; Olsen, Carl Erik

    2016-01-01

    in Escherichia coli cytosol. Introduction of two plasmids encoding the methionine chain elongation pathway into E. coli resulted in production of 25mgL(-1) of dihomo-methionine. In addition to chain-elongated methionine products, side-products from chain elongation of leucine were produced. Methionine...... supplementation enhanced dihomo-methionine production to 57mgL(-1), while keeping a steady level of the chain-elongated leucine products. Engineering of the de-compartmentalized pathway of dihomo-methionine in E. coli cytosol provides an important first step for microbial production of the health...

  3. Pleiohomeotic interacts with the core transcription elongation factor Spt5 to regulate gene expression in Drosophila.

    Directory of Open Access Journals (Sweden)

    Robert Harvey

    Full Text Available The early elongation checkpoint regulated by Positive Transcription Elongation Factor b (P-TEFb is a critical control point for the expression of many genes. Spt5 interacts directly with RNA polymerase II and has an essential role in establishing this checkpoint, and also for further transcript elongation. Here we demonstrate that Drosophila Spt5 interacts both physically and genetically with the Polycomb Group (PcG protein Pleiohomeotic (Pho, and the majority of Pho binding sites overlap with Spt5 binding sites across the genome in S2 cells. Our results indicate that Pho can interact with Spt5 to regulate transcription elongation in a gene specific manner.

  4. The RNA chain elongation rate in Escherichia coli depends on the growth rate

    DEFF Research Database (Denmark)

    Vogel, Ulla; Jensen, Kaj Frank

    1994-01-01

    We determined the rates of mRNA and protein chain elongation on the lacZ gene during exponential growth on different carbon sources. The RNA chain elongation rate was calculated from measurements of the time elapsing between induction of lacZ expression and detection of specific hybridization...... with a probe near the 3' end of the mRNA. The elongation rate for the transcripts decreased 40% when the growth rate decreased by a factor of 4, and it always correlated with the rate of translation elongation. A similar growth rate dependency was seen for transcription on the infB gene and on a part...

  5. Super-Resolution Microscopy: Shedding Light on the Cellular Plasma Membrane.

    Science.gov (United States)

    Stone, Matthew B; Shelby, Sarah A; Veatch, Sarah L

    2017-02-17

    Lipids and the membranes they form are fundamental building blocks of cellular life, and their geometry and chemical properties distinguish membranes from other cellular environments. Collective processes occurring within membranes strongly impact cellular behavior and biochemistry, and understanding these processes presents unique challenges due to the often complex and myriad interactions between membrane components. Super-resolution microscopy offers a significant gain in resolution over traditional optical microscopy, enabling the localization of individual molecules even in densely labeled samples and in cellular and tissue environments. These microscopy techniques have been used to examine the organization and dynamics of plasma membrane components, providing insight into the fundamental interactions that determine membrane functions. Here, we broadly introduce the structure and organization of the mammalian plasma membrane and review recent applications of super-resolution microscopy to the study of membranes. We then highlight some inherent challenges faced when using super-resolution microscopy to study membranes, and we discuss recent technical advancements that promise further improvements to super-resolution microscopy and its application to the plasma membrane.

  6. SERF: A Simple, Effective, Robust, and Fast Image Super-Resolver From Cascaded Linear Regression.

    Science.gov (United States)

    Hu, Yanting; Wang, Nannan; Tao, Dacheng; Gao, Xinbo; Li, Xuelong

    2016-09-01

    Example learning-based image super-resolution techniques estimate a high-resolution image from a low-resolution input image by relying on high- and low-resolution image pairs. An important issue for these techniques is how to model the relationship between high- and low-resolution image patches: most existing complex models either generalize hard to diverse natural images or require a lot of time for model training, while simple models have limited representation capability. In this paper, we propose a simple, effective, robust, and fast (SERF) image super-resolver for image super-resolution. The proposed super-resolver is based on a series of linear least squares functions, namely, cascaded linear regression. It has few parameters to control the model and is thus able to robustly adapt to different image data sets and experimental settings. The linear least square functions lead to closed form solutions and therefore achieve computationally efficient implementations. To effectively decrease these gaps, we group image patches into clusters via k-means algorithm and learn a linear regressor for each cluster at each iteration. The cascaded learning process gradually decreases the gap of high-frequency detail between the estimated high-resolution image patch and the ground truth image patch and simultaneously obtains the linear regression parameters. Experimental results show that the proposed method achieves superior performance with lower time consumption than the state-of-the-art methods.

  7. One-Dimensional Super Calabi-Yau Manifolds and their Mirrors

    CERN Document Server

    Noja, Simone; Piazza, Francesco Dalla; Marrani, Alessio; Re, Riccardo

    2016-01-01

    We apply a definition of generalised super Calabi-Yau variety (SCY) to supermanifolds of complex dimension one. We get that the class of all SCY's of bosonic dimension one and reduced manifold equal to $\\mathbb{P}^1$ is given by $\\mathbb{P}^{1|2} $ and the weighted projective super space $\\mathbb{WP}^{1|1}_{(2)}$. Then we compute the corresponding sheaf cohomology of superforms, showing that the cohomology with picture number one is infinite dimensional, while the de Rham cohomology remains finite dimensional. Moreover, we provide the complete real and holomorphic de Rham cohomology for generic projective super spaces $\\mathbb P^{n|m}$. We also determine the automorphism groups, which for $\\mathbb{P}^{1|2} $ results to be larger than the projective supergroup. Finally, we show that $\\mathbb{P}^{1|2} $ is self mirror, whereas $\\mathbb{WP} ^{1|1}_{(2)}$ has a zero dimensional mirror. The mirror map for $\\mathbb{P}^{1|2}$ endows it with a structure of $N=2$ super Riemann surface.

  8. Novel optical super-resolution pattern with upright edges diffracted by a tiny thin aperture.

    Science.gov (United States)

    Wu, Jiu Hui; Zhou, Kejiang

    2015-08-24

    In the past decade numerous efforts have been concentrated to achieve optical imaging resolution beyond the diffraction limit. In this letter a thin microcavity theory of near-field optics is proposed by using the power flow theorem firstly. According to this theory, the near-field optical diffraction from a tiny aperture whose diameter is less than one-tenth incident wavelength embedded in a thin conducting film is investigated by considering this tiny aperture as a thin nanocavity. It is very surprising that there exists a kind of novel super-resolution diffraction patterns showing resolution better than λ/80 (λ is the incident wavelength), which is revealed for the first time to our knowledge in this letter. The mechanism that has allowed the imaging with this kind of super-resolution patterns is due to the interaction between the incident wave and the thin nanocavity with a complex wavenumber. More precisely, these super-resolution patterns with discontinuous upright peaks are formed by one or three items of the integration series about the cylindrical waves according to our simulation results. This novel optical super-resolution with upright edges by using the thin microcavity theory presented in the study could have potential applications in the future semiconductor lithography process, nano-size laser-drilling technology, microscopy, optical storage, optical switch, and optical information processing.

  9. SuperTools Test and Evaluation Plan

    Energy Technology Data Exchange (ETDEWEB)

    Mannos, Tom J. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States). Mixed Signal ASIC Design

    2017-01-01

    Superconducting electronics (SCE) represents a potential path to efficient exascale computing for HPC and data center applications, but SCE-based circuit design lags far behind its CMOS equivalent. IARPA’s ongoing C3 program and its developing SuperTools program aim to jumpstart SCE R&D with the near-term goal of producing a high-speed, low-energy, 64-bit RISC processor using Josephson Junction based logic cells. SuperTools performers will develop software tools for efficient SCE design and accurate simulation and characterization of JJ-based circuits, which include the RSFQ, RQL, and AQFP logic families. T&E teams from NIST, MIT Lincoln Lab, Berkeley Lab, and Sandia National Labs will evaluate the tools and fabricate test circuits to compare with simulated results. The five-year, three-phase program includes 48 performer deliverables, three annual technical exchange meetings, and annual site visits.

  10. Italian super-eruption larger than thought

    Science.gov (United States)

    Schultz, Colin

    2012-07-01

    Recent research suggested that the super-eruption of the Campi Flegrei caldera volcano in southern Italy about 40,000 years ago may have played a part in wiping out, or forcing the migration of, the Neanderthal and modern human populations in the eastern Mediterranean regions that were covered in ash. Now a new modeling study by Costa et al. suggests that this eruption may have been even larger than previously thought. This Campi Flegrei eruption produced a widespread ash layer known as Campanian Ignimbrite (CI). Using ash thickness measurements collected at 115 sites and a three-dimensional ash dispersal model, the researchers found that the CI super-eruption would have spread 250-300 cubic kilometers of ash across a 3.7-million-square kilometer region—2 to 3 times previous ash volume estimates.

  11. Optical super-resolution microscopy in neurobiology.

    Science.gov (United States)

    Sigrist, Stephan J; Sabatini, Bernardo L

    2012-02-01

    Understanding the highly plastic nature of neurons requires the dynamic visualization of their molecular and cellular organization in a native context. However, due to the limited resolution of standard light microscopy, many of the structural specializations of neurons cannot be resolved. A recent revolution in light microscopy has given rise to several super-resolution light microscopy methods yielding 2-10-fold higher resolution than conventional microscopy. We here describe the principles behind these techniques as well as their application to the analysis of the molecular architecture of the synapse. Furthermore, we discuss the potential for continued development of super-resolution microscopy as necessary for live imaging of neuronal structure and function in the brain.

  12. Super-resolution microscopy: a comparative treatment.

    Science.gov (United States)

    Kasuboski, James M; Sigal, Yury J; Joens, Matthew S; Lillemeier, Bjorn F; Fitzpatrick, James A J

    2012-10-01

    One of the fundamental limitations of optical microscopy is that of diffraction, or in essence, how small a beam of light can be focused by using an optical lens system. This constraint, or barrier if you will, was theoretically described by Ernst Abbe in 1873 and is roughly equal to half the wavelength of light used to probe the system. Many structures, particularly those within cells, are much smaller than this limit and thus are difficult to visualize. Over the last two decades, a new field of super-resolution imaging has been created and been developed into a broad range of techniques that allow routine imaging beyond the far-field diffraction limit of light. In this unit we outline the basic principles of the various super-resolution imaging modalities, paying particular attention to the technical considerations for biological imaging. Furthermore, we discuss their various applications in the imaging of both fixed and live biological samples.

  13. (Super-)renormalizably dressed black holes

    CERN Document Server

    Ayón-Beato, Eloy; Méndez-Zavaleta, Julio A

    2015-01-01

    Black holes supported by self-interacting conformal scalar fields can be considered as renormalizably dressed since the conformal potential is nothing but the top power-counting renormalizable self-interaction in the relevant dimension. On the other hand, potentials defined by powers which are lower than the conformal one are also phenomenologically relevant since they are in fact super-renormalizable. In this work we provide a new map that allows to build black holes dressed with all the (super-)renormalizable contributions starting from known conformal seeds. We explicitly construct several new examples of these solutions in dimensions $D=3$ and $D=4$, including not only stationary configurations but also time-dependent ones.

  14. Super/subradiant second harmonic generation

    Science.gov (United States)

    Koganov, Gennady A.; Shuker, Reuben

    2017-04-01

    A scheme for active second harmonics generation is suggested. The system comprises N three-level atoms in ladder configuration, situated into a resonant cavity. The system generates the field whose frequency is twice the frequency of the pumping laser, and the field phase is locked to the phase of the pumping field. It is found that the system can lase in either superradiant or subradiant regime, depending on the number of atoms N. When N passes some critical value the transition from the super to subradiance occurs in a phase-transition-like manner. Stability study of the steady state supports this conclusion. For experimental realization of the super/subradiant second harmonics generation we propose semiconductor quantum well structures, superconducting quantum circuits, and evanescently coupled waveguides in which equally spaced levels relevant to this study exist.

  15. Pulsating stars in SuperWASP

    Directory of Open Access Journals (Sweden)

    Holdsworth Daniel L.

    2017-01-01

    Full Text Available SuperWASP is one of the largest ground-based surveys for transiting exoplanets. To date, it has observed over 31 million stars. Such an extensive database of time resolved photometry holds the potential for extensive searches of stellar variability, and provide solid candidates for the upcoming TESS mission. Previous work by e.g. [15], [5], [12] has shown that the WASP archive provides a wealth of pulsationally variable stars. In this talk I will provide an overview of the SuperWASP project, present some of the published results from the survey, and some of the on-going work to identify key targets for the TESS mission.

  16. Robust super-resolution without regularization

    Energy Technology Data Exchange (ETDEWEB)

    Pham, T Q [Canon Information Systems Research Australia, 1 Thomas Holt drive, North Ryde, NSW 2113 (Australia); Vliet, L J v [Quantitative Imaging Group, Department of Imaging Science and Technology, Faculty of Applied Sciences, Delft University of Technology, Lorentzweg 1, 2628 CJ Delft (Netherlands); Schutte, K [Electro-Optics Group, TNO Defence, Security and Safety, PO Box 96864, 2509 JG The Hague (Netherlands)

    2008-07-15

    Super-resolution restoration is the problem of restoring a high-resolution scene from multiple degraded low-resolution images under motion. Due to imaging blur and noise, this problem is ill-posed. Additional constraints such as smoothness of the solution (i.e. regularization) is often required to obtain a stable solution. While regularizing the cost function is a standard practice in image restoration, we propose a restoration algorithm that does not require this extra regularization term. The robustness of the algorithm is achieved by a robust error norm that does not response to intensity outliers. With the outliers suppressed, our solution behaves similarly to a maximum-likelihood solution under the presence of Gaussian noise. The effectiveness of our algorithm is demonstrated with super-resolution restoration of real infrared image sequences under severe aliasing and intensity outliers.

