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Sample records for wall joins elongating

  1. Development of Joining Technologies for the ITER Blanket First Wall

    Energy Technology Data Exchange (ETDEWEB)

    Choi, Byoung Kwon; Jung, Yang Il; Park, Dong Jun; Kim, Hyun Gil; Park, Sang Yoon; Park, Jeong Yong; Jeong, Yong Hwan; Lee, Dong Won; Kim, Suk Kwon [KAERI, Daejeon (Korea, Republic of)

    2011-01-15

    The design of the ITER blanket first wall includes the Beryllium amour tiles joined to CuCrZr heat sink with stainless steel cooling tubes. For the ITER application, the Be/CuCrZr/SS joint was proposed as a first wall material. The joining of Be/CuCrZr as well as CuCrZr/SS was generally carried out by using a hot isostatic pressing (CuC) in many countries. The joining strength for Be/CuCrZr is relatively lower than that for CuCrZr/SS, since we usually forms surface oxides (BeO) and brittle a metallics with Cu. Therefore, the joining technology for the Be/CuCrZr joint has been investigated. Be is apt to adsorb oxygen in an air atmosphere, so we should be etched to eliminate the surface pre-oxide using a chemical solution and Ar ions in a vacuum chamber. Then we is coated with a first was to prevent further oxidation. The kinds of a first we are chosen to be able to enhance the joining strength as inhibiting excessive be diffusion. The performance of the Be/CuCrZr/SS joint used for the ITER first wall is primarily dependent on the joining strength of the Be/CuCrZr interface. The Cr/Cu and Ti/Cr/Cu interlayers enabled the successful joining of be tile to CuCrZr plate. Moreover, ion-beam assisted deposition (IBAD) increased joining strength of the Be/CuCrZr joint mock-ups. IBAD induced the increased packing of depositing atoms, which resulted in denser and more adhesive interlayers. The interlayers formed by IBAD process revealed about 40% improved resistance to the scratch test. It is suggested that the improved adhesion of coating interlayers enabled tight joining of Be and CuCrZr blocks. As compared to without IBAD coating, the shear strength as well as the 4-point bend strength were increased more than 20% depending on interlayer types and coating conditions

  2. 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...

  3. In Vivo Cell Wall Loosening by Hydroxyl Radicals during Cress Seed Germination and Elongation Growth

    NARCIS (Netherlands)

    Muller, K.; Linkies, A.; Vreeburg, R.A.M.; Fry, S.C.; Krieger-Liszkay, A.; Leubner-Metzger, G.

    2009-01-01

    Loosening of cell walls is an important developmental process in key stages of the plant life cycle, including seed germination, elongation growth, and fruit ripening. Here, we report direct in vivo evidence for hydroxyl radical (·OH)-mediated cell wall loosening during plant seed germination and se

  4. Magnetarc Welding - peculiarities of joining thin wall tubes

    OpenAIRE

    2010-01-01

    The paper presents the MAGNETARC welding of thin tubes achieved with an original longitudinal magnetization system, designed to assure the magnetic flux concentration on tube wall. Process main stages are presented, from the arc initiation until the molten metal appears, upsetting is achieved and the weld forms. Infrared thermography was used for temperature measurements and process visualization. Macro and microstructural analysis accompanies the hardness tests made on correspondingly weld...

  5. Stimulation of elongation growth and cell wall loosening in rice coleoptiles under microgravity conditions in space.

    Science.gov (United States)

    Hoson, Takayuki; Soga, Kouichi; Mori, Ryuji; Saiki, Mizue; Nakamura, Yukiko; Wakabayashi, Kazuyuki; Kamisaka, Seiichiro

    2002-09-01

    We analyzed the growth rate and the cell wall properties of coleoptiles of rice seedlings grown at 23.6 degrees C for 68.5, 91.5 and 136 h during the Space Shuttle STS-95 mission. In space, elongation growth of coleoptiles was stimulated and the cell wall extensibility increased. Also, the levels of the cell wall polysaccharides per unit length of coleoptiles and the relative content of the high molecular mass matrix polysaccharides decreased in space. These differences in the cell wall polysaccharides could be involved in increasing the cell wall extensibility, leading to growth stimulation of rice coleoptiles in space.

  6. Multi-omics analysis identifies genes mediating the extension of cell walls in the Arabidopsis thaliana root elongation zone

    Directory of Open Access Journals (Sweden)

    Michael H Wilson

    2015-02-01

    Full Text Available Plant cell wall composition is important for regulating growth rates, especially in roots. However, neither analyses of cell wall composition nor transcriptomes on their own can comprehensively reveal which genes and processes are mediating growth and cell elongation rates. This study reveals the benefits of carrying out multiple analyses in combination. Sections of roots from five anatomically and functionally defined zones in Arabidopsis thaliana were prepared and divided into three biological replicates. We used glycan microarrays and antibodies to identify the major classes of glycans and glycoproteins present in the cell walls of these sections, and identified the expected decrease in pectin and increase in xylan from the meristematic zone (MS, through the rapid and late elongation zones (REZ, LEZ to the maturation zone and the rest of the root, including the emerging lateral roots. Other compositional changes included extensin and xyloglucan levels peaking in the REZ and increasing levels of arabinogalactan-proteins (AGP epitopes from the MS to the LEZ, which remained high through the subsequent mature zones. Immuno-staining using the same antibodies identified the tissue and (subcellular localization of many epitopes. Extensins were localized in epidermal and cortex cell walls, while AGP glycans were specific to different tissues from root-hair cells to the stele. The transcriptome analysis found several gene families peaking in the REZ. These included a large family of peroxidases (which produce the reactive oxygen species needed for cell expansion, and three xyloglucan endo-transglycosylase/hydrolase genes (XTH17, XTH18 and XTH19. The significance of the latter may be related to a role in breaking and re-joining xyloglucan cross-bridges between cellulose microfibrils, a process which is required for wall expansion. Knockdowns of these XTHs resulted in shorter root lengths, confirming a role of the corresponding proteins in root

  7. Multi-omics analysis identifies genes mediating the extension of cell walls in the Arabidopsis thaliana root elongation zone

    DEFF Research Database (Denmark)

    Wilson, Michael H; Holman, Tara J; Sørensen, Iben

    2015-01-01

    produce the reactive oxygen species (ROS) needed for cell expansion), and three xyloglucan endo-transglycosylase/hydrolase genes (XTH17, XTH18, and XTH19). The significance of the latter may be related to a role in breaking and re-joining xyloglucan cross-bridges between cellulose microfibrils, a process......Plant cell wall composition is important for regulating growth rates, especially in roots. However, neither analyses of cell wall composition nor transcriptomes on their own can comprehensively reveal which genes and processes are mediating growth and cell elongation rates. This study reveals...... which is required for wall expansion. Knockdowns of these XTHs resulted in shorter root lengths, confirming a role of the corresponding proteins in root extension growth....

  8. Joining and fabrication techniques for high temperature structures including the first wall in fusion reactor

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Ho Jin; Lee, B. S.; Kim, K. B

    2003-09-01

    The materials for PFC's (Plasma Facing Components) in a fusion reactor are severely irradiated with fusion products in facing the high temperature plasma during the operation. The refractory materials can be maintained their excellent properties in severe operating condition by lowering surface temperature by bonding them to the high thermal conducting materials of heat sink. Hence, the joining and bonding techniques between dissimilar materials is considered to be important in case of the fusion reactor or nuclear reactor which is operated at high temperature. The first wall in the fusion reactor is heated to approximately 1000 .deg. C and irradiated severely by the plasma. In ITER, beryllium is expected as the primary armour candidate for the PFC's; other candidates including W, Mo, SiC, B4C, C/C and Si{sub 3}N{sub 4}. Since the heat affected zones in the PFC's processed by conventional welding are reported to have embrittlement and degradation in the sever operation condition, both brazing and diffusion bonding are being considered as prime candidates for the joining technique. In this report, both the materials including ceramics and the fabrication techniques including joining technique between dissimilar materials for PFC's are described. The described joining technique between the refractory materials and the dissimilar materials may be applicable for the fusion reactor and Generation-4 future nuclear reactor which are operated at high temperature and high irradiation.

  9. Status of Joining Thin Sheet and Thin Wall Tubes of 14YWT

    Energy Technology Data Exchange (ETDEWEB)

    Hoelzer, David T. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Unocic, Kinga A. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Tang, Wei [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Feng, Zhili [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)

    2015-09-18

    Beginning this fiscal year, the FCRD research project initiated an investigation on joining thin sections of the advanced ODS 14YWT ferritic alloy. Friction stir welding (FSW) was investigated as a method to join thin plate and tubing of 14YWT since it is a solid state joining method that has been shown in past studies to be a promising method for joining plates of ODS alloys, such as 14YWT. However, this study will attempt to be the first to demonstrate if FSW can successfully join thin plates and thin wall tubing of 14YWT. In the first FSW attempt, a 1.06 cm thick plate of 14YWT (SM13 heat) was successfully rolled at 1000ºC to the target thickness of 0.1 cm with no edge cracking. This achievement is a highlight since previous attempts to roll 14YWT plates have resulted in extensive cracking. For the FSW run, a pin tool being developed by the ORNL FSW Process Development effort was used. The first FSW run successfully produced a bead-on-plate weld in the 0.1 cm thick plate. The quality of the weld zone appears very good with no evidence of large defects such as cavities. The microstructural characterization study of the bead-on-plate weld zone has been initiated to compare the results of the microstructure analysis with those obtained in the reference microstructural analysis of the 14YWT (SM13 heat) that showed ultra-fine grain size of 0.43 μm and a high number density of ~2-5 nm sizes oxygen-enriched nanoclusters.

  10. Xyloglucan antibodies inhibit auxin-induced elongation and cell wall loosening of azuki bean epicotyls but not of oat coleoptiles.

    Science.gov (United States)

    Hoson, T; Masuda, Y; Sone, Y; Misaki, A

    1991-06-01

    Polyclonal antibodies were raised in rabbits against isoprimeverose (Xyl(1)Glc(1)), xyloglucan heptasaccharides (Xyl(3)Glc(4)), and octasaccharides (Gal(1)Xyl(3)Glc(4)). Antibodies specific for hepta- and octasaccharides suppressed auxin-induced elongation of epicotyl segments of azuki bean (Vigna angularis Ohwi and Ohashi cv Takara). These antibodies also inhibited auxin-induced cell wall loosening (decrease in the minimum stress-relaxation time and the relaxation rate of the cell walls) of azuki segments. However, none of the antibodies influenced auxin-induced elongation or cell wall loosening of coleoptile segments of oat (Avena sativa L. cv Victory). Auxin caused a decrease in molecular mass of xyloglucans in the cell walls of azuki epicotyls and oat coleoptiles. The antibodies inhibited such a change in molecular mass of xyloglucans in both species. Preimmune serum exhibited little or no inhibitory effect on auxin-induced elongation, cell wall loosening, or breakdown of xyloglucans. The results support the view that the breakdown of xyloglucans is associated with the cell wall loosening responsible for auxin-induced elongation in dicotyledons. The view does not appear to be applicable to poaceae, because the inhibition of xyloglucan breakdown by the antibodies did not influence auxin-induced elongation or cell wall loosening of oat coleoptiles.

  11. A new picture of cell wall protein dynamics in elongating cells of Arabidopsis thaliana: Confirmed actors and newcomers

    Directory of Open Access Journals (Sweden)

    Jamet Elisabeth

    2008-09-01

    Full Text Available Abstract Background Cell elongation in plants requires addition and re-arrangements of cell wall components. Even if some protein families have been shown to play roles in these events, a global picture of proteins present in cell walls of elongating cells is still missing. A proteomic study was performed on etiolated hypocotyls of Arabidopsis used as model of cells undergoing elongation followed by growth arrest within a short time. Results Two developmental stages (active growth and after growth arrest were compared. A new strategy consisting of high performance cation exchange chromatography and mono-dimensional electrophoresis was established for separation of cell wall proteins. This work allowed identification of 137 predicted secreted proteins, among which 51 had not been identified previously. Apart from expected proteins known to be involved in cell wall extension such as xyloglucan endotransglucosylase-hydrolases, expansins, polygalacturonases, pectin methylesterases and peroxidases, new proteins were identified such as proteases, proteins related to lipid metabolism and proteins of unknown function. Conclusion This work highlights the CWP dynamics that takes place between the two developmental stages. The presence of proteins known to be related to cell wall extension after growth arrest showed that these proteins may play other roles in cell walls. Finally, putative regulatory mechanisms of protein biological activity are discussed from this global view of cell wall proteins.

  12. Stiff mutant genes of phycomyces affect turgor pressure and wall mechanical properties to regulate elongation growth rate.

    Science.gov (United States)

    Ortega, Joseph K E; Munoz, Cindy M; Blakley, Scott E; Truong, Jason T; Ortega, Elena L

    2012-01-01

    Regulation of cell growth is paramount to all living organisms. In plants, algae and fungi, regulation of expansive growth of cells is required for development and morphogenesis. Also, many sensory responses of stage IVb sporangiophores of Phycomyces blakesleeanus are produced by regulating elongation growth rate (growth responses) and differential elongation growth rate (tropic responses). "Stiff" mutant sporangiophores exhibit diminished tropic responses and are found to be defective in at least five genes; madD, E, F, G, and J. Prior experimental research suggests that the defective genes affect growth regulation, but this was not verified. All the growth of the single-celled stalk of the stage IVb sporangiophore occurs in a short region termed the "growth zone." Prior experimental and theoretical research indicates that elongation growth rate of the stage IVb sporangiophore can be regulated by controlling the cell wall mechanical properties within the growth zone and the magnitude of the turgor pressure. A quantitative biophysical model for elongation growth rate is required to elucidate the relationship between wall mechanical properties and turgor pressure during growth regulation. In this study, it is hypothesized that the mechanical properties of the wall within the growth zone of stiff mutant sporangiophores are different compared to wild type (WT). A biophysical equation for elongation growth rate is derived for fungal and plant cells with a growth zone. Two strains of stiff mutants are studied, C149 madD120 (-) and C216 geo- (-). Experimental results demonstrate that turgor pressure is larger but irreversible wall deformation rates within the growth zone and growth zone length are smaller for stiff mutant sporangiophores compared to WT. These findings can explain the diminished tropic responses of the stiff mutant sporangiophores. It is speculated that the defective genes affect the amount of wall-building material delivered to the inner cell wall.

  13. Metabolomic and transcriptomic insights into how cotton fiber transitions to secondary wall sythesis, represses lignification, and prolongs elongation

    Science.gov (United States)

    Cotton fiber morphogenesis reflects extreme elongation and staged cell wall differentiation in an easily isolated single cell. Uncovering the cellular control mechanisms can lead to strategies for producing improved cotton fiber for textiles and other uses. To identify potential controls of the high...

  14. Intracellulair Organization: A Prerequisite for Root Hair Elongation and Cell Wall Deposition

    NARCIS (Netherlands)

    Emons, A.M.C.; Ketelaar, M.J.

    2009-01-01

    Cell growth requires not only production of matter, but in addition, the targeting, transport, and delivery of this matter to the site of cell expansion. Thus, a proper organization of cell structure, the cytoarchitecture, is a necessity for cell elongation. The actual process of cell growth in a ce

  15. Cell wall growth during elongation and division : one ring to bind them?

    NARCIS (Netherlands)

    Scheffers, Dirk-Jan

    2007-01-01

    The role of the cell division protein FtsZ in bacterial cell wall (CW) synthesis is believed to be restricted to localizing proteins involved in the synthesis of the septal wall. Elsewhere, compelling evidence is provided that in Caulobacter crescentus, FtsZ plays an additional role in CW synthesis

  16. Xyloglucan Antibodies Inhibit Auxin-Induced Elongation and Cell Wall Loosening of Azuki Bean Epicotyls but Not of Oat Coleoptiles 1

    Science.gov (United States)

    Hoson, Takayuki; Masuda, Yoshio; Sone, Yoshiaki; Misaki, Akira

    1991-01-01

    Polyclonal antibodies were raised in rabbits against isoprimeverose (Xyl1Glc1), xyloglucan heptasaccharides (Xyl3Glc4), and octasaccharides (Gal1Xyl3Glc4). Antibodies specific for hepta- and octasaccharides suppressed auxin-induced elongation of epicotyl segments of azuki bean (Vigna angularis Ohwi and Ohashi cv Takara). These antibodies also inhibited auxin-induced cell wall loosening (decrease in the minimum stress-relaxation time and the relaxation rate of the cell walls) of azuki segments. However, none of the antibodies influenced auxin-induced elongation or cell wall loosening of coleoptile segments of oat (Avena sativa L. cv Victory). Auxin caused a decrease in molecular mass of xyloglucans in the cell walls of azuki epicotyls and oat coleoptiles. The antibodies inhibited such a change in molecular mass of xyloglucans in both species. Preimmune serum exhibited little or no inhibitory effect on auxin-induced elongation, cell wall loosening, or breakdown of xyloglucans. The results support the view that the breakdown of xyloglucans is associated with the cell wall loosening responsible for auxin-induced elongation in dicotyledons. The view does not appear to be applicable to poaceae, because the inhibition of xyloglucan breakdown by the antibodies did not influence auxin-induced elongation or cell wall loosening of oat coleoptiles. ImagesFigure 1Figure 2 PMID:16668221

  17. β-d-Glucan Antibodies Inhibit Auxin-Induced Cell Elongation and Changes in the Cell Wall of Zea Coleoptile Segments 1

    Science.gov (United States)

    Hoson, Takayuki; Nevins, Donald J.

    1989-01-01

    Antiserum was raised against the Avena sativa L. caryopsis β-d-glucan fraction with an average molecular weight of 1.5 × 104. Polyclonal antibodies recovered from the serum after Protein A-Sepharose column chromatography precipitated when cross-reacted with high molecular weight (1→3), (1→4)-β-d-glucans. These antibodies were effective in suppression of cell wall autohydrolytic reactions and auxin-induced decreases in noncellulosic glucose content of the cell wall of maize (Zea mays L.) coleoptiles. The results indicate antibody-mediated interference with in situ β-d-glucan degradation. The antibodies at a concentration of 200 micrograms per milliliter also suppress auxin-induced elongation by about 40% and cell wall loosening (measured by the minimum stress-relaxation time of the segments) of Zea coleoptiles. The suppression of elongation by antibodies was imposed without a lag period. Auxin-induced elongation, cell wall loosening, and chemical changes in the cell walls were near the levels of control tissues when segments were subjected to antibody preparation precipitated by a pretreatment with Avena caryopsis β-d-glucans. These results support the idea that the degradation of (1→3), (1→4)-β-d-glucans by cell wall enzymes is associated with the cell wall loosening responsible for auxin-induced elongation. PMID:16666935

  18. beta-d-Glucan Antibodies Inhibit Auxin-Induced Cell Elongation and Changes in the Cell Wall of Zea Coleoptile Segments.

    Science.gov (United States)

    Hoson, T; Nevins, D J

    1989-08-01

    Antiserum was raised against the Avena sativa L. caryopsis beta-d-glucan fraction with an average molecular weight of 1.5 x 10(4). Polyclonal antibodies recovered from the serum after Protein A-Sepharose column chromatography precipitated when cross-reacted with high molecular weight (1-->3), (1-->4)-beta-d-glucans. These antibodies were effective in suppression of cell wall autohydrolytic reactions and auxin-induced decreases in noncellulosic glucose content of the cell wall of maize (Zea mays L.) coleoptiles. The results indicate antibody-mediated interference with in situ beta-d-glucan degradation. The antibodies at a concentration of 200 micrograms per milliliter also suppress auxin-induced elongation by about 40% and cell wall loosening (measured by the minimum stress-relaxation time of the segments) of Zea coleoptiles. The suppression of elongation by antibodies was imposed without a lag period. Auxin-induced elongation, cell wall loosening, and chemical changes in the cell walls were near the levels of control tissues when segments were subjected to antibody preparation precipitated by a pretreatment with Avena caryopsis beta-d-glucans. These results support the idea that the degradation of (1-->3), (1-->4)-beta-d-glucans by cell wall enzymes is associated with the cell wall loosening responsible for auxin-induced elongation.

  19. Cell wall elongation mode in Gram-negative bacteria is determined by peptidoglycan architecture.

    Science.gov (United States)

    Turner, Robert D; Hurd, Alexander F; Cadby, Ashley; Hobbs, Jamie K; Foster, Simon J

    2013-01-01

    Cellular integrity and morphology of most bacteria is maintained by cell wall peptidoglycan, the target of antibiotics essential in modern healthcare. It consists of glycan strands, cross-linked by peptides, whose arrangement determines cell shape, prevents lysis due to turgor pressure and yet remains dynamic to allow insertion of new material, and hence growth. The cellular architecture and insertion pattern of peptidoglycan have remained elusive. Here we determine the peptidoglycan architecture and dynamics during growth in rod-shaped Gram-negative bacteria. Peptidoglycan is made up of circumferentially oriented bands of material interspersed with a more porous network. Super-resolution fluorescence microscopy reveals an unexpected discontinuous, patchy synthesis pattern. We present a consolidated model of growth via architecture-regulated insertion, where we propose only the more porous regions of the peptidoglycan network that are permissive for synthesis.

  20. Multi-omics analysis identifies genes mediating the extension of cell walls in the Arabidopsis thaliana root elongation zone

    DEFF Research Database (Denmark)

    Wilson, Michael H; Holman, Tara J; Sørensen, Iben;

    2015-01-01

    and glycoproteins present in the cell walls of these sections, and identified the expected decrease in pectin and increase in xylan from the meristematic zone (MS), through the rapid and late elongation zones (REZ, LEZ) to the maturation zone and the rest of the root, including the emerging lateral roots. Other...

  1. Rapid Changes in Cell Wall Yielding of Elongating Begonia argenteo-guttata L. Leaves in Response to Changes in Plant Water Status 1

    Science.gov (United States)

    Serpe, Marcelo D.; Matthews, Mark A.

    1992-01-01

    Elongation and epidermal cell turgor (P) of Begonia argenteoguttata L. leaves were simultaneously measured to determine the wall-yielding behavior of growing leaf cells in response to changes in plant water status. Rapid changes in plant water status were imposed by irrigating the rooting media with solutions of −0.20 and −0.30 MPa mannitol. These treatments caused decreases in P of 0.09 and 0.17 MPa, respectively. The decreases in P were complete within 10 min, and P did not change thereafter. Following treatments, leaf elongation was nil for periods of 25 to 38 min. Subsequently, elongation recovered to steady rates that were 45 or 75% lower than in the well-watered controls. Leaves of plants that were pretreated with −0.30 MPa of mannitol and rewatered showed an increase in P of 0.19 MPa, which was complete within 15 min; P did not change thereafter. Rewatering caused a several-fold increase in leaf elongation rates, which subsequently declined while P was increasing, to reach steady rates similar to that of the controls. Several estimates of elastic deformation indicated that most of the elongation responses to altered P were due to changes in irreversible deformation. The results showed that the initial effects of changes in P on leaf elongation were partially compensated for by changes in the cell wall-yielding properties. We conclude that linear relationships between P and adjusted growth rates are not necessarily indicative of constant wall-yielding properties. Instead, these relationships may reflect the effect of P on wall-loosening processes. PMID:16653208

  2. Rapid Changes in Cell Wall Yielding of Elongating Begonia argenteo-guttata L. Leaves in Response to Changes in Plant Water Status.

    Science.gov (United States)

    Serpe, M D; Matthews, M A

    1992-12-01

    Elongation and epidermal cell turgor (P) of Begonia argenteoguttata L. leaves were simultaneously measured to determine the wall-yielding behavior of growing leaf cells in response to changes in plant water status. Rapid changes in plant water status were imposed by irrigating the rooting media with solutions of -0.20 and -0.30 MPa mannitol. These treatments caused decreases in P of 0.09 and 0.17 MPa, respectively. The decreases in P were complete within 10 min, and P did not change thereafter. Following treatments, leaf elongation was nil for periods of 25 to 38 min. Subsequently, elongation recovered to steady rates that were 45 or 75% lower than in the well-watered controls. Leaves of plants that were pretreated with -0.30 MPa of mannitol and rewatered showed an increase in P of 0.19 MPa, which was complete within 15 min; P did not change thereafter. Rewatering caused a several-fold increase in leaf elongation rates, which subsequently declined while P was increasing, to reach steady rates similar to that of the controls. Several estimates of elastic deformation indicated that most of the elongation responses to altered P were due to changes in irreversible deformation. The results showed that the initial effects of changes in P on leaf elongation were partially compensated for by changes in the cell wall-yielding properties. We conclude that linear relationships between P and adjusted growth rates are not necessarily indicative of constant wall-yielding properties. Instead, these relationships may reflect the effect of P on wall-loosening processes.

  3. A review of joining techniques for SiC{sub f}/SiC composites for first wall applications

    Energy Technology Data Exchange (ETDEWEB)

    Lewinsohn, C.A.; Jones, R.H. [Pacific Northwest National Lab., Richland, WA (United States)

    1998-09-01

    Many methods for joining monolithic and composite silicon carbide are available. Three techniques are candidates for use in fusion energy systems: in-situ displacement reactions, pre-ceramic polymer adhesives, and reaction bonding. None of the methods are currently developed enough to satisfy all of the criteria required, i.e., low temperature fabrication, high strength, and radiation stability. 58 refs.

  4. Inhibition of fucosylation of cell wall components by 2-fluoro 2-deoxy-L-fucose induces defects in root cell elongation.

    Science.gov (United States)

    Dumont, Marie; Lehner, Arnaud; Bardor, Muriel; Burel, Carole; Vauzeilles, Boris; Lerouxel, Olivier; Anderson, Charles T; Mollet, Jean-Claude; Lerouge, Patrice

    2015-12-01

    Screening of commercially available fluoro monosaccharides as putative growth inhibitors in Arabidopsis thaliana revealed that 2-fluoro 2-l-fucose (2F-Fuc) reduces root growth at micromolar concentrations. The inability of 2F-Fuc to affect an Atfkgp mutant that is defective in the fucose salvage pathway indicates that 2F-Fuc must be converted to its cognate GDP nucleotide sugar in order to inhibit root growth. Chemical analysis of cell wall polysaccharides and glycoproteins demonstrated that fucosylation of xyloglucans and of N-linked glycans is fully inhibited by 10 μm 2F-Fuc in Arabidopsis seedling roots, but genetic evidence indicates that these alterations are not responsible for the inhibition of root development by 2F-Fuc. Inhibition of fucosylation of cell wall polysaccharides also affected pectic rhamnogalacturonan-II (RG-II). At low concentrations, 2F-Fuc induced a decrease in RG-II dimerization. Both RG-II dimerization and root growth were partially restored in 2F-Fuc-treated seedlings by addition of boric acid, suggesting that the growth phenotype caused by 2F-Fuc was due to a deficiency of RG-II dimerization. Closer investigation of the 2F-Fuc-induced growth phenotype demonstrated that cell division is not affected by 2F-Fuc treatments. In contrast, the inhibitor suppressed elongation of root cells and promoted the emergence of adventitious roots. This study further emphasizes the importance of RG-II in cell elongation and the utility of glycosyltransferase inhibitors as new tools for studying the functions of cell wall polysaccharides in plant development. Moreover, supplementation experiments with borate suggest that the function of boron in plants might not be restricted to RG-II cross-linking, but that it might also be a signal molecule in the cell wall integrity-sensing mechanism.