  17. Penrose Pixels for Super-Resolution.

    Science.gov (United States)

    Ben-Ezra, M; Lin, Zhouchen; Wilburn, Bennett; Zhang, Wei

    2011-07-01

    We present a novel approach to reconstruction-based super-resolution that uses aperiodic pixel tilings, such as a Penrose tiling or a biological retina, for improved performance. To this aim, we develop a new variant of the well-known error back projection super-resolution algorithm that makes use of the exact detector model in its back projection operator for better accuracy. Pixels in our model can vary in shape and size, and there may be gaps between adjacent pixels. The algorithm applies equally well to periodic or aperiodic pixel tilings. We present analysis and extensive tests using synthetic and real images to show that our approach using aperiodic layouts substantially outperforms existing reconstruction-based algorithms for regular pixel arrays. We close with a discussion of the feasibility of manufacturing CMOS or CCD chips with pixels arranged in Penrose tilings.

  18. Temporal super resolution using variational methods

    DEFF Research Database (Denmark)

    Keller, Sune Høgild; Lauze, Francois Bernard; Nielsen, Mads

    2010-01-01

    and intensities are calculated simultaneously in a multiresolution setting. A frame doubling version of our algorithm is implemented and in testing it, we focus on making the motion of high contrast edges to seem smooth and thus reestablish the illusion of motion pictures.......Temporal super resolution (TSR) is the ability to convert video from one frame rate to another and is as such a key functionality in modern video processing systems. A higher frame rate than what is recorded is desired for high frame rate displays, for super slow-motion, and for video/film format...... conversion (where also lower frame rates than recorded is sometimes required). We discuss and detail the requirements imposed by the human visual system (HVS) on TSR algorithms, of which the need for (apparent) fluid motion, also known as the phi-effect, is the principal one. This problem is typically...

  19. Structural basis of transcription: An RNA polymerase II elongation complex at 3.3 Å resolution

    OpenAIRE

    Gnatt, A; Cramer, P; Fu, J.; Bushnell, D; Kornberg, R

    2001-01-01

    The crystal structure of RNA polymerase II in the act of transcription was determined at 3.3  resolution. Duplex DNA is seen entering the main cleft of the enzyme and unwinding before the active site. Nine base pairs of DNA-RNA hybrid extend from the active center at nearly right angles to the entering DNA, with the 39 end of the RNA in the nucleotide addition site. The 39 end is positioned above a pore, through which nucleotides may enter and through which RNA may be extruded during back-tr...

  20. Structural Model of RNA Polymerase II Elongation Complex with Complete Transcription Bubble Reveals NTP Entry Routes.

    Directory of Open Access Journals (Sweden)

    Lu Zhang

    2015-07-01

    Full Text Available The RNA polymerase II (Pol II is a eukaryotic enzyme that catalyzes the synthesis of the messenger RNA using a DNA template. Despite numerous biochemical and biophysical studies, it remains elusive whether the "secondary channel" is the only route for NTP to reach the active site of the enzyme or if the "main channel" could be an alternative. On this regard, crystallographic structures of Pol II have been extremely useful to understand the structural basis of transcription, however, the conformation of the unpaired non-template DNA part of the full transcription bubble (TB is still unknown. Since diffusion routes of the nucleoside triphosphate (NTP substrate through the main channel might overlap with the TB region, gaining structural information of the full TB is critical for a complete understanding of Pol II transcription process. In this study, we have built a structural model of Pol II with a complete transcription bubble based on multiple sources of existing structural data and used Molecular Dynamics (MD simulations together with structural analysis to shed light on NTP entry pathways. Interestingly, we found that although both channels have enough space to allow NTP loading, the percentage of MD conformations containing enough space for NTP loading through the secondary channel is twice higher than that of the main channel. Further energetic study based on MD simulations with NTP loaded in the channels has revealed that the diffusion of the NTP through the main channel is greatly disfavored by electrostatic repulsion between the NTP and the highly negatively charged backbones of nucleotides in the non-template DNA strand. Taken together, our results suggest that the secondary channel is the major route for NTP entry during Pol II transcription.

  1. Structural Model of RNA Polymerase II Elongation Complex with Complete Transcription Bubble Reveals NTP Entry Routes.

    Science.gov (United States)

    Zhang, Lu; Silva, Daniel-Adriano; Pardo-Avila, Fátima; Wang, Dong; Huang, Xuhui

    2015-07-01

    The RNA polymerase II (Pol II) is a eukaryotic enzyme that catalyzes the synthesis of the messenger RNA using a DNA template. Despite numerous biochemical and biophysical studies, it remains elusive whether the "secondary channel" is the only route for NTP to reach the active site of the enzyme or if the "main channel" could be an alternative. On this regard, crystallographic structures of Pol II have been extremely useful to understand the structural basis of transcription, however, the conformation of the unpaired non-template DNA part of the full transcription bubble (TB) is still unknown. Since diffusion routes of the nucleoside triphosphate (NTP) substrate through the main channel might overlap with the TB region, gaining structural information of the full TB is critical for a complete understanding of Pol II transcription process. In this study, we have built a structural model of Pol II with a complete transcription bubble based on multiple sources of existing structural data and used Molecular Dynamics (MD) simulations together with structural analysis to shed light on NTP entry pathways. Interestingly, we found that although both channels have enough space to allow NTP loading, the percentage of MD conformations containing enough space for NTP loading through the secondary channel is twice higher than that of the main channel. Further energetic study based on MD simulations with NTP loaded in the channels has revealed that the diffusion of the NTP through the main channel is greatly disfavored by electrostatic repulsion between the NTP and the highly negatively charged backbones of nucleotides in the non-template DNA strand. Taken together, our results suggest that the secondary channel is the major route for NTP entry during Pol II transcription.

  2. Stability of RNA chain elongation complexes formed with RNA polymerase and denatured DNA templates.

    Directory of Open Access Journals (Sweden)

    Misumi,Hiromasa

    1989-12-01

    Full Text Available In vivo inactivation of cystathionine gamma-lyase by D,L-propargylglycine, a suicide inhibitor, was found to be less profound in rat kidney than in the liver. We investigated the cause of this difference using rat tissues. We fractionated kidney extract to characterize the substance which protected enzyme, and found that cysteine exhibits protecting action. Addition of 0.3 mM L-cysteine to the incubation mixture containing dialyzed kidney supernatant and 0.5 mM D,L-propargylglycine resulted in the protection of cystathionine gamma-lyase from the inactivation by the inhibitor. The content of cysteine in the kidney was six-fold higher than that in the liver. Thus, we have concluded that one of the reasons why the in vivo inactivation of cystathionine gamma-lyase in rat kidney was less than that in the liver is the presence of a higher concentration of cysteine in the kidney. S-Carboxymethylcysteine, a cysteine derivative, exhibited a similar, but weaker, protective effect.

  3. Super-pharm的生意经

    Institute of Scientific and Technical Information of China (English)

    韦少雯

    2006-01-01

    Super-pharm,这家可直译为“超级药店”的以色列最大的药品、化妆品及个人护理品零售企业,是由全球排名前几十位的亿万富翁、犹太人Murray Koffler创立的家族企业。

  4. Super Resolution Imaging Applied to Scientific Images

    Science.gov (United States)

    2007-05-01

    investigator, (3) development of Papoulis -Gerchberg method to implement the analytic continuation of spectral details, (4) exploration of contourlet and...off with noise present in the observation. In [30] we make use of Papoulis -Gerchberg algorithm of signal extrapolation to perform Image super...we have used a training database consisting of high resolution images. For Papoulis -Gerchberg method number of iterations and the filter used both

  5. The SuperNova Early Warning System

    OpenAIRE

    Scholberg, K.

    2008-01-01

    A core collapse in the Milky Way will produce an enormous burst of neutrinos in detectors world-wide. Such a burst has the potential to provide an early warning of a supernova's appearance. I will describe the nature of the signal, the sensitivity of current detectors, and SNEWS, the SuperNova Early Warning System, a network designed to alert astronomers as soon as possible after the detected neutrino signal.

  6. (Super-)renormalizably dressed black holes

    OpenAIRE

    Ayón-Beato, Eloy; Hassaïne, Mokhtar; Méndez-Zavaleta, Julio A.

    2015-01-01

    Black holes supported by self-interacting conformal scalar fields can be considered as renormalizably dressed since the conformal potential is nothing but the top power-counting renormalizable self-interaction in the relevant dimension. On the other hand, potentials defined by powers which are lower than the conformal one are also phenomenologically relevant since they are in fact super-renormalizable. In this work we provide a new map that allows to build black holes dressed with all the (su...

  7. Dating With Super Junior-M

    Institute of Scientific and Technical Information of China (English)

    2009-01-01

    担心情人节没人陪?还在幻想能与谁约会?2009年2月14日,梦想照进现实,SJ-M将在上海举办“情人Superman-Super Junior-M 2009上海歌会”,化身你的甜蜜情人,与你一起共度浪漫情人节。

  8. Super-Kamiokande - Present and Future

    Energy Technology Data Exchange (ETDEWEB)

    Suzuki, Y. [Kamioka Observatory, Institute for Cosmic Ray Research, University of Tokyo, Higashi-Mozumi, Kamioka-chou, Hida-city, Gifu 506-1205 (Japan)

    2004-12-15

    We summarize the latest results on the atmospheric and solar neutrinos from Super-Kamiokande. The atmospheric neutrino oscillation analyses with two flavors and with three flavor are discussed and the new results based on the L/E analysis are shown. New solar neutrino results based on the un-binned method is discussed. The current status of SK-II and the future prospects for SK neutrino oscillation experiment are summarized.

  9. The (Super)String Theories' Problems

    CERN Document Server

    Naboulsi, R

    2003-01-01

    (Super)String theories are theoretical ideas that go beyond the standard model of particle and high energy physics and show promise for unifying all forces in nature including the gravitational one. In this unification a prominent role is played by the duality symmetries which relate different theories. I present a review of these developements and discuss their problems and possible impact in low-energy physics. We explain and discuss some ideas concerning string field theories from noncommutative geometry.

  10. T-Duality from super Lie n-algebra cocycles for super p-branes

    CERN Document Server

    Fiorenza, Domenico; Schreiber, Urs

    2016-01-01

    We compute the $L_\\infty$-theoretic dimensional reduction of the F1/D$p$-brane super $L_\\infty$-cocycles with coefficients in rationalized twisted K-theory from the 10d type IIA and type IIB super Lie algebras down to 9d. We show that the two resulting coefficient $L_\\infty$-algebras are naturally related by an $L_\\infty$-isomorphism which we find to act on the super $p$-brane cocycles by the infinitesimal version of the rules of topological T-duality and inducing an isomorphism between $K^0$ and $K^1$, rationally. Moreover, we show that these $L_\\infty$-algebras are the homotopy quotients of the RR-charge coefficients by the "T-duality Lie 2-algebra". We find that the induced $L_\\infty$-extension is a gerby extension of a 9+(1+1) dimensional (i.e. "doubled") T-duality correspondence super-spacetime, which serves as a local model for T-folds. We observe that this still extends, via the D0-brane cocycle of its type IIA factor, to a 10+(1+1)-dimensional super Lie algebra. Finally we observe that this satisfies ...

  11. SuperB Progress Reports - Physics

    CERN Document Server

    O'Leary, B.; Ramon, M.; Pous, E.; De Fazio, F.; Palano, A.; Eigen, G.; Asgeirsson, D.; Cheng, C.H.; Chivukula, A.; Echenard, B.; Hitlin, D.G.; Porter, F.; Rakitin, A.; Heinemeyer, S.; McElrath, B.; Andreassen, R.; Meadows, B.; Sokoloff, M.; Blanke, M.; Lesiak, T.; Shindou, T.; Ronga, F.; Baldini, W.; Bettoni, D.; Calabrese, R.; Cibinetto, G.; Luppi, E.; Rama, M.; Bossi, F.; Guido, E.; Patrignani, C.; Tosi, S.; Davies, C.; Lunghi, E.; Haisch, U.; Hurth, T.; Westhoff, S.; Crivellin, A.; Hofer, L.; Goto, T.; Brown, David Nathan; Branco, G.C.; Zupan, J.; Herrero, M.; Rodriguez-Sanchez, A.; Simi, G.; Tackmann, F.J.; Biassoni, P.; Lazzaro, A.; Lombardo, V.; Palombo, F.; Stracka, S.; Lindemann, D.M.; Robertson, S.H.; Duling, B.; Gemmler, K.; Gorbahn, M.; Jager, S.; Paradisi, P.; Straub, D.M.; Bigi, I.; Asner, D.M.; Fast, J.E.; Kouzes, R.T.; Morandin, M.; Rotondo, M.; Ben-Haim, E.; Arnaud, N.; Burmistrov, L.; Kou, E.; Perez, A.; Stocchi, A.; Viaud, B.; Domingo, F.; Piccinini, F.; Manoni, E.; Batignani, G.; Cervelli, A.; Forti, F.; Giorgi, M.; Lusiani, A.; Oberhof, B.; Paoloni, E.; Neri, N.; Walsh, J.; Bevan, A.; Bona, M.; Walker, C.; Weiland, C.; Lenz, A.; Gonzalez-Sprinberg, G.; Faccini, R.; Renga, F.; Polosa, A.; Silvestrini, L.; Virto, J.; Ciuchini, M.; Lubicz, V.; Tarantino, C.; Wilson, F.F.; Carpinelli, M.; Huber, T.; Mannel, T.; Graham, M.; Ratcliff, B.N.; Santoro, V.; Sekula, S.; Shougaev, K.; Soffer, A.; Shimizu, Y.; Gambino, P.; Mussa, R.; Nardecchia, M.; Stal, O.; Bernabeu, J.; Botella, F.; Jung, M.; Lopez March, N.; Martinez Vidal, F.; Oyanguren, A.; Pich, A.; Lozano, M.A.Sanchis; Vidal, J.; Vives, O.; Banerjee, S.; Roney, J.M.; Petrov, A.A.; Flood, K.

    2010-01-01

    SuperB is a high luminosity e+e- collider that will be able to indirectly probe new physics at energy scales far beyond the reach of any man made accelerator planned or in existence. Just as detailed understanding of the Standard Model of particle physics was developed from stringent constraints imposed by flavour changing processes between quarks, the detailed structure of any new physics is severely constrained by flavour processes. In order to elucidate this structure it is necessary to perform a number of complementary studies of a set of golden channels. With these measurements in hand, the pattern of deviations from the Standard Model behavior can be used as a test of the structure of new physics. If new physics is found at the LHC, then the many golden measurements from SuperB will help decode the subtle nature of the new physics. However if no new particles are found at the LHC, SuperB will be able to search for new physics at energy scales up to 10-100 TeV. In either scenario, flavour physics measure...

  12. Super Marx Generator for Thermonuclear Ignition

    CERN Document Server

    Winterberg, Friedwardt

    2008-01-01

    In ongoing electric pulse power driven inertial confinement fusion experiments, Marx generators are connected in parallel with the target in the center of a ring of the Marx generators. There the currents, not the voltages add up. Instead of connecting a bank of Marx generator in parallel, one may connect them in series, adding up their voltages, not the currents. If, for example, fifty 20 MV Marx generators are connected in series, they would add up to a gigavolt. But to prevent breakdown, the adding up of the voltages in such a super-Marx generator must be fast. For this reason, it is proposed that each of the Marx generators charges up a fast discharge capacitor, with the thusly charged fast capacitors becoming the elements of a second stage super Marx generator. In a super Marx generator, the Marx generators also assume the role of the resistors in the original Marx circuit. With a voltage of 10^9 Volt and a discharge current of 10^7 Ampere, the generation of a 10^16 Watt GeV proton beam becomes possible,...

  13. The SuperNEMO tracking detector

    CERN Document Server

    Cascella, M

    2015-01-01

    The SuperNEMO detector will search for neutrinoless double beta decay at the Modane Underground Laboratory on the French-Italian border. This decay mode, if observed, would be proof that the neutrino is its own antiparticle, would constitute evidence for total lepton number violation, and could allow a measurement of the absolute neutrino mass. The SuperNEMO experiment is designed to reach a half-life sensitivity of $10^{26}$ years corresponding to an effective Majorana neutrino mass of $50-100~$meV. The SuperNEMO detector design allows complete topological reconstruction of the double beta decay event enabling excellent levels of background rejection. In the event of a discovery, such topological measurements will be vital in determining the nature of the lepton number violating process. This reconstruction will be performed by a gaseous tracking detector, consisting of 2034 drift cells per module operated in Geiger mode. The tracker of the Demonstrator Module is currently under construction in the UK. This ...

  14. SuperB Technical Design Report

    CERN Document Server

    Baszczyk, M; Kolodziej, J; Kucewicz, W; Sapor, M; Jeremie, A; Pous, E Grauges; Bruno, G E; De Robertis, G; Diacono, D; Donvito, G; Fusco, P; Gargano, F; Giordano, F; Loddo, F; Loparco, F; Maggi, G P; Manzari, V; Mazziotta, M N; Nappi, E; Palano, A; Santeramo, B; Sgura, I; Silvestris, L; Spinoso, V; Eigen, G; Zalieckas, J; Zhuo, Z; Jenkovszky, L; Balbi, G; Boldini, M; Bonacorsi, D; Cafaro, V; D'Antone, I; Dallavalle, G M; Di Sipio, R; Fabbri, F; Fabbri, L; Gabrielli, A; Galli, D; Giacomelli, P; Giordano, V; Giorgi, F M; Grandi, C; Lax, I; Meo, S Lo; Marconi, U; Montanari, A; Pellegrini, G; Piccinini, M; Rovelli, T; Cesari, N Semprini; Torromeo, G; Tosi, N; Travaglini, R; Vagnoni, V M; Valentinetti, S; Villa, M; Zoccoli, A; Caron, J -F; Hearty, C; Lu, P F -T; Mattison, T S; McKenna, J A; So, R Y -C; Barnyakov, M Yu; Blinov, V E; Botov, A A; Druzhinin, V P; Golubev, V B; Kononov, S A; Kravchenko, E A; Levichev, E B; Onuchin, A P; Serednyakov, S I; Shtol, D A; Skovpen, Y I; Solodov, E P; Cardini, A; Carpinelli, M; Chao, D S -T; Cheng, C H; Doll, D A; Echenard, B; Flood, K; Hanson, J; Hitlin, D G; Ongmongkolkul, P; Porter, F C; Zhu, R Y; Randazzo, N; Burelo, E De La Cruz; Zheng, Y; Campos, P; De Silva, M; Kathirgamaraju, A; Meadows, B; Pushpawela, B; Shi, Y; Sokoloff, M; Castro, G Lopez; Ciaschini, V; Franchini, P; Giacomini, F; Paolini, A; Polania, G A Calderon; Laczek, S; Romanowicz, P; Szybinski, B; Czuchry, M; Flis, L; Harezlak, D; Kocot, J; Radecki, M; Sterzel, M; Szepieniec, T; Szymocha, T; Wójcik, P; Andreotti, M; Baldini, W; Calabrese, R; Carassiti, V; Cibinetto, G; Ramusino, A Cotta; Evangelisti, F; Gianoli, A; Luppi, E; Malaguti, R; Manzali, M; Melchiorri, M; Munerato, M; Padoan, C; Santoro, V; Tomassetti, L; Beretta, M M; Biagini, M; Boscolo, M; Capitolo, E; de Sangro, R; Esposito, M; Felici, G; Finocchiaro, G; Gatta, M; Gatti, C; Guiducci, S; Lauciani, S; Patteri, P; Peruzzi, I; Piccolo, M; Raimondi, P; Rama, M; Sanelli, C; Tomassini, S; Fabbricatore, P; Delepine, D; Santos, M A Reyes; Chrzaszcz, M; Grzymkowski, R; Knap, P; Kotula, J; Lesiak, T; Ludwin, J; Michalowski, J; Pawlik, B; Rachwal, B; Stodulski, M; Wiechczynski, J; Witek, M; Zawiejski, L; Zdybal, M; Aushev, V Y; Ustynov, A; Arnaud, N; Bambade, P; Beigbeder, C; Bogard, F; Borsato, M; Breton, D; Brossard, J; Burmistrov, L; Charlet, D; Chaumat, V; Dadoun, O; Berni, M El; Maalmi, J; Puill, V; Rimbault, C; Stocchi, A; Tocut, V; Variola, A; Wallon, S; Wormser, G; Grancagnolo, F; Ben-Haim, E; Sitt, S; Baylac, M; Bourrion, O; Deconto, J -M; Martinez, Y Gomez; Monseu, N; Muraz, J -F; Real, J -S; Vescovi, C; Cenci, R; Jawahery, A; Roberts, D; Twedt, E W; Cheaib, R; Lindemann, D; Nderitu, S; Patel, P; Robertson, S H; Swersky, D; Warburton, A; Flores, E Cuautle; Sanchez, G Toledo; Biassoni, P; Bombelli, L; Citterio, M; Coelli, S; Fiorini, C; Liberali, V; Monti, M; Nasri, B; Neri, N; Palombo, F; Sabatini, F; Stabile, A; Berra, A; Giachero, A; Gotti, C; Lietti, D; Maino, M; Pessina, G; Prest, M; Martin, J -P; Simard, M; Starinski, N; Taras, P; Drutskoy, A; Makarychev, S; Nefediev, A V; Aloisio, A; Cavaliere, S; De Nardo, G; Della Pietra, M; Doria, A; Giordano, R; Ordine, A; Pardi, S; Russo, G; Sciacca, C; Bigi, I I; Jessop, C P; Wang, W; Bellato, M; Benettoni, M; Corvo, M; Crescente, A; Corso, F Dal; Dosselli, U; Fanin, C; Gianelle, A; Longo, S; Michelotto, M; Montecassiano, F; Morandin, M; Pengo, R; Posocco, M; Rotondo, M; Simi, G; Stroili, R; Gaioni, L; Manazza, A; Manghisoni, M; Ratti, L; Re, V; Traversi, G; Zucca, S; Bizzaglia, S; Bizzarri, M; Cecchi, C; Germani, S; Lebeau, M; Lubrano, P; Manoni, E; Papi, A; Rossi, A; Scolieri, G; Batignani, G; Bettarini, S; Casarosa, G; Cervelli, A; Fella, A; Forti, F; Giorgi, M; Lilli, L; Lusiani, A; Oberhof, B; Paladino, A; Pantaleo, F; Paoloni, E; Perez, A L Perez; Rizzo, G; Walsh, J; Téllez, A Fernández; Beck, G; Berman, M; Bevan, A; Gannaway, F; Inguglia, G; Martin, A J; Morris, J; Bocci, V; Capodiferro, M; Chiodi, G; Dafinei, I; Drenska, N V; Faccini, R; Ferroni, F; Gargiulo, C; Gauzzi, P; Luci, C; Lunadei, R; Martellotti, G; Pellegrino, F; Pettinacci, V; Pinci, D; Recchia, L; Ruggeri, D; Zullo, A; Camarri, P; Cardarelli, R; De Santis, C; Di Ciaccio, A; Di Felice, V; Di Palma, F; Di Simone, A; Marcelli, L; Messi, R; Moricciani, D; Sparvoli, R; Tammaro, S; Branchini, P; Budano, A; Bussino, S; Ciuchini, M; Nguyen, F; Passeri, A; Ruggieri, F; Spiriti, E; Wilson, F; Monzon, I Leon; Millan-Almaraz, J R; Podesta-Lerma, P L M; Aston, D; Dey, B; Fisher, A; Jackson, P D; Leith, D W G S; Luitz, S; MacFarlane, D; McCulloch, M; Metcalfe, S; Novokhatski, A; Osier, S; Prepost, R; Ratcliff, B; Seeman, J; Sullivan, M; Va'vra, J; Wienands, U; Wisniewski, W; Altschul, B D; Purohit, M V; Baudot, J; Ripp-Baudot, I; Cirrone, G A P; Cuttone, G; Bezshyyko, O; Dolinska, G; Soffer, A; Bianchi, F; De Mori, F; Filippi, A; Gamba, D; Marcello, S; Bomben, M; Bosisio, L; Cristaudo, P; Lanceri, L; Liberti, B; Rashevskaya, I; Stella, C; Vallazza, E S; Vitale, L; Auriemma, G; Satriano, C; Vidal, F Martinez; de Cos, J Mazorra; Oyanguren, A; Valls, P Ruiz; Beaulieu, A; Dejong, S; Franta, J; Lewczuk, M J; Roney, M; Sobie, R

    2013-01-01

    In this Technical Design Report (TDR) we describe the SuperB detector that was to be installed on the SuperB e+e- high luminosity collider. The SuperB asymmetric collider, which was to be constructed on the Tor Vergata campus near the INFN Frascati National Laboratory, was designed to operate both at the Upsilon(4S) center-of-mass energy with a luminosity of 10^{36} cm^{-2}s^{-1} and at the tau/charm production threshold with a luminosity of 10^{35} cm^{-2}s^{-1}. This high luminosity, producing a data sample about a factor 100 larger than present B Factories, would allow investigation of new physics effects in rare decays, CP Violation and Lepton Flavour Violation. This document details the detector design presented in the Conceptual Design Report (CDR) in 2007. The R&D and engineering studies performed to arrive at the full detector design are described, and an updated cost estimate is presented. A combination of a more realistic cost estimates and the unavailability of funds due of the global economic ...