  5. Gibberellin (GA3) enhances cell wall invertase activity and mRNA levels in elongating dwarf pea (Pisum sativum) shoots

    Science.gov (United States)

    Wu, L. L.; Mitchell, J. P.; Cohn, N. S.; Kaufman, P. B.

    1993-01-01

    The invertase (EC 3.2.1.26) purified from cell walls of dwarf pea stems to homogeneity has a molecular mass of 64 kilodaltons (kD). Poly(A)+RNA was isolated from shoots of dwarf pea plants, and a cDNA library was constructed using lambda gt11 as an expression vector. The expression cDNA library was screened with polyclonal antibodies against pea cell wall invertase. One invertase cDNA clone was characterized as a full-length cDNA with 1,863 base pairs. Compared with other known invertases, one homologous region in the amino acid sequence was found. The conserved motif, Asn-Asp-Pro-Asn-Gly, is located near the N-terminal end of invertase. Northern blot analysis showed that the amount of invertase mRNA (1.86 kb) was rapidly induced to a maximal level 4 h after GA3 treatment, then gradually decreased to the control level. The mRNA level at 4 h in GA3-treated peas was fivefold higher than that of the control group. The maximal increase in activity of pea cell wall invertase elicited by GA3 occcured at 8 h after GA3 treatment. This invertase isoform was shown immunocytochemically to be localized in the cell walls, where a 10-fold higher accumulation occurred in GA3-treated tissue compared with control tissue. This study indicates that the expression of the pea shoot cell-wall invertase gene could be regulated by GA3 at transcriptional and/or translational levels.

  6. Transient gibberellin application promotes Arabidopsis thaliana hypocotyl cell elongation without maintaining transverse orientation of microtubules on the outer tangential wall of epidermal cells

    KAUST Repository

    Sauret-Güeto, Susanna

    2011-11-25

    The phytohormone gibberellin (GA) promotes plant growth by stimulating cellular expansion. Whilst it is known that GA acts by opposing the growth-repressing effects of DELLA proteins, it is not known how these events promote cellular expansion. Here we present a time-lapse analysis of the effects of a single pulse of GA on the growth of Arabidopsis hypocotyls. Our analyses permit kinetic resolution of the transient growth effects of GA on expanding cells. We show that pulsed application of GA to the relatively slowly growing cells of the unexpanded light-grown Arabidopsis hypocotyl results in a transient burst of anisotropic cellular growth. This burst, and the subsequent restoration of initial cellular elongation rates, occurred respectively following the degradation and subsequent reappearance of a GFP-tagged DELLA (GFP-RGA). In addition, we used a GFP-tagged α-tubulin 6 (GFP-TUA6) to visualise the behaviour of microtubules (MTs) on the outer tangential wall (OTW) of epidermal cells. In contrast to some current hypotheses concerning the effect of GA on MTs, we show that the GA-induced boost of hypocotyl cell elongation rate is not dependent upon the maintenance of transverse orientation of the OTW MTs. This confirms that transverse alignment of outer face MTs is not necessary to maintain rapid elongation rates of light-grown hypocotyls. Together with future studies on MT dynamics in other faces of epidermal cells and in cells deeper within the hypocotyl, our observations advance understanding of the mechanisms by which GA promotes plant cell and organ growth. © 2011 Blackwell Publishing Ltd.

  7. Purification and characterization of soluble (cytosolic) and bound (cell wall) isoforms of invertases in barley (Hordeum vulgare) elongating stem tissue

    Science.gov (United States)

    Karuppiah, N.; Vadlamudi, B.; Kaufman, P. B.

    1989-01-01

    Three different isoforms of invertases have been detected in the developing internodes of barley (Hordeum vulgare). Based on substrate specificities, the isoforms have been identified to be invertases (beta-fructosidases EC 3.2.1.26). The soluble (cytosolic) invertase isoform can be purified to apparent homogeneity by diethylaminoethyl cellulose, Concanavalin-A Sepharose, organo-mercurial Sepharose, and Sephacryl S-300 chromatography. A bound (cell wall) invertase isoform can be released by 1 molar salt and purified further by the same procedures as above except omitting the organo-mercurial Sepharose affinity chromatography step. A third isoform of invertase, which is apparently tightly associated with the cell wall, cannot be isolated yet. The soluble and bound invertase isoforms were purified by factors of 60- and 7-fold, respectively. The native enzymes have an apparent molecular weight of 120 kilodaltons as estimated by gel filtration. They have been identified to be dimers under denaturing and nondenaturing conditions. The soluble enzyme has a pH optimum of 5.5, Km of 12 millimolar, and a Vmax of 80 micromole per minute per milligram of protein compared with cell wall isozyme which has a pH optimum of 4.5, Km of millimolar, and a Vmax of 9 micromole per minute per milligram of protein.

  8. Ceramic joining

    Energy Technology Data Exchange (ETDEWEB)

    Loehman, R.E. [Sandia National Lab., Albuquerque, NM (United States)

    1996-04-01

    This paper describes the relation between reactions at ceramic-metal interfaces and the development of strong interfacial bonds in ceramic joining. Studies on a number of systems are described, including silicon nitrides, aluminium nitrides, mullite, and aluminium oxides. Joints can be weakened by stresses such as thermal expansion mismatch. Ceramic joining is used in a variety of applications such as solid oxide fuel cells.

  9. 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

  10. Joining Forces

    Institute of Scientific and Technical Information of China (English)

    2009-01-01

    The Chinese and U.S. navies are bound to work together for the common good of the international community Sino-U.S. military relations recently received another boost. The Japan-Ibased U.S. destroyer USS Fitzgerald joined Chinese and foreign naval vessels in a grand international fleet review to celebrate the 60th anniversary of the founding of the Navy of the People’s Liberation Army (PLA) in the coastal city of Qingdao

  11. LAMP Joining between Ceramic and Plastic

    Science.gov (United States)

    Kawahito, Yousuke; Nishimoto, Kouji; Katayama, Seiji

    Joining of dissimilar materials is necessary and important from a manufacturing viewpoint. Therefore, the authors have developed a new laser direct joining method between a metal and a plastic which is named Laser Assisted Metal and Plastic (LAMP) joining method. In this research, LAMP joining was applied to join silicon nitride Si3N4 ceramic and polyethylene terephthalate (PET) engineering plastic, although metal was replaced by ceramic. The tensile shear strength of obtained joints was 3100 N at the maximum, which was strong enough to elongate a PET base plate of 2 mm in thickness and 30 mm in width. Moreover, transmission electron microscopes (TEM) observation demonstrates that the ceramic and the plastic are tightly bonded on atomic or molecular sized level.

  12. HHF test with 80x80x1 Be/Cu/SS Mock-ups for verifying the joining technology of the ITER blanket First Wall

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Dong Won; Bae, Young Dug; Kim, Suk Kwon; Hong, Bong Guen; Jeong, Yong Hwan; Park, Jeong Yong; Choi, Byung Kwon; Jung, Hyun Kyu

    2008-11-15

    Through the fabrication of the Cu/SS and Be/Cu joint specimens, fabrication procedure such as material preparation, canning, degassing, HIP (Hot Isostatic Pressing), PHHT (Post HIP heat treatment) was established. The HIP conditions (1050 .deg. C, 100 MPa 2 hr for Cu/SS, 580 .deg. C 100 MPa 2 hr for Be/Cu) were developed through the investigation on joint specimen fabricated with the various HIP conditions; the destructive tests of joint include the microstructure observation of the interface with the examination of the elemental distribution, tension test, bend test, Charpy impact test and fracture toughness test. However, since the joint should be tested under the High Heat Flux (HHF) conditions like the ITER operation for verifying its joint integrity, several HHF tests were performed like the previous HHF test with the Cu/SS, Be/Cu, Be/Cu/SS Mock-ups. In the present study, the HHF test with Be/Cu/SS Mock-ups, which have 80 mm x 80 mm single Be tile and each material depths were kept to be the same as the ITER blanket FW. The Mock-ups fabricated with three kinds of interlayers such as Cr/Ti/Cu, Ti/Cr/Cu, Ti/Cu, which were different from the developed interlayer (Cr/Cu), total 6 Mock-ups were fabricated. Preliminary analysis were performed to decide the test conditions; they were tested with up to 2.5 MW/m2 of heat fluxes and 20 cycles for each Mock-up in a given heat flux. They were tested with JUDITH-1 at FZJ in Germany. During tests, all Mock-ups showed delamination or full detachment of Be tile and it can be concluded that the joints with these interlayers have a bad joining but it can be used as a good data for developing the Be/Cu joint with HIP.

  13. Joining of advanced materials

    CERN Document Server

    Messler, Robert W

    1993-01-01

    Provides an unusually complete and readable compilation of the primary and secondary options for joining conventional materials in non-conventional ways. Provides unique coverage of adhesive bonding using both organic and inorganic adhesives, cements and mortars. Focuses on materials issues without ignoring issues related to joint design, production processing, quality assurance, process economics, and joining performance in service.Joining of advanced materials is a unique treatment of joining of both conventional and advanced metals andalloys, intermetallics, ceramics, glasses, polymers, a

  14. Joining by plastic deformation

    DEFF Research Database (Denmark)

    Mori, Ken-ichiro; Bay, Niels; Fratini, Livan

    2013-01-01

    opportunities to design new products through joining dissimilar materials. This paper aims to provide an overview of the state of the art in such joining processes, including cold welding, friction stir welding, self-pierce riveting, mechanical clinching and joining by forming. The paper includes description...... of the mechanism of joint formation, and analysis of joint performance and applicability. © 2013 CIRP....

  15. HHF Test with FMS/FMS Mock-ups for Verifying the Joining Technology of the Liquid TBM First Wall in the ITER

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Dong Won; Bae, Young Dug; Kim, Suk Kwon; Song, Woo Sub; Chang, Doo Hee; Kim, Tae Sung; Kim, Bum Ryul; Hong, Bong Guen; Park, Jung Yong; Choi, Byung Kwon; Jeong, Yong Hwan

    2008-11-15

    Through the fabrication of the FMS joint specimens, fabrication procedure such as material preparation, canning, degassing, HIP (Hot Isostatic Pressing), PHHT (Post HIP heat treatment) was established. The HIP conditions (1050 .deg. C, 100 MPa 2 hr) were developed through the investigation on joint specimen fabricated with the various HIP conditions; the destructive tests of joint include the microstructure observation of the interface with the examination of the elemental distribution, tension test, bend test, Charpy impact test and fracture toughness test. However, since the joint should be tested under the High Heat Flux (HHF) conditions like the ITER operation for verifying its joint integrity, HHF tests were performed like the previous HHF test with the Cu/SS, Be/Cu, Be/Cu/SS mock-ups for the ITER blanket First Wall (FW). In the present study, the HHF test with FMS/FMS mock-ups, which have 26 mm x 30 mm x 50 mm of dimensions with 10 mm x 20 mm of cooling channel, were kept to be the same as the designed FW of the KO HCML TBM. Three mock-ups were fabricated with one, two, and three channels and two channels mock-up among them was used for the microstructure observation after cutting itself. Others were used for the HHF test under 0.5 to 1.5 MW/m{sup 2} of heat fluxes and 20 cycles for each mock-up in a given heat flux. The test conditions were determined through the ANSYS-CFX analysis with the designed KO TBM parameters. They were tested with NBI test stand at KAERI, which were developed and operated for the KSTAR heating. Both mock-ups were survived below 1.5 MW/m{sup 2} of heat flux with 20 cycles but they were broken at 1.5 MW/m{sup 2} of heat flux due to the CHF in the wall, which is around 1.46 MW/m{sup 2} of heat flux in this case. Numbers of the cycle to failure were induced through mechanical analysis with ANSYS code but the expected values were much higher than those of tested cycles.

  16. wall

    Directory of Open Access Journals (Sweden)

    Irshad Kashif

    2016-01-01

    Full Text Available Maintaining indoor climatic conditions of buildings compatible with the occupant comfort by consuming minimum energy, especially in a tropical climate becomes a challenging problem for researchers. This paper aims to investigate this problem by evaluating the effect of different kind of Photovoltaic Trombe wall system (PV-TW on thermal comfort, energy consumption and CO2 emission. A detailed simulation model of a single room building integrated with PV-TW was modelled using TRNSYS software. Results show that 14-35% PMV index and 26-38% PPD index reduces as system shifted from SPV-TW to DGPV-TW as compared to normal buildings. Thermal comfort indexes (PMV and PPD lie in the recommended range of ASHARE for both DPV-TW and DGPV-TW except for the few months when RH%, solar radiation intensity and ambient temperature were high. Moreover PVTW system significantly reduces energy consumption and CO2 emission of the building and also 2-4.8 °C of temperature differences between indoor and outdoor climate of building was examined.

  17. Danes join SCOAP3

    CERN Multimedia

    2007-01-01

    The Danish Library Agency is joining CERN 's SCOAP3 project (Sponsoring Consortium for Open Access Publishing in Particle Physics). From the December 20 announcement : The Danish Library Agency is pleased to announce, that it has signed an Expression of interest to join SCOAP3.

  18. Common Influence Join

    DEFF Research Database (Denmark)

    Yiu, Man Lung; Mamoulis, Nikos; Karras, Panagiotis

    2008-01-01

    We identify and formalize a novel join operator for two spatial pointsets P and Q. The common influence join (CIJ) returns the pairs of points (p,q),p isin P,q isin Q, such that there exists a location in space, being closer to p than to any other point in P and at the same time closer to q than...

  19. Joining of dissimilar materials

    Science.gov (United States)

    Tucker, Michael C; Lau, Grace Y; Jacobson, Craig P

    2012-10-16

    A method of joining dissimilar materials having different ductility, involves two principal steps: Decoration of the more ductile material's surface with particles of a less ductile material to produce a composite; and, sinter-bonding the composite produced to a joining member of a less ductile material. The joining method is suitable for joining dissimilar materials that are chemically inert towards each other (e.g., metal and ceramic), while resulting in a strong bond with a sharp interface between the two materials. The joining materials may differ greatly in form or particle size. The method is applicable to various types of materials including ceramic, metal, glass, glass-ceramic, polymer, cermet, semiconductor, etc., and the materials can be in various geometrical forms, such as powders, fibers, or bulk bodies (foil, wire, plate, etc.). Composites and devices with a decorated/sintered interface are also provided.

  20. Pulse joining cartridges

    Energy Technology Data Exchange (ETDEWEB)

    Golovashchenko, Sergey Fedorovich; Bonnen, John Joseph Francis

    2016-08-23

    A pulsed joining tool includes a tool body that defines a cavity that receives an inner tubular member and an outer tubular member and a pulse joining cartridge. The tubular members are nested together with the cartridge being disposed around the outer tubular member. The cartridge includes a conductor, such as a wire or foil, that extends around the outer tubular member and is insulated to separate a supply segment from a return segment. A source of stored electrical energy is discharged through the conductor to join the tubular members with an electromagnetic force pulse.

  1. 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.

  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. Advanced Joining Technology

    Science.gov (United States)

    1982-01-01

    Ti-6Al-6V-2Sn, Ti-6Al-2Cb-lTa-0.8Mo (Ti-100), Ti-7Al-4Mo, Ti-6Al-2Mo-4Zr-2Sn, Ti-5Mo-4.5Al-l.5Cr ( Corona 5), and Ti-3Al-2.5Sn. Ti-6A1...Cummins Engine Company as being optimistic about the use of zirconia materials in this application. METALS (FOR JOINING TO CERAMICS) The metals of

  4. Recent progress in ceramic joining

    Energy Technology Data Exchange (ETDEWEB)

    Loehman, R.E.

    1998-09-01

    Both fundamental and practical aspects of ceramic joining are understood well enough for many, if not most, applications requiring moderate strengths at room temperature. This paper argues that the two greatest needs in ceramic joining are for techniques to join buried interfaces by selective heating, and methods for joining ceramics for use at temperatures of 800 to 1,200 C. Heating with microwave radiation or with high-energy electron beams has been used to join buried ceramic interfaces, for example SiC to SiC. Joints with varying levels of strength at temperatures of 600 to 1,000 C have been made using four techniques: (1) transient liquid phase bonding; (2) joining with refractory braze alloys; (3) joining with refractory glass compositions; and (4) joining using preceramic polymers. Joint strengths as high as 550 MPa at 1,000 C have been reported for silicon nitride-silicon nitride bonds tested in four-point flexure.

  5. Fast and scalable inequality joins

    KAUST Repository

    Khayyat, Zuhair

    2016-09-07

    Inequality joins, which is to join relations with inequality conditions, are used in various applications. Optimizing joins has been the subject of intensive research ranging from efficient join algorithms such as sort-merge join, to the use of efficient indices such as (Formula presented.)-tree, (Formula presented.)-tree and Bitmap. However, inequality joins have received little attention and queries containing such joins are notably very slow. In this paper, we introduce fast inequality join algorithms based on sorted arrays and space-efficient bit-arrays. We further introduce a simple method to estimate the selectivity of inequality joins which is then used to optimize multiple predicate queries and multi-way joins. Moreover, we study an incremental inequality join algorithm to handle scenarios where data keeps changing. We have implemented a centralized version of these algorithms on top of PostgreSQL, a distributed version on top of Spark SQL, and an existing data cleaning system, Nadeef. By comparing our algorithms against well-known optimization techniques for inequality joins, we show our solution is more scalable and several orders of magnitude faster. © 2016 Springer-Verlag Berlin Heidelberg

  6. Structural Join and Staircase Join Algorithms of Sibling Relationship

    Institute of Scientific and Technical Information of China (English)

    Chang-Xuan Wan; Xi-Ping Liu

    2007-01-01

    The processing of XML queries can result in evaluation of various structural relationships. Efficient algorithms for evaluating ancestor-descendant and parent-child relationships have been proposed. Whereas the problems of evaluating preceding-sibling-following-sibling and preceding-following relationships are still open. In this paper, we studied the struc-tural join and staircase join for sibling relationship. First, the idea of how to filter out and minimize unnecessary reads of elements using parent's structural information is introduced, which can be used to accelerate structural joins of parent-child and preceding-sibling-following-sibling relationships. Second, two efficient structural join algorithms of sibling relationship are proposed. These algorithms lead to optimal join performance: nodes that do not participate in the join can be judged beforehand and then skipped using B+-tree index. Besides, each element list joined is scanned sequentially once at most.Furthermore, output of join results is sorted in document order. We also discussed the staircase join algorithm for sibling axes. Studies show that, staircase join for sibling axes is close to the structural join for sibling axes and shares the samecharacteristic of high efficiency. Our experimental results not only demonstrate the effectiveness of our optimizing techniquesfor sibling axes, but also validate the efficiency of our algorithms. As far as we know, this is the first work addressing thisproblem specially.

  7. Method of joining ceramics

    Science.gov (United States)

    Henager, Jr., Charles H.; Brimhall, John L.

    2000-01-01

    According to the method of the present invention, joining a first bi-element carbide to a second bi-element carbide, has the steps of: (a) forming a bond agent containing a metal carbide and silicon; (b) placing the bond agent between the first and second bi-element carbides to form a pre-assembly; and (c) pressing and heating the pre-assembly in a non-oxidizing atmosphere to a temperature effective to induce a displacement reaction creating a metal silicon phase bonding the first and second bi-element carbides.

  8. Ring-constrained Join

    DEFF Research Database (Denmark)

    Yiu, Man Lung; Karras, Panagiotis; Mamoulis, Nikos

    2008-01-01

    from the conventional distance joins and closest pairs problems. We are not aware of efficient processing algorithms for RCJ in the literature. A brute-force solution requires computational cost quadratic to input size and it does not scale well for large datasets. In view of this, we develop efficient....... This new operation has important applications in decision support, e.g., placing recycling stations at fair locations between restaurants and residential complexes. Clearly, RCJ is defined based on a geometric constraint but not on distances between points. Thus, our operation is fundamentally different...

  9. Joining of Beryllium

    Energy Technology Data Exchange (ETDEWEB)

    Goldberg, A

    2006-02-01

    A handbook dealing with the many aspects of beryllium that would be important for the users of this metal is currently being prepared. With an introduction on the applications, advantages and limitations in the use of this metal the following topics will be discussed in this handbook: physical, thermal, and nuclear properties; extraction from the ores; purification and casting of ingots; production and types of beryllium powders; consolidation methods, grades, and properties; mechanical properties with emphasis on the various factors affecting these properties; forming and mechanical working; welding, brazing, bonding, and fastening; machining; powder deposition; corrosion; health aspects; and examples of production of components. This report consists of ''Section X--Joining'' from the handbook. The prefix X is maintained here for the figures, tables and references. In this section the different methods used for joining beryllium and the advantages, disadvantages and limitations of each are presented. The methods discussed are fusion welding, brazing, solid state bonding (diffusion bonding and deformation bonding), soldering, and mechanical fastening. Since beryllium has a high affinity for oxygen and nitrogen with the formation of oxides and nitrides, considerable care must be taken on heating the metal, to protect it from the ambient atmosphere. In addition, mating surfaces must be cleaned and joints must be designed to minimize residual stresses as well as locations for stress concentration (notch effects). In joining any two metals the danger exists of having galvanic corrosion if the part is subjected to moisture or to any type of corroding environment. This becomes a problem if the less noble (anodic) metal has a significantly smaller area than the more noble (cathodic) metal since the ions (positive charges) from the anodic (corroding) metal must correspond to the number of electrons (negative charges) involved at the cathode. Beryllium

  10. Innovative cold joining technologies based on tube forming

    Directory of Open Access Journals (Sweden)

    Alves Luis M.

    2015-01-01

    Full Text Available This paper is focused on innovative cold joining technologies for connecting tubes and fixing tubes to sheets. The proposed technologies are based on the utilization of plastic instability waves in thin-walled tubes subjected to axial compression and may be seen as an alternative to conventional joining technologies based on mechanical fixing with fasteners, welding and structural adhesive bonding. Besides allowing connecting dissimilar materials and being successfully employed in fixture conditions that are difficult and costly to achieve by means of conventional joining the new proposed technologies also cope with the growing concerns on the demand, lifecycle and recycling of materials.

  11. 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 + ...

  12. Defining the Transition from Cell Elongation to Secondary Cell Wall Biosynthesis:Promoter Analyses,Transcript Profiling,and Genomic Analysis of Near-isogenic Germplasms that Differ in Fiber Strength

    Institute of Scientific and Technical Information of China (English)

    TRIPLETT Barbara A; HINCHLIFFE Doug; KIM Hee-Jin; ZHANG Hong-bin; MEREDITH William R Jr

    2008-01-01

    @@ A distinct set of homoeologous cellulose synthase catalytic subunit (CesA) genes are coordinately up-regulated with the onset of secondary wall formation in cotton fiber as shown by quantitative-RTPCR.

  13. Join Operations in Temporal Databases

    DEFF Research Database (Denmark)

    Gao, D.; Jensen, Christian Søndergaard; Snodgrass, R.T.

    2005-01-01

    this need for efficient join evaluation in temporal databases. Our purpose is twofold. We first survey all previously proposed temporal join operators. While many temporal join operators have been defined in previous work, this work has been done largely in isolation from competing proposals, with little......Joins are arguably the most important relational operators. Poor implementations are tantamount to computing the Cartesian product of the input relations. In a temporal database, the problem is more acute for two reasons. First, conventional techniques are designed for the evaluation of joins...... with equality predicates rather than the inequality predicates prevalent in valid-time queries. Second, the presence of temporally varying data dramatically increases the size of a database. These factors indicate that specialized techniques are needed to efficiently evaluate temporal joins. We address...

  14. Join Operations in Temporal Databases

    DEFF Research Database (Denmark)

    Gao, D.; Jensen, Christian Søndergaard; Snodgrass, R.T.

    2005-01-01

    Joins are arguably the most important relational operators. Poor implementations are tantamount to computing the Cartesian product of the input relations. In a temporal database, the problem is more acute for two reasons. First, conventional techniques are designed for the evaluation of joins...... with equality predicates rather than the inequality predicates prevalent in valid-time queries. Second, the presence of temporally varying data dramatically increases the size of a database. These factors indicate that specialized techniques are needed to efficiently evaluate temporal joins. We address...... this need for efficient join evaluation in temporal databases. Our purpose is twofold. We first survey all previously proposed temporal join operators. While many temporal join operators have been defined in previous work, this work has been done largely in isolation from competing proposals, with little...

  15. Finland to Join ESO

    Science.gov (United States)

    2004-02-01

    Finland will become the eleventh member state of the European Southern Observatory (ESO) [1]. Today, during a ceremony at the ESO Headquarters in Garching (Germany), a corresponding Agreement was signed by the Finnish Minister of Education and Science, Ms. Tuula Haatainen and the ESO Director General, Dr. Catherine Cesarsky, in the presence of other high officials from Finland and the ESO member states (see Video Clip 02/04 below). Following subsequent ratification by the Finnish Parliament of the ESO Convention and the associated protocols [2], it is foreseen that Finland will formally join ESO on July 1, 2004. Uniting European Astronomy ESO PR Photo 03/04 ESO PR Photo 03/04 Caption : Signing of the Finland-ESO Agreement on February 9, 2004, at the ESO Headquarters in Garching (Germany). At the table, the ESO Director General, Dr. Catherine Cesarsky, and the Finnish Minister of Education and Science, Ms. Tuula Haatainen . [Preview - JPEG: 400 x 499 pix - 52k] [Normal - JPEG: 800 x 997 pix - 720k] [Full Res - JPEG: 2126 x 2649 pix - 2.9M] The Finnish Minister of Education and Science, Ms. Tuula Haatainen, began her speech with these words: "On behalf of Finland, I am happy and proud that we are now joining the European Southern Observatory, one of the most successful megaprojects of European science. ESO is an excellent example of the potential of European cooperation in science, and along with the ALMA project, more and more of global cooperation as well." She also mentioned that besides science ESO offers many technological challenges and opportunities. And she added: "In Finland we will try to promote also technological and industrial cooperation with ESO, and we hope that the ESO side will help us to create good working relations. I am confident that Finland's membership in ESO will be beneficial to both sides." Dr. Catherine Cesarsky, ESO Director General, warmly welcomed the Finnish intention to join ESO. "With the accession of their country to ESO, Finnish

  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. On the Expressiveness of Joining

    Directory of Open Access Journals (Sweden)

    Thomas Given-Wilson

    2015-08-01

    Full Text Available The expressiveness of communication primitives has been explored in a common framework based on the pi-calculus by considering four features: synchronism (asynchronous vs synchronous, arity (monadic vs polyadic data, communication medium (shared dataspaces vs channel-based, and pattern-matching (binding to a name vs testing name equality vs intensionality. Here another dimension coordination is considered that accounts for the number of processes required for an interaction to occur. Coordination generalises binary languages such as pi-calculus to joining languages that combine inputs such as the Join Calculus and general rendezvous calculus. By means of possibility/impossibility of encodings, this paper shows coordination is unrelated to the other features. That is, joining languages are more expressive than binary languages, and no combination of the other features can encode a joining language into a binary language. Further, joining is not able to encode any of the other features unless they could be encoded otherwise.