  15. Predicting the occurrence of super-storms

    Directory of Open Access Journals (Sweden)

    N. Srivastava

    2005-11-01

    Full Text Available A comparative study of five super-storms (Dst<-300 nT of the current solar cycle after the launch of SoHO, to identify solar and interplanetary variables that influence the magnitude of resulting geomagnetic storms, is described. Amongst solar variables, the initial speed of a CME is considered the most reliable predictor of the strength of the associated geomagnetic storm because fast mass ejections are responsible for building up the ram pressure at the Earth's magnetosphere. However, although most of the super-storms studied were associated with high speed CMEs, the Dst index of the resulting geomagnetic storms varied between -300 to -472 nT. The most intense storm of 20 November 2003, (Dst ~ -472 nT had its source in a comparatively smaller active region and was associated with a relatively weaker, M-class flare while all other super-storms had their origins in large active regions and were associated with strong X-class flares. However, this superstorm did not show any associated extraordinary solar and interplanetary characteristics. The study also reveals the challenge in the reliable prediction of the magnitude of a geomagnetic storm from solar and interplanetary variables.

  16. Structure and freezing of a fluid of long elongated molecules

    Energy Technology Data Exchange (ETDEWEB)

    Mishra, Pankaj; Ram, Jokhan; Singh, Yashwant [Department of Physics, Banaras Hindu University, Varanasi-221 005 (India)

    2004-03-17

    The pair correlation functions of a fluid of long elongated molecules interacting via the Gay-Berne pair potential are calculated using the Percus-Yevick integral equation theory. Numerical accuracy has been examined by considering a large number of spherical harmonic coefficients for each orientation-dependent functions for a system of molecules having a length-to-breadth ratio equal to 4.4 at different densities and temperatures. The pair correlation functions of the isotropic fluid found from the Percus-Yevick theory have been used in the density-functional theory to locate the isotropic-nematic, isotropic-smectic A and nematic-smectic A transitions. It is found that at low temperatures the fluid freezes directly into the smectic A phase on increasing the density. The nematic phase is found to stabilize in between the isotropic and smectic A phases only at high temperatures and high densities. The calculated phase diagram is in good qualitative agreement with computer simulation results.

  17. APOBEC3G inhibits elongation of HIV-1 reverse transcripts.

    Directory of Open Access Journals (Sweden)

    Kate N Bishop

    2008-12-01

    Full Text Available APOBEC3G (A3G is a host cytidine deaminase that, in the absence of Vif, restricts HIV-1 replication and reduces the amount of viral DNA that accumulates in cells. Initial studies determined that A3G induces extensive mutation of nascent HIV-1 cDNA during reverse transcription. It has been proposed that this triggers the degradation of the viral DNA, but there is now mounting evidence that this mechanism may not be correct. Here, we use a natural endogenous reverse transcriptase assay to show that, in cell-free virus particles, A3G is able to inhibit HIV-1 cDNA accumulation not only in the absence of hypermutation but also without the apparent need for any target cell factors. We find that although reverse transcription initiates in the presence of A3G, elongation of the cDNA product is impeded. These data support the model that A3G reduces HIV-1 cDNA levels by inhibiting synthesis rather than by inducing degradation.

  18. Amplitude-dependent contraction/elongation of nonlinear Lamb waves

    Science.gov (United States)

    Packo, Pawel; Staszewski, Wieslaw J.; Uhl, Tadeusz; Leamy, Michael J.

    2016-04-01

    Nonlinear elastic guided waves find application in various disciplines of science and engineering, such as non- destructive testing and structural health monitoring. Recent recognition and quantification of their amplitude- dependent changes in spectral properties has contributed to the development of new monitoring concepts for mechanical structures. The focus of this work is to investigate and predict amplitude-dependent shifts in Lamb wave dispersion curves. The theory for frequency/wavenumber shifts for plate waves, based on a Lindstedt-Poincaré perturbation approach, was presented by the authors in previous years. Equivalently, spectral properties changes can be seen as wavelength contraction/elongation. Within the proposed framework, the wavelength of a Lamb wave depends on several factors; e.g., wave amplitude and second-, third- and fourth-order elastic constants, and others. Various types of nonlinear effects are considered in presented studies. Sensitivity studies for model parameters, i.e. higher-order elastic constants, are performed to quantify their influence on Lamb wave frequency/wavenumber shifting, and to identify the key parameters governing wavelength tuning.

  19. 2008 OG$_{19}$: A highly elongated Trans-Neptunian Object

    CERN Document Server

    Fernández-Valenzuela, Estela; Duffard, René; Santos-Sanz, Pablo; Morales, Nicolás

    2015-01-01

    From two observing runs during the 2014 summer at Calar Alto Observatory in Almer\\'ia (Spain) and at Sierra Nevada Observatory in Granada (Spain), we were able to derive CCD photometry of the Trans-Neptunian Object 2008 OG$_{19}$. We analyzed the time series and obtained a double-peaked light curve with a peak to valley amplitude of (0.437 $\\pm$ 0.011) mag and a rotational period of (8.727$\\pm$ 0.003) h. This implies that this object is very elongated, closely resembling Varuna's case. The photometry also allowed us to obtain an absolute magnitude in R-band of (4.39 $\\pm$ 0.07) mag. From this result we estimated an equivalent diameter of 2008 OG$_{19}$ which is 619$^{+56}_{-113}$ km using an average albedo for Scattered Disk Objects. Finally we interpreted the results under the assumption of hydrostatic equilibrium and found a lower limit for the density of 544$^{+42}_{-4}$ kg$\\,$m$^{-3}$. However, a more likely density is (609 $\\pm$ 4) kg$\\,$m$^{-3}$ using an aspect angle of 60$^\\circ$, which corresponds to ...

  20. Elongational Flow Assists with the Assembly of Protein Nanofibrils

    Science.gov (United States)

    Mittal, Nitesh; Kamada, Ayaka; Lendel, Christofer; Lundell, Fredrik; Soderberg, Daniel

    2016-11-01

    Controlling the aggregation process of protein-based macromolecular structures in a confined environment using small-scale flow devices and understanding their assembly mechanisms is essential to develop bio-based materials. Whey protein, a protein mixture with β-lactoglobulin as main component, is able to self-assemble into amyloid-like protein nanofibers which are stabilized by hydrogen bonds. The conditions at which the fibrillation process occurs can affect the properties and morphology of the fibrils. Here, we show that the morphology of protein nanofibers greatly affects their assembly. We used elongational flow based double flow-focusing device for this study. In-situ behavior of the straight and flexible fibrils in the flow channel is determined using small-angle X-ray scattering (SAXS) technique. Our process combines hydrodynamic alignment with dispersion to gel-transition that produces homogeneous and smooth fibers. Moreover, successful alignment before gelation demands a proper separation of the time-scales involved, which we tried to identify in the current study. The presented approach combining small scale flow devices with in-situ synchrotron X-ray studies and protein engineering is a promising route to design high performance protein-based materials with controlled physical and chemical properties. We acknowledge the support from Wallenberg Wood Science Center.

  1. Optics for multimode lasers with elongated depth of field

    Science.gov (United States)

    Laskin, Alexander; Laskin, Vadim; Ostrun, Aleksei

    2017-02-01

    Modern multimode high-power lasers are widely used in industrial applications and control of their radiation, especially by focusing, is of great importance. Because of relatively low optical quality, characterized by high values of specifications Beam Parameter Product (BPP) or M², the depth of field by focusing of multimode laser radiation is narrow. At the same time laser technologies like deep penetration welding, cutting of thick metal sheets get benefits from elongated depth of field in area of focal plane, therefore increasing of zone along optical axis with minimized spot size is important technical task. As a solution it is suggested to apply refractive optical systems splitting an initial laser beam into several beamlets, which are focused in different foci separated along optical axis with providing reliable control of energy portions in each separate focus, independently of beam size or mode structure. With the multi-focus optics, the length of zone of material processing along optical axis is defined rather by distances between separate foci, which are determined by optical design of the optics and can be chosen according to requirements of a particular laser technology. Due to stability of the distances between foci there is provided stability of a technology process. This paper describes some design features of refractive multi-focus optics, examples of real implementations and experimental results will be presented as well.

  2. Movement of elongation factor G between compact and extended conformations.

    Science.gov (United States)

    Salsi, Enea; Farah, Elie; Netter, Zoe; Dann, Jillian; Ermolenko, Dmitri N

    2015-01-30

    Previous structural studies suggested that ribosomal translocation is accompanied by large interdomain rearrangements of elongation factor G (EF-G). Here, we follow the movement of domain IV of EF-G relative to domain II of EF-G using ensemble and single-molecule Förster resonance energy transfer. Our results indicate that ribosome-free EF-G predominantly adopts a compact conformation that can also, albeit infrequently, transition into a more extended conformation in which domain IV moves away from domain II. By contrast, ribosome-bound EF-G predominantly adopts an extended conformation regardless of whether it is interacting with pretranslocation ribosomes or with posttranslocation ribosomes. Our data suggest that ribosome-bound EF-G may also occasionally sample at least one more compact conformation. GTP hydrolysis catalyzed by EF-G does not affect the relative stability of the observed conformations in ribosome-free and ribosome-bound EF-G. Our data support a model suggesting that, upon binding to a pretranslocation ribosome, EF-G moves from a compact to a more extended conformation. This transition is not coupled to but likely precedes both GTP hydrolysis and mRNA/tRNA translocation.

  3. Electrostatics control actin filament nucleation and elongation kinetics.

    Science.gov (United States)

    Crevenna, Alvaro H; Naredi-Rainer, Nikolaus; Schönichen, André; Dzubiella, Joachim; Barber, Diane L; Lamb, Don C; Wedlich-Söldner, Roland

    2013-04-26

    The actin cytoskeleton is a central mediator of cellular morphogenesis, and rapid actin reorganization drives essential processes such as cell migration and cell division. Whereas several actin-binding proteins are known to be regulated by changes in intracellular pH, detailed information regarding the effect of pH on the actin dynamics itself is still lacking. Here, we combine bulk assays, total internal reflection fluorescence microscopy, fluorescence fluctuation spectroscopy techniques, and theory to comprehensively characterize the effect of pH on actin polymerization. We show that both nucleation and elongation are strongly enhanced at acidic pH, with a maximum close to the pI of actin. Monomer association rates are similarly affected by pH at both ends, although dissociation rates are differentially affected. This indicates that electrostatics control the diffusional encounter but not the dissociation rate, which is critical for the establishment of actin filament asymmetry. A generic model of protein-protein interaction, including electrostatics, explains the observed pH sensitivity as a consequence of charge repulsion. The observed pH effect on actin in vitro agrees with measurements of Listeria propulsion in pH-controlled cells. pH regulation should therefore be considered as a modulator of actin dynamics in a cellular environment.

  4. The undulatory swimming gait of elongated swimmers revisited.

    Science.gov (United States)

    Iosilevskii, Gil

    2017-03-31

    An undulatory swimming gait is characterized by short lateral displacement waves that propagate backwards along the body of the swimmer faster than it swims. Hydrodynamic theory of elongated bodies predicts that if the amplitude of the displacement waves does not increase toward the caudal end, the part of the swimmer posteriad of the dorso-ventrally widest point takes no part in propulsion. It also predicts that if the amplitude does increase, then the hydrodynamic propulsion efficiency suffers. Cusk eels have their widest point located in the anterior half of the body with the bulk of their locomotive muscles located posteriad of it; indeed, they swim so that the amplitude of the propulsion wave increases toward the caudal end. Anguillid eels have their widest point posteriad of the mid-body, and their locomotive muscles are distributed along their entire length-but they swim as cusk eels, using the posterior half only. Apparently, both use hydrodynamically inefficient gaits. The paper questions the definition of propulsion efficiency and shows that biomechanical considerations are more important than hydrodynamic, and that most probably fish adjust their gait to maximize the ratio between the energy made good (the product of thrust and distance) and the chemical energy consumed by the muscles. The role of body shape is discussed.

  5. Elongated Silicon-Carbon Bonds at Graphene Edges.

    Science.gov (United States)

    Chen, Qu; Robertson, Alex W; He, Kuang; Gong, Chuncheng; Yoon, Euijoon; Kirkland, Angus I; Lee, Gun-Do; Warner, Jamie H

    2016-01-26

    We study the bond lengths of silicon (Si) atoms attached to both armchair and zigzag edges using aberration corrected transmission electron microscopy with monochromation of the electron beam. An in situ heating holder is used to perform imaging of samples at 800 °C in order to reduce chemical etching effects that cause rapid structure changes of graphene edges at room temperature under the electron beam. We provide detailed bond length measurements for Si atoms both attached to edges and also as near edge substitutional dopants. Edge reconstruction is also involved with the addition of Si dopants. Si atoms bonded to the edge of graphene are compared to substitutional dopants in the bulk lattice and reveal reduced out-of-plane distortion and bond elongation. An extended linear array of Si atoms at the edge is found to be energy-favorable due to inter-Si interactions. These results provide detailed structural information about the Si-C bonds in graphene, which may have importance in future catalytic and electronic applications.

  6. Supramolecular chemistry of pyrazolyl complexes

    OpenAIRE

    2008-01-01

    The purpose of this review is to describe the progress in the supramolecular chemistry of the pyrazolyl-based metal complexes. The text is written under the structural point of view, emphasizing the role of the covalent and non-covalent interactions in the rational construction of super and supramolecules.