  18. 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

  19. 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.

  20. Effects of prefabricated hole structure on cold-pressing joining reliability between dissimilar sheets

    Science.gov (United States)

    Jin, Cheng Chuang; Li, Feng; Wang, Mo Nan; Bao, Ze Ping

    2016-12-01

    The structural form of prefabricated holes is one of the important factors to determine the quality and reliability of cold-pressing joining between dissimilar sheets. Different numbers of holes with the same area will lead to different wall thickness distributions and joining strengths. This paper takes the cold-pressing joining between AA1100 pure aluminum sheet and SS304 stainless steel sheet as an example, the further study results show that the end of aluminum sheet has an increasing tendency along the directions of length and width in the process of cold-pressing joining. The wall thickness of joints shows a symmetrical distribution on both sides and the joining thickness decreases from the center to both sides sequentially. With the continuous increase of the punch loading pressure, the average thinning ratio of the joints becomes larger. By contrast, when the other parameters are all the same, the joining strength is the most ideal when the punch loading pressure is 250 kN. The loading pressure which is too small or large is easy to cause an insufficient joining strength or defects. This paper provides a scientific basis in this aspect for optimizing the cold-pressing joining plan and designing a reasonable joint structure. It can also promote the existing cold-pressing joining technologies to be mature, and enrich the existing solid-state joining technology.

  1. Blind-date Conversation Joining

    Directory of Open Access Journals (Sweden)

    Luca Cesari

    2013-07-01

    Full Text Available We focus on a form of joining conversations among multiple parties in service-oriented applications where a client may asynchronously join an existing conversation without need to know in advance any information about it. More specifically, we show how the correlation mechanism provided by orchestration languages enables a form of conversation joining that is completely transparent to clients and that we call 'blind-date joining'. We provide an implementation of this strategy by using the standard orchestration language WS-BPEL. We then present its formal semantics by resorting to COWS, a process calculus specifically designed for modelling service-oriented applications. We illustrate our approach by means of a simple, but realistic, case study from the online games domain.

  2. Spain to Join ESO

    Science.gov (United States)

    2006-02-01

    /infrared astronomical observing site in Europe and site of the Spanish 10m GranTeCan telescope now nearing completion. With the high quality of Spanish astronomical research as well as the technological competence of Spanish industry, it is only fitting that Spain should join ESO, world-leader in ground-based astronomy. Through ESO Spain will enjoy full access both to all of ESO's current facilities and to unrestricted participation in the great projects that ESO is planning for the future. Spain is already an active partner of the Atacama Large Millimeter Array (ALMA), whose construction and operations are led on behalf of Europe by ESO. ESO's Council approved the admission of Spain at its 107th meeting held in Garching on 7 and 8 December 2005. High resolution images and their captions are available on this page.

  3. 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.

  4. 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...

  5. 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...

  6. 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.

  7. Progress in Joining Ceramics to Metals

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    The research and development of joining methods of ceramics to metals, especially brazing, diffusion bonding and partial transition liquid phase bonding, were introduced. Some opinions were put forward. For new composites emerging, it is necessary to develop new joining methods, particularly in the field of high temperature technique for joining ceramics to superalloys.

  8. Lightning fast and space efficient inequality joins

    KAUST Repository

    Khayyat, Zuhair

    2015-09-01

    Inequality joins, which join relational tables on inequality conditions, are used in various applications. While there have been a wide range of optimization methods for joins in database systems, from algorithms such as sort-merge join and band join, to various indices such as B+-tree, R*-tree and Bitmap, inequality joins have received little attention and queries containing such joins are usually very slow. In this paper, we introduce fast inequality join algorithms. We put columns to be joined in sorted arrays and we use permutation arrays to encode positions of tuples in one sorted array w.r.t. the other sorted array. In contrast to sort-merge join, we use space efficient bit-arrays that enable optimizations, such as Bloom filter indices, for fast computation of the join results. We have implemented a centralized version of these algorithms on top of PostgreSQL, and a distributed version on top of Spark SQL. We have compared against well known optimization techniques for inequality joins and show that our solution is more scalable and several orders of magnitude faster.

  9. Lightning Fast and Space Efficient Inequality Joins

    KAUST Repository

    Khayyat, Zuhair

    2015-09-01

    Inequality joins, which join relational tables on inequality conditions, are used in various applications. While there have been a wide range of optimization methods for joins in database systems, from algorithms such as sort-merge join and band join, to various indices such as B+-tree,R*-tree and Bitmap, inequality joins have received little attention and queries containing such joins are usually very slow. In this paper, we introduce fast inequality join algorithms. We put columns to be joined in sorted arrays and we use permutation arrays to encode positions of tuples in one sorted array w.r.t. the other sorted array. In contrast to sort-merge join, we use space effcient bit-arrays that enable optimizations, such as Bloom filter indices, for fast computation of the join results. We have implemented a centralized version of these algorithms on top of PostgreSQL, and a distributed version on top of Spark SQL. We have compared against well known optimization techniques for inequality joins and show that our solution is more scalable and several orders of magnitude faster.

  10. 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.

  11. 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.

  12. Why join the Staff Association

    CERN Multimedia

    Association du personnel

    2011-01-01

    Becoming a member of the Staff Association (SA) is above all a personal choice, showing that the joining person’s commitment and adherence to values such as solidarity, social cohesion, etc.In September, the SA launches a membership campaign to convince a maximum number to join, to inform, arouse interest and support. Posters, emails and individual contacts are part of the campaign programme, just like this editorial. As far as individual contacts are concerned, we ask you to give time and lend an ear to the delegates of your department in the Staff Council, who will approach you, in order to make an open and constructive discussion possible. Do not hesitate to ask questions and let them know your thoughts about the SA, as (constructive) criticism enables us to progress. The Staff Association and its role of collective representation The Staff Association, via its delegates, represents collectively all staff of the Organization before the Director-General and Member States. To do this, staff rep...

  13. Flexible Friction Stir Joining Technology

    Energy Technology Data Exchange (ETDEWEB)

    Feng, Zhili [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Lim, Yong Chae [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Mahoney, Murray [MegaStir Technologies LLC, Orem, UT (United States); Sanderson, Samuel [MegaStir Technologies LLC, Orem, UT (United States); Larsen, Steve [MegaStir Technologies LLC, Orem, UT (United States); Steel, Russel [MegaStir Technologies LLC, Orem, UT (United States); Fleck, Dale [MegaStir Technologies LLC, Orem, UT (United States); Fairchild, Doug P [ExxonMobil, Upstream Research Company (URC), Houston, TX (United States); Wasson, Andrew J [ExxonMobil, Upstream Research Company (URC), Houston, TX (United States); Babb, Jon [MegaStir Technologies LLC, Orem, UT (United States); Higgins, Paul [MegaStir Technologies LLC, Orem, UT (United States)

    2015-07-23

    Reported herein is the final report on a U.S. Department of Energy (DOE) Advanced Manufacturing Office (AMO) project with industry cost-share that was jointly carried out by Oak Ridge National Laboratory (ORNL), ExxonMobil Upstream Research Company (ExxonMobil), and MegaStir Technologies (MegaStir). The project was aimed to advance the state of the art of friction stir welding (FSW) technology, a highly energy-efficient solid-state joining process, for field deployable, on-site fabrications of large, complex and thick-sectioned structures of high-performance and high-temperature materials. The technology innovations developed herein attempted to address two fundamental shortcomings of FSW: 1) the inability for on-site welding and 2) the inability to weld thick section steels, both of which have impeded widespread use of FSW in manufacturing. Through this work, major advance has been made toward transforming FSW technology from a “specialty” process to a mainstream materials joining technology to realize its pervasive energy, environmental, and economic benefits across industry.

  14. 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...

  15. Efficient Privacy Preserving Protocols for Similarity Join

    Directory of Open Access Journals (Sweden)

    Bilal Hawashin

    2012-04-01

    Full Text Available During the similarity join process, one or more sources may not allow sharing its data with other sources. In this case, a privacy preserving similarity join is required. We showed in our previous work [4] that using long attributes, such as paper abstracts, movie summaries, product descriptions, and user feedbacks, could improve the similarity join accuracy using supervised learning. However, the existing secure protocols for similarity join methods can not be used to join sources using these long attributes. Moreover, the majority of the existing privacy‐preserving protocols do not consider the semantic similarities during the similarity join process. In this paper, we introduce a secure efficient protocol to semantically join sources when the join attributes are long attributes. We provide two secure protocols for both scenarios when a training set exists and when there is no available training set. Furthermore, we introduced the multi‐label supervised secure protocol and the expandable supervised secure protocol. Results show that our protocols can efficiently join sources using the long attributes by considering the semantic relationships among the long string values. Therefore, it improves the overall secure similarity join performance.

  16. Movement of endogenous calcium in the elongating zone of graviresponding roots of Zea mays

    Science.gov (United States)

    Moore, R.; Cameron, I. L.; Smith, N. K.

    1989-01-01

    Endogenous calcium (Ca) accumulates along the lower side of the elongating zone of horizontally oriented roots of Zea mays cv. Yellow Dent. This accumulation of Ca correlates positively with the onset of gravicurvature, and occurs in the cytoplasm, cell walls and mucilage of epidermal cells. Corresponding changes in endogenous Ca do not occur in cortical cells of the elongating zone of intact roots. These results indicate that the calcium asymmetries associated with root gravicurvature occur in the outermost layers of the root.

  17. Join Cost for Unit Selection Speech Synthesis

    OpenAIRE

    Vepa, Jithendra

    2004-01-01

    Undoubtedly, state-of-the-art unit selection-based concatenative speech systems produce very high quality synthetic speech. this is due to a large speech database containing many instances of each speech unit, with a varied and natural distribution of prosodic and spectral characteristics. the join cost, which measures how well two units can be joined together is one of the main criteria for selecting appropriate units from this large speech database. The ideal join cost is one that measur...

  18. 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.

  19. The Acid Growth Theory of auxin-induced cell elongation is alive and well

    Science.gov (United States)

    Rayle, D. L.; Cleland, R. E.

    1992-01-01

    Plant cells elongate irreversibly only when load-bearing bonds in the walls are cleaved. Auxin causes the elongation of stem and coleoptile cells by promoting wall loosening via cleavage of these bonds. This process may be coupled with the intercalation of new cell wall polymers. Because the primary site of auxin action appears to be the plasma membrane or some intracellular site, and wall loosening is extracellular, there must be communication between the protoplast and the wall. Some "wall-loosening factor" must be exported from auxin-impacted cells, which sets into motion the wall loosening events. About 20 years ago, it was suggested that the wall-loosening factor is hydrogen ions. This idea and subsequent supporting data gave rise to the Acid Growth Theory, which states that when exposed to auxin, susceptible cells excrete protons into the wall (apoplast) at an enhanced rate, resulting in a decrease in apoplastic pH. The lowered wall pH then activates wall-loosening processes, the precise nature of which is unknown. Because exogenous acid causes a transient (1-4 h) increase in growth rate, auxin must also mediate events in addition to wall acidification for growth to continue for an extended period of time. These events may include osmoregulation, cell wall synthesis, and maintenance of the capacity of walls to undergo acid-induced wall loosening. At present, we do not know if these phenomena are tightly coupled to wall acidification or if they are the products of multiple independent signal transduction pathways.

  20. Efficient Joins with Compressed Bitmap Indexes

    Energy Technology Data Exchange (ETDEWEB)

    Computational Research Division; Madduri, Kamesh; Wu, Kesheng

    2009-08-19

    We present a new class of adaptive algorithms that use compressed bitmap indexes to speed up evaluation of the range join query in relational databases. We determine the best strategy to process a join query based on a fast sub-linear time computation of the join selectivity (the ratio of the number of tuples in the result to the total number of possible tuples). In addition, we use compressed bitmaps to represent the join output compactly: the space requirement for storing the tuples representing the join of two relations is asymptotically bounded by min(h; n . cb), where h is the number of tuple pairs in the result relation, n is the number of tuples in the smaller of the two relations, and cb is the cardinality of the larger column being joined. We present a theoretical analysis of our algorithms, as well as experimental results on large-scale synthetic and real data sets. Our implementations are efficient, and consistently outperform well-known approaches for a range of join selectivity factors. For instance, our count-only algorithm is up to three orders of magnitude faster than the sort-merge approach, and our best bitmap index-based algorithm is 1.2x-80x faster than the sort-merge algorithm, for various query instances. We achieve these speedups by exploiting several inherent performance advantages of compressed bitmap indexes for join processing: an implicit partitioning of the attributes, space-efficiency, and tolerance of high-cardinality relations.

  1. Efficient Joins with Compressed Bitmap Indexes

    Energy Technology Data Exchange (ETDEWEB)

    Computational Research Division; Madduri, Kamesh; Wu, Kesheng

    2009-08-19

    We present a new class of adaptive algorithms that use compressed bitmap indexes to speed up evaluation of the range join query in relational databases. We determine the best strategy to process a join query based on a fast sub-linear time computation of the join selectivity (the ratio of the number of tuples in the result to the total number of possible tuples). In addition, we use compressed bitmaps to represent the join output compactly: the space requirement for storing the tuples representing the join of two relations is asymptotically bounded by min(h; n . cb), where h is the number of tuple pairs in the result relation, n is the number of tuples in the smaller of the two relations, and cb is the cardinality of the larger column being joined. We present a theoretical analysis of our algorithms, as well as experimental results on large-scale synthetic and real data sets. Our implementations are efficient, and consistently outperform well-known approaches for a range of join selectivity factors. For instance, our count-only algorithm is up to three orders of magnitude faster than the sort-merge approach, and our best bitmap index-based algorithm is 1.2x-80x faster than the sort-merge algorithm, for various query instances. We achieve these speedups by exploiting several inherent performance advantages of compressed bitmap indexes for join processing: an implicit partitioning of the attributes, space-efficiency, and tolerance of high-cardinality relations.

  2. Join Order Selection - Good Enough is Easy

    NARCIS (Netherlands)

    Waas, F.; Pellenkoft, A.J.

    2000-01-01

    Uniform sampling of join orders is known to be a competitive alternative to transformation-based optimization techniques. However, uniformity of the sampling process is difficult to establish and only for a restricted class of join queries techniques are known. In this paper, we investigate non-un

  3. Authenticated join processing in outsourced databases

    KAUST Repository

    Yang, Yin

    2009-01-01

    Database outsourcing requires that a query server constructs a proof of result correctness, which can be verified by the client using the data owner\\'s signature. Previous authentication techniques deal with range queries on a single relation using an authenticated data structure (ADS). On the other hand, authenticated join processing is inherently more complex than ranges since only the base relations (but not their combination) are signed by the owner. In this paper, we present three novel join algorithms depending on the ADS availability: (i) Authenticated Indexed Sort Merge Join (AISM), which utilizes a single ADS on the join attribute, (ii) Authenticated Index Merge Join (AIM) that requires an ADS (on the join attribute) for both relations, and (iii) Authenticated Sort Merge Join (ASM), which does not rely on any ADS. We experimentally demonstrate that the proposed methods outperform two benchmark algorithms, often by several orders of magnitude, on all performance metrics, and effectively shift the workload to the outsourcing service. Finally, we extend our techniques to complex queries that combine multi-way joins with selections and projections. ©2009 ACM.

  4. Xyloglucan Endotransglycosylase Activity in Carrot Cell Suspensions during cell Elongation and Somatic Embryogenesis.

    Science.gov (United States)

    Hetherington, P. R.; Fry, S. C.

    1993-11-01

    Xyloglucan endotransglycosylase (XET) has been proposed to contribute to cell elongation through wall loosening. To explore this relationship further, we assayed this enzyme activity in suspensions of carrot (Daucus carota L.) cells exhibiting various rates of cell elongation. In one cell line, elongation was induced by dilution into dichlorophenoxyacetic acid (2,4-D)-free medium. During this elongation, 93% of the XET activity was found in the culture medium; in nonelongating controls, by contrast, 68% was found in the cell extracts even though the specific activity of these extracts was lower than in the elongating cells. By far the highest rates of XET secretion per cell were in the elongating cells. A second cell line was induced to undergo somatic embryogenesis by dilution into 2,4-D-free medium. During the first 6 d, numerous globular embryoids composed of small, isodiametric cells were formed in the absence of cell elongation; extracellular XET activity was almost undetectable, and intracellular specific activity markedly declined. After 6 d, heart, torpedo, and cotyledonary embryoids began to appear (i.e. cell elongation resumed); the intracellular specific activity of XET rose rapidly and >80% of the XET activity accumulated in the medium. Thus, nonexpanding cell suspensions (whether or not they were rapidly dividing) produced and secreted less XET activity than did expanding cells. We propose that a XET molecule has an ephemeral wall-loosening role while it passes through the load-bearing layer of the wall on its way from the protoplast into the culture medium.

  5. Welding and Joining of Titanium Aluminides

    Directory of Open Access Journals (Sweden)

    Jian Cao

    2014-06-01

    Full Text Available Welding and joining of titanium aluminides is the key to making them more attractive in industrial fields. The purpose of this review is to provide a comprehensive overview of recent progress in welding and joining of titanium aluminides, as well as to introduce current research and application. The possible methods available for titanium aluminides involve brazing, diffusion bonding, fusion welding, friction welding and reactive joining. Of the numerous methods, solid-state diffusion bonding and vacuum brazing have been most heavily investigated for producing reliable joints. The current state of understanding and development of every welding and joining method for titanium aluminides is addressed respectively. The focus is on the fundamental understanding of microstructure characteristics and processing–microstructure–property relationships in the welding and joining of titanium aluminides to themselves and to other materials.

  6. Magnetomotive forming for precision sizing and joining of large-diameter tubes

    Science.gov (United States)

    Bennight, J. D.; Schwinghamer, R. J.

    1969-01-01

    Portable electromagnetic coil enables high precision expansion or constriction and joining of large diameter metal tubes. A nonconducting mandrel or forming die is used on the side of the tubes wall opposite the coil. The coil is insulated from the tube by a thin plastic sleeve.

  7. 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...

  8. 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...

  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 viscos...

  10. Why do people join trade unions?

    DEFF Research Database (Denmark)

    Toubøl, Jonas; Jensen, Carsten Strøby

    level on union recruitment, which is not done before. Workplace union density is taken to measure the strength of the workplace’s custom of being union member creating an instrumental incentive to join the union. Self-placement on a political left-right scale measures political attitude taken...... to be a value rational motive. The statistical results indicate that the most important predictor of joining the union is workplace union density and only in a secondary manner does political attitude matter. It is concluded that the normative pressure of one’s colleagues is the dominating reason for joining...

  11. Why do people join trade unions?

    DEFF Research Database (Denmark)

    Toubøl, Jonas; Jensen, Carsten Strøby

    to be a value rational motive. The statistical results indicate that the most important predictor of joining the union is workplace union density and only in a secondary manner does political attitude matter. It is concluded that the normative pressure of one’s colleagues is the dominating reason for joining...... level on union recruitment, which is not done before. Workplace union density is taken to measure the strength of the workplace’s custom of being union member creating an instrumental incentive to join the union. Self-placement on a political left-right scale measures political attitude taken...

  12. Microwave joining of SiC

    Energy Technology Data Exchange (ETDEWEB)

    Silberglitt, R.; Ahmad, I.; Tian, Y.L. [FM Technologies, Inc., Fairfax, VA (United States)] [and others

    1997-04-01

    The purpose of this work is to optimize the properties of SiC-SiC joints made using microwave energy. The current focus is on identification of the most effective joining methods for scale-up to large tube assemblies, including joining using SiC produced in situ from chemical precursors. During FY 1996, a new microwave applicator was designed, fabricated and tested that provides the capability for vacuum baking of the specimens and insulation and for processing under inert environment. This applicator was used to join continuous fiber-reinforced (CFCC) SiC/SiC composites using a polymer precursor to form a SiC interlayer in situ.

  13. A Join Index for XML Data Warehouses

    CERN Document Server

    Mahboubi, Hadj; Darmont, Jérôme

    2008-01-01

    XML data warehouses form an interesting basis for decision-support applications that exploit complex data. However, native-XML database management systems (DBMSs) currently bear limited performances and it is necessary to research for ways to optimize them. In this paper, we propose a new join index that is specifically adapted to the multidimensional architecture of XML warehouses. It eliminates join operations while preserving the information contained in the original warehouse. A theoretical study and experimental results demonstrate the efficiency of our join index. They also show that native XML DBMSs can compete with XML-compatible, relational DBMSs when warehousing and analyzing XML data.

  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. Rapid elongation of arteries and veins in rats with a tissue expander.

    Science.gov (United States)

    Stark, G B; Hong, C; Futrell, J W

    1987-10-01

    The saphenous arteries and veins of 40 rats were elongated with 20-cc tissue expanders underlying the leg adductor muscles. The mean rate of successful elongation of the vessels was 84 +/- 47 percent SD, with a maximum gain of 140 percent. The fastest mean elongation velocity reached 45 percent per day. Thrombosis occurred only with stretching velocities of more than 10 percent per day, which seemed to be a safe margin. Distribution of the volume into many intervals was safer than infrequent high-volume injections. Histology showed no reduction in vessel wall diameter or loss intimal integrity. Subendothelial cellular proliferation was an indicator of this rapid regeneration. Microvascular anastomoses performed in elongated arteries and veins had the same patency rate (90 percent) as in controls.

  16. Recrafting the Neighbor-Joining Method

    DEFF Research Database (Denmark)

    Mailund; Brodal, Gerth Stølting; Fagerberg, Rolf;

    2006-01-01

    Background: The neighbor-joining method by Saitou and Nei is a widely used method for constructing phylogenetic trees. The formulation of the method gives rise to a canonical Θ(n3) algorithm upon which all existing implementations are based. Methods: In this paper we present techniques for speeding...... up the canonical neighbor-joining method. Our algorithms construct the same phylogenetic trees as the canonical neighbor-joining method. The best-case running time of our algorithms are O(n2) but the worst-case remains O(n3). We empirically evaluate the performance of our algoritms on distance...... neighbor-joining method. Conclusions: The experiments show that our algorithms also yield a significant speed-up, already for medium sized instances....

  17. DSCu/SS joining techniques development and testing

    Energy Technology Data Exchange (ETDEWEB)

    Sato, Satoshi; Hatano, Toshihisa; Furuya, Kazuyuki; Kuroda, Toshimasa; Enoeda, Mikio; Takatsu, Hideyuki [Japan Atomic Energy Research Inst., Naka, Ibaraki (Japan). Naka Fusion Research Establishment

    1998-01-01

    Joining techniques of alumina dispersion strengthened copper alloy (DSCu) and type 316L stainless steel (SS) has been investigated aiming at applying to the fabrication of the ITER first wall/blanket. As the joining method, Hot Isostatic Pressing (HIP) of solid plates and/or blocks has been pursued. By a screening test including HIP temperatures of 980-1050degC, it was concluded that the HIP temperature of 1050degC would be optimum for the simultaneous HIPping of DSCu/DSCu, DSCu/SS and SS/SS. With DSCu/SS joint specimens HIPped at 1050degC, tensile, impact, fatigue, crack propagation, and fracture toughness tests were performed as well as mechanical test of structural model with one SS circular tube embedded. Typically, the properties of the joints were almost the same as those of DSCu or SS base metal with the same heat treatment of the HIP process, thus good joints were obtained, though parts of properties were decreased at elevated test temperature. Typical results of the mechanical test of structural mode indicated that a crack initiated at the inner surface of the SS tube under cyclic operation, and the lifetime of the first wall structure could be evaluated by existing SS fatigue data. Two HIPped first wall panel mock-ups were successfully fabricated with built-in coolant tubes: one was 300 mm long and the other 800 mm long. The former was thermo-mechanically tested with high heat fluxes corresponding to the ITER operation conditions. The mock-up showed good heat removal performance during the high heat flux tests. In addition, there were no cracks and delaminations found at HIPped interfaces by microscopic observation after all tests. Ultrasonic testing have been tried as a non-destructive examination method, and detectable defect size at SS/SS, DSCu/DSCu and DSCu/SS joint interfaces were estimated. (author)

  18. Speeding Up Neighbour-Joining Tree Construction

    DEFF Research Database (Denmark)

    Brodal, Gerth Stølting; Fagerberg, Rolf; Mailund, Thomas

    A widely used method for constructing phylogenetic trees is the neighbour-joining method of Saitou and Nei. We develope heuristics for speeding up the neighbour-joining method which generate the same phylogenetic trees as the original method. All heuristics are based on using a quad-tree to guide...... the search for the next pair of nodes to join, but di#er in the information stored in quad-tree nodes, the way the search is performed, and in the way the quad-tree is updated after a join. We empirically evaluate the performance of the heuristics on distance matrices obtained from the Pfam collection...... of alignments, and compare the running time with that of the QuickTree tool, a well-known and widely used implementation of the standard neighbour-joining method. The results show that the presented heuristics can give a significant speed-up over the standard neighbour-joining method, already for medium sized...

  19. Speeding Up Neighbour-Joining Tree Construction

    DEFF Research Database (Denmark)

    Brodal, Gerth Stølting; Fagerberg, Rolf; Mailund, Thomas

    A widely used method for constructing phylogenetic trees is the neighbour-joining method of Saitou and Nei. We develope heuristics for speeding up the neighbour-joining method which generate the same phylogenetic trees as the original method. All heuristics are based on using a quad-tree to guide...... the search for the next pair of nodes to join, but di#er in the information stored in quad-tree nodes, the way the search is performed, and in the way the quad-tree is updated after a join. We empirically evaluate the performance of the heuristics on distance matrices obtained from the Pfam collection...... of alignments, and compare the running time with that of the QuickTree tool, a well-known and widely used implementation of the standard neighbour-joining method. The results show that the presented heuristics can give a significant speed-up over the standard neighbour-joining method, already for medium sized...

  20. Trajectory similarity join in spatial networks

    KAUST Repository

    Shang, Shuo

    2017-09-07

    The matching of similar pairs of objects, called similarity join, is fundamental functionality in data management. We consider the case of trajectory similarity join (TS-Join), where the objects are trajectories of vehicles moving in road networks. Thus, given two sets of trajectories and a threshold θ, the TS-Join returns all pairs of trajectories from the two sets with similarity above θ. This join targets applications such as trajectory near-duplicate detection, data cleaning, ridesharing recommendation, and traffic congestion prediction. With these applications in mind, we provide a purposeful definition of similarity. To enable efficient TS-Join processing on large sets of trajectories, we develop search space pruning techniques and take into account the parallel processing capabilities of modern processors. Specifically, we present a two-phase divide-and-conquer algorithm. For each trajectory, the algorithm first finds similar trajectories. Then it merges the results to achieve a final result. The algorithm exploits an upper bound on the spatiotemporal similarity and a heuristic scheduling strategy for search space pruning. The algorithm\\'s per-trajectory searches are independent of each other and can be performed in parallel, and the merging has constant cost. An empirical study with real data offers insight in the performance of the algorithm and demonstrates that is capable of outperforming a well-designed baseline algorithm by an order of magnitude.

  1. Effect of Ti and Si interlayer materials on the joining of SiC ceramics

    Energy Technology Data Exchange (ETDEWEB)

    Jung, Yang Il; Park, Jung Hwan; Kim, Hyun Gil; Park, Dong Jun; Park, Jeong Yong; Kim, Weon Ju [LWR Fuel Technology Division, Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)

    2016-08-15

    SiC-based ceramic composites are currently being considered for use in fuel cladding tubes in light-water reactors. The joining of SiC ceramics in a hermetic seal is required for the development of ceramic-based fuel cladding tubes. In this study, SiC monoliths were diffusion bonded using a Ti foil interlayer and additional Si powder. In the joining process, a very low uniaxial pressure of ∼0.1 MPa was applied, so the process is applicable for joining thin-walled long tubes. The joining strength depended strongly on the type of SiC material. Reaction-bonded SiC (RB-SiC) showed a higher joining strength than sintered SiC because the diffusion reaction of Si was promoted in the former. The joining strength of sintered SiC was increased by the addition of Si at the Ti interlayer to play the role of the free Si in RB-SiC. The maximum joint strength obtained under torsional stress was ∼100 MPa. The joint interface consisted of TiSi{sub 2}, Ti{sub 3}SiC{sub 2}, and SiC phases formed by a diffusion reaction of Ti and Si.

  2. 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

  3. 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.

  4. 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....

  5. 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.

  6. 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.

  7. 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

  8. Joining Techniques for Ferritic ODS Alloys

    Energy Technology Data Exchange (ETDEWEB)

    V.G. Krishnardula; V.G. Krishnardula; D.E. Clark; T.C. Totemeier

    2005-06-01

    This report presents results of research on advanced joining techniques for ferritic oxide-dispersion strengthened alloys MA956 and PM2000. The joining techniques studied were resistance pressure welding (also known as pressure forge welding), transient liquid phase bonding, and diffusion bonding. All techniques were shown to produce sound joints in fine-grained, unrecrystallized alloys. Post-bond heat treatment to produce a coarse-grained, recrystallized microstructure resulted in grain growth across the bondline for transient liquid phase and diffusion bonds, giving microstructures essentially identical to that of the parent alloy in the recrystallized condition. The effects of bond orientation, boron interlayer thickness, and bonding parameters are discussed for transient liquid phase and diffusion bonding. The report concludes with a brief discussion of ODS joining techniques and their applicability to GEN IV reactor systems.

  9. Thin layer joining by gas adsorption

    Energy Technology Data Exchange (ETDEWEB)

    Taga, Yasunori, E-mail: y-taga@isc.chubu.ac.jp; Fukumura, Toshio

    2014-10-01

    Highlights: • We report thin layer molecular joining between glass and COP by gas adsorption. Thickness of joining layer is 1–2 nm and joining process was carried out at low temperature at about 100 °C. • Adhesion strength measured by 180 degree peel test revealed to be 1–10 N/25 mm and the joined stack showed high durability for practical use. - Abstract: Attempt has been made to join borosilicate glass and cycloolefin (COP) polymer film by using gas adsorption method. After corona plasma treat, COP was exposed to (3-glycidoxypropyl) trimethoxysilane (GPS) and glass to (3-aminopropyl) triethoxysilane (APS) both in air atmosphere, resulting in co-adsorption of water vapor in the atmosphere and organosilane gases. Surface characterization of plasma treated and gas adsorbed surfaces was carried out by X-ray photoelectron spectroscopy (XPS) using Mg Kα X-ray source. Joining was carried out by a roll laminator after contact of both surfaces at room temperature, followed by annealing at 130 °C for 10 min. Adhesion strength was evaluated by 180 degree peel test based on ASTM D-903 and durability was examined under the conditions of 60 °C and 95% RH. It was found that after plasma treatment, complex functional groups such as C-H, C-O, C=O, O-C=O and CO{sub 3} were found on COP and O-H on glass. Thickness of GPS gas adsorption layer on COP was evaluated by the XPS to be at least 1.1 nm by taking inelastic mean free path of Si{sub 2p} photoelectron into consideration. Joining force was found to be more than 5 N/25 mm corresponding to almost equal to COP bulk tensile strength. In addition, durability of this adhesion strength remained unchanged over 2000 h even after exposure to the durability test conditions of 60 °C and 95% RH. The results can be explained in terms of formation of H-H hydrogen bonding and Si-O covalent bonding via silanols will be made at the interface as a result of lamination and annealing processes. In conclusion, ultrathin joining method

  10. DNA Double Strand Break Response and Limited Repair Capacity in Mouse Elongated Spermatids

    Directory of Open Access Journals (Sweden)

    Emad A. Ahmed

    2015-12-01

    Full Text Available Spermatids are extremely sensitive to genotoxic exposures since during spermiogenesis only error-prone non homologous end joining (NHEJ repair pathways are available. Hence, genomic damage may accumulate in sperm and be transmitted to the zygote. Indirect, delayed DNA fragmentation and lesions associated with apoptotic-like processes have been observed during spermatid elongation, 27 days after irradiation. The proliferating spermatogonia and early meiotic prophase cells have been suggested to retain a memory of a radiation insult leading later to this delayed fragmentation. Here, we used meiotic spread preparations to localize phosphorylate histone H2 variant (γ-H2AX foci marking DNA double strand breaks (DSBs in elongated spermatids. This technique enabled us to determine the background level of DSB foci in elongated spermatids of RAD54/RAD54B double knockout (dko mice, severe combined immunodeficiency SCID mice, and poly adenosine diphosphate (ADP-ribose polymerase 1 (PARP1 inhibitor (DPQ-treated mice to compare them with the appropriate wild type controls. The repair kinetics data and the protein expression patterns observed indicate that the conventional NHEJ repair pathway is not available for elongated spermatids to repair the programmed and the IR-induced DSBs, reflecting the limited repair capacity of these cells. However, although elongated spermatids express the proteins of the alternative NHEJ, PARP1-inhibition had no effect on the repair kinetics after IR, suggesting that DNA damage may be passed onto sperm. Finally, our genetic mutant analysis suggests that an incomplete or defective meiotic recombinational repair of Spo11-induced DSBs may lead to a carry-over of the DSB damage or induce a delayed nuclear fragmentation during the sensitive programmed chromatin remodeling occurring in elongated spermatids.

  11. Phospholipids enhance nucleation but not elongation of apolipoprotein C-II amyloid fibrils.

    Science.gov (United States)

    Ryan, Timothy M; Teoh, Chai L; Griffin, Michael D W; Bailey, Michael F; Schuck, Peter; Howlett, Geoffrey J

    2010-06-25

    Amyloid fibrils and their oligomeric intermediates accumulate in several age-related diseases where their presence is considered to play an active role in disease progression. A common characteristic of amyloid fibril formation is an initial lag phase indicative of a nucleation-elongation mechanism for fibril assembly. We have investigated fibril formation by human apolipoprotein (apo) C-II. ApoC-II readily forms amyloid fibrils in a lipid-dependent manner via an initial nucleation step followed by fibril elongation, breaking, and joining. We used fluorescence techniques and stopped-flow analysis to identify the individual kinetic steps involved in the activation of apoC-II fibril formation by the short-chain phospholipid dihexanoyl phosphatidylcholine (DHPC). Submicellar DHPC activates fibril formation by promoting the rapid formation of a tetrameric species followed by a slow isomerisation that precedes monomer addition and fibril growth. Global fitting of the concentration dependence of apoC-II fibril formation showed that DHPC increased the overall tetramerisation constant from 7.5 x 10(-13) to 1.2 x 10(-6) microM(-3) without significantly affecting the rate of fibril elongation, breaking, or joining. Studies on the effect of DHPC on the free pool of apoC-II monomer and on fibril formation by cross-linked apoC-II dimers further demonstrate that DHPC affects nucleation but not elongation. These studies demonstrate the capacity of small lipid compounds to selectively target individual steps in the amyloid fibril forming pathway.

  12. The minimal Bacillus subtilis nonhomologous end joining repair machinery.

    Directory of Open Access Journals (Sweden)

    Miguel de Vega

    Full Text Available It is widely accepted that repair of double-strand breaks in bacteria that either sporulate or that undergo extended periods of stationary phase relies not only on homologous recombination but also on a minimal nonhomologous end joining (NHEJ system consisting of a dedicated multifunctional ATP-dependent DNA Ligase D (LigD and the DNA-end-binding protein Ku. Bacillus subtilis is one of the bacterial members with a NHEJ system that contributes to genome stability during the stationary phase and germination of spores, having been characterized exclusively in vivo. Here, the in vitro analysis of the functional properties of the purified B. subtilis LigD (BsuLigD and Ku (BsuKu proteins is presented. The results show that the essential biochemical signatures exhibited by BsuLigD agree with its proposed function in NHEJ: i inherent polymerization activity showing preferential insertion of NMPs, ii specific recognition of the phosphate group at the downstream 5' end, iii intrinsic ligase activity, iv ability to promote realignments of the template and primer strands during elongation of mispaired 3' ends, and v it is recruited to DNA by BsuKu that stimulates the inherent polymerization and ligase activities of the enzyme allowing it to deal with and to hold different and unstable DNA realignments.

  13. Parallel evaluation of multi-join queries

    NARCIS (Netherlands)

    Wilschut, A.N.; Flokstra, Jan; Apers, Peter M.G.

    1995-01-01

    A number of execution strategies for parallel evaluation of multi-join queries have been proposed in the literature; their performance was evaluated by simulation. In this paper we give a comparative performance evaluation of four execution strategies by implementing all of them on the same parallel

  14. Microwave joining of SiC

    Energy Technology Data Exchange (ETDEWEB)

    Silberglitt, R.; Ahmad, I. [FM Technologies, Inc., Fairfax, VA (United States); Black, W.M. [George Mason Univ., Fairfax, VA (United States)] [and others

    1995-05-01

    The purpose of this work is to optimize the properties of SiC-SiC joints made using microwave energy. The current focus is on optimization of time-temperature profiles, production of SiC from chemical precursors, and design of new applicators for joining of long tubes.

  15. Human-powered Sorts and Joins

    CERN Document Server

    Marcus, Adam; Karger, David; Madden, Samuel; Miller, Robert

    2011-01-01

    Crowdsourcing markets like Amazon's Mechanical Turk (MTurk) make it possible to task people with small jobs, such as labeling images or looking up phone numbers, via a programmatic interface. MTurk tasks for processing datasets with humans are currently designed with significant reimplementation of common workflows and ad-hoc selection of parameters such as price to pay per task. We describe how we have integrated crowds into a declarative workflow engine called Qurk to reduce the burden on workflow designers. In this paper, we focus on how to use humans to compare items for sorting and joining data, two of the most common operations in DBMSs. We describe our basic query interface and the user interface of the tasks we post to MTurk. We also propose a number of optimizations, including task batching, replacing pairwise comparisons with numerical ratings, and pre-filtering tables before joining them, which dramatically reduce the overall cost of running sorts and joins on the crowd. In an experiment joining tw...

  16. Large-Scale Similarity Joins With Guarantees

    DEFF Research Database (Denmark)

    Pagh, Rasmus

    2015-01-01

    The ability to handle noisy or imprecise data is becoming increasingly important in computing. In the database community the notion of similarity join has been studied extensively, yet existing solutions have offered weak performance guarantees. Either they are based on deterministic filtering te...

  17. Joining Forces: Working with Spirituality in Organisations.

    Science.gov (United States)

    Snell, Robin; And Others

    1991-01-01

    Includes "Joining Forces" (Lindamood); "Spiritual Dimension of the Learning Organisation" (Hawkins); "Management--A 'Spiritual' Foundation?" (Nevard); "Hermit in Organisations" (Murray); "Towards a Spiritual Perspective on Behavior at Work" (Henson); "On Uncertainty" (Adlam); "Spirituality in Organisations" (Lee); "Ecological Organisation" (Conn);…

  18. Large-Scale Similarity Joins With Guarantees

    DEFF Research Database (Denmark)

    Pagh, Rasmus

    2015-01-01

    The ability to handle noisy or imprecise data is becoming increasingly important in computing. In the database community the notion of similarity join has been studied extensively, yet existing solutions have offered weak performance guarantees. Either they are based on deterministic filtering te...

  19. The RNA polymerase II elongation complex.

    Science.gov (United States)

    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.

  20. Possibilities of joining techniques application at railway lines joining and maintenance

    Directory of Open Access Journals (Sweden)

    I. Samardžić

    2011-10-01

    Full Text Available This paper presents most important techniques which is possible to apply at joining of railway lines as well as maintenance procedure. Beside thermit welding as a older joint process for that job (since 1895. it is mentioned flash welding as a modern joining technique interesting from the point of cost efficiency. In a case of maintance tasks it is necessary to caunt arc welding processes and thermit welding, too. Authors gave some experimental date collected during investigation on railway lines joining techniques application.

  1. Stimulation of elongation growth and xyloglucan breakdown in Arabidopsis hypocotyls under microgravity conditions in space.

    Science.gov (United States)

    Soga, Kouichi; Wakabayashi, Kazuyuki; Kamisaka, Seiichiro; Hoson, Takayuki

    2002-10-01

    Seedlings of Arabidopsis thaliana (L.) Heynh. (ecotype Columbia and an ethylene-resistant mutant etr1-1) were cultivated for 68.5, 91.5 and 136 h on board during the Space Shuttle STS-95 mission, and changes in the elongation growth and the cell wall properties of hypocotyls were analyzed. Elongation growth of dark-grown hypocotyls of both Columbia and etr1-1 was stimulated under microgravity conditions in space. There were no clear differences in the degree of growth stimulation between Columbia and etr1-1, indicating that the ethylene level was not abnormally high in the cultural environment of this space experiment. Microgravity also increased the mechanical extensibility of cell walls in both cultivars, and such an increase was attributed to the increase in the apparent irreversible extensibility. The levels of cell wall polysaccharides per unit length of hypocotyls decreased in space. Microgravity also reduced the weight-average molecular mass of xyloglucans in the hemicellulose-II fraction. Also, the activity of xyloglucan-degrading enzymes extracted from hypocotyl cell walls increased under microgravity conditions. These results suggest that microgravity reduces the molecular mass of xyloglucans by increasing xyloglucan-degrading activity. Modifications of xyloglucan metabolism as well as the thickness of cell wall polysaccharides seem to be involved in an increase in the cell wall extensibility, leading to growth stimulation of Arabidopsis hypocotyls in space.

  2. Boron deficiency inhibits root cell elongation via an ethylene/auxin/ROS-dependent pathway in Arabidopsis seedlings

    Science.gov (United States)

    Camacho-Cristóbal, Juan J.; Martín-Rejano, Esperanza M.; Herrera-Rodríguez, M. Begoña; Navarro-Gochicoa, M. Teresa; Rexach, Jesús; González-Fontes, Agustín

    2015-01-01

    One of the earliest symptoms of boron (B) deficiency is the inhibition of root elongation which can reasonably be attributed to the damaging effects of B deprivation on cell wall integrity. It is shown here that exposure of wild-type Arabidopsis thaliana seedlings to B deficiency for 4h led to a drastic inhibition of root cell length in the transition between the elongation and differentiation zones. To investigate the possible mediation of ethylene, auxin, and reactive oxygen species (ROS) in the effect of B deficiency on root cell elongation, B deficiency was applied together with aminoethoxyvinylglycine (AVG, a chemical inhibitor of ethylene biosynthesis), silver ions (Ag+, an antagonist of ethylene perception), α-(phenylethyl-2‐oxo)‐indoleacetic acid (PEO-IAA, a synthetic antagonist of TIR1 receptor function), and diphenylene iodonium (DPI, an inhibitor of ROS production). Interestingly, all these chemicals partially or fully restored cell elongation in B-deficient roots. To further explore the possible role of ethylene and auxin in the inhibition of root cell elongation under B deficiency, a genetic approach was performed by using Arabidopsis mutants defective in the ethylene (ein2‐1) or auxin (eir1-4 and aux1-22) response. Root cell elongation in these mutants was less sensitive to B-deficient treatment than that in wild-type plants. Altogether, these results demonstrated that a signalling pathway involving ethylene, auxin, and ROS participates in the reduction of root cell elongation when Arabidopsis seedlings are subjected to B deficiency. A similar signalling process has been described to reduce root elongation rapidly under various types of cell wall stress which supports the idea that this signalling pathway is triggered by the impaired cell wall integrity caused by B deficiency. PMID:25922480

  3. Association of specific pectin methylesterases with Al-induced root elongation inhibition in rice.

    Science.gov (United States)

    Yang, Xiao Ying; Zeng, Zhang Hui; Yan, Jing Ying; Fan, Wei; Bian, Hong Wu; Zhu, Mu Yuan; Yang, Jian Li; Zheng, Shao Jian

    2013-08-01

    The negative charges of cell wall pectin molecules attributed by pectin methylesterase (PME, EC 3.1.1.11) contribute to Al binding capacity. We examined the expression profiles of 35 members of the PME gene family in the root apex of an Al-sensitive rice 'Zhefu802' under Al stress. While root elongation was inhibited by 40% after 3-h exposure to 25 µM Al, cell wall PME activity and the abundance of eight PME genes transcripts were increased. The same Al treatment which had almost no effect on root elongation of an Al-resistant rice ssp. japonica 'Nipponbare' did not change the expression patterns of these eight PME genes. However, when Al concentration was increased to 50 µM, by which the root elongation of 'Nipponbare' was inhibited by 40% too, the expression of these PME genes were also upregulated except two genes with no signal. These suggest a possible correlation between the upregulated genes and Al-induced inhibition of root elongation in rice. Furthermore, these eight PME genes behaved differently when subjected to CdCl2 and LaCl3 treatments, implying the specificity of different PME genes in response to different metal toxicities. The transgenic rice overexpressing one of these eight PME genes OsPME14 showed higher PME activity and Al content in root tip cell wall, and became more sensitive to Al stress, verifying the involvement of the specific PME gene in Al toxicity. Therefore, our results provided the molecular evidence to connect the expression of specific PME genes with the Al-induced inhibition of root elongation in rice.

  4. 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.

  5. 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

  6. 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.

  7. Asbestos in Plaster and Wall Systems

    Science.gov (United States)

    This collection of letters and clarification on final rules provides guidance on Asbestos National Emissions Standard for Hazardous Air Pollutants for asbestos-containing join compounds, and asbestos-containing materials found in plaster and wall systems.

  8. Analysis of Five Differentially Expressed Gene Familiesin Fast Elongating Cotton Fiber

    Institute of Scientific and Technical Information of China (English)

    Jian-XunFENG; Sheng-JianJI; Yong-HuiSHI; YuXU; GangWEI; Yu-XianZHU

    2004-01-01

    Using the suppression subtractive hybridization method, we isolated five gene families,including proline-rich proteins (PRPs), arabinogalactan proteins (AGPs), expansins, tubulins and lipid transfer proteins (LTPs), from fast elongating cotton fiber cells. Expression profile analysis using cDNA array technology showed that most of these gene families were highly expressed during early cotton fiber developmental stages (0-20 days post anthesis, DPA). Many transcripts accumulated over 50 fold in 10 DPA fiber cells than in 0 DPA samples. The entire gene family-AGP, together with 20 individual members in other 4 gene families, are reported in cotton for the first time. Accumulation of cell wall proteins, wall loosening enzymes, microtubules and lipid transfer proteins may contribute directly to the elongation and development of fiber cells.

  9. Analysis of Five Differentially Expressed Gene Families in Fast Elongating Cotton Fiber

    Institute of Scientific and Technical Information of China (English)

    Jian-Xun FENG; Sheng-Jian JI; Yong-Hui SHI; Yu XU; Gang WEI; Yu-Xian ZHU

    2004-01-01

    Using the suppression subtractive hybridization method, we isolated five gene families,including proline-rich proteins (PRPs), arabinogalactan proteins (AGPs), expansins, tubulins and lipid transfer proteins (LTPs), from fast elongating cotton fiber cells. Expression profile analysis using cDNA array technology showed that most of these gene families were highly expressed during early cotton fiber developmental stages (0-20 days post anthesis, DPA). Many transcripts accumulated over 50-fold in 10 DPA fiber cells than in 0 DPA samples. The entire gene family-AGP, together with 20 individual members in other 4 gene families, are reported in cotton for the first time. Accumulation of cell wall proteins, wall loosening enzymes, microtubules and lipid transfer proteins may contribute directly to the elongation and development of fiber cells.

  10. Machining, joining and modifications of advanced materials

    CERN Document Server

    Altenbach, Holm

    2016-01-01

    This book presents the latest advances in mechanical and materials engineering applied to the machining, joining and modification of modern engineering materials. The contributions cover the classical fields of casting, forming and injection moulding as representative manufacturing methods, whereas additive manufacturing methods (rapid prototyping and laser sintering) are treated as more innovative and recent technologies that are paving the way for the manufacturing of shapes and features that traditional methods are unable to deliver. The book also explores water jet cutting as an innovative cutting technology that avoids the heat build-up typical of classical mechanical cutting. It introduces readers to laser cutting as an alternative technology for the separation of materials, and to classical bonding and friction stir welding approaches in the context of joining technologies. In many cases, forming and machining technologies require additional post-treatment to achieve the required level of surface quali...

  11. Thin layer joining by gas adsorption

    Science.gov (United States)

    Taga, Yasunori; Fukumura, Toshio

    2014-10-01

    Attempt has been made to join borosilicate glass and cycloolefin (COP) polymer film by using gas adsorption method. After corona plasma treat, COP was exposed to (3-glycidoxypropyl) trimethoxysilane (GPS) and glass to (3-aminopropyl) triethoxysilane (APS) both in air atmosphere, resulting in co-adsorption of water vapor in the atmosphere and organosilane gases. Surface characterization of plasma treated and gas adsorbed surfaces was carried out by X-ray photoelectron spectroscopy (XPS) using Mg Kα X-ray source. Joining was carried out by a roll laminator after contact of both surfaces at room temperature, followed by annealing at 130 °C for 10 min. Adhesion strength was evaluated by 180 degree peel test based on ASTM D-903 and durability was examined under the conditions of 60 °C and 95% RH. It was found that after plasma treatment, complex functional groups such as Csbnd H, Csbnd O, Cdbnd O, Osbnd Cdbnd O and CO3 were found on COP and Osbnd H on glass. Thickness of GPS gas adsorption layer on COP was evaluated by the XPS to be at least 1.1 nm by taking inelastic mean free path of Si2p photoelectron into consideration. Joining force was found to be more than 5 N/25 mm corresponding to almost equal to COP bulk tensile strength. In addition, durability of this adhesion strength remained unchanged over 2000 h even after exposure to the durability test conditions of 60 °C and 95% RH. The results can be explained in terms of formation of Hsbnd H hydrogen bonding and Sisbnd O covalent bonding via silanols will be made at the interface as a result of lamination and annealing processes. In conclusion, ultrathin joining method by gas adsorption was established by the formation of hydrogen and covalent bonds at the interface by low temperature reaction process.

  12. Fundamentals of metals joining with lasers

    Energy Technology Data Exchange (ETDEWEB)

    Jellison, J.L.

    1991-01-01

    The intrinsic characteristic of a laser as a metals joining heat source is high intensity (high irradiance). Other advantages stem from the ability to optically manipulate the beam and the inertness of light. Optimal application of laser technology to metals joining is supported by a fundamental understanding of the physics of the process. The interaction of the laser beam with metals is highly materials and process dependent. Metals joining with lasers in a absence of an understanding of beam-materials interactions would appear to be a highly unpredictable process. This is because of the complexity of beam-material interactions. For example, absorptivity varies by more than an order of magnitude as a function of alloy, temperature, oxide thickness, and laser wavelength. Also, in most laser welding and brazing processing, evaporation of metal creates a significant plume, and beam-plume interactions can markedly alter the spatial distribution of energy at the plume-metal interface. The probability of the beam being absorbed by the plume increases with the square of the wavelength, whereas the propensity for scattering of the beam by particles in the beam is inversely proportional to wavelength. Also, the beam can be refracted due to thermal and compositional gradients in the plume. In selecting a laser process for a given application, understanding each of these physical effects and others is helpful. In many ways, the physics of metals joining with lasers is only qualitatively understood at the present time. This paper overviews the present understanding of the process and identifies areas where research is required to clarify our process understanding.

  13. Bacterial Nonhomologous End Joining Requires Teamwork

    OpenAIRE

    Matthews, Lindsay A.; Lyle A. Simmons

    2014-01-01

    All living organisms must repair DNA double-stranded breaks (DSBs) in order to survive. Many bacteria rely on nonhomologous end joining (NHEJ) when only a single copy of the genome is available and maintain NHEJ pathways with a minimum of two proteins. In this issue, Bhattarai and colleagues identify additional factors that can work together to aid in survival of stationary-phase cells with chromosomal breaks.

  14. Electron beam joining of structural ceramics

    Energy Technology Data Exchange (ETDEWEB)

    Turman, B.N.; Glass, S.J.; Halbleib, J.A.; Helmich, D.R.; Loehman, R.E.