  7. Mammary epithelial tubes elongate through MAPK-dependent coordination of cell migration.

    Science.gov (United States)

    Huebner, Robert J; Neumann, Neil M; Ewald, Andrew J

    2016-03-15

    Mammary branching morphogenesis is regulated by receptor tyrosine kinases (RTKs). We sought to determine how these RTK signals alter proliferation and migration to accomplish tube elongation in mouse. Both behaviors occur but it has been difficult to determine their relative contribution to elongation in vivo, as mammary adipocytes scatter light and limit the depth of optical imaging. Accordingly, we utilized 3D culture to study elongation in an experimentally accessible setting. We first used antibodies to localize RTK signals and discovered that phosphorylated ERK1/2 (pERK) was spatially enriched in cells near the front of elongating ducts, whereas phosphorylated AKT was ubiquitous. We next observed a gradient of cell migration speeds from rear to front of elongating ducts, with the front characterized by both high pERK and the fastest cells. Furthermore, cells within elongating ducts oriented both their protrusions and their migration in the direction of tube elongation. By contrast, cells within the organoid body were isotropically protrusive. We next tested the requirement for proliferation and migration. Early inhibition of proliferation blocked the creation of migratory cells, whereas late inhibition of proliferation did not block continued duct elongation. By contrast, pharmacological inhibition of either MEK or Rac1 signaling acutely blocked both cell migration and duct elongation. Finally, conditional induction of MEK activity was sufficient to induce collective cell migration and ductal elongation. Our data suggest a model for ductal elongation in which RTK-dependent proliferation creates motile cells with high pERK, the collective migration of which acutely requires both MEK and Rac1 signaling.

  8. STED super-resolution microscopy reveals an array of MINOS clusters along human mitochondria.

    Science.gov (United States)

    Jans, Daniel C; Wurm, Christian A; Riedel, Dietmar; Wenzel, Dirk; Stagge, Franziska; Deckers, Markus; Rehling, Peter; Jakobs, Stefan

    2013-05-28

    The mitochondrial inner membrane organizing system (MINOS) is a conserved large hetero-oligomeric protein complex in the mitochondrial inner membrane, crucial for the maintenance of cristae morphology. MINOS has been suggested to represent the core of an extended protein network that controls mitochondrial function and structure, and has been linked to several human diseases. The spatial arrangement of MINOS within mitochondria is ill-defined, however. Using super-resolution stimulated emission depletion (STED) microscopy and immunogold electron microscopy, we determined the distribution of three known human MINOS subunits (mitofilin, MINOS1, and CHCHD3) in mammalian cells. Super-resolution microscopy revealed that all three subunits form similar clusters within mitochondria, and that MINOS is more abundant in mitochondria around the nucleus than in peripheral mitochondria. At the submitochondrial level, mitofilin, a core MINOS subunit, is preferentially localized at cristae junctions. In primary human fibroblasts, mitofilin labeling uncovered a regularly spaced pattern of clusters arranged in parallel to the cell growth surfaces. We suggest that this array of MINOS complexes might explain the observed phenomenon of largely horizontally arranged cristae junctions that connect the inner boundary membrane to lamellar cristae. The super-resolution images demonstrate an unexpectedly high level of regularity in the nanoscale distribution of the MINOS complex in human mitochondria, supporting an integrating role of MINOS in the structural organization of the organelle.

  9. Sus1 is recruited to coding regions and functions during transcription elongation in association with SAGA and TREX2

    Science.gov (United States)

    Pascual-García, Pau; Govind, Chhabi K.; Queralt, Ethel; Cuenca-Bono, Bernardo; Llopis, Ana; Chavez, Sebastián; Hinnebusch, Alan G.; Rodríguez-Navarro, Susana

    2008-01-01

    Gene transcription, RNA biogenesis, and mRNA transport constitute a complicated process essential for all eukaryotic cells. The transcription/export factor Sus1 plays a key role in coupling transcription activation with mRNA export, and it resides in both the SAGA and TREX2 complexes. Moreover, Sus1 is responsible for GAL1 gene gating at the nuclear periphery, which is important for its transcriptional status. Here, we show that Sus1 is required during transcription elongation and is associated with the elongating form of RNA Polymerase II (RNAP II) phosphorylated on Ser5 and Ser2 of the C-terminal domain (CTD). In addition, Sus1 copurifies with the essential mRNA export factors Yra1 and Mex67, which bind to the mRNA cotranscriptionally. Consistently, ChIP analysis reveals that Sus1 is present at coding regions dependent on transcription in a manner stimulated by Kin28-dependent CTD phosphorylation. Strikingly, eliminating the TREX2 component Sac3 or the SAGA subunit Ubp8 partially impairs Sus1 targeting to coding sequences and upstream activating sequences (UAS). We found, unexpectedly, that Sgf73 is necessary for association of Sus1 with both SAGA and TREX2, and that its absence dramatically reduces Sus1 occupancy of UAS and ORF sequences. Our results reveal that Sus1 plays a key role in coordinating gene transcription and mRNA export by working at the interface between the SAGA and TREX2 complexes during transcription elongation. PMID:18923079

  10. Influence of Gradual Elongation to the Patella Tendon Insertion in Rabbits

    Directory of Open Access Journals (Sweden)

    Hirotaka Mutsuzaki

    2014-08-01

    Full Text Available The purpose of this study was to examine the histological changes at the patella tendon (PT insertion site under gradual elongation in rabbits. Gradual elongation of the PT was performed using external fixation for 4 weeks, with a lengthening speed of 0.5 mm/day (elongation group; n = 24. Rabbits in the sham group underwent the same surgical procedure without gradual elongation (sham group; n = 24. Eight animals were sacrificed 1, 2 and 4 weeks after surgery in each group, respectively. Average thicknesses of stained glycosaminoglycan (GAGs areas by Safranin-O staining in the total cartilage layer and the uncalcified fibrocartilage layer in the elongation group were significantly higher than that in the sham group at 4 weeks (p < 0.05 and that in the intact PT group (n = 6, p < 0.05. In the elongation group, the peak in the average thicknesses of the stained GAGs areas in the total cartilage layer and the uncalcified fibrocartilage layer were observed at 4 weeks. Gradual elongation of PT insertion significantly affected the increase in the average thicknesses of the stained GAGs areas in the cartilage layer especially in the uncalcified fibrocartilage layer at 4 weeks in rabbits. Clinically, insertions of tendon and ligament can extend during gradual elongation using external fixation more than 4 weeks after the operation.

  11. SHORT HYPOCOTYL 1 encodes a SMARCA3-like chromatin remodeling factor regulating elongation

    Science.gov (United States)

    Understanding the mechanisms and control of hypocotyl elongation is important for greenhouse vegetable crop production. In this study, we identified SHORT HYPOCOTYL1 (SH1) in cucumber which regulates low-dosage ultraviolet B (LDUVB)-dependent hypocotyl elongation by recruiting the cucumber UVR8 sign...

  12. Rwandan female genital modification: elongation of the Labia minora and the use of local botanical species

    NARCIS (Netherlands)

    Koster, M.; Price, L.L.

    2008-01-01

    The elongation of the labia minora is classified as a Type IV female genital mutilation by the World Health Organization. However, the term mutilation carries with it powerful negative connotations. In Rwanda, the elongation of the labia minora and the use of botanicals to do so is meant to increase

  13. Elongational viscosity of narrow molar mass distribution star and pom-pom polystyrene

    DEFF Research Database (Denmark)

    Rasmussen, Henrik K.; Nielsen, Jens Kromann; Hassager, Ole

    2006-01-01

    We have measured the transient and steady uniaxial elongational viscosity, using the filament stretching rheometer (FSR), of two narrow molar mass distribution (MMD) long-chain branched polystyrene melts: AnBAm (a ‘pom-pom’ molecule) and AnB (a ‘asymmetric star’ molecule). The elongational...

  14. Methanol as an alternative electron donor in chain elongation for butyrate and caproate formation

    NARCIS (Netherlands)

    Chen, W.S.; Ye, Y.; Steinbusch, K.J.J.; Strik, D.P.B.T.B.; Buisman, C.J.N.

    2016-01-01

    Chain elongation is an emerging mixed culture biotechnology converting acetate into valuable biochemicals by using ethanol as an external electron donor. In this study we proposed to test another potential electron donor, methanol, in chain elongation. Methanol can be produced through the thermoc

  15. Sucrose-induced hypocotyl elongation of Arabidopsis seedlings in darkness depends on the presence of gibberellins.

    Science.gov (United States)

    Zhang, Yongqiang; Liu, Zhongjuan; Wang, Liguang; Zheng, Sheng; Xie, Jiping; Bi, Yurong

    2010-09-15

    In this study, the effects of sucrose on hypocotyl elongation of Arabidopsis seedlings in light and in dark were investigated. Sucrose suppressed the hypocotyl elongation of Arabidopsis seedlings in light, but stimulated elongation in dark. Application of paclobutrazol (PAC, a gibberellin biosynthesis inhibitor) impaired the effects of sucrose on hypocotyl elongation, suggesting that endogenous GAs is required for sucrose-induced hypocotyl elongation in the dark. Exogenous GA(3) application reversed the repression caused by PAC application, indicating that exogenous GA(3) could substitute, at least partially, for endogenous GAs in sucrose-induced hypocotyl elongation. In addition, we found that GA 3-oxidase 1 (GA3ox1), encoding a key enzyme involved in endogenous bioactive GA biosynthesis, was up-regulated by sucrose in the dark, whereas GIBBERELLIN INSENSITIVE DWARF 1a (AtGID1a), encoding a GA receptor and playing an important role during GAs degradation to DELLA proteins (DELLAs, repressors of GA-induced plant growth), was down-regulated. These results imply that endogenous bioactive GA levels are expected to be enhanced, but the degradation of DELLAs was inhibited by sucrose in dark. Thus, our data suggest that the sucrose-induced hypocotyl elongation in the dark does not result from GA-induced degradation of DELLAs. We conclude that sucrose can stimulate hypocotyl elongation of Arabidopsis seedlings in the dark in a GA-dependent manner.

  16. Elongational viscosity of narrow molar mass distribution star and pom-pom polystyrene

    DEFF Research Database (Denmark)

    Rasmussen, Henrik K.; Nielsen, Jens Kromann; Hassager, Ole;

    2006-01-01

    We have measured the transient and steady uniaxial elongational viscosity, using the filament stretching rheometer (FSR), of two narrow molar mass distribution (MMD) long-chain branched polystyrene melts: AnBAm (a ‘pom-pom’ molecule) and AnB (a ‘asymmetric star’ molecule). The elongational...

  17. Rwandan female genital modification: elongation of the Labia minora and the use of local botanical species

    NARCIS (Netherlands)

    Koster, M.; Price, L.L.

    2008-01-01

    The elongation of the labia minora is classified as a Type IV female genital mutilation by the World Health Organization. However, the term mutilation carries with it powerful negative connotations. In Rwanda, the elongation of the labia minora and the use of botanicals to do so is meant to increase

  18. The influence of elongation exercises on the anterior-posterior spine curvatures

    Directory of Open Access Journals (Sweden)

    Drzał-Grabiec Justyna

    2014-01-01

    Full Text Available Introduction: Elongation exercises are designed to reduce existing pathological or increased physiological curvatures of the spine. The aim of the study was to evaluate the changes occurring in the parameters describing the anterior-posterior spinal curvatures during the performance of symmetric elongation exercises.

  19. Disentangling the Trichoderma viridescens complex

    NARCIS (Netherlands)

    Jaklitsch, W.M.; Samuels, G.J.; Ismaiel, A.; Voglmayr, H.

    2013-01-01

    Trichoderma viridescens is recognised as a species complex. Multigene analyses based on the translation elongation factor 1-alpha encoding gene (tef1), a part of the rpb2 gene, encoding the second largest RNA polymerase subunit and the larger subunit of ATP citrate lyase (acl1) reveals 13 phylogenet

  20. Disentangling the Trichoderma viridescens complex

    NARCIS (Netherlands)

    Jaklitsch, W.M.; Samuels, G.J.; Ismaiel, A.; Voglmayr, H.

    2013-01-01

    Trichoderma viridescens is recognised as a species complex. Multigene analyses based on the translation elongation factor 1-alpha encoding gene (tef1), a part of the rpb2 gene, encoding the second largest RNA polymerase subunit and the larger subunit of ATP citrate lyase (acl1) reveals 13

  1. Super-Resolution Imaging on Microfluidic Super-Resolution Near-Field Structure

    Institute of Scientific and Technical Information of China (English)

    WANG Pei; TANG Lin; ZHANG Dou-Guo; LU Yong-Hua; JIAO Xiao-Jin; XIE Jian-Ping; MING Hai

    2005-01-01

    @@ We present a new concept of the microfluidic super-resolution near-field structure (MSRENS) based on a microfluidic structure and a super-resolution near-field structure. The near-field distance control, "nano-probe"and scanning can be realized simultaneously using the MSRENS, which is similar to a near-field scanning optical microscope. The design and simulation results are presented. Numerical simulation has demonstrated that the MSRENS with spatial resolution beyond the diffraction limit could be applicable in chemistry, biologics, and many other fields.