    1995-04-01

    Feasibility of ceramic joining using a high energy (10 MeV) electron beam. The experiments used refractory metals as bonding materials in buried interfaces between Si{sub 3}N{sub 4} pieces. Because the heat capacity of the metal bonding layer is much lower than the ceramic, the metal reaches much higher temperatures than the adjoining ceramic. Using the right combination of beam parameters allows the metal to be melted without causing the adjoining ceramics to melt or decompose. Beam energy deposition and thermal simulations were performed to guide the experiments. Joints were shear tested and interfaces between the metal and the ceramic were examined to identify the bonding mechanism. Specimens joined by electron beams were compared to specimens produced by hot-pressing. Similar reactions occurred using both processes. Reactions between the metal and ceramic produced silicides that bond the metal to the ceramic. The molybdenum silicide reaction products appeared to be more brittle than the platinum silicides. Si{sub 3}N{sub 4} was also joined to Si{sub 3} N{sub 4} directly. The bonding appears to have been produced by the flow of intergranular glass into the interface. Shear strength was similar to the metal bonded specimens. Bend specimens Of Si{sub 3}N{sub 4} were exposed to electron beams with similar parameters to those used in joining experiments to determine how beam exposure degrades the strength. Damage was macroscopic in nature with craters being tonned by material ablation, and cracking occurring due to excessive thermal stresses. Si was also observed on the surface indicating the Si{sub 3}N{sub 4} was decomposing. Bend strength after exposure was 62% of the asreceived strength. No obvious microstructural differences were observed in the material close to the damaged region compared to material in regions far away from the damage.

  15. Laser direct joining of metal and plastic

    Energy Technology Data Exchange (ETDEWEB)

    Katayama, Seiji [Joining and Welding Research Institute, Osaka University, 11-1 Mihogaoka, Ibaraki, Osaka 567-0047 (Japan); Kawahito, Yousuke [Joining and Welding Research Institute, Osaka University, 11-1 Mihogaoka, Ibaraki, Osaka 567-0047 (Japan)], E-mail: kawahito@jwri.osaka-u.ac.jp

    2008-12-15

    We have developed an innovative rapid laser direct joining process of metal and plastic lap plates without adhesives or glues. The joints made between a Type 304 stainless steel plate and a polyethylene terephthalate (PET) plastic sheet of 30 mm width possessed tensile shear loads of about 3000 N. Transmission electron microscope photographs of the joint demonstrated that Type 304 and the PET were bonded on the atomic, molecular or nanostructural level through a Cr oxide film.

  16. Hybrid Recommender System for Joining Virtual Communities

    Directory of Open Access Journals (Sweden)

    Leila Esmaeili

    2012-03-01

    Full Text Available The variety of social networks and virtual communities has created problematic for users of different ages and preferences; in addition, since the true nature of groups is not clearly outlined, users are uncertain about joining various virtual groups and usually face the trouble of joining the undesired ones. As a solution, in this study, we introduced the hybrid community recommender system which offers customized recommendations based on user preferences. Although techniques such as content based filtering and collaborative filtering methods are available, these techniques are not enough efficient and in some cases make problems and bring limitations to users. Our method is based on a combination of content based filtering and collaborative filtering methods. It is created by selecting related features of users based on supervised entropy as well as using association rules and classification method. Supposing users in each community or group share similar characteristics, by hierarchical clustering, heterogeneous members are identified and removed. Unlike other methods, this is also applicable for users who have just joined the social network where they do not have any connections or group memberships. In such situations, this method could still offer recommendations.

  17. Worst-case Optimal Join Algorithms

    CERN Document Server

    Ngo, Hung Q; Ré, Christopher; Rudra, Atri

    2012-01-01

    Efficient join processing is one of the most fundamental and well-studied tasks in database research. In this work, we examine algorithms for natural join queries over many relations and describe a novel algorithm to process these queries optimally in terms of worst-case data complexity. Our result builds on recent work by Atserias, Grohe, and Marx, who gave bounds on the size of a full conjunctive query in terms of the sizes of the individual relations in the body of the query. These bounds, however, are not constructive: they rely on Shearer's entropy inequality which is information-theoretic. Thus, the previous results leave open the question of whether there exist algorithms whose running time achieve these optimal bounds. An answer to this question may be interesting to database practice, as it is known that any algorithm based on the traditional select-project-join style plans typically employed in an RDBMS are asymptotically slower than the optimal for some queries. We construct an algorithm whose runn...

  18. Joining and surfacing of advanced materials

    Institute of Scientific and Technical Information of China (English)

    Andrzej Kolasa; Wladyslaw Wlosinski

    2004-01-01

    The application of advanced materials, i.e. advanced ceramics, glasses, intermetallic phases and various type of composites, not only depends on their manufacture processes including a great input of know-how, but also on their abilities for processing, among which the joining processes play an important role. The uses of advanced materials are changing rapidly, with a major emphasis on technical applications, especially the components of machines, apparatus and technical devices expected to withstand very heavy exploitation conditions. Furthermore,these materials are becoming more complex, in terms of being strengthened and toughened by transformation processes as well as by the addition of other ceramic or metallic materials including nanomaterials. The successful use of advanced materials requires the development of equally advanced joining materials, processes and technology. Some selected examples of results of joining advanced materials with the use of various procedures as well as surface modification of structural components with the use of advanced materials obtained in the Welding Engineering Department of Warsaw University of Technology, Poland, are presented.

  19. High energy electron beams for ceramic joining

    Energy Technology Data Exchange (ETDEWEB)

    Turman, B.N.; Glass, S.J.; Halbleib, J.A.; Helmich, D.R.; Loehman, R.E. [Sandia National Labs., Albuquerque, NM (United States); Clifford, J.R. [Titan Corp., Albuquerque, NM (United States)

    1994-12-31

    Joining of structural ceramics is possible using high melting point metals such as Mo and Pt that are heated with a high energy electron beam, with the potential for high temperature joining. A 10 MeV electron beam can penetrate through 1 cm of ceramic, offering the possibility of buried interface joining. Because of transient heating and the lower heat capacity of the metal relative to the ceramic, a pulsed high power beam has the potential for melting the metal without decomposing or melting the ceramic. We have demonstrated the feasibility of the process with a series of 10 MeV, 1 kW electron beam experiments. Shear strengths up to 28 MPa have been measured. This strength is comparable to that reported in the literature for bonding silicon nitride to molybdenum with copper-silver-titanium braze, but weaker than that reported for Si{sub 3}N{sub 4}-Si{sub 3}N{sub 4} with gold-nickel braze. The bonding mechanism appears to be a thin silicide layer.

  20. Joining of beta-SiC by spark plasma sintering

    Energy Technology Data Exchange (ETDEWEB)

    Grasso, Salvatore [Queen Mary, University of London; Tatarko, Peter [Institute of Physics of Materials, Academy of Sciences of the Czech Republic; Rizzo, S. [Politecnico di Torino; Porwal, Harshit [Queen Mary, University of London; Hu, Chunfeng [Ningbo Institute of Materials Technology & Engineering; Katoh, Yutai [ORNL; Salvo, M [Politecnico di Torino; Reece, Michael John [University of London; Ferraris, Monica [Politecnico di Torino

    2014-01-01

    Spark plasma sintering (SPS) was employed to join monolithic -SiC with or without titanium as intermediate joining material. Both the localizedand rapid heating contributed to the inherent energy saving of electric current assisted joining technique. The effects of uniaxial pressure and surfacepreparation were analyzed independently with respect to the flexural strength and the morphology of the joints. In particular samples polisheddown to 1 m and joined at 1900 C for 5 min achieved the strength of the as received material. The failure occurred outside the joining interface,confirming the optimum quality of the joint. Pressure in combination with surface preparation was necessary to achieve perfect adhesion and porefree direct joining of SiC. The use of Ti foil as a joining material and pressure allowed joining of unpolished SiC.

  1. Optimizing joins between two partitioned relations in distributed databases

    Energy Technology Data Exchange (ETDEWEB)

    Ceri, S.; Gottlob, G.

    1986-06-01

    In this paper, the authors analyzed the optimization of joins between two partitioned relations in distributed databases. They discuss the ''semantic'' optimization of joins, semi-join reduction, and join optimization. Finally, they have presented an overall procedure for join optimization which uses semi-join reduction and join optimization as building blocks. Several results of this paper, such as the principles of semantic optimization and Proposition 1, are simple in nature but appear to be very important from an application viewpoint. The join optimization program presented in Section 5 can be realistically applied, because the authors introduced a simplification of the program which reduces the number of decision variables.

  2. MICROWAVE JOINING OF ALUMINA CERAMIC AND HYDROXYLAPATITE BIOCERAMIC

    Institute of Scientific and Technical Information of China (English)

    1999-01-01

    Microwave joining is a rapid developmental new techniqu e in recent years.This paper introduces a new microwave joining equipment which was made by our lab,succeeds in alumina ceramic-hydroxylapatite bioceramic j o in in the equipment, and analyzes the join situation of join boundary by using s canni ng electron microscope(SEM),this paper analyzes the mechanism of microwave joini ng also.

  3. Root elongation, water stress, and mechanical impedance: a review of limiting stresses and beneficial root tip traits.

    Science.gov (United States)

    Bengough, A Glyn; McKenzie, B M; Hallett, P D; Valentine, T A

    2011-01-01

    Root elongation in drying soil is generally limited by a combination of mechanical impedance and water stress. Relationships between root elongation rate, water stress (matric potential), and mechanical impedance (penetration resistance) are reviewed, detailing the interactions between these closely related stresses. Root elongation is typically halved in repacked soils with penetrometer resistances >0.8-2 MPa, in the absence of water stress. Root elongation is halved by matric potentials drier than about -0.5 MPa in the absence of mechanical impedance. The likelihood of each stress limiting root elongation is discussed in relation to the soil strength characteristics of arable soils. A survey of 19 soils, with textures ranging from loamy sand to silty clay loam, found that ∼10% of penetration resistances were >2 MPa at a matric potential of -10 kPa, rising to nearly 50% >2 MPa at - 200 kPa. This suggests that mechanical impedance is often a major limitation to root elongation in these soils even under moderately wet conditions, and is important to consider in breeding programmes for drought-resistant crops. Root tip traits that may improve root penetration are considered with respect to overcoming the external (soil) and internal (cell wall) pressures resisting elongation. The potential role of root hairs in mechanically anchoring root tips is considered theoretically, and is judged particularly relevant to roots growing in biopores or from a loose seed bed into a compacted layer of soil.

  4. 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.

  5. 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...

  6. 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...

  7. Evaluating the Upset Protrusion Joining (UPJ) Method to Join magnesium Castings to Dissimilar Metals

    Energy Technology Data Exchange (ETDEWEB)

    Logan, Stephen D. [FCA US LLC

    2015-08-19

    This presentation discusses advantages and best practices for incorporating magnesium in automotive component applications to achieve substantial mass reduction, as well as some of the key challenges with respect to joining, coating, and galvanic corrosion, before providing an introduction and status update of the U.S. Department of Energy and Department of Defense jointly sponsored Upset Protrusion Joining (UPJ) process development and evaluation project. This update includes sharing performance results of a benchmark evaluation of the self-pierce riveting (SPR) process for joining dissimilar magnesium (Mg) to aluminum (Al) materials in four unique coating configurations before introducing the UPJ concept and comparing performance results of the joints made with the UPJ process to those made with the SPR process.

  8. Interpolation of microtubules into cortical arrays during cell elongation and differentiation in roots of Azolla pinnata.

    Science.gov (United States)

    Hardham, A R; Gunning, B E

    1979-06-01

    Longitudinal sections of roots of Azolla pinnata R. Br. were prepared for electron microscopy so that cortical microtubules could be counted along the longitudinal walls in cell files in the endodermis, pericycle, and inner and outer cortex, and in sieve and xylem elements. With the exception of the xylem, where there are no transverse cell divisions, each file of cells commences with its initial cell and then possesses a zone of concomitant cell expansion and transverse cell division, followed, after completion of the divisions, by a zone of terminal cell differentiation. The cells augment their population of cortical microtubules as they elongate and divide, showing a net increase of up to 0.6 micron of polymerized microtubule length per min. Two main sub-processes were found: (i) When a longitudinal wall is first formed it is supplied with a higher number of microtubules per unit length of wall than it will have later, when it is being expanded. This initial quota becomes diluted as the second sub-process commences. (ii) The cells interpolate new microtubules at a rate which is characteristic of the cell, and, in the endodermis, of the face of the cell, while the cell elongates. Most cell types thus maintain a set density of cortical microtubules while they elongate and divide. Comparisons of endodermal cells in untreated controls, and roots that had been treated with colchicine, low temperature, or high pressure indicate that the initial quota of microtubules, and the later interpolations, and differentially sensitive to microtuble perturbations. Three types of behaviour, all related to changes in the cell walls, were noted as cortex, xylem and sieve element cells entered their respective phases of cell differentiation. The cortical cells expanded in all dimensions, and the interpolation of microtubules diminished or ceased. The sieve elements continued to elongate, and interpolated at a high rate, reaching unusually high densities of microtubules when the cell

  9. Joining of HHF materials applying electroplating technology

    Energy Technology Data Exchange (ETDEWEB)

    Krauss, Wolfgang, E-mail: wolfgang.krauss@kit.edu; Lorenz, Julia; Konys, Jürgen

    2014-10-15

    Highlights: • Electroplating of fillers is industrially relevant for brazing in fusion. • Interlayers (Ni or Pd) improve adherence and reduce failure risks. • Tungsten and Eurofer joints successfully fabricated by electroplating. • Mechanical and non-destructive testing integrated into qualification. • Shear strength of W joints comparable with conventionally brazed steel. - Abstract: Tungsten will be used as armor material for blanket shielding and is designated as high heat flux material for divertors, beyond application of improved W composite alloys as structural material. Independent from design (water- or helium-cooled), a successful development is inherently correlated with joining of tungsten with functional components. Depending on the design variants, the fabricated joints have to guarantee specific functional or structural properties, e.g., good thermal conductivity or mechanical load transmission. Tungsten shows lacks in adapted joining due to its metallurgical behavior ranging from immiscibility over bad wetting to brittle intermetallic phase formation. Electroplating has shown to overcome such drawbacks and that homogeneous functional (e.g., Ni or Pd) and filler (e.g., Cu) layers can be deposited. In this paper the progress achieved in development of electroplating processes for joining W to W or steel to steel will be shown. The main focus will be the characterization of the processed joints applying metallurgical investigations including SEM/EDX analyses and non-destructive testing. The mechanical stability of the produced joints is demonstrated by presenting recent shear test data. The W–W joints failed due to cracking in W, whereas the steel–steel joints cracked in the brazing zone at about 200 N/mm{sup 2} load.

  10. Thin shells joining local cosmic string geometries

    Energy Technology Data Exchange (ETDEWEB)

    Eiroa, Ernesto F. [Universidad de Buenos Aires, Ciudad Universitaria Pabellon I, Departamento de Fisica, Facultad de Ciencias Exactas y Naturales, Buenos Aires (Argentina); Instituto de Astronomia y Fisica del Espacio (IAFE, CONICET-UBA), Buenos Aires (Argentina); Rubin de Celis, Emilio; Simeone, Claudio [Universidad de Buenos Aires, Ciudad Universitaria Pabellon I, Departamento de Fisica, Facultad de Ciencias Exactas y Naturales, Buenos Aires (Argentina); Ciudad Universitaria Pabellon I, IFIBA-CONICET, Buenos Aires (Argentina)

    2016-10-15

    In this article we present a theoretical construction of spacetimes with a thin shell that joins two different local cosmic string geometries. We study two types of global manifolds, one representing spacetimes with a thin shell surrounding a cosmic string or an empty region with Minkowski metric, and the other corresponding to wormholes which are not symmetric across the throat located at the shell. We analyze the stability of the static configurations under perturbations preserving the cylindrical symmetry. For both types of geometries we find that the static configurations can be stable for suitable values of the parameters. (orig.)

  11. Thin shells joining local cosmic string geometries

    CERN Document Server

    Eiroa, Ernesto F; Simeone, Claudio

    2016-01-01

    In this article we present a theoretical construction of spacetimes with a thin shell that joins two different local cosmic string geometries. We study two types of global manifolds, one representing spacetimes with a standard thin shell and the other corresponding to wormholes which are not symmetric across the throat located at the shell. We analyze the stability of the static configurations under perturbations preserving the cylindrical symmetry. For both types of geometries we find that the static configurations can be stable for suitable values of the parameters.

  12. The usages of JOIN2 authority records

    CERN Document Server

    CERN. Geneva; Thiele, Robert

    2017-01-01

    An important base of the common JOIN2 repository infrastructure of DESY, DKFZ, FZJ, GSI, MLZ and RWTH Aachen are about 134 000 authority records for grants, projects, large-scale infrastructures, cooperations, journals, and different kinds of keys. All instances are using the authorities together. We will present how these authority data are used for different purposes e.g. the recent and upcoming obligations to report to regard to our funding and the data export to openAire. Furthermore, we discuss this in dependence to the German “Kerndatensatz Forschung”, which will be the new standard for future.

  13. Identification of genes involved in the ACC-mediated control of root cell elongation in Arabidopsis thaliana

    Directory of Open Access Journals (Sweden)

    Markakis Marios

    2012-11-01

    Full Text Available Abstract Background Along the root axis of Arabidopsis thaliana, cells pass through different developmental stages. In the apical meristem repeated cycles of division increase the numbers of cells. Upon leaving the meristem, these cells pass the transition zone where they are physiologically and mechanically prepared to undergo subsequent rapid elongation. During the process of elongation epidermal cells increase their length by 300% in a couple of hours. When elongation ceases, the cells acquire their final size, shape and functions (in the differentiation zone. Ethylene administered as its precursor 1-aminocyclopropane-1-carboxylic acid (ACC is capable of inhibiting elongation in a concentration-dependent way. Using a microarray analysis, genes and/or processes involved in this elongation arrest are identified. Results Using a CATMA-microarray analysis performed on control and 3h ACC-treated roots, 240 differentially expressed genes were identified. Quantitative Real-Time RT-PCR analysis of the 10 most up and down regulated genes combined with literature search confirmed the accurateness of the analysis. This revealed that inhibition of cell elongation is, at least partly, caused by restricting the events that under normal growth conditions initiate elongation and by increasing the processes that normally stop cellular elongation at the end of the elongation/onset of differentiation zone. Conclusions ACC interferes with cell elongation in the Arabidopsis thaliana roots by inhibiting cells from entering the elongation process and by immediately stimulating the formation of cross-links in cell wall components, diminishing the remaining elongation capacity. From the analysis of the differentially expressed genes, it becomes clear that many genes identified in this response, are also involved in several other kind of stress responses. This suggests that many responses originate from individual elicitors, but that somewhere in the downstream

  14. A case of elongated styloid process in a modern-age skull from Puerto Cabello, Venezuela.

    Science.gov (United States)

    Dąbrowski, P; Gronkiewicz, S; Soliński, D; Pers, A; Lachowski, K; Domagała, Z

    2015-01-01

    The styloid process (SP) arises from cartilage of the second branchial arch and tends to calcify during later life. If the length of the SP is more than 30 mm, it can be considered abnormally elongated. Clinical symptoms associated with elongation of this type are defined as Eagle's syndrome. The paper presents a case of an elongated SP in a modern skull from Puerto Cabello, Venezuela, obtained from a series of skulls of African slaves kept at the Department of Anthropology, Polish Academy of Sciences in Wroclaw. The skull belonged to a male individual, aged ca. 55 years at death (maturus). In terms of basic anthropometric features it had slightly greater facial width parameters in comparison to the cerebral part, and a shorter length of neurocranium when compared to average values of morphological features in African skulls from Uganda. Further macroscopic analysis revealed the presence of an elongated SP (ca. 70.1 mm) with secondary lesions remaining after a healed fracture. Imaging of the bone structure of the elongated SP was carried out using a computed to-mography scan, with multilevel image analysis without contrast. The elongation and calcification of the left ligament in anterior orientation could have caused irritation to the structure of cranial nerves, running within the parapharyngeal space, and to sympathetic fibres running in the wall of cervical arteries. Analyses of craniological materials recovered during excavations or as part of old osteological collections are rare due to the fragility of this bone structure, and for that reason they may be a valuable source of information on the health status of historic human populations.

  15. Teens join the MoEDAL collaboration

    CERN Multimedia

    Stephanie Hills

    2013-01-01

    The principal investigator for any institute joining an experimental collaboration is generally a self-assured researcher with evident leadership skills and an in-depth knowledge of their subject gained over many years. Katherine Evans fits the brief in every respect, except that she is 17 years old and her research institute is the Langton Star Centre, based at the Simon Langton Grammar School for Boys. The school has just joined the MoEDAL experiment.   Teacher Becky Parker (left) with two students from the Simon Langton Grammar School for Boys in the MoEDAL experimental area. MoEDAL, the latest LHC experiment has detectors located close to the interaction point of the LHCb experiment. This new experiment is designed to search for the highly ionizing avatars of new physics at the LHC, specifically the magnetic monopole or dyon and other highly ionizing stable massive particles from a number of beyond-the-Standard-Model scenarios. MoEDAL was approved in 2010 and is due to start taking data i...

  16. 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...

  17. FE-simulation of the Presta joining process for assembled camshafts - modelling of the joining process

    Science.gov (United States)

    Scherzer, R.; Silbermann, C. B.; Landgraf, R.; Ihlemann, J.

    2017-03-01

    The Presta joining process is based on the separate manufacturing of internal profiled cams and shafts with previously widened diameters at the intended cam seat through rolling. With regard to further optimization and enhancement, the two substeps are modelled and simulated using FEM. The results of the rolling process simulation are employed as the starting point for the simulation of the joining step, which is presented in this contribution. First, the shaft is widened with a profile oriented orthogonal to the shaft axis at the intended cam seat. Subsequently, the shaft is joined with a cam that has an internal profile oriented parallel to the shaft axis. Due to plastic deformations these perpendicular profiles form a tight fit. Because of these complex plastic deformations, that are related to large local forming degrees, the use of precise material models is essential. Moreover, it is necessary to maintain the deformation history of the rolling simulation in the joining step with regard to effects like kinematic or isotropic hardening. For that purpose, the applied material model’s invariance under change of the reference configuration is used by transferring its internal state variables from one simulation step to another. Finally, the results of the simulation are compared to measurements of series production.

  18. Wonderful Walls

    Science.gov (United States)

    Greenman, Jim

    2006-01-01

    In this article, the author emphasizes the importance of "working" walls in children's programs. Children's programs need "working" walls (and ceilings and floors) which can be put to use for communication, display, storage, and activity space. The furnishings also work, or don't work, for the program in another sense: in aggregate, they serve as…

  19. Ambiguous walls

    DEFF Research Database (Denmark)

    Mody, Astrid

    2012-01-01

    The introduction of Light Emitting Diodes (LEDs) in the built environment has encouraged myriad applications, often embedded in surfaces as an integrated part of the architecture. Thus the wall as responsive luminous skin is becoming, if not common, at least familiar. Taking into account how wall...

  20. Hypergravity inhibits elongation growth of azuki bean epicotyls independently of the direction of stimuli

    Science.gov (United States)

    Soga, K.; Wakabayashi, K.; Kamisaka, S.; Hoson, T.

    We examined the effects of basipetal, horizontal, and acropetal hypergravity stimulation on growth and cell wall properties of azuki bean seedlings. Horizontal and acropetal hypergravity inhibited elongation growth of epicotyls by decreasing the cell wall extensibility, as did basipetal hypergravity. Hypergravity stimulation increased the thickness of cell walls and suppressed xyloglucan breakdown regardless of direction. All hypergravity treatments increased the pH in the apoplastic fluid, which is involved in the processes of the suppression of xyloglucan breakdown. Gadolinium and lanthanum, both blockers of mechanoreceptors, nullified the growth-inhibiting effects of hypergravity. These results show that growth inhibition by hypergravity is independent of its direction in azuki bean epicotyls. The findings also suggest that mechanoreceptors on the plasma membrane perceive the gravity signal independently of its direction, and affect growth of azuki bean epicotyls.

  1. Alpha-expansins in the semiaquatic ferns Marsilea quadrifolia and Regnellidium diphyllum: evolutionary aspects and physiological role in rachis elongation.

    Science.gov (United States)

    Kim, J H; Cho, H T; Kende, H

    2000-12-01

    To investigate the evolutionary history of expansins and their role in cell elongation in early land plants, we isolated two alpha-expansin genes, Mq-EXP1 and Rd-EXP1, respectively, from the semiaquatic ferns Marsilea quacdrifolia L. and Regnellidium diphyllum Lindm. The deduced amino acid sequences of the fern expansins exhibit a high degree of identity to those of seed plants, showing that expansin genes were conserved during the evolution of vascular plants. Gel-blot analysis of M. quadrifolia and R. diphyllum genomic DNA indicated that, in both ferns, alpha-expansins are encoded by multigene families. Expression of alpha-expansin genes probed with Mq-EXP1 was confined to the elongating region of the Marsilea rachis. Cell-wall proteins of M. quadrifolia induced in-vitro extension of acidified cucumber cell walls. In R. diphyllum, expression of Rd-EXP1 increased when elongation of the rachis was enhanced by submergence or ethylene. These results indicate that alpha-expansins act as wall-loosening proteins in ferns, as has been proposed for angiosperms. In addition, Rd-EXP1 may play a role in mediating elongation of the rachis in submerged plants.

  2. I/O-Efficient Similarity Join

    DEFF Research Database (Denmark)

    Pagh, Rasmus; Pham, Ninh Dang; Silvestri, Francesco;

    2015-01-01

    We present an I/O-efficient algorithm for computing similarity joins based on locality-sensitive hashing (LSH). In contrast to the filtering methods commonly suggested our method has provable sub-quadratic dependency on the data size. Further, in contrast to straightforward implementations of known...... LSH-based algorithms on external memory, our approach is able to take significant advantage of the available internal memory: Whereas the time complexity of classical algorithms includes a factor of N ρ, where ρ is a parameter of the LSH used, the I/O complexity of our algorithm merely includes...... a factor (N/M)ρ, where N is the data size and M is the size of internal memory. Our algorithm is randomized and outputs the correct result with high probability. It is a simple, recursive, cache-oblivious procedure, and we believe that it will be useful also in other computational settings such as parallel...

  3. Stability of Join the Shortest Queue Networks

    CERN Document Server

    Bramson, Maury

    2010-01-01

    Join the shortest queue (JSQ) refers to networks whose incoming jobs are assigned to the shortest queue from among a randomly chosen subset of the queues in the system. After completion of service at the queue, a job leaves the network. We show that, for all non- idling service disciplines and for general interarrival and service time distributions, such networks are stable when they are subcritical. We then obtain uniform bounds on the tails of the marginal distributions of the equilibria for families of such networks; these bounds are employed to show relative compactness of the marginal distributions. We also present a family of subcritical JSQ networks whose workloads in equilibrium are much larger than for the corresponding networks where each incoming job is assigned randomly to a queue. Part of this work generalizes results in Foss and Chernova [12], which applied fluid limits to study networks with the FIFO discipline. Here, we apply an appropriate Lyapunov function.

  4. Conjoint Forming - Technologies for Simultaneous Forming and Joining

    Science.gov (United States)

    Groche, P.; Wohletz, S.; Mann, A.; Krech, M.; Monnerjahn, V.