  2. SuperB: An opportunity to study baryons with beauty and bottom super-nuclei

    Energy Technology Data Exchange (ETDEWEB)

    Feliciello, A., E-mail: Alessandro.Feliciello@to.infn.it [Istituto Nazionale di Fisica Nucleare, Sezione di Torino, Via P. Giuria 1, I-10125 Torino (Italy)

    2012-05-01

    SuperB is an INFN flagship project for a new high-luminosity heavy-flavor factory. Along with its companion detector, it is dedicated to the search for CP violation effects in the B meson sector with the aim of looking for direct and indirect signals of new physics, beyond the Standard Model. However it could offer as well the opportunity for a systematic, high-statistics study of b baryon properties and for a search for bottom super-nuclei, that is bound nuclear systems with an explicit content of beauty.

  3. RESEARCH NOTES On the support of super-Brownian motion with super-Brownian immigration

    Institute of Scientific and Technical Information of China (English)

    洪文明; 钟惠芳

    2001-01-01

    The support properties of the super Brownian motion with random immigration Xρ1 are considered,where the immigration rate is governed by the trajectory of another super-Brownian motion ρ. When both the initial state Xρo of the process and the immigration rate process ρo are of finite measure and with compact supports, the probability of the support of the process Xρi dominated by a ball is given by the solutions of a singular elliptic boundary value problem.

  4. Super-hybrid composites - An emerging structural material

    Science.gov (United States)

    Chamis, C. C.; Lark, R. F.; Sullivan, T. L.

    1975-01-01

    Specimens of super-hybrids and advanced fiber composites were subjected to extensive tests to determine their mechanical properties, including impact and thermal fatigue. The super-hybrids were fabricated by a procedure similar to that reported by Chamis et al., (1975). Super-hybrids subjected to 1000 cycles of thermal fatigue from -100 to 300 F retained over 90% of their longitudinal flexural strength and over 75% of their transverse flexural strength; their transverse flexural strength may be as high as 8 times that of a commercially supplied boron/1100-Al composite. The thin specimen Izod longitudinal impact resistance of the super-hybrids was twice that of the boron/110-Al material. Super-hybrids subjected to transverse tensile loads exhibited nonlinear stress-strain relationships. The experimentally determined initial membrane (in-plane) and bending elastic properties of super-hybrids were predicted adequately by linear laminate analysis.

  5. Infantile encephalopathy and defective mitochondrial DNA translation in patients with mutations of mitochondrial elongation factors EFG1 and EFTu.

    Science.gov (United States)

    Valente, Lucia; Tiranti, Valeria; Marsano, Rene Massimiliano; Malfatti, Edoardo; Fernandez-Vizarra, Erika; Donnini, Claudia; Mereghetti, Paolo; De Gioia, Luca; Burlina, Alberto; Castellan, Claudio; Comi, Giacomo P; Savasta, Salvatore; Ferrero, Iliana; Zeviani, Massimo

    2007-01-01

    Mitochondrial protein translation is a complex process performed within mitochondria by an apparatus composed of mitochondrial DNA (mtDNA)-encoded RNAs and nuclear DNA-encoded proteins. Although the latter by far outnumber the former, the vast majority of mitochondrial translation defects in humans have been associated with mutations in RNA-encoding mtDNA genes, whereas mutations in protein-encoding nuclear genes have been identified in a handful of cases. Genetic investigation involving patients with defective mitochondrial translation led us to the discovery of novel mutations in the mitochondrial elongation factor G1 (EFG1) in one affected baby and, for the first time, in the mitochondrial elongation factor Tu (EFTu) in another one. Both patients were affected by severe lactic acidosis and rapidly progressive, fatal encephalopathy. The EFG1-mutant patient had early-onset Leigh syndrome, whereas the EFTu-mutant patient had severe infantile macrocystic leukodystrophy with micropolygyria. Structural modeling enabled us to make predictions about the effects of the mutations at the molecular level. Yeast and mammalian cell systems proved the pathogenic role of the mutant alleles by functional complementation in vivo. Nuclear-gene abnormalities causing mitochondrial translation defects represent a new, potentially broad field of mitochondrial medicine. Investigation of these defects is important to expand the molecular characterization of mitochondrial disorders and also may contribute to the elucidation of the complex control mechanisms, which regulate this fundamental pathway of mtDNA homeostasis.

  6. Infantile Encephalopathy and Defective Mitochondrial DNA Translation in Patients with Mutations of Mitochondrial Elongation Factors EFG1 and EFTu

    Science.gov (United States)

    Valente, Lucia; Tiranti, Valeria; Marsano, René Massimiliano; Malfatti, Edoardo; Fernandez-Vizarra, Erika; Donnini, Claudia; Mereghetti, Paolo; De Gioia, Luca; Burlina, Alberto; Castellan, Claudio; Comi, Giacomo P.; Savasta, Salvatore; Ferrero, Iliana; Zeviani, Massimo

    2007-01-01

    Mitochondrial protein translation is a complex process performed within mitochondria by an apparatus composed of mitochondrial DNA (mtDNA)–encoded RNAs and nuclear DNA–encoded proteins. Although the latter by far outnumber the former, the vast majority of mitochondrial translation defects in humans have been associated with mutations in RNA-encoding mtDNA genes, whereas mutations in protein-encoding nuclear genes have been identified in a handful of cases. Genetic investigation involving patients with defective mitochondrial translation led us to the discovery of novel mutations in the mitochondrial elongation factor G1 (EFG1) in one affected baby and, for the first time, in the mitochondrial elongation factor Tu (EFTu) in another one. Both patients were affected by severe lactic acidosis and rapidly progressive, fatal encephalopathy. The EFG1-mutant patient had early-onset Leigh syndrome, whereas the EFTu-mutant patient had severe infantile macrocystic leukodystrophy with micropolygyria. Structural modeling enabled us to make predictions about the effects of the mutations at the molecular level. Yeast and mammalian cell systems proved the pathogenic role of the mutant alleles by functional complementation in vivo. Nuclear-gene abnormalities causing mitochondrial translation defects represent a new, potentially broad field of mitochondrial medicine. Investigation of these defects is important to expand the molecular characterization of mitochondrial disorders and also may contribute to the elucidation of the complex control mechanisms, which regulate this fundamental pathway of mtDNA homeostasis. PMID:17160893

  7. Internal carotid dissection caused by an elongated styloid process (Eagle syndrome).

    Science.gov (United States)

    Sveinsson, Olafur; Kostulas, Nikolaos; Herrman, Lars

    2013-06-11

    Eagle syndrome (symptoms associated with an elongated styloid process (SP)) is commonly divided into two presentations. First, the so-called classic Eagle syndrome where patients can present with unilateral sore throat, dysphagia, tinnitus, unilateral facial and neck pain and otalgia. Second, there is the vascular or stylocarotid form of Eagle syndrome in which the elongated SP is in contact with the extracranial internal carotid artery. We describe two cases of internal carotid artery dissection associated with an elongated SP. One is a patient with ischaemic stroke and another with transient ischaemic attacks caused by an elongated SP. A surgical resection of the SP was performed on the former patient. Both patients were treated with anticoagulation and recovered well. A literature search only revealed two prior descriptions of carotid dissection in the context of an elongated SP.

  8. Conflict between translation initiation and elongation in vertebrate mitochondrial genomes.

    Directory of Open Access Journals (Sweden)

    Xuhua Xia

    Full Text Available The strand-biased mutation spectrum in vertebrate mitochondrial genomes results in an AC-rich L-strand and a GT-rich H-strand. Because the L-strand is the sense strand of 12 protein-coding genes out of the 13, the third codon position is overall strongly AC-biased. The wobble site of the anticodon of the 22 mitochondrial tRNAs is either U or G to pair with the most abundant synonymous codon, with only one exception. The wobble site of Met-tRNA is C instead of U, forming the Watson-Crick match with AUG instead of AUA, the latter being much more frequent than the former. This has been attributed to a compromise between translation initiation and elongation; i.e., AUG is not only a methionine codon, but also an initiation codon, and an anticodon matching AUG will increase the initiation rate. However, such an anticodon would impose selection against the use of AUA codons because AUA needs to be wobble-translated. According to this translation conflict hypothesis, AUA should be used relatively less frequently compared to UUA in the UUR codon family. A comprehensive analysis of mitochondrial genomes from a variety of vertebrate species revealed a general deficiency of AUA codons relative to UUA codons. In contrast, urochordate mitochondrial genomes with two tRNA(Met genes with CAU and UAU anticodons exhibit increased AUA codon usage. Furthermore, six bivalve mitochondrial genomes with both of their tRNA-Met genes with a CAU anticodon have reduced AUA usage relative to three other bivalve mitochondrial genomes with one of their two tRNA-Met genes having a CAU anticodon and the other having a UAU anticodon. We conclude that the translation conflict hypothesis is empirically supported, and our results highlight the fine details of selection in shaping molecular evolution.

  9. Calcium and gibberellin-induced elongation of lettuce hypocotyl sections.

    Science.gov (United States)

    Moll, C; Jones, R L

    1981-08-01

    The relationship between calcium ions and gibberellic acid (GA3)-induced growth in the excised hypocotyl of lettuce (Lactuca sativa L.) was investigated. The short-term kinetics of growth responses were measured using a linear displacement transducer. Test solutions were added either as drops to the filter paper on which the hypocotyl stood ("non-flow-past") or by switching solution flowing past the base of hypocotyl ("flow-past"), resulting in differences in growth behavior. Drops of CaCl2 added at a high concentration (10 mM) inhibited growth within a few minutes. This inhibition was reversed by ethylenediaminetetraacetic acid (EDTA). Drops of EDTA or ethyleneglycol-bis(2-aminoethylether)-tetraacetic acid caused a rapid increase in growth rate. Growth induced by EDTA was not further promoted by GA3. A continuous H2O flow resulted in growth rates comparable to those in response to GA3. Addition of CaCl2 to the flow-past medium inhibited growth and this inhibition was reversed by a decrease in CaCl2 concentration. The growth rate was found to be a function of CaCl2 concentration. When a constant CaCl2 concentration was maintained by the flow-past medium, a shift in pH from 5.5 to 4.25 had no obvious effect on hypocotyl elongation. Gibberellic acid was found to reverse the inhibitory effect of CaCl2, causing an increase in growth rate similar to that found previously when GA3 was added to hypocotyls grown in H2O under non-flow-past conditions. We propose that gibberellin controls extension growth in lettuce hypocotyl sections by regulating the uptake of Ca(2+) by the hypocotyl cells.

  10. On Super Edge-Antimagicness of Subdivided Stars

    Directory of Open Access Journals (Sweden)

    Raheem A.

    2015-11-01

    Full Text Available Enomoto, Llado, Nakamigawa and Ringel (1998 defined the concept of a super (a, 0-edge-antimagic total labeling and proposed the conjecture that every tree is a super (a, 0-edge-antimagic total graph. In the support of this conjecture, the present paper deals with different results on super (a, d-edge-antimagic total labeling of subdivided stars for d ∈ {0, 1, 2, 3}.

  11. Super-resolution optical telescopes with local light diffraction shrinkage

    OpenAIRE

    Changtao Wang; Dongliang Tang; Yanqin Wang; Zeyu Zhao; Jiong Wang; Mingbo Pu; Yudong Zhang; Wei Yan; Ping Gao; Xiangang Luo

    2015-01-01

    Suffering from giant size of objective lenses and infeasible manipulations of distant targets, telescopes could not seek helps from present super-resolution imaging, such as scanning near-field optical microscopy, perfect lens and stimulated emission depletion microscopy. In this paper, local light diffraction shrinkage associated with optical super-oscillatory phenomenon is proposed for real-time and optically restoring super-resolution imaging information in a telescope system. It is found ...

  12. The Robotic Super-LOTIS Telescope: Results & Future Plans

    OpenAIRE

    Williams, G. G.; Milne, P. A.; Park, H.S.; Barthelmy, S. D.; Hartmann, D. H.; Updike, A.; Hurley, K.

    2008-01-01

    We provide an overview of the robotic Super-LOTIS (Livermore Optical Transient Imaging System) telescope and present results from gamma-ray burst (GRB) afterglow observations using Super-LOTIS and other Steward Observatory telescopes. The 0.6-m Super-LOTIS telescope is a fully robotic system dedicated to the measurement of prompt and early time optical emission from GRBs. The system began routine operations from its Steward Observatory site atop Kitt Peak in April 2000 and currently operates ...

  13. Spin groups of super metrics and a theorem of Rogers

    Science.gov (United States)

    Fulp, Ronald

    2017-01-01

    We derive the canonical forms of super Riemannian metrics and the local isometry groups of such metrics. For certain super metrics we also compute the simply connected covering groups of the local isometry groups and interpret these as local spin groups of the super metric. Super metrics define reductions OSg of the relevant frame bundle. When principal bundles S˜g exist with structure group the simply connected covering group G ˜ of the structure group of OSg , representations of G ˜ define vector bundles associated to S˜g whose sections are "spinor fields" associated with the super metric g . Using a generalization of a Theorem of Rogers, which is itself one of the main results of this paper, we show that for super metrics we call body reducible, each such simply connected covering group G ˜ is a super Lie group with a conventional super Lie algebra as its corresponding super Lie algebra. Some of our results were known to DeWitt (1984) using formal Grassmann series and others were known by Rogers using finitely many Grassmann generators and passing to a direct limit. We work exclusively in the category of G∞ supermanifolds with G∞ mappings. Our supernumbers are infinite series of products of Grassmann generators subject to convergence in the ℓ1 norm introduced by Rogers (1980, 2007).

  14. New Results from Super-K and K2K

    CERN Document Server

    Wilkes, R J

    2002-01-01

    This paper summarizes recent (as of SSI-02, in some cases updated in November, 2002) results from the Super-Kamiokande and K2K experiments. The interpretation of Super-Kamiokande results on atmospheric and solar neutrinos provides strong evidence for neutrino oscillations, hence non-zero neutrino mass. While statistics are still limited, K2K data are consistent with Super-Kamiokande results on neutrino oscillations. The effort to reconstruct Super-Kamiokande following a cascade of phototube implosions in November, 2001 is described. Plans for the future are also discussed.

  15. Video super-resolution using simultaneous motion and intensity calculations

    DEFF Research Database (Denmark)

    Keller, Sune Høgild; Lauze, Francois Bernard; Nielsen, Mads

    2011-01-01

    for the joint estimation of a super-resolution sequence and its flow field. Via the calculus of variations, this leads to a coupled system of partial differential equations for image sequence and motion estimation. We solve a simplified form of this system and as a by-product we indeed provide a motion field...... for super-resolved sequences. Computing super-resolved flows has to our knowledge not been done before. Most advanced super-resolution (SR) methods found in literature cannot be applied to general video with arbitrary scene content and/or arbitrary optical flows, as it is possible with our simultaneous VSR...

  16. Predicting complex mineral structures using genetic algorithms.

    Science.gov (United States)

    Mohn, Chris E; Kob, Walter

    2015-10-28

    We show that symmetry-adapted genetic algorithms are capable of finding the ground state of a range of complex crystalline phases including layered- and incommensurate super-structures. This opens the way for the atomistic prediction of complex crystal structures of functional materials and mineral phases.

  17. Super-Hamiltonian Structures and Conservation Laws of a New Six-Component Super-Ablowitz-Kaup-Newell-Segur Hierarchy

    Directory of Open Access Journals (Sweden)

    Fucai You

    2014-01-01

    Full Text Available A six-component super-Ablowitz-Kaup-Newell-Segur (-AKNS hierarchy is proposed by the zero curvature equation associated with Lie superalgebras. Supertrace identity is used to furnish the super-Hamiltonian structures for the resulting nonlinear superintegrable hierarchy. Furthermore, we derive the infinite conservation laws of the first two nonlinear super-AKNS equations in the hierarchy by utilizing spectral parameter expansions. PACS: 02.30.Ik; 02.30.Jr; 02.20.Sv.

  18. Activation of a cryptic splice site in the mitochondrial elongation factor GFM1 causes combined OXPHOS deficiency☆

    Science.gov (United States)

    Simon, Mariella T.; Ng, Bobby G.; Friederich, Marisa W.; Wang, Raymond Y.; Boyer, Monica; Kircher, Martin; Collard, Renata; Buckingham, Kati J.; Chang, Richard; Shendure, Jay; Nickerson, Deborah A.; Bamshad, Michael J.; Van Hove, Johan L.K.; Freeze, Hudson H.; Abdenur, Jose E.

    2017-01-01

    We report the clinical, biochemical, and molecular findings in two brothers with encephalopathy and multi-systemic disease. Abnormal transferrin glycoforms were suggestive of a type I congenital disorder of glycosylation (CDG). While exome sequencing was negative for CDG related candidate genes, the testing revealed compound heterozygous mutations in the mitochondrial elongation factor G gene (GFM1). One of the mutations had been reported previously while the second, novel variant was found deep in intron 6, activating a cryptic splice site. Functional studies demonstrated decreased GFM1 protein levels, suggested disrupted assembly of mitochondrial complexes III and V and decreased activities of mitochondrial complexes I and IV, all indicating combined OXPHOS deficiency. PMID:28216230

  19. Complex matrix model duality

    Energy Technology Data Exchange (ETDEWEB)

    Brown, T.W.

    2010-11-15

    The same complex matrix model calculates both tachyon scattering for the c=1 non-critical string at the self-dual radius and certain correlation functions of half-BPS operators in N=4 super- Yang-Mills. It is dual to another complex matrix model where the couplings of the first model are encoded in the Kontsevich-like variables of the second. The duality between the theories is mirrored by the duality of their Feynman diagrams. Analogously to the Hermitian Kontsevich- Penner model, the correlation functions of the second model can be written as sums over discrete points in subspaces of the moduli space of punctured Riemann surfaces. (orig.)

  20. N=1 supersymmetry and super-QED in Atiyah-Ward space-time

    CERN Document Server

    D'Andrade, M A; Magalhães, M N P; De Andrade, M A; Del Cima, O M; Magalhães, M N P

    1995-01-01

    In this work the supersymmetric gauge invariant action for the massive Abelian N=1 super-{\\QED} in the Atiyah-Ward space-time ({\\DDdd}) is formulated. The questions concerning the scheme of the gauge invariance in {\\DDdd} by means of gauging the massive N=1 super-{\\QED} are investigated. We study how to ensure the gauge invariance at the expenses of the introduction of a complex vector superfield. We discuss the Wess-Zumino gauge and thereupon we conclude that in this gauge, only the imaginary part of the complex vector field, B_{\\m}, gauges a U(1)-symmetry, whereas its real part gauges a Weyl symmetry. We build up the gauge invariant massive term by introducing four scalar superfields: a pair of chiral and a pair of anti-chiral superfields; the supermultiplets of each pair have opposite U(1)-charges. We carry out a dimensional reduction {\\it{\\`a la}} Scherk of the massive N=1 super-{\\QED} action from {\\DDdd} to {\\Ddd}. Truncations are needed in order to suppress unphysical modes and one ends up with a parity...

  1. Super-Liouville - Double Liouville correspondence

    CERN Document Server

    Hadasz, Leszek

    2014-01-01

    The AGT motivated relation between the tensor product of the N=1 super-Liouville field theory with the imaginary free fermion (SL) and a certain projected tensor products of the real and the imaginary Liouville field theories (LL) is analyzed. Using conformal field theory techniques we give a complete proof of the equivalence in the NS sector. It is shown that SL-LL correspondence is based on the equivalence of chiral objects including suitably chosen chiral structure constants of all three Liouville theories involved.

  2. A Trio of Super-Earths

    Science.gov (United States)

    2008-06-01

    Today, at an international conference, a team of European astronomers announced a remarkable breakthrough in the field of extra-solar planets. Using the HARPS instrument at the ESO La Silla Observatory, they have found a triple system of super-Earths around the star HD 40307. Moreover, looking at their entire sample studied with HARPS, the astronomers count a total of 45 candidate planets with a mass below 30 Earth masses and an orbital period shorter than 50 days. This implies that one solar-like star out of three harbours such planets. A trio of Super-Earths ESO PR Photo 19a/08 A trio of Super-Earths "Does every single star harbour planets and, if yes, how many?" wonders planet hunter Michel Mayor from Geneva Observatory. "We may not yet know the answer but we are making huge progress towards it." Since the discovery in 1995 of a planet around the star 51 Pegasi by Mayor and Didier Queloz, more than 270 exoplanets have been found, mostly around solar-like stars. Most of these planets are giants, such as Jupiter or Saturn, and current statistics show that about 1 out of 14 stars harbours this kind of planet. "With the advent of much more precise instruments such as the HARPS spectrograph on ESO's 3.6-m telescope at La Silla, we can now discover smaller planets, with masses between 2 and 10 times the Earth's mass," says Stéphane Udry, one of Mayor's colleagues. Such planets are called super-Earths, as they are more massive than the Earth but less massive than Uranus and Neptune (about 15 Earth masses). The group of astronomers have now discovered a system of three super-Earths around a rather normal star, which is slightly less massive than our Sun, and is located 42 light-years away towards the southern Doradus and Pictor constellations. "We have made very precise measurements of the velocity of the star HD 40307 over the last five years, which clearly reveal the presence of three planets," says Mayor. The planets, having 4.2, 6.7, and 9.4 times the mass of the

  3. SuperLU users' guide

    Energy Technology Data Exchange (ETDEWEB)

    Demmel, James W.; Gilbert, John R.; Li, Xiaoye S.

    1999-11-01

    This document describes a collection of three related ANSI C subroutine libraries for solving sparse linear systems of equations AX = B: Here A is a square, nonsingular, n x n sparse matrix, and X and B are dense n x nrhs matrices, where nrhs is the number of right-hand sides and solution vectors. Matrix A need not be symmetric or definite; indeed, SuperLU is particularly appropriate for matrices with very unsymmetric structure. All three libraries use variations of Gaussian elimination optimized to take advantage both of sparsity and the computer architecture, in particular memory hierarchies (caches) and parallelism.

  4. Production of super-smooth articles

    Energy Technology Data Exchange (ETDEWEB)

    Duchane, D.V.

    1981-05-29

    Super-smooth rounded or formed articles made of thermoplastic materials including various poly(methyl methacrylate) or acrylonitrile-butadiene-styrene copolymers are produced by immersing the articles into a bath, the composition of which is slowly changed with time. The starting composition of the bath is made up of at least one solvent for the polymer and a diluent made up of at least one nonsolvent for the polymer and optional materials which are soluble in the bath. The resulting extremely smooth articles are useful as mandrels for laser fusion and should be useful for a wide variety of other purposes, for example lenses.

  5. Emergent Super-Virasoro on Magnetic Branes

    CERN Document Server

    D'Hoker, Eric

    2016-01-01

    The low energy limit of the stress tensor, gauge current, and supercurrent two-point correlators are calculated in the background of the supersymmetric magnetic brane solution to gauged five-dimensional supergravity constructed by Almuhairi and Polchinski. The resulting correlators provide evidence for the emergence of an N=2 super-Virasoro algebra of right-movers, in addition to a bosonic Virasoro algebra and a $U(1) \\oplus U(1)$-current algebra of left-movers (or the parity transform of left- and right-movers depending on the sign of the magnetic field), in the holographically dual strongly interacting two-dimensional effective field theory of the lowest Landau level.

  6. Super-utilizers get red carpet treatment.

    Science.gov (United States)

    2014-01-01

    MetroHealth Medical Center in Cleveland has partnered with two health plans to provide intensive care coordination for high-cost patients with multiple medical problems and, often, behavioral health issues. Nurse practitioners at two primary care sites provide one-on-one care coordination for super-utilizers. They assess the patients' needs, help coordinate community resources, and prepare a treatment plan that is flagged when patients visit the emergency department. The nurse practitioners meet with health plan representatives monthly and brainstorm on ways to meet patients' needs.

  7. Super computer made with Linux cluster

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Jeong Hun; Oh, Yeong Eun; Kim, Jeong Seok

    2002-01-15

    This book consists of twelve chapters, which introduce super computer made with Linux cluster. The contents of this book are Linux cluster, the principle of cluster, design of Linux cluster, general things for Linux, building up terminal server and client, Bear wolf cluster by Debian GNU/Linux, cluster system with red hat, Monitoring system, application programming-MPI, on set-up and install application programming-PVM, with PVM programming and XPVM application programming-open PBS with composition and install and set-up and GRID with GRID system, GSI, GRAM, MDS, its install and using of tool kit.

  8. Transfer function characteristics of super resolving systems

    Science.gov (United States)

    Milster, Tom D.; Curtis, Craig H.

    1992-01-01

    Signal quality in an optical storage device greatly depends on the optical system transfer function used to write and read data patterns. The problem is similar to analysis of scanning optical microscopes. Hopkins and Braat have analyzed write-once-read-many (WORM) optical data storage devices. Herein, transfer function analysis of magnetooptic (MO) data storage devices is discussed with respect to improving transfer-function characteristics. Several authors have described improving the transfer function as super resolution. However, none have thoroughly analyzed the MO optical system and effects of the medium. Both the optical system transfer function and effects of the medium of this development are discussed.

  9. Medical care at the Super Bowl.

    Science.gov (United States)

    Ellis, J M

    2000-06-01

    Although coordinating medical care at the Super Bowl is something that we look forward to and have a lot of fun doing, we take it very seriously and understand the importance of delivering medical care at what many people consider to be the greatest sporting event in the world. It is certainly one of the most watched and recognized events in the world and because of this, we attempt to set up a system that will allow for the best medical care available and standardization of this medical care through our experience within Medical Sports Group.

  10. PERFORMANCE ANALYSIS OF MULTI-TURN EXTRACTION FROM THE PROTON SYNCHROTRON TO THE SUPER PROTON SYNCHROTRON

    CERN Document Server

    Abernethy, Samuel

    2016-01-01

    Within CERN's accelerator complex, the extraction from the Proton Synchrotron to the Super Proton Synchrotron has been done using the so-called ``Continuous Transfer" (CT) method since the 1970's. A new technique, known as Multi-Turn Extraction (MTE), has now been implemented and is in full operation. This report examines a holistic performance analysis of the novel technique in multiple aspects of the accelerator complex, as well as a direct comparison with its predecessor, CT, from the implementation of MTE in 2010 until the end of 2015.

  11. Epigenetic Control of Macrophage Shape Transition towards an Atypical Elongated Phenotype by Histone Deacetylase Activity.