    2016-03-01

    The market demand for new products optimized for e. g. lightweight applications or smart components leads to new challenges in production engineering. Hybrid structures represent one promising approach. They aim at higher product performance by using a suitable combination of different materials. The developments of hybrid structures stimulate the research on joining of dissimilar materials. Since they allow for joining dissimilar materials without external heating technologies based on joining by plastic deformation seem to be of special attractiveness. The paper at hand discusses the conjoint forming approach. This approach combines forming and joining in one process. Two or more workpieces are joined while at least one workpiece is plastically deformed. After presenting the fundamental joining mechanisms, the conjoint forming approach is discussed comprehensively. Examples of conjoint processes demonstrate the effectiveness and reveal the underlying phenomena.

  5. Joining Technology of Dissimilar Materials for Automotive Components(Ⅱ)

    Institute of Scientific and Technical Information of China (English)

    Meung Ho Rhee; Jong Ho Song; Woo Young Chung; Young Myoung Kim

    2004-01-01

    Joining techniques of dissimilar materials for lightweight multi-material automotive body structure were discussed. The joining of 1 .4 mm thickness steel and 2 mm thickness of Al were performed by the new method that is hybrid laser welding system. After aluminum and steel were welded by laser hybrid welding process, the micro-structure investment and the micro-hardness test were carried out. Hybrid laser welding promises a bright future in joining technology of dissimilar materials for automotive components.

  6. QuickJoin—Fast Neighbour-Joining Tree Reconstruction

    DEFF Research Database (Denmark)

    Mailund; Pedersen, Christian N. Storm

    2004-01-01

    We have built a tool for fast construction of very large phylogenetic trees. The tool uses heuristics for speeding up the neighbour-joining algorithm—while still constructing the same tree as the original neighbour-joining algorithm—making it possible to construct trees for ~8000 species in less...... than ten minutes on a single desktop PC. In comparison, the same task takes more than 30 minutes using the QuickTree neighbour-joining implementation....

  7. QuickJoin—Fast Neighbour-Joining Tree Reconstruction

    DEFF Research Database (Denmark)

    Mailund; Pedersen, Christian N. Storm

    2004-01-01

    We have built a tool for fast construction of very large phylogenetic trees. The tool uses heuristics for speeding up the neighbour-joining algorithm—while still constructing the same tree as the original neighbour-joining algorithm—making it possible to construct trees for ~8000 species in less...... than ten minutes on a single desktop PC. In comparison, the same task takes more than 30 minutes using the QuickTree neighbour-joining implementation....

  8. Wall Turbulence.

    Science.gov (United States)

    Hanratty, Thomas J.

    1980-01-01

    This paper gives an account of research on the structure of turbulence close to a solid boundary. Included is a method to study the flow close to the wall of a pipe without interferring with it. (Author/JN)

  9. Evaluating the Upset Protrusion Joining (UPJ) Method to Join Magnesium Castings to Dissimilar Metals

    Energy Technology Data Exchange (ETDEWEB)

    Logan, Stephen [FCA US LLC

    2016-02-24

    This presentation discusses advantages and best practices for incorporating magnesium in automotive component applications to achieve substantial mass reduction, as well as some of the key challenges with respect to joining, coating, and galvanic corrosion, before providing an introduction and status update of the U.S. Department of Energy and Department of Defense jointly sponsored Upset Protrusion Joining (UPJ) process development and evaluation project. This update includes sharing performance results of a benchmark evaluation of the self-pierce riveting (SPR) process for joining dissimilar magnesium (Mg) to aluminum (Al) materials in four unique coating configurations before introducing the UPJ concept and comparing performance results of the joints made with the UPJ process to those made with the SPR process. Key results presented include: • The benchmark SPR process can produce good joints in the MgAM60B-Al 6013 joint configuration with minimal cracking in the Mg coupons if the rivet is inserted from the Mg side into the Al side. • Numerous bare Mg to bare Al joints made with the SPR process separated after only 6-wks of accelerated corrosion testing due to fracture of the rivet as a result of hydrogen embrittlement • For the same joint configurations, UPJ demonstrated substantially higher pre-corrosion joint strengths and post-corrosion joint strengths, primarily because of the larger diameter protrusion compared to smaller SPR rivet diameter and reduced degradation due to accelerated corrosion exposure • As with the SPR process, numerous bare Mg to bare Al joints made with the UPJ process also separated after 6-wks of accelerated corrosion testing, but unlike the SPR experience, the UPJ joints experienced degradation of the boss and head because of galvanic corrosion of the Mg casting, not hydrogen embrittlement of the steel rivet. • In the configuration where both the Mg and Al were pretreated with Alodine 5200 prior to joining and the complete

  10. UK Announces Intention to Join ESO

    Science.gov (United States)

    2000-11-01

    Summary The Particle Physics and Astronomy Research Council (PPARC) , the UK's strategic science investment agency, today announced that the government of the United Kingdom is making funds available that provide a baseline for this country to join the European Southern Observatory (ESO) . The ESO Director General, Dr. Catherine Cesarsky , and the ESO Community warmly welcome this move towards fuller integration in European astronomy. "With the UK as a potential member country of ESO, our joint opportunities for front-line research and technology will grow significantly", she said. "This announcement is a clear sign of confidence in ESO's abilities, most recently demonstrated with the construction and operation of the unique Very Large Telescope (VLT) on Paranal. Together we will look forward with confidence towards new, exciting projects in ground-based astronomy." It was decided earlier this year to place the 4-m UK Visible and Infrared Survey Telescope (VISTA) at Paranal, cf. ESO Press Release 03/00. Following negotiations between ESO and PPARC, a detailed proposal for the associated UK/ESO Agreement with the various entry modalities will now be presented to the ESO Council for approval. Before this Agreement can enter into force, the ESO Convention and associated protocols must also be ratified by the UK Parliament. Research and key technologies According to the PPARC press release, increased funding for science, announced by the UK government today, will enable UK astronomers to prepare for the next generation of telescopes and expand their current telescope portfolio through membership of the European Southern Observatory (ESO). The uplift to its baseline budget will enable PPARC to enter into final negotiations for UK membership of the ESO. This will ensure that UK astronomers, together with their colleagues in the ESO member states, are actively involved in global scale preparations for the next generation of astronomy facilities. among these are ALMA

  11. CERN clubs join the fiftieth anniversary party!

    CERN Multimedia

    2004-01-01

    CERN's clubs are planning to celebrate the Organization's 50th anniversary by organising a variety of special events. It's raining projects! CERN's clubs have chosen to celebrate the Organization's Golden Jubilee, each in its own style, by organising a whole host of anniversary events. While the Cine-Club continues to screen films made in the Member States on Thursday evenings, other clubs are organising special races and tournaments to honour CERN's 50th year. The CERN Rugby Club led the way in early April when it hosted a children's tournament which brought the Laboratory firmly into the view of its many young participants. On 24 April, the Cycling Club moves to centre stage as it takes its members on a unique 50-km discovery trip around the countryside above the tunnel of the future LHC. The Croquet Club, the Running Club, the Horse Riding Club and the Golf Club will all be joining the party in May and June. After that, football, softball, cycling, pétanque and sailing are just some of the items on a sp...

  12. 49 CFR 192.283 - Plastic pipe: Qualifying joining procedures.

    Science.gov (United States)

    2010-10-01

    ... 49 Transportation 3 2010-10-01 2010-10-01 false Plastic pipe: Qualifying joining procedures. 192... Materials Other Than by Welding § 192.283 Plastic pipe: Qualifying joining procedures. (a) Heat fusion... for making plastic pipe joints by a heat fusion, solvent cement, or adhesive method, the...

  13. PEJA: Progressive Energy-Efficient Join Processing for Sensor Networks

    Institute of Scientific and Technical Information of China (English)

    Yong-Xuan Lai; Yi-Long Chen; Hong Chen

    2008-01-01

    Sensor networks are widely used in many applications to collaboratively collect information from the physical environment. In these applications, the exploration of the relationship and linkage of sensing data within multiple regions can be naturally expressed by joining tuples in these regions. However, the highly distributed and resource-constraint nature of the network makes join a challenging query. In this paper, we address the problem of processing join query among different regions progressively and energy-efficiently in sensor networks. The proposed algorithm PEJA (Progressive Energy-efficient Join Algorithm) adopts an event-driven strategy to output the joining results as soon as possible, and alleviates the storage shortage problem in the in-network nodes. It also installs filters in the joining regions to prune unmatchable tuples in the early processing phase, saving lots of unnecessary transmissions. Extensive experiments on both synthetic and real world data sets indicate that the PEJA scheme outperforms other join algorithms, and it is effective in reducing the number of transmissions and the delay of query results during the join processing.

  14. 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...

  15. Toroid Joining Gun. [thermoplastic welding system using induction heating

    Science.gov (United States)

    Buckley, J. D.; Fox, R. L.; Swaim, R J.

    1985-01-01

    The Toroid Joining Gun is a low cost, self-contained, portable low powered (100-400 watts) thermoplastic welding system developed at Langley Research Center for joining plastic and composite parts using an induction heating technique. The device developed for use in the fabrication of large space sructures (LSST Program) can be used in any atmosphere or in a vacuum. Components can be joined in situ, whether on earth or on a space platform. The expanded application of this welding gun is in the joining of thermoplastic composites, thermosetting composites, metals, and combinations of these materials. Its low-power requirements, light weight, rapid response, low cost, portability, and effective joining make it a candidate for solving many varied and unique bonding tasks.

  16. 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.

  17. 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

  18. Brazil to Join the European Southern Observatory

    Science.gov (United States)

    2010-12-01

    The Federative Republic of Brazil has yesterday signed the formal accession agreement paving the way for it to become a Member State of the European Southern Observatory (ESO). Following government ratification Brazil will become the fifteenth Member State and the first from outside Europe. On 29 December 2010, at a ceremony in Brasilia, the Brazilian Minister of Science and Technology, Sergio Machado Rezende and the ESO Director General, Tim de Zeeuw signed the formal accession agreement aiming to make Brazil a Member State of the European Southern Observatory. Brazil will become the fifteen Member State and the first from outside Europe. Since the agreement means accession to an international convention, the agreement must now be submitted to the Brazilian Parliament for ratification [1]. The signing of the agreement followed the unanimous approval by the ESO Council during an extraordinary meeting on 21 December 2010. "Joining ESO will give new impetus to the development of science, technology and innovation in Brazil as part of the considerable efforts our government is making to keep the country advancing in these strategic areas," says Rezende. The European Southern Observatory has a long history of successful involvement with South America, ever since Chile was selected as the best site for its observatories in 1963. Until now, however, no non-European country has joined ESO as a Member State. "The membership of Brazil will give the vibrant Brazilian astronomical community full access to the most productive observatory in the world and open up opportunities for Brazilian high-tech industry to contribute to the European Extremely Large Telescope project. It will also bring new resources and skills to the organisation at the right time for them to make a major contribution to this exciting project," adds ESO Director General, Tim de Zeeuw. The European Extremely Large Telescope (E-ELT) telescope design phase was recently completed and a major review was

  19. Microtubules and CESA tracks at the inner epidermal wall align independently of those on the outer wall of light-grown Arabidopsis hypocotyls.

    Science.gov (United States)

    Chan, Jordi; Eder, Magdalena; Crowell, Elizabeth Faris; Hampson, Janet; Calder, Grant; Lloyd, Clive

    2011-04-01

    Microtubules are classically described as being transverse, which is perpendicular to the direction of cell elongation. However, fixation studies have indicated that microtubules can be variably aligned across the epidermis of elongating shoots. In addition, microtubules are reported to have different orientations on inner and outer epidermal surfaces, undermining the idea of hoop-reinforcement. Here, long-term movies of Arabidopsis seedlings expressing GFP-TUA6 allowed microtubule alignment to be directly correlated with the rate of elongation within individual growing cells. We also investigated whether microtubule alignment at the inner or the outer epidermal wall better reflected the growth rate. Movies confirmed that transverse microtubules form on the inner wall throughout elongation, but orientation of microtubules is variable at the outer wall, where they tend to become transverse only during episodes of accelerated growth. Because this appears to contradict the concept that circumferential arrays of transverse microtubules or microfibrils are essential for cell elongation, we checked the organisation of cellulose synthase tracks using GFP-CESA3 and found a similar mismatch between trajectories on inner and outer epidermal surfaces. We conclude that microtubule alignment on the inner wall appears to be a more stable predictor of growth anisotropy, whereas outer-wall alignment is more sensitive to the elongation rate.

  20. Modeling Non-homologous End Joining

    Science.gov (United States)

    Li, Yongfeng

    2013-01-01

    Non-homologous end joining (NHEJ) is the dominant DNA double strand break (DSB) repair pathway and involves several NHEJ proteins such as Ku, DNA-PKcs, XRCC4, Ligase IV and so on. Once DSBs are generated, Ku is first recruited to the DNA end, followed by other NHEJ proteins for DNA end processing and ligation. Because of the direct ligation of break ends without the need for a homologous template, NHEJ turns out to be an error-prone but efficient repair pathway. Some mechanisms have been proposed of how the efficiency of NHEJ repair is affected. The type of DNA damage is an important factor of NHEJ repair. For instance, the length of DNA fragment may determine the recruitment efficiency of NHEJ protein such as Ku [1], or the complexity of the DNA breaks [2] is accounted for the choice of NHEJ proteins and subpathway of NHEJ repair. On the other hand, the chromatin structure also plays a role of the accessibility of NHEJ protein to the DNA damage site. In this talk, some mathematical models of NHEJ, that consist of series of biochemical reactions complying with the laws of chemical reaction (e.g. mass action, etc.), will be introduced. By mathematical and numerical analysis and parameter estimation, the models are able to capture the qualitative biological features and show good agreement with experimental data. As conclusions, from the viewpoint of modeling, how the NHEJ proteins are recruited will be first discussed for connection between the classical sequential model [4] and recently proposed two-phase model [5]. Then how the NHEJ repair pathway is affected, by the length of DNA fragment [6], the complexity of DNA damage [7] and the chromatin structure [8], will be addressed

  1. Wall Art

    Science.gov (United States)

    McGinley, Connie Q.

    2004-01-01

    The author of this article, an art teacher at Monarch High School in Louisville, Colorado, describes how her experience teaching in a new school presented an exciting visual challenge for an art teacher--monotonous brick walls just waiting for decoration. This school experienced only minimal instances of graffiti, but as an art teacher, she did…

  2. Spatial and Temporal Quantitative Analysis of Cell Division and Elongation Rate in Growing Wheat Leaves under Saline Conditions

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    Leaf growth in grasses is determined by the cell division and elongation rates, with the duration of cell elongation being one of the processes that is the most sensitive to salinity. Our objective was to investigate the distribution profiles of cell production, cell length and the duration of cell elongation in the growing zone of the wheat leaf during the steady growth phase. Plants were grown in loamy soil with or without 120 mmol/L NaCl in a growth chamber, and harvested at day 3 after leaf 4 emerged. Results show that the elongation rate of leaf 4 was reduced by 120 mmol/L NaCl during the steady growth phase. The distribution profile of the lengths of abaxial epidermal cells of leaf 4 during the steady growth stage shows a sigmoidal pattern along the leaf axis for both treatments. Although salinity did not affect or even increased the length of the epidermal cells in some locations in the growth zone compared to the control treatment, the final length of the epidermal cells was reduced by 14% at 120 mmol/L NaCl. Thus, we concluded that the observed reduction in the leaf elongation rate derived in part from the reduced cell division rate and either the shortened cell elongation zone or shortened duration of cell elongation. This suggests that more attention should be paid to the effects of salinity on those properties of cell production and the period of cell maturation that are related to the properties of cell wall.

  3. A Modeling Approach for Plastic-Metal Laser Direct Joining

    Science.gov (United States)

    Lutey, Adrian H. A.; Fortunato, Alessandro; Ascari, Alessandro; Romoli, Luca

    2017-09-01

    Laser processing has been identified as a feasible approach to direct joining of metal and plastic components without the need for adhesives or mechanical fasteners. The present work sees development of a modeling approach for conduction and transmission laser direct joining of these materials based on multi-layer optical propagation theory and numerical heat flow simulation. The scope of this methodology is to predict process outcomes based on the calculated joint interface and upper surface temperatures. Three representative cases are considered for model verification, including conduction joining of PBT and aluminum alloy, transmission joining of optically transparent PET and stainless steel, and transmission joining of semi-transparent PA 66 and stainless steel. Conduction direct laser joining experiments are performed on black PBT and 6082 anticorodal aluminum alloy, achieving shear loads of over 2000 N with specimens of 2 mm thickness and 25 mm width. Comparison with simulation results shows that consistently high strength is achieved where the peak interface temperature is above the plastic degradation temperature. Comparison of transmission joining simulations and published experimental results confirms these findings and highlights the influence of plastic layer optical absorption on process feasibility.

  4. 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...

  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. 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.

  7. 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.

  8. Solid State Joining of Dissimilar Titanium Alloys

    Science.gov (United States)

    Morton, Todd W.

    Solid state joining of titanium via friction stir welding and diffusion bonding have emerged as enablers of efficient monolithic structural designs by the eliminations fasteners for the aerospace industry. As design complexity and service demands increase, the need for joints of dissimilar alloys has emerged. Complex thermomechanical conditions in friction stir weld joints and high temperature deformation behavior differences between alloys used in dissimilar joints gives rise to a highly variable flow pattern within a stir zone. Experiments performed welding Ti-6Al-4V to beta21S show that mechanical intermixing of the two alloys is the primary mechanism for the generation of the localized chemistry and microstructure, the magnitude of which can be directly related to pin rotation and travel speed weld parameters. Mechanical mixing of the two alloys is heavily influenced by strain rate softening phenomena, and can be used to manipulate weld nugget structure by switching which alloy is subjected to the advancing side of the pin. Turbulent mixing of a weld nugget and a significant reduction in defects and weld forces are observed when the beta21S is put on the advancing side of the weld where higher strain rates are present. Chemical diffusion driven by the heat of weld parameters is characterized using energy dispersive x-ray spectroscopy (EDS) and is shown to be a secondary process responsible for generating short-range chemical gradients that lead to a gradient of alpha particle structures. Diffusion calculations are inconsistent with an assumption of steady-state diffusion and show that material interfaces in the weld nugget evolve through the break-down of turbulent interface features generated by material flows. A high degree of recrystallization is seen throughout the welds, with unique, hybrid chemistry grains that are generated at material interfaces in the weld nugget that help to unify the crystal structure of dissimilar alloys. The degree of

  9. 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.

  10. (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...

  11. CLIMBING WALL

    CERN Multimedia

    1999-01-01

    The FIRE AND RESCUE Group of TIS Commission informs that the climbing wall in the yard of the Fire-fighters Station, is intended for the sole use of the members of that service, and recalls that access to this installation is forbidden for safety reasons to all persons not belonging to the Service.CERN accepts no liability for damage or injury suffered as a result of failure to comply with this interdiction.TIS/DI

  12. Joining SI3N4 for Advanced Turbomachinery Applications

    Energy Technology Data Exchange (ETDEWEB)

    GLASS, S. JILL; LOEHMAN, RONALD E.; HOSKING, F. MICHAEL; STEPHENS JR., JOHN J.; VIANCO, PAUL T.; NEILSEN, MICHAEL K.; WALKER, CHARLES A.; POLLINGER, J.P.; MAHONEY, F.M.; QUILLEN, B.G.

    2000-07-01

    The main objective of this project was to develop reliable, low-cost techniques for joining silicon nitride (Si{sub 3}N{sub 4}) to itself and to metals. For Si{sub 3}N{sub 4} to be widely used in advanced turbomachinery applications, joining techniques must be developed that are reliable, cost-effective, and manufacturable. This project addressed those needs by developing and testing two Si{sub 3}N{sub 4} joining systems; oxynitride glass joining materials and high temperature braze alloys. Extensive measurements were also made of the mechanical properties and oxidation resistance of the braze materials. Finite element models were used to predict the magnitudes and positions of the stresses in the ceramic regions of ceramic-to-metal joints sleeve and butt joints, similar to the geometries used for stator assemblies.

  13. Study on the Hinge-joined Plate Method

    Directory of Open Access Journals (Sweden)

    Li Sha

    2015-01-01

    Full Text Available In order to verify and perfect the theory of hinge-joined plate method and make it serve the bridge design better, this paper was written based on an actual bridge, and the ANSYS finite element model was established. Compared the hinge-joined plate method results with the analysis results and through the investigation and data analysis, it could be found that the assumption that the hinge-joined plate theory for the board lateral force transmission is reasonable, but the assuming hinge joints that only withstand shear stress and just have the shear checking is unreasonable. At the same time, this paper also proved that the strength reduction getting from the old and new concrete interface should be taken into account when using the hinge-joined plate method to calculate the transverse distribution coefficient and the effects on overall stiffness that the joint depth and thickness of deck pavement to the beam bridge.

  14. Women's Heart Disease: Join the Heart Truth Community

    Science.gov (United States)

    ... this page please turn JavaScript on. Feature: Women's Heart Disease Join The Heart Truth Community Past Issues / Winter ... introduced as the national symbol for women and heart disease awareness in 2002 by the NHLBI. The Red ...

  15. Microwave joining of SiC ceramics and composites

    Energy Technology Data Exchange (ETDEWEB)

    Ahmad, I.; Silberglitt, R.; Tian, Y.L. [FM Technologies, Inc., Fairfax, VA (United States); Katz, J.D. [Los Alamos National Lab., NM (United States)

    1997-04-01

    Potential applications of SiC include components for advanced turbine engines, tube assemblies for radiant burners and petrochemical processing and heat exchangers for high efficiency electric power generation systems. Reliable methods for joining SiC are required in order to cost-effectively fabricate components for these applications from commercially available shapes and sizes. This manuscript reports the results of microwave joining experiments performed using two different types of SiC materials. The first were on reaction bonded SiC, and produced joints with fracture toughness equal to or greater than that of the base material over an extended range of joining temperatures. The second were on continuous fiber-reinforced SiC/SiC composite materials, which were successfully joined with a commercial active brazing alloy, as well as by using a polymer precursor.

  16. Joining Silicon Carbide Components for Space Propulsion Project

    Data.gov (United States)

    National Aeronautics and Space Administration — This SBIR Phase I program will identify the joining materials and demonstrate the processes that are suited for construction of advanced ceramic matrix composite...

  17. TRANSFORMER FOR JOINING UNBALANCED TO BALANCED TRANSMISSION MEANS

    Science.gov (United States)

    Bittner, B.J.; Opperman, R.H.

    1960-06-28

    An improved transformer is invented for joining an unbalanced transmission means to a balanced transmission means and is useful, for example, in transmitting an electromagnetic signal from a coaxial cable to a balanced dipole antenna.

  18. Fastening, coupling and joining technique between diaspora and irredenta

    Science.gov (United States)

    Bauer, C.-O.

    1980-06-01

    The problem of eliminating the present divergence and shattering (diaspora) in the treatment of problems of the fastening, coupling, and joining technique on different technical branches is examined. It is shown that by an appropriate independence the fastening, coupling and joining techniques can recognize and consequently utilize the numerous performance reserves which are concealed by the present organization and action due to the lack of systematically tended works.

  19. Model Checking Processes Specified In Join-Calculus Algebra

    Directory of Open Access Journals (Sweden)

    Sławomir Piotr Maludziński

    2014-01-01

    Full Text Available This article presents a model checking tool used to verify concurrent systems specified in join-calculus algebra. The temporal properties of systems under verification are expressed in CTL logic. Join-calculus algebra with its operational semantics defined by the chemical abstract machine serves as the basic method for the specification of concurrent systems and their synchronization mechanisms, and allows the examination of more complex systems.

  20. Parametric weight evaluation of joined wings by structural optimization

    Science.gov (United States)

    Miura, Hirokazu; Shyu, Albert T.; Wolkovitch, Julian

    1988-01-01

    Joined-wing aircraft employ tandem wings having positive and negative sweep and dihedral, arranged to form diamond shapes in both plan and front views. An optimization method was applied to study the effects of joined-wing geometry parameters on structural weight. The lightest wings were obtained by increasing dihedral and taper ratio, decreasing sweep and span, increasing fraction of airfoil chord occupied by structural box, and locating the joint inboard of the front wing tip.

  1. Alternative end-joining mechanisms: a historical perspective

    OpenAIRE

    Anabelle eDecottignies

    2013-01-01

    In the presence of functional DNA repair pathways, DNA double-strand breaks (DSBs) are mainly repaired by non-homologous end-joining (NHEJ) or homologous recombination (HR), two conserved pathways that protect cells from aberrant chromosomal rearrangements. During the past two decades however, unusual and presumably distinct DNA end-joining repair activities have been unraveled in NHEJ-deficient cells and these are likely to operate in various chromosomal contexts and species. Most alternativ...

  2. Top scientists join Stephen Hawking at Perimeter Institute

    Science.gov (United States)

    Banks, Michael

    2009-03-01

    Nine leading researchers are to join Stephen Hawking as visiting fellows at the Perimeter Institute for Theoretical Physics in Ontario, Canada. The researchers, who include string theorists Leonard Susskind from Stanford University and Asoka Sen from the Harisch-Chandra Research Institute in India, will each spend a few months of the year at the institute as "distinguished research chairs". They will be joined by another 30 scientists to be announced at a later date.