    Directory of Open Access Journals (Sweden)

    Mariana Cabanel

    Full Text Available Inflammatory chronic pathologies are complex processes characterized by an imbalance between the resolution of the inflammatory phase and the establishment of tissue repair. The main players in these inflammatory pathologies are bone marrow derived monocytes (BMDMs. However, how monocyte differentiation is modulated to give rise to specific macrophage subpopulations (M1 or M2 that may either maintain the chronic inflammatory process or lead to wound healing is still unclear. Considering that inhibitors of Histone Deacetylase (HDAC have an anti-inflammatory activity, we asked whether this enzyme would play a role on monocyte differentiation into M1 or M2 phenotype and in the cell shape transition that follows. We then induced murine bone marrow progenitors into monocyte/macrophage differentiation pathway using media containing GM-CSF and the HDAC blocker, Trichostatin A (TSA. We found that the pharmacological inhibition of HDAC activity led to a shape transition from the typical macrophage pancake-like shape into an elongated morphology, which was correlated to a mixed M1/M2 profile of cytokine and chemokine secretion. Our results present, for the first time, that HDAC activity acts as a regulator of macrophage differentiation in the absence of lymphocyte stimuli. We propose that HDAC activity down regulates macrophage plasticity favoring the pro-inflammatory phenotype.

  12. An Interbacterial NAD(P)+ Glycohydrolase Toxin Requires Elongation Factor Tu for Delivery to Target Cells

    Energy Technology Data Exchange (ETDEWEB)

    Whitney, John C.; Quentin, Dennis; Sawai, Shin; LeRoux, Michele; Harding, Brittany N.; Ledvina, Hannah E.; Tran, Bao Q.; Robinson, Howard; Goo, Young Ah; Goodlett, David R.; Raunser, Stefan; Mougous, Joseph D.

    2015-10-08

    Type VI secretion (T6S) influences the composition of microbial communities by catalyzing the delivery of toxins between adjacent bacterial cells. Here, we demonstrate that a T6S integral membrane toxin from Pseudomonas aeruginosa, Tse6, acts on target cells by degrading the universally essential dinucleotides NAD+ and NADP+. Structural analyses of Tse6 show that it resembles mono-ADP-ribosyltransferase proteins, such as diphtheria toxin, with the exception of a unique loop that both excludes proteinaceous ADP-ribose acceptors and contributes to hydrolysis. We find that entry of Tse6 into target cells requires its binding to an essential housekeeping protein, translation elongation factor Tu (EF-Tu). These proteins participate in a larger assembly that additionally directs toxin export and provides chaperone activity. Visualization of this complex by electron microscopy defines the architecture of a toxin-loaded T6S apparatus and provides mechanistic insight into intercellular membrane protein delivery between bacteria.

  13. Slit and Robo regulate dendrite branching and elongation of space-filling neurons in Drosophila.

    Science.gov (United States)

    Dimitrova, Svetla; Reissaus, André; Tavosanis, Gaia

    2008-12-01

    Space-filling neurons extensively sample their receptive fields with fine dendritic branches. In this study we show that a member of the conserved Robo receptor family, Robo, and its ligand Slit regulate the dendritic differentiation of space-filling neurons. Loss of Robo or Slit function leads to faster elongating and less branched dendrites of the complex and space-filling class IV multi-dendritic dendrite-arborization (md-da) neurons in the Drosophila embryonic peripheral nervous system, but not of the simpler class I neurons. The total dendrite length of Class IV neurons is not modified in robo or slit mutant embryos. Robo mediates this process cell-autonomously. Upon Robo over-expression in md-da neurons the dendritic tree is simplified and time-lapse analysis during larval stages indicates that this is due to reduction in the number of newly formed branches. We propose that Slit, through Robo, provides an extrinsic signal to coordinate the growth rate and the branching level of space-filling neurons, thus allowing them to appropriately cover their target field.

  14. Evolutionarily conserved binding of translationally controlled tumor protein to eukaryotic elongation factor 1B.

    Science.gov (United States)

    Wu, Huiwen; Gong, Weibin; Yao, Xingzhe; Wang, Jinfeng; Perrett, Sarah; Feng, Yingang

    2015-04-03

    Translationally controlled tumor protein (TCTP) is an abundant protein that is highly conserved in eukaryotes. However, its primary function is still not clear. Human TCTP interacts with the metazoan-specific eukaryotic elongation factor 1Bδ (eEF1Bδ) and inhibits its guanine nucleotide exchange factor (GEF) activity, but the structural mechanism remains unknown. The interaction between TCTP and eEF1Bδ was investigated by NMR titration, structure determination, paramagnetic relaxation enhancement, site-directed mutagenesis, isothermal titration calorimetry, and HADDOCK docking. We first demonstrated that the catalytic GEF domain of eEF1Bδ is not responsible for binding to TCTP but rather a previously unnoticed central acidic region (CAR) domain in eEF1Bδ. The mutagenesis data and the structural model of the TCTP-eEF1Bδ CAR domain complex revealed the key binding residues. These residues are highly conserved in eukaryotic TCTPs and in eEF1B GEFs, including the eukaryotically conserved eEF1Bα, implying the interaction may be conserved in all eukaryotes. Interactions were confirmed between TCTP and the eEF1Bα CAR domain for human, fission yeast, and unicellular photosynthetic microalgal proteins, suggesting that involvement in protein translation through the conserved interaction with eEF1B represents a primary function of TCTP. © 2015 by The American Society for Biochemistry and Molecular Biology, Inc.

  15. Ultrastructural nuclear defects and increased chromosome aneuploidies in spermatozoa with elongated heads.

    Science.gov (United States)

    Prisant, N; Escalier, D; Soufir, J-C; Morillon, M; Schoevaert, D; Misrahi, M; Tachdjian, G

    2007-04-01

    Cellular and molecular mechanisms leading to elongated sperm heads are not known. We have analysed the nuclear status of spermatozoa with elongated heads. Fourteen men with at least 30% of spermatozoa with an elongated nucleus were studied and compared with five fertile men as controls. Sperm morphology was analysed by a quantitative ultrastructural analysis. Sperm chromosomal content was assessed by three-colour fluorescence in-situ hybridization (chromosomes X, Y, 18). Y chromosome microdeletion and karyotype were analysed. Elongated sperm head rates of the patients were 46.9% (30-75 versus 0-2% in the control group) by light microscopy and 34.4% by electron microscopy. In all patients, the chromatin was poorly condensed in elongated sperm heads (50% of elongated nuclei). No anomalies of sperm biochemical markers were found. All the men showed normal karyotype (46,XY) and absence of Y chromosome microdeletion. Aneuploidy rates of gonosomes and chromosome 18 were significantly increased in patients (1.64- and 3.6-fold, P = 0.006 and 0.026, respectively). This study demonstrates that impaired chromatin compaction and slightly increased chromosome aneuploidies are found in spermatozoa with an elongated head, suggesting possible mechanisms such as meiotic non-disjunctions or spermiogenesis anomalies.

  16. Molecular mechanism of Ena/VASP-mediated actin-filament elongation.

    Science.gov (United States)

    Breitsprecher, Dennis; Kiesewetter, Antje K; Linkner, Joern; Vinzenz, Marlene; Stradal, Theresia E B; Small, John Victor; Curth, Ute; Dickinson, Richard B; Faix, Jan

    2011-02-01

    Ena/VASP proteins are implicated in a variety of fundamental cellular processes including axon guidance and cell migration. In vitro, they enhance elongation of actin filaments, but at rates differing in nearly an order of magnitude according to species, raising questions about the molecular determinants of rate control. Chimeras from fast and slow elongating VASP proteins were generated and their ability to promote actin polymerization and to bind G-actin was assessed. By in vitro TIRF microscopy as well as thermodynamic and kinetic analyses, we show that the velocity of VASP-mediated filament elongation depends on G-actin recruitment by the WASP homology 2 motif. Comparison of the experimentally observed elongation rates with a quantitative mathematical model moreover revealed that Ena/VASP-mediated filament elongation displays a saturation dependence on the actin monomer concentration, implying that Ena/VASP proteins, independent of species, are fully saturated with actin in vivo and generally act as potent filament elongators. Moreover, our data showed that spontaneous addition of monomers does not occur during processive VASP-mediated filament elongation on surfaces, suggesting that most filament formation in cells is actively controlled.

  17. Transcription factor cooperativity in early adipogenic hotspots and super-enhancers

    DEFF Research Database (Denmark)

    Siersbæk, Rasmus; Rabiee, Atefeh; Nielsen, Ronni;

    2014-01-01

    It is becoming increasingly clear that transcription factors operate in complex networks through thousands of genomic binding sites, many of which bind several transcription factors. However, the extent and mechanisms of crosstalk between transcription factors at these hotspots remain unclear....... Using a combination of advanced proteomics and genomics approaches, we identify ∼12,000 transcription factor hotspots (∼400 bp) in the early phase of adipogenesis, and we find evidence of both simultaneous and sequential binding of transcription factors at these regions. We demonstrate that hotspots...... are highly enriched in large super-enhancer regions (several kilobases), which drive the early adipogenic reprogramming of gene expression. Our results indicate that cooperativity between transcription factors at the level of hotspots as well as super-enhancers is very important for enhancer activity...

  18. Comparison of Super Stuff and paraffin wax bolus in radiation therapy of irregular surfaces.

    Science.gov (United States)

    Humphries, S M; Boyd, K; Cornish, P; Newman, F D

    1996-01-01

    Irregular facial contours can make radiation therapy of head and neck tumors difficult. Isodose lines become skewed, making treatment planning complex. A traditional solution to this problem is the paraffin wax box bolus. Such a bolus is made to fit the irregular surface compensating for the topology and creating an even surface. The fabrication of a wax bolus can be a difficult and time-consuming process. A method that is simple and efficient has been devised. Super Stuff bolus can be easily molded and has approximately the same effect as a similar paraffin wax bolus. This was verified by irradiating a Rando head phantom with both a paraffin wax bolus and a Super Stuff bolus. Doses to various points of interest were measured with thermoluminescent dosimetry (TLD) chips (LiF). The particular case addressed is malignant melanoma of the nasal septum, but the technique described can be useful in the treatment of other sites as well.

  19. Sensing Super-Position: Human Sensing Beyond the Visual Spectrum

    Science.gov (United States)

    Maluf, David A.; Schipper, John F.

    2007-01-01

    The coming decade of fast, cheap and miniaturized electronics and sensory devices opens new pathways for the development of sophisticated equipment to overcome limitations of the human senses. This paper addresses the technical feasibility of augmenting human vision through Sensing Super-position by mixing natural Human sensing. The current implementation of the device translates visual and other passive or active sensory instruments into sounds, which become relevant when the visual resolution is insufficient for very difficult and particular sensing tasks. A successful Sensing Super-position meets many human and pilot vehicle system requirements. The system can be further developed into cheap, portable, and low power taking into account the limited capabilities of the human user as well as the typical characteristics of his dynamic environment. The system operates in real time, giving the desired information for the particular augmented sensing tasks. The Sensing Super-position device increases the image resolution perception and is obtained via an auditory representation as well as the visual representation. Auditory mapping is performed to distribute an image in time. The three-dimensional spatial brightness and multi-spectral maps of a sensed image are processed using real-time image processing techniques (e.g. histogram normalization) and transformed into a two-dimensional map of an audio signal as a function of frequency and time. This paper details the approach of developing Sensing Super-position systems as a way to augment the human vision system by exploiting the capabilities of Lie human hearing system as an additional neural input. The human hearing system is capable of learning to process and interpret extremely complicated and rapidly changing auditory patterns. The known capabilities of the human hearing system to learn and understand complicated auditory patterns provided the basic motivation for developing an image-to-sound mapping system. The

  20. Evolution and allometry of calcaneal elongation in living and extinct primates.

    Directory of Open Access Journals (Sweden)

    Doug M Boyer

    Full Text Available Specialized acrobatic leaping has been recognized as a key adaptive trait tied to the origin and subsequent radiation of euprimates based on its observed frequency in extant primates and inferred frequency in extinct early euprimates. Hypothesized skeletal correlates include elongated tarsal elements, which would be expected to aid leaping by allowing for increased rates and durations of propulsive acceleration at takeoff. Alternatively, authors of a recent study argued that pronounced distal calcaneal elongation of euprimates (compared to other mammalian taxa was related primarily to specialized pedal grasping. Testing for correlations between calcaneal elongation and leaping versus grasping is complicated by body size differences and associated allometric affects. We re-assess allometric constraints on, and the functional significance of, calcaneal elongation using phylogenetic comparative methods, and present an evolutionary hypothesis for the evolution of calcaneal elongation in primates using a Bayesian approach to ancestral state reconstruction (ASR. Results show that among all primates, logged ratios of distal calcaneal length to total calcaneal length are inversely correlated with logged body mass proxies derived from the area of the calcaneal facet for the cuboid. Results from phylogenetic ANOVA on residuals from this allometric line suggest that deviations are explained by degree of leaping specialization in prosimians, but not anthropoids. Results from ASR suggest that non-allometric increases in calcaneal elongation began in the primate stem lineage and continued independently in haplorhines and strepsirrhines. Anthropoid and lorisid lineages show stasis and decreasing elongation, respectively. Initial increases in calcaneal elongation in primate evolution may be related to either development of hallucal-grasping or a combination of grasping and more specialized leaping behaviors. As has been previously suggested, subsequent