  3. ASKAP Joins the Hunt for Mysterious Bursts

    Science.gov (United States)

    Kohler, Susanna

    2017-05-01

    A new telescope, the Australian Square Kilometre Array Pathfinder (ASKAP), has joined the search for energetic and elusive fast radio bursts. And in just a few days of looking, its already had success!Elusive TransientsThe Parkes radio telescope, which has detected all but five of the fast radio bursts published to date, has a very narrow field of view. [CSIRO]Fast radio bursts are mysterious millisecond-duration radio pulses that were first discovered around a decade ago. Since that time particularly in recent years weve made some progress toward the goal of localizing them. Were now fairly convinced that fast radio bursts come from outside of the galaxy, and yet theyre enormously bright orders of magnitude more luminous than any pulse seen from the Milky Way.Better identification of where these mysterious bursts come from would help us to determine what they are. But so far, weve discovered only around 30 such bursts, despite the fact that theyre estimated to occur at a rate of 3,000 events per day across the whole sky.Why are they so hard to find? Due to their short duration, effective detection would require instantaneous coverage of a very large fraction of the sky. The Parkes radio telescope which has detected all but five of the fast radio bursts published to date has a field of view spanning less than a square degree,significantly limiting our ability to rapidly survey for these transients.FRB 170107s band-averaged pulse (top) and dynamic spectrum (bottom). [Bannister et al. 2017]A New Array in TownA new player is now on the scene, however, and its already had huge success. ASKAP is a wide-field radio telescope made up of an array of 12-meter antennas. Using phased-array-feed technology, ASKAP is able to instantaneously observe an effective area of 160 square degrees an enormous field compared to Parkes 0.6 square degrees! This capability significantly increases our chances of being able to detect fast radio bursts.In a new study led by Keith Bannister

  4. Joining Dissimilar Materials Using Friction Stir Scribe Technique

    Energy Technology Data Exchange (ETDEWEB)

    Upadhyay, Piyush [Pacific Northwest National Laboratory, Richland 99352, WA e-mail: piyush.upadhyay@pnnl.gov; Hovanski, Yuri [Pacific Northwest National Laboratory, Richland 99352, WA; Jana, Saumyadeep [Pacific Northwest National Laboratory, Richland 99352, WA; Fifield, Leonard S. [Pacific Northwest National Laboratory, Richland 99352, WA

    2016-10-03

    Development of a robust and cost-effective method of joining dissimilar materials could provide a critical pathway to enable widespread use of multi-material designs and components in mainstream industrial applications. The use of multi-material components such as steel-aluminum and aluminum-polymer would allow design engineers to optimize material utilization based on service requirements and could often lead to weight and cost reductions. However, producing an effective joint between materials with vastly different thermal, microstructural, and deformation responses is highly problematic using conventional joining and/or fastening methods. This is especially challenging in cost sensitive, high volume markets that largely rely on low cost joining solutions. Friction stir scribe technology was developed to meet the demands of joining materials with drastically different properties and melting regimes. The process enables joining of light metals like magnesium and aluminum to high temperature materials like steel and titanium. Viable joints between polymer composites and metal can also be made using this method. This paper will present the state of the art, progress made, and challenges associated with this innovative derivative of friction stir welding in reference to joining dissimilar metals and polymer/metal combinations.

  5. JOINING DISSIMILAR MATERIALS USING FRICTION STIR SCRIBE TECHNIQUE

    Energy Technology Data Exchange (ETDEWEB)

    Upadhyay, Piyush; Hovanski, Yuri; Jana, Saumyadeep; Fifield, Leonard S.

    2016-09-01

    Development of robust and cost effective method of joining dissimilar materials can provide a critical pathway to enable widespread use of multi-material design and components in mainstream industrial applications. The use of multi-material components such as Steel-Aluminum, Aluminum-Polymer allows design engineers to optimize material utilization based on service requirements and often lead weight and cost reductions. However producing an effective joint between materials with vastly different thermal, microstructural and deformation response is highly problematic using conventional joining and /or fastening methods. This is especially challenging in cost sensitive high volume markets that largely rely on low–cost joining solutions. Friction Stir Scribe technology was developed to meet the demands of joining materials with drastically different properties and melting regimes. The process enables joining of light metals like Magnesium and Aluminum to high temperature materials like Steels and Titanium. Additionally viable joints between polymer composites and metal can also be made using this method. This paper will present state of the art, progress made and challenges associated with this innovative derivative of Friction Stir welding in reference to joining dissimilar metals and polymer/metal combinations.

  6. Cell Wall Assembly in Fucus Zygotes

    Science.gov (United States)

    Quatrano, Ralph S.; Stevens, Patricia T.

    1976-01-01

    Fertilization triggers the assembly of a cell wall around the egg cell of three brown algae, Fucus vesiculosus, F. distichus, and F. inflatus. New polysaccharide polymers are continually being added to the cell wall during the first 24 hours of synchronous embryo development. This wall assembly involves the extracellular deposition of fibrillar material by cytoplasmic vesicles fusing with the plasma membrane. One hour after fertilization a fragmented wall can be isolated free of cytoplasm and contains equal amounts of cellulose and alginic acid with no fucose-containing polymers (fucans) present. Birefringence of the wall caused by oriented cellulose microfibrils is not detected in all zygotes until 4 hours, at which time intact cell walls can be isolated that retain the shape of the zygote. These walls have a relatively low ratio of fucose to xylose and little sulfate when compared to walls from older embryos. When extracts of walls from 4-hour zygotes are subjected to cellulose acetate electrophoresis at pH 7, a single fucan (F1) can be detected. By 12 hours, purified cell walls are composed of fucans containing a relatively high ratio of fucose to xylose and high levels of sulfate, and contain a second fucan (F2) which is electrophoretically distinct from F1. F2 appears to be deposited in only a localized region of the wall, that which elongates to form the rhizoid cell. Throughout wall assembly, the polyuronide block co-polymer alginic acid did not significantly vary its mannuronic (M) to guluronic (G) acid ratio (0.33-0.55) or its block distribution (MG, 54%; GG, 30%; MM, 16%). From 6 to 24 hours of embryo development, the proportion of the major polysaccharide components found in purified walls is stable. Alginic acid is the major polymer and comprises about 60% of the total wall, while cellulose and the fucans each make-up about 20% of the remainder. During the extracellular assembly of this wall, the intracellular levels of the storage glucan laminaran

  7. Edge effects in finite elongated carbon nanotubes

    CERN Document Server

    Hod, O; Scuseria, G E; Hod, Oded; Peralta, Juan E.; Scuseria, Gustavo E.

    2006-01-01

    The importance of finite-size effects for the electronic structure of long zigzag and armchair carbon nanotubes is studied. We analyze the electronic structure of capped (6,6), (8,0), and (9,0) single walled carbon nanotubes as a function of their length up to 60 nm, using a divide and conquer density functional theory approach. For the metallic nanotubes studied, most of the physical features appearing in the density of states of an infinite carbon nanotube are recovered at a length of 40 nm. The (8,0) semi-conducting nanotube studied exhibits pronounced edge effects within the energy gap that scale as the inverse of the length of the nanotube. As a result, the energy gap reduces from the value of ~1 eV calculated for the periodic system to a value of ~0.25 eV calculated for a capped 62 nm long CNT. These edge effects are expected to become negligible only at tube lengths exceeding 6 micrometers. Our results indicate that careful tailoring of the nature of the system and its capping units should be applied w...

  8. Alternative end-joining mechanisms: a historical perspective

    Directory of Open Access Journals (Sweden)

    Anabelle eDecottignies

    2013-04-01

    Full Text Available In the presence of functional DNA repair pathways, DNA double-strand breaks (DSBs are mainly repaired by non-homologous end-joining (NHEJ or homologous recombination (HR, two conserved pathways that protect cells from aberrant chromosomal rearrangements. During the past two decades however, unusual and presumably distinct DNA end-joining repair activities have been unraveled in NHEJ-deficient cells and these are likely to operate in various chromosomal contexts and species. Most alternative DNA end-joining events reported so far appear to involve microhomologous sequences and are likely to rely on a subset of HR enzymes, namely those responsible for the single-strand annealing mechanism of HR, and on DNA Ligase III. Usually, microhomologies are not initially present at DSB ends and thus need to be unmasked through DNA end resection, a process that can lead to extensive nucleotide loss and is therefore highly mutagenic. In addition to microhomology-mediated end-joining events, recent studies in mammalian cells point towards the existence of a distinct and still ill defined alternative end-joining pathway that does not appear to rely on pre-existing microhomologies and may possibly involve DNA Ligase I.Whether dependent on microhomologies or not, alternative DNA end-joining mechanisms are likely to be highly mutagenic in vivo, being able to drive telomere fusion events and cancer-associated chromosomal translocations in mouse models. In the future, it will be important to better characterize the genetic requirements of these mutagenic alternative mechanisms of DNA end-joining.

  9. Spark plasma sintering and spark plasma joining of refractory ceramics

    Science.gov (United States)

    Hoefer, Jeffrey Andrew

    Consolidation of refractory ceramics such as boron carbide (B4C) and silicon carbide (SiC) by conventional sintering techniques (pressure-less sintering, hot pressing, hot isostatic pressing etc.) can prove challenging due to the high temperatures required for sintering. Typically sintering additives are used in order to decrease sintering temperature, but at the sacrifice of purity. Typically B4C requires sintering temperatures above 2000°C without the use of additives, while SiC is generally considered not sinterable without additives, and requires temperatures above 2000°C even with additives. Spark Plasma Sintering (SPS) has emerged as a technology that can reduce the sintering temperature considerably compared to more conventional techniques. The simultaneous application of pressure, heat, and current can reduce sintering temperatures without the use of sintering aids to 1600°C and 2000°C for boron carbide and silicon carbide respectively. One shortcoming of SPS, however, is the difficulty in producing complex shapes. Therefore, for carbide materials such as B4C and SiC, which are difficult to machine, the ability to produce complex shapes is worthy of investigation. One means of creating complex shapes is by joining simple shapes. Joining of monolithic ceramics, in particular SiC, has been achieved, however in all cases an intermediate joining material is used (Ti foil, Silica Powder etc.). Joining of materials using SPS, or as it is called, Spark Plasma Joining, can eliminate the need for an intermediate joining material, producing a high purity and high strength joint. This study investigates SPS of 3 different B4C Powders, as well as SPS joining of simple shape monolithic SiC. Sintering parameters such as temperature, pressure, time, and heating rate are all considered. Influence of sintering parameters on density, grain size, mechanical strength, and joint quality is investigated in detail.

  10. 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...

  11. 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.

  12. 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.

  13. 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

  14. 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.

  15. 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

  16. New Joining Technology for Optimized Metal/Composite Assemblies

    Directory of Open Access Journals (Sweden)

    Holger Seidlitz

    2014-01-01

    Full Text Available The development of a new joining technology, which is used to manufacture high strength hybrid constructions with thermoplastic composites (FRP and metals, is introduced. Similar to natural regulation effects at trees, fibers around the FRP joint become aligned along the lines of force and will not be destroyed by the joining process. This is achieved by the local utilization of the specific plastic flow properties of the FRT and metal component. Compared with usual joining methods—such as flow drill screws, blind and self-piercing rivets—noticeably higher tensile properties can be realized through the novel process management. The load-bearing capability increasing effect could be proved on hybrid joints with hot-dip galvanized steel HX420LAD and orthotropic glass—as well as carbon—fiber reinforced plastics. The results, which were determined in tensile-shear and cross-shear tests according to DIN EN ISO 14273 and DIN EN ISO 14272, are compared with holding loads of established joining techniques with similar joining point diameter and material combinations.

  17. Comparison of the outer and inner epidermis : inhibition of auxin-induced elongation of maize coleoptiles by glucan antibodies.

    Science.gov (United States)

    Hoson, T; Masuda, Y; Nevins, D J

    1992-04-01

    Polyclonal antibodies, raised against beta-d-glucans prepared from oat (Avena sativa L.) caryopses, cross-reacted specifically with (1-->3),(1-->4)-beta-d-glucans when challenged in a dot blot analysis of related polymers bound to a cellulose thin layer chromatography plate. The antibodies suppressed indoleacetic acid (IAA)-induced elongation of segments from maize (Zea mays L.) coleoptiles when the outer surface was abraded. However, IAA-induced elongation of nonabraded segments or segments with abrasion restricted to the interior of the cylinder was not influenced by the antibodies. Fab fragments prepared from the antibodies gave similar results. The capacity for IAA to overcome outward curvature of split coleoptile segments was partially reversed by treatment of the segments with the antibodies. Fluorescence microscopy revealed that antibody penetration was largely restricted to the epidermal cell wall region. These results support the view that the degradation of (1-->3),(1-->4)-beta-d-glucans in the outer epidermal cell wall serves an essential role in auxin-induced elongation of Poaceae coleoptiles.

  18. Determinant and inverse of join matrices on two sets

    CERN Document Server

    Mattila, Mika

    2011-01-01

    Let $(P,\\preceq)$ be a lattice and $f$ a complex-valued function on $P$. We define meet and join matrices on two arbitrary subsets $X$ and $Y$ of $P$ by $(X,Y)_f=(f(x_i\\wedge y_j))$ and $[X,Y]_f=(f(x_i\\vee x_j))$ respectively. Here we present expressions for the determinant and the inverse of $[X,Y]_f$. Our main goal is to cover the case when $f$ is not semimultiplicative since the formulas presented earlier for $[X,Y]_f$ cannot be applied in this situation. In cases when $f$ is semimultiplicative we obtain several new and known formulas for the determinant and inverse of $(X,Y)_f$ and the usual meet and join matrices $(S)_f$ and $[S]_f$. We also apply these formulas to LCM, MAX, GCD and MIN matrices, which are special cases of join and meet matrices.

  19. Permanent wire splicing by an explosive joining process

    Science.gov (United States)

    Bement, Laurence J.; Kushnick, Anne C.

    1991-11-01

    The invention is an apparatus and method for wire splicing using an explosive joining process. The apparatus consists of a prebent, U-shaped strap of metal that slides over prepositioned wires. A standoff means separates the wires from the strap before joining. An adhesive means holds two ribbon explosives in position centered over the U-shaped strap. A detonating means connects to the ribbon explosives. The process involves spreading strands of each wire to be joined into a flat plane. The process then requires alternating each strand in alignment to form a mesh-like arrangement with an overlapped area. The strap slides over the strands of the wires, and the standoff means is positioned between the two surfaces. The detonating means then initiates the ribbon explosives that drive the strap to accomplish a high velocity, angular collision between the mating surfaces. This collision creates surface melts and collision bonding results in electron sharing linkups.

  20. Advances in Solid State Joining of High Temperature Alloys

    Science.gov (United States)

    Ding, Jeff; Schneider, Judy

    2011-01-01

    Many of the metals used in the oil and gas industry are difficult to fusion weld including Titanium and its alloys. Solid state joining processes are being pursued as an alternative process to produce robust structures more amenable to high pressure applications. Various solid state joining processes include friction stir welding (FSW) and a patented modification termed thermal stir welding (TSW). The configuration of TSWing utilizes an induction coil to preheat the material minimizing the burden on the weld tool extending its life. This provides the ability to precisely select and control the temperature to avoid detrimental changes to the microstructure. The work presented in this presentation investigates the feasibility of joining various titanium alloys using the solid state welding processes of FSW and TSW. Process descriptions and attributes of each weld process will be presented. Weld process set ]up and welding techniques will be discussed leading to the challenges experienced. Mechanical property data will also be presented.

  1. Growth and cell wall changes in rice roots during spaceflight.

    Science.gov (United States)

    Hoson, Takayuki; Soga, Kouichi; Wakabayashi, Kazuyuki; Kamisaka, Seiichiro; Tanimoto, Eiichi

    2003-08-01

    We analyzed the changes in growth and cell wall properties of roots of rice (Oryza sativa L. cv. Koshihikari) grown for 68.5, 91.5, and 136 h during the Space Shuttle STS-95 mission. In space, most of rice roots elongated in a direction forming a constant mean angle of about 55 degrees with the perpendicular base line away from the caryopsis in the early phase of growth, but later the roots grew in various directions, including away from the agar medium. In space, elongation growth of roots was stimulated. On the other hand, some of elasticity moduli and viscosity coefficients were higher in roots grown in space than on the ground, suggesting that the cell wall of space-grown roots has a lower capacity to expand than the controls. The levels of both cellulose and the matrix polysaccharides per unit length of roots decreased greatly, whereas the ratio of the high molecular mass polysaccharides in the hemicellulose fraction increased in space-grown roots. The prominent thinning of the cell wall could overwhelm the disadvantageous changes in the cell wall mechanical properties, leading to the stimulation of elongation growth in rice roots in space. Thus, growth and the cell wall properties of rice roots were strongly modified under microgravity conditions during spaceflight.

  2. Implementation of Join-based Algorithm in Matlab%Join-based算法在Matlab中的实现

    Institute of Scientific and Technical Information of China (English)

    余翠兰

    2014-01-01

    Join-based is a famous algorithm for mining spatial co-location patterns. Spatial co-location patterns are traditionally defined as the subsets of features whose instances are frequently located together in geographic space. Firstly, the working principle of join-based algorithm is described, Then, a plant distributing dataset of “Three Parallel Rivers of Yunnan Protected Area”to mining symbiotic plant species as an example, this paper presents the detailed implementation process of the join-based algorithm in Matlab,and gave out the optimal operation results.%Join-based算法是一种著名的空间co-location模式挖掘算法,co-location模式代表的是一组空间特征的子集,它们的实例在空间中频繁的关联。首先描述了Join-based算法的工作原理,然后以挖掘三江并流珍希植物的共生物种问题为例利用matlab进行了程序实现,给出了运行的最优结果。

  3. ROMANIA'S MACROECONOMIC ACHIEVEMENTS FOR JOINING THE UNIQUE EUROPEAN CURENCY

    Directory of Open Access Journals (Sweden)

    SILVIA POPESCU

    2011-04-01

    Full Text Available The Romanian government has announced plans to join the eurozone by 2015. Currently, the leu is not yet part of ERM II but plans to join in 2010-2012. The economic advantages of the monetary union grow with expansion of the Euro zone. There is also a high level of skepticism; the main fear about the Euro is the inflation –that is considerable promoted by the Euro currency’s exchange rate in comparison with 2002; another restraint is due to member states inability to establish their own interest rates. The IMF arose the option of joining the Euro zone criteria relaxing. A one-sided Euro’s joining was suggested by International Monetary Fund on March-April 2009, in a confidential report mentioned by The Financial Times as the emergent states in Central and Eastern Europe to be able to pass to the unique currency, but not being represented in the Central European Bank Board. By its side, CEB considers that emergent states of the European Union must not pass to the unique currency unilaterally, because such a fact could under-mine the trust in Euro currency worldwide. This option would hardly deepen the macroeconomic controversies inside the Euro zone and would contradict the previous conditions already imposed. An acceptable solution could be the fastening of emergent countries joining the Exchange Rate Mechanism 2, after they are aware of risks arisen by such a step. The European Commission endorses in the Convergence Report on 2010 that Romania doesn’t meet any criteria needed by passing to the unique European currency, respectively: prices stability; budget position of the government; stability of exchange rate; interest convergence on long run and there are also law impediments. Our paper discusses arguments for a faster passing to the Euro currency versus arguments for a late joining the Euro currency in Romania.

  4. Retroaortic left renal vein joining the left common iliac vein

    Energy Technology Data Exchange (ETDEWEB)

    Brancatelli, G.; Galia, M.; Finazzo, M.; Sparacia, G.; Pardo, S.; Lagalla, R. [Dept. of Radiology ' ' P. Cignolini' ' , Univ. of Palermo (Italy)

    2000-11-01

    Retroaortic left renal vein joining the left common iliac vein is a rare congenital anomaly in the development of the inferior vena cava. To our knowledge, only one case has been reported in the literature; however, its imaging features have never been described. A 27-year-old male presented with a 1-year history of recurrent right flank pain, dysuria, hematuria, and fever (39 C). Computed tomography and MR venography showed a retroaortic left renal vein joining the left common iliac vein. We present the CT and MR venography findings and discuss their feasibility in showing this congenital anomaly. (orig.)

  5. AN ABSTRACT RELATIONAL MODEL AND NATURAL JOIN FUNCTORS

    OpenAIRE

    Kato, Akihiko

    1983-01-01

    A meta-model for database models called an abstract relational model which is obtained by a categorical abstraction of a relational model is proposed. This meta-model represents various database models, e.g. relational, network, hierarchical models as special cases. It is proved that a natural join is the right adjoint of a decomposition in the relational model. On the other hand, in our abstract relational model a natural join is defined as the right adjoint of a decomposition. A sufficient ...

  6. Superplasticity and joining of zirconia-based ceramics

    Energy Technology Data Exchange (ETDEWEB)

    Dominguez-Rodriguez, A.; Gutierrez-Mora, F.; Jimenez-Melendo, M.; Chaim, R.; Routbort, J. L.

    1999-12-10

    Steady-state creep and joining of alumina/zirconia composites containing alumina volume fractions of 20, 60, and 85% have been investigated between 1,250 and 1,350 C. Superplasticity of these compounds is controlled by grain-boundary sliding and the creep rate is a function of alumina volume fraction, not grain size. Using the principles of superplasticity, pieces of the composite have been joined by applying the stress required to achieve 5 to 10% strain to form a strong interface at temperatures as low as 1,200 C.

  7. Application of Bees Algorithm in Multi-Join Query Optimization

    Directory of Open Access Journals (Sweden)

    Mohammad Alamery

    2012-09-01

    Full Text Available Multi-join query optimization is an important technique for designing and implementing database management system. It is a crucial factor that affects the capability of database. This paper proposes a Bees algorithm that simulates the foraging behavior of honey bee swarm to solve Multi-join query optimization problem. The performance of the Bees algorithm and Ant Colony Optimization algorithm are compared with respect to computational time and the simulation result indicates that Bees algorithm is more effective and efficient.

  8. On the Complexity of Inner Product Similarity Join

    DEFF Research Database (Denmark)

    Ahle, Thomas Dybdahl; Pagh, Rasmus; Razenshteyn, Ilya

    2016-01-01

    been known on the lower bound side. In this paper we initiate a systematic study of inner product similarity join, showing new lower and upper bounds. Our main results are: Approximation hardness of IPS join in subquadratic time, assuming the strong exponential time hypothesis. New upper and lower...... bounds for (A)LSH-based algorithms. In particular, we show that asymmetry can be avoided by relaxing the LSH definition to only consider the collision probability of distinct elements. A new indexing method for IPS based on linear sketches, implying that our hardness results are not far from being tight...

  9. Ideal synchronizer for marked pairs in fork-join network

    CERN Document Server

    Vyshenski, S V; Dubenskaya, Yu Yu

    2008-01-01

    We introduce a new functional element (synchronizer for marked pairs) meant to join results of parallel processing in two-branch fork-join queueing network. Approximations for distribution of sojourn time at the synchronizer are derived along with a validity domain. Calculations are performed assuming that: arrivals to the network form a Poisson process, each branch operates like an M/M/N queueing system. It is shown that a mean quantity of jobs in the synchronizer is bounded below by the value, defined by parameters of the network (which contains the synchronizer) and does not depend upon performance and particular properties of the synchronizer.

  10. Environmentally friendly joining of tubes by their ends

    DEFF Research Database (Denmark)

    Silva, Carlos M.A.; Nielsen, Chris Valentin; Alves, Luis M.;

    2015-01-01

    This paper proposes an environmentally friendly joining process for connecting tubes by their ends that has the potential to replace current solutions based on fastened, crimped, welded, brazed or adhesive bonded joints. The process is based on a new type of tubular lap joint produced by local...... plastic instability and compression beading that has a substantial overlap with the counterfacing surfaces of the mating tubes to be joined. The presentation combines independent characterization of the materials, experimentation and numerical simulation of the process in order to identify the modes...

  11. Joining three car body steel sheets by clinching method

    Science.gov (United States)

    Kaščák, Ľuboš; Spišák, Emil; Majerníková, Jana

    2016-12-01

    The optimization of a car body in terms of cost can be achieved by using different materials in various positions of the car in order to utilize specific properties of each different material. Resistance spot welding is the most used method of joining in car body production, but it is not always easy or even possible to join some combination of materials by this method. Clinching is an alternative method to spot welding, as a combination of drawing and forming. The research is focused on the evaluation of clinched joints' properties using shearing test and metallographic observation of material structure.

  12. Acetylesterase-Mediated Deacetylation of Pectin Impairs Cell Elongation, Pollen Germination, and Plant Reproduction

    Energy Technology Data Exchange (ETDEWEB)

    Gou J. Y.; Liu C.; Miller, L. M.; Hou, G.; Yu, X.-H.; Chen, X.-Y.

    2012-01-01

    Pectin is a major component of the primary cell wall of higher plants. Some galacturonyl residues in the backbone of pectinaceous polysaccharides are often O-acetylated at the C-2 or C-3 position, and the resulting acetylesters change dynamically during the growth and development of plants. The processes involve both enzymatic acetylation and deacetylation. Through genomic sequence analysis, we identified a pectin acetylesterase (PAE1) from black cottonwood (Populus trichocarpa). Recombinant Pt PAE1 exhibited preferential activity in releasing the acetate moiety from sugar beet (Beta vulgaris) and potato (Solanum tuberosum) pectin in vitro. Overexpressing Pt PAE1 in tobacco (Nicotiana tabacum) decreased the level of acetyl esters of pectin but not of xylan. Deacetylation engendered differential changes in the composition and/or structure of cell wall polysaccharides that subsequently impaired the cellular elongation of floral styles and filaments, the germination of pollen grains, and the growth of pollen tubes. Consequently, plants overexpressing PAE1 exhibited severe male sterility. Furthermore, in contrast to the conventional view, PAE1-mediated deacetylation substantially lowered the digestibility of pectin. Our data suggest that pectin acetylesterase functions as an important structural regulator in planta by modulating the precise status of pectin acetylation to affect the remodeling and physiochemical properties of the cell wall's polysaccharides, thereby affecting cell extensibility.

  13. Falling walls

    CERN Multimedia

    It was 20 years ago this week that the Berlin wall was opened for the first time since its construction began in 1961. Although the signs of a thaw had been in the air for some time, few predicted the speed of the change that would ensue. As members of the scientific community, we can take a moment to reflect on the role our field played in bringing East and West together. CERN’s collaboration with the East, primarily through links with the Joint Institute for Nuclear Research, JINR, in Dubna, Russia, is well documented. Less well known, however, is the role CERN played in bringing the scientists of East and West Germany together. As the Iron curtain was going up, particle physicists on both sides were already creating the conditions that would allow it to be torn down. Cold war historian Thomas Stange tells the story in his 2002 CERN Courier article. It was my privilege to be in Berlin on Monday, the anniversary of the wall’s opening, to take part in a conference entitled &lsquo...

  14. 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.

  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. Polyamine sharing between tubulin dimers favours microtubule nucleation and elongation via facilitated diffusion.

    Directory of Open Access Journals (Sweden)

    Alain Mechulam

    2009-01-01

    Full Text Available We suggest for the first time that the action of multivalent cations on microtubule dynamics can result from facilitated diffusion of GTP-tubulin to the microtubule ends. Facilitated diffusion can promote microtubule assembly, because, upon encountering a growing nucleus or the microtubule wall, random GTP-tubulin sliding on their surfaces will increase the probability of association to the target sites (nucleation sites or MT ends. This is an original explanation for understanding the apparent discrepancy between the high rate of microtubule elongation and the low rate of tubulin association at the microtubule ends in the viscous cytoplasm. The mechanism of facilitated diffusion requires an attraction force between two tubulins, which can result from the sharing of multivalent counterions. Natural polyamines (putrescine, spermidine, and spermine are present in all living cells and are potent agents to trigger tubulin self-attraction. By using an analytical model, we analyze the implication of facilitated diffusion mediated by polyamines on nucleation and elongation of microtubules. In vitro experiments using pure tubulin indicate that the promotion of microtubule assembly by polyamines is typical of facilitated diffusion. The results presented here show that polyamines can be of particular importance for the regulation of the microtubule network in vivo and provide the basis for further investigations into the effects of facilitated diffusion on cytoskeleton dynamics.

  17. A Wind Tunnel Investigation of Joined Wing Scissor Morphing

    Science.gov (United States)

    2006-06-01

    wing stalls when the rear wing stalls [23]. While this improves efficiency it also decreases the wetted area while maintaining the same lifting...Analysis and Optimization on Joined-Wing Configurations. Dir. Dong-Hwan Lee and P. C. Chen. Slide Program. Zona Technology. 2. Bagwill, Tracy L., and

  18. All-round joining method with carbon fiber reinforced interface

    Science.gov (United States)

    Miwa, Noriyoshi; Tanaka, Kazunori; Kamiya, Yoshiko; Nishi, Yoshitake

    2008-08-01

    Carbon fiber reinforced polymer (CFRP) has been recently applied to not only wing, but also fan blades of turbo fan engines. To prevent impact force, leading edge of titanium was often mounted on the CFRP fan blades with adhesive force. In order to enhance the joining strength, a joining method with carbon fiber reinforced interface has been developed. By using nickel-coated carbon fibers, a joining sample with carbon fiber-reinforced interface between CFRP and CFRM has been successfully developed. The joining sample with nickel-coated carbon fiber interface exhibits the high tensile strength, which was about 10 times higher than that with conventional adhesion. On the other hand, Al-welding methods to steel, Cu and Ti with carbon fiber reinforced interface have been successfully developed to lighten the parts of machines of racing car and airplane. Carbon fibers in felt are covered with metals to protect the interfacial reaction. The first step of the welding method is that the Al coated felt is contacted and wrapped with molten aluminum solidified under gravity pressure, whereas the second step is that the felt with double layer of Ni and Al is contacted and wrapped with molten steel (Cu or Ti) solidified under gravity pressure. Tensile strength of Al-Fe (Cu or Ti) welded sample with carbon fiber reinforced interface is higher than those of Al-Fe (Cu or Ti) welded sample.

  19. Efficient and scalable graph similarity joins in MapReduce.

    Science.gov (United States)

    Chen, Yifan; Zhao, Xiang; Xiao, Chuan; Zhang, Weiming; Tang, Jiuyang

    2014-01-01

    Along with the emergence of massive graph-modeled data, it is of great importance to investigate graph similarity joins due to their wide applications for multiple purposes, including data cleaning, and near duplicate detection. This paper considers graph similarity joins with edit distance constraints, which return pairs of graphs such that their edit distances are no larger than a given threshold. Leveraging the MapReduce programming model, we propose MGSJoin, a scalable algorithm following the filtering-verification framework for efficient graph similarity joins. It relies on counting overlapping graph signatures for filtering out nonpromising candidates. With the potential issue of too many key-value pairs in the filtering phase, spectral Bloom filters are introduced to reduce the number of key-value pairs. Furthermore, we integrate the multiway join strategy to boost the verification, where a MapReduce-based method is proposed for GED calculation. The superior efficiency and scalability of the proposed algorithms are demonstrated by extensive experimental results.

  20. Advanced manufacturing technologies modern machining, advanced joining, sustainable manufacturing

    CERN Document Server

    2017-01-01

    This book provides details and collective information on working principle, process mechanism, salient features, and unique applications of various advanced manufacturing techniques and processes belong. The book is divided in three sessions covering modern machining methods, advanced repair and joining techniques and, finally, sustainable manufacturing. The latest trends and research aspects of those fields are highlighted.

  1. Joining of beryllium by braze welding technique: preliminary results

    Energy Technology Data Exchange (ETDEWEB)

    Banaim, P.; Abramov, E. [Ben-Gurion Univ. of the Negev, Beersheba (Israel); Zalkind, S.; Eden, S.

    1998-01-01

    Within the framework of some applications, there is a need to join beryllium parts to each other. Gas Tungsten Arc Braze Welds were made in beryllium using 0.3 mm commercially Aluminum (1100) shim preplaced at the joint. The welds exhibited a tendency to form microcracks in the Fusion Zone and Heat Affected Zone. All the microcracks were backfilled with Aluminum. (author)

  2. Loop-lifted staircase join: from XPath to XQuery

    NARCIS (Netherlands)

    Boncz, P.A.; Grust, T.; Keulen, M. van; Manegold, S.; Rittinger, J.; Teubner, J.

    2005-01-01

    Various techniques have been proposed for efficient evaluation of XPath expressions, where the XPath location steps are rooted in a single sequence of context nodes. Among these techniques, the staircase join allows to evaluate XPath location steps along arbitrary axes in at most one scan over the X

  3. Non-homologous end joining: emerging themes and unanswered questions

    OpenAIRE

    Radhakrishnan, Sarvan Kumar; Jette, Nicholas; Lees-Miller, Susan P.

    2014-01-01

    Non-homologous end joining (NHEJ) is the major pathway for the repair of ionizing radiation induced DNA double strand breaks in human cells. Here, we discuss current insights into the mechanism of NHEJ and the interplay between NHEJ and other pathways for repair of IR-induced DNA damage.

  4. Reactive Commercial Ni/Al Nanolayers for Joining Lightweight Alloys

    Science.gov (United States)

    Simões, Sónia; Viana, Filomena; Vieira, Manuel F.

    2014-05-01

    Reactive nanoscale multilayer foils for use in joining techniques have attracted a great deal of attention. A common feature of these nanolayers is the large amount of heat released during the reaction between the layers to form a new phase. In this study, films of alternated Ni and Al nanolayers (NanoFoil® made by the Indium Corporation) with period (bilayer thickness) close to 54 nm and with a thickness of 60 μm were used as local heat sources to bond lightweight alloys. The as-deposited Ni and Al alternated nanolayers evolve into NiAl nanometric grains when the multilayer, ignited by an electrical discharge, reacts. Joining of lightweight alloys was performed at room temperature under pressures of 10-80 MPa. The ability of the nanolayers to join these alloys by high temperature diffusion bonding was also investigated. The microstructural and chemical characterizations of the interfaces were performed on cross-sections of the joints by scanning electron microscopy and energy dispersive x-ray spectroscopy. Ni/Al nanolayers are an effective means of joining titanium alloys at room temperature. A sound interface, mainly composed by NiAl grains, is obtained in joints of TiAl/TiAl and TiAl/Inconel, produced with NanoFoil® by annealing at 700 ºC, during 60 min under a pressure of 10 MPa. The low shear strength revealed a weak adhesion of the nanofoil to the base materials.

  5. Two hospitals join forces to sponsor "A Woman's Comfort Day".

    Science.gov (United States)

    1995-01-01

    Two Baton Rouge, La., hospitals--usually strong competitors--decided to join forces and collaborate on a special event for the women of the community. "A Woman's Comfort Day," now in its third year, was the successful result. If they're feeling good about themselves, can the Super Bowl be far behind?

  6. Oracle joins CERN Openlab to advance grid computing

    CERN Multimedia

    2003-01-01

    "CERN and Oracle Corporation today announced that Oracle is joining the CERN openlab for DataGrid applications to collaborate in creating new grid computing technologies and exploring new computing and data management solutions far beyond today's Internet-based computing" (1 page).

  7. Joining the un global compact in spain : an institutional Aproach

    Directory of Open Access Journals (Sweden)

    Ainhoa garayar erro

    2012-07-01

    On the other hand, it can be asserted that the respondent organisations do not perceive major threats from the institutional environment that might undermine the legitimacy gained by joining the GC. Nonetheless, the Spanish organisations participating in the GC highlight the fact that the main institutional factor that might undermine the organization's legitimacy is weak governance and corruption.

  8. 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.

  9. 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

  10. Wall to Wall Optimal Transport

    CERN Document Server

    Hassanzadeh, Pedram; Doering, Charles R

    2013-01-01

    The calculus of variations is employed to find steady divergence-free velocity fields that maximize transport of a tracer between two parallel walls held at fixed concentration for one of two constraints on flow strength: a fixed value of the kinetic energy or a fixed value of the enstrophy. The optimizing flows consist of an array of (convection) cells of a particular aspect ratio Gamma. We solve the nonlinear Euler-Lagrange equations analytically for weak flows and numerically (and via matched asymptotic analysis in the fixed energy case) for strong flows. We report the results in terms of the Nusselt number Nu, a dimensionless measure of the tracer transport, as a function of the Peclet number Pe, a dimensionless measure of the energy or enstrophy of the flow. For both constraints the maximum transport Nu_{MAX}(Pe) is realized in cells of decreasing aspect ratio Gamma_{opt}(Pe) as Pe increases. For the fixed energy problem, Nu_{MAX} \\sim Pe and Gamma_{opt} \\sim Pe^{-1/2}, while for the fixed enstrophy scen...

  11. 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.

  12. An end-joining repair mechanism in Escherichia coli

    Science.gov (United States)

    Chayot, Romain; Montagne, Benjamin; Mazel, Didier; Ricchetti, Miria

    2010-01-01

    Bridging broken DNA ends via nonhomologous end-joining (NHEJ) contributes to the evolution and stability of eukaryote genomes. Although some bacteria possess a simplified NHEJ mechanism, the human commensal Escherichia coli is thought to rely exclusively on homology-directed mechanisms to repair DNA double-strand breaks (DSBs). We show here that laboratory and pathogenic E. coli strains possess a distinct end-joining activity that repairs DSBs and generates genome rearrangements. This mechanism, named alternative end-joining (A-EJ), does not rely on the key NHEJ proteins Ku and Ligase-D which are absent in E. coli. Differently from classical NHEJ, A-EJ is characterized by extensive end-resection largely due to RecBCD, by overwhelming usage of microhomology and extremely rare DNA synthesis. We also show that A-EJ is dependent on the essential Ligase-A and independent on Ligase-B. Importantly, mutagenic repair requires a functional Ligase-A. Although generally mutagenic, accurate A-EJ also occurs and is frequent in some pathogenic bacteria. Furthermore, we show the acquisition of an antibiotic-resistance gene via A-EJ, refuting the notion that bacteria gain exogenous sequences only by recombination-dependent mechanisms. This finding demonstrates that E. coli can integrate unrelated, nonhomologous exogenous sequences by end-joining and it provides an alternative strategy for horizontal gene transfer in the bacterial genome. Thus, A-EJ contributes to bacterial genome evolution and adaptation to environmental challenges. Interestingly, the key features of A-EJ also appear in A-NHEJ, an alternative end-joining mechanism implicated in chromosomal translocations associated with human malignancies, and we propose that this mutagenic repair might have originated in bacteria. PMID:20133858

  13. 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 ...

  14. A graph-based sliding window multi-join over data stream

    Institute of Scientific and Technical Information of China (English)

    ZHANG Liang; Byeong-Seob You; GE Jun-wei; LIU Zhao-hong; Hae-Young Bae

    2007-01-01

    Join operation is a critical problem when dealing with sliding window over data streams. There have been many optimization strategies for sliding window join in the literature, but a simple heuristic is always used for selecting the join sequence of many sliding windows, which is ineffectively. The graph-based approach is proposed to process the problem. The sliding window join model is introduced primarily. In this model vertex represent join operator and edge indicated the join relationship among sliding windows. Vertex weight and edge weight represent the cost of join and the reciprocity of join operators respectively. Then good query plan with minimal cost can be found in the model. Thus a complete join algorithm combining setting up model, finding optimal query plan and executing query plan is shown. Experiments show that the graph-based approach is feasible and can work better in above environment.

  15. 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.

  16. 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...

  17. 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...

  18. 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.

  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. 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.

  2. 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

  3. 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...

  4. 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.

  5. 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...

  6. 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

  7. 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.

  8. Design and Analysis of HIP joined W and Ferritic-Martensitic Steel Mockup for Fusion Reactor Divertor Development

    Energy Technology Data Exchange (ETDEWEB)

    Lee, D. W.; Shin, K. I.; Kim, S. K.; Jin, H. G.; Lee, E. H.; Yoon, J. S. [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of); Moon, S. Y.; Hong, B. G. [Chonbuk National Univ., Jeonju (Korea, Republic of)

    2013-10-15

    Korea has developed a Helium Cooled Ceramic Reflector (HCCR) based Test Blanket System (TBS) for an ITER, which consists of the First Wall (FW), Breeding Zone (BZ), Side Wall (SW), and BZ box. Among them, the FW is an important component which faces the plasma directly and, therefore, it is subjected to high heat and neutron loads. The FW of the TBM is considered to be composed of a beryllium (Be) armor as a plasma-facing material and Ferritic-Martensitic (FM) steel as a structure material, or a tungsten (W) armor and FM steel, or bare FM steel. Since Be/FMS and bare FMS were developed and proved by high heat flux (HHF) test, W armor and FM steel joining, fabricated mock-ups, and preparation of the high heat flux (HHF) test for integrity investigation are introduced in the present study. For the application to fusion reactor, joining methods with W to FMS has been developed. The W mock-up was fabricated with HIP considering Ti interlayer and PHHT condition. And the HHF test was prepared by performing the preliminary analysis to determine the test conditions. From the analysis heating and cooling conditions were determined for 0.5 and 1.0 MW/m2 heat fluxes. In the near future, the thermal life-time will be evaluated to determine the test period of the mockups by the mechanical analysis with ANSYS.

  9. Joining dissimilar materials using Friction Stir scribe technique

    Energy Technology Data Exchange (ETDEWEB)

    Upadhyay, Piyush; Hovanski, Yuri; Jana, Saumyadeep; Fifield, Leonard S.

    2016-10-03

    The ability to effectively join materials with vastly different melting points like Aluminum-Steel, Polymer composites - metals has been one of the road blocks in realizing multi-material components for light weighting efforts. Friction stir scribe (FSS) technique is a promising method that produces continuous overlap joint between materials with vastly different melting regimes and high temperature flow characteristics. FSS uses an offset cutting tool at the tip of the FSW pin to create an insitu mechanical interlock between material interfaces. With investments from Vehicle Technology office, US DOE and several automotive manufacturers and suppliers PNNL is developing the FSS process and has demonstrated viability of joining several material combinations. Details of welding trails, unique challenges and mitigation strategies in different material combinations will be discussed. Joint characterization including mechanical tests and joint performances will also be presented.

  10. Joining of Oxide Dispersion Strengthened Steels for Advanced Reactors

    Science.gov (United States)

    Baker, B. W.; Brewer, L. N.

    2014-12-01

    The design, manufacture, and experimental analysis of structural materials capable of operation in the high temperatures, corrosive environments, and radiation damage spectra of future reactor designs remain one of the key pacing items for advanced reactor designs. The most promising candidate structural materials are vanadium-based refractory alloys, silicon carbide composites and oxide dispersion strengthened steels. Of these, oxide dispersion strengthened steels are a likely near-term candidate to meet required demands. This paper reviews different variants of oxide dispersion strengthened steels and discusses their capability with regard to high-temperature strength, corrosion resistance, and radiation damage resistance. Additionally, joining of oxide dispersion strengthened steels, which has been cited as a limiting factor preventing their use, is addressed and reviewed. Specifically, friction stir welding of these steels is reviewed as a promising joining method for oxide dispersion strengthened steels.

  11. Joining and Integration of Silicon Carbide for Turbine Engine Applications

    Science.gov (United States)

    Halbig, Michael C.; Singh, Mrityunjay; Coddington, Bryan; Asthana, Rajiv

    2010-01-01

    The critical need for ceramic joining and integration technologies is becoming better appreciated as the maturity level increases for turbine engine components fabricated from ceramic and ceramic matrix composite materials. Ceramic components offer higher operating temperatures and reduced cooling requirements. This translates into higher efficiencies and lower emissions. For fabricating complex shapes, diffusion bonding of silicon carbide (SiC) to SiC is being developed. For the integration of ceramic parts to the surrounding metallic engine system, brazing of SiC to metals is being developed. Overcoming the chemical, thermal, and mechanical incompatibilities between dissimilar materials is very challenging. This presentation will discuss the types of ceramic components being developed by researchers and industry and the benefits of using ceramic components. Also, the development of strong, crack-free, stable bonds will be discussed. The challenges and progress in developing joining and integration approaches for a specific application, i.e. a SiC injector, will be presented.

  12. Joining of Silicon Carbide: Diffusion Bond Optimization and Characterization

    Science.gov (United States)

    Halbig, Michael C.; Singh, Mrityunjay

    2008-01-01

    Joining and integration methods are critically needed as enabling technologies for the full utilization of advanced ceramic components in aerospace and aeronautics applications. One such application is a lean direct injector for a turbine engine to achieve low NOx emissions. In the application, several SiC substrates with different hole patterns to form fuel and combustion air channels are bonded to form the injector. Diffusion bonding is a joining approach that offers uniform bonds with high temperature capability, chemical stability, and high strength. Diffusion bonding was investigated with the aid of titanium foils and coatings as the interlayer between SiC substrates to aid bonding. The influence of such variables as interlayer type, interlayer thickness, substrate finish, and processing time were investigated. Optical microscopy, scanning electron microscopy, and electron microprobe analysis were used to characterize the bonds and to identify the reaction formed phases.

  13. A triple helix-loop-helix/basic helix-loop-helix cascade controls cell elongation downstream of multiple hormonal and environmental signaling pathways in Arabidopsis.

    Science.gov (United States)

    Bai, Ming-Yi; Fan, Min; Oh, Eunkyoo; Wang, Zhi-Yong

    2012-12-01

    Environmental and endogenous signals, including light, temperature, brassinosteroid (BR), and gibberellin (GA), regulate cell elongation largely by influencing the expression of the paclobutrazol-resistant (PRE) family helix-loop-helix (HLH) factors, which promote cell elongation by interacting antagonistically with another HLH factor, IBH1. However, the molecular mechanism by which PREs and IBH1 regulate gene expression has remained unknown. Here, we show that IBH1 interacts with and inhibits a DNA binding basic helix-loop-helix (bHLH) protein, HBI1, in Arabidopsis thaliana. Overexpression of HBI1 increased hypocotyl and petiole elongation, whereas dominant inactivation of HBI1 and its homologs caused a dwarf phenotype, indicating that HBI1 is a positive regulator of cell elongation. In vitro and in vivo experiments showed that HBI1 directly bound to the promoters and activated two EXPANSIN genes encoding cell wall-loosening enzymes; HBI1's DNA binding and transcriptional activities were inhibited by IBH1, but the inhibitory effects of IBH1 were abolished by PRE1. The results indicate that PREs activate the DNA binding bHLH factor HBI1 by sequestering its inhibitor IBH1. Altering each of the three factors affected plant sensitivities to BR, GA, temperature, and light. Our study demonstrates that PREs, IBH1, and HBI1 form a chain of antagonistic switches that regulates cell elongation downstream of multiple external and endogenous signals.

  14. Nonlinear Aeroelastic Analysis of Joined-Wing Configurations

    Science.gov (United States)

    Cavallaro, Rauno

    Aeroelastic design of joined-wing configurations is yet a relatively unexplored topic which poses several difficulties. Due to the overconstrained nature of the system combined with structural geometric nonlinearities, the behavior of Joined Wings is often counterintuitive and presents challenges not seen in standard layouts. In particular, instability observed on detailed aircraft models but never thoroughly investigated, is here studied with the aid of a theoretical/computational framework. Snap-type of instabilities are shown for both pure structural and aeroelastic cases. The concept of snap-divergence is introduced to clearly identify the true aeroelastic instability, as opposed to the usual aeroelastic divergence evaluated through eigenvalue approach. Multi-stable regions and isola-type of bifurcations are possible characterizations of the nonlinear response of Joined Wings, and may lead to branch-jumping phenomena well below nominal critical load condition. Within this picture, sensitivity to (unavoidable) manufacturing defects could have potential catastrophic effects. The phenomena studied in this work suggest that the design process for Joined Wings needs to be revisited and should focus, when instability is concerned, on nonlinear post-critical analysis since linear methods may provide wrong trend indications and also hide potentially catastrophical situations. Dynamic aeroelastic analyses are also performed. Flutter occurrence is critically analyzed with frequency and time-domain capabilities. Sensitivity to different-fidelity aeroelastic modeling (fluid-structure interface algorithm, aerodynamic solvers) is assessed showing that, for some configurations, wake modeling (rigid versus free) has a strong impact on the results. Post-flutter regimes are also explored. Limit cycle oscillations are observed, followed, in some cases, by flip bifurcations (period doubling) and loss of periodicity of the solution. Aeroelastic analyses are then carried out on a

  15. Electron Beam Welding to Join Gamma Titanium Aluminide Articles

    Science.gov (United States)

    Kelly, Thomas Joseph (Inventor)

    2008-01-01

    A method is provided for welding two gamma titanium aluminide articles together. The method includes preheating the two articles to a welding temperature of from about 1700 F to about 2100 F, thereafter electron beam welding the two articles together at the welding temperature and in a welding vacuum to form a welded structure, and thereafter annealing the welded structure at an annealing temperature of from about 1800 F to about 2200 F, to form a joined structure.

  16. M2-Edge Colorings Of Cacti And Graph Joins

    Directory of Open Access Journals (Sweden)

    Czap Július

    2016-02-01

    Full Text Available An edge coloring φ of a graph G is called an M2-edge coloring if |φ(v| ≤ 2 for every vertex v of G, where φ(v is the set of colors of edges incident with v. Let 2(G denote the maximum number of colors used in an M2-edge coloring of G. In this paper we determine 2(G for trees, cacti, complete multipartite graphs and graph joins.

  17. Nonhomologous DNA End Joining in Cell-Free Extracts

    OpenAIRE

    Sheetal Sharma; Raghavan, Sathees C.

    2010-01-01

    Among various DNA damages, double-strand breaks (DSBs) are considered as most deleterious, as they may lead to chromosomal rearrangements and cancer when unrepaired. Nonhomologous DNA end joining (NHEJ) is one of the major DSB repair pathways in higher organisms. A large number of studies on NHEJ are based on in vitro systems using cell-free extracts. In this paper, we summarize the studies on NHEJ performed by various groups in different cell-free repair systems.

  18. Nonhomologous DNA End Joining in Cell-Free Extracts

    Directory of Open Access Journals (Sweden)

    Sheetal Sharma

    2010-01-01

    Full Text Available Among various DNA damages, double-strand breaks (DSBs are considered as most deleterious, as they may lead to chromosomal rearrangements and cancer when unrepaired. Nonhomologous DNA end joining (NHEJ is one of the major DSB repair pathways in higher organisms. A large number of studies on NHEJ are based on in vitro systems using cell-free extracts. In this paper, we summarize the studies on NHEJ performed by various groups in different cell-free repair systems.

  19. Retrieval of Spatial Join Pattern Instances from Sensor Networks

    DEFF Research Database (Denmark)

    Yiu, Man Lung; Mamoulis, Nikos; Bakiras, Spiridon

    2009-01-01

    We study the continuous evaluation of spatial join queries and extensions thereof, defined by interesting combinations of sensor readings (events) that co-occur in a spatial neighborhood. An example of such a pattern is "a high temperature reading in the vicinity of at least four high-pressure re...... for sensing, and network topology. Finally, we experimentally compare the effectiveness of the proposed solutions on an experimental platform that emulates real sensor networks....

  20. Joining Networks in the World of Open Science

    Directory of Open Access Journals (Sweden)

    Riitta Liisa Maijala

    2016-12-01

    Full Text Available Whereas the first digital revolution of science by digitisation changed the scientific practices of data collection, analysis and reporting of results, the second digital revolution, i.e. open science, will also challenge the current roles of researchers, research organisations, libraries and publishers. From the early days of development, research libraries have joined different networks and been among the most active stakeholders working towards open science. Cohesive networks are needed for coordinated actions and support, whereas bridging networks can provide new approaches and novel information. The Finnish Open Science and Research Initiative is presented in this paper as an example of joining networks, motivating individuals and organisations to deliver high-quality services, infrastructures and competence building to promote a transition towards open science. This paper also presents milestones such as the publication of the academic publishing costs of Finnish research organisations and the maturity level of open science operating cultures in HEIs. Based on the experience of the Finnish open science initiative, joining different networks at the national level on an open mode of operation can significantly speed up the transition towards the era of open science.

  1. Laser -Based Joining of Metallic and Non-metallic Materials

    Science.gov (United States)

    Padmanabham, G.; Shanmugarajan, B.

    Laser as a high intensity heat source can be effectively used for joining of materials by fusion welding and brazing in autogenous or in hybrid modes. In autogenous mode, welding is done in conduction , deep penetration , and keyhole mode. However, due to inherently high energy density available from a laser source, autogenous keyhole welding is the most popular laser welding mode. But, it has certain limitations like need for extremely good joint fit-up, formation of very hard welds in steel , keyhole instability, loss of alloying elements, etc. To overcome these limitations, innovative variants such as laser-arc hybrid welding , induction-assisted welding , dual beam welding , etc., have been developed. Using laser heat, brazing can be performed by melting a filler to fill the joints, without melting the base materials. Accomplishing laser-based joining as mentioned above requires appropriate choice of laser source, beam delivery system, processing head with appropriate optics and accessories. Basic principles of various laser-based joining processes, laser system technology, process parameters, metallurgical effects on different base materials, joint performance, and applications are explained in this chapter.

  2. Consider the workhorse: Nonhomologous end-joining in budding yeast.

    Science.gov (United States)

    Emerson, Charlene H; Bertuch, Alison A

    2016-10-01

    DNA double strand breaks (DSBs) are dangerous sources of genome instability and must be repaired by the cell. Nonhomologous end-joining (NHEJ) is an evolutionarily conserved pathway to repair DSBs by direct ligation of the ends, with no requirement for a homologous template. While NHEJ is the primary DSB repair pathway in mammalian cells, conservation of the core NHEJ factors throughout eukaryotes makes the pathway attractive for study in model organisms. The budding yeast, Saccharomyces cerevisiae, has been used extensively to develop a functional picture of NHEJ. In this review, we will discuss the current understanding of NHEJ in S. cerevisiae. Topics include canonical end-joining, alternative end-joining, and pathway regulation. Particular attention will be paid to the NHEJ mechanism involving core factors, including Yku70/80, Dnl4, Lif1, and Nej1, as well as the various factors implicated in the processing of the broken ends. The relevance of chromatin dynamics to NHEJ will also be discussed. This review illustrates the use of S. cerevisiae as a powerful system to understand the principles of NHEJ, as well as in pioneering the direction of the field.

  3. Consider the workhorse: Nonhomologous end joining in budding yeast

    Science.gov (United States)

    Emerson, Charlene H.; Bertuch, Alison A.

    2017-01-01

    DNA double strand breaks (DSBs) are dangerous sources of genome instability and must be repaired by the cell. Nonhomologous end joining (NHEJ) is an evolutionarily conserved pathway to repair DSBs by direct ligation of the ends, with no requirement for a homologous template. While NHEJ is the primary DSB repair pathway in mammalian cells, conservation of the core NHEJ factors throughout eukaryotes make the pathway attractive for study in model organisms. The budding yeast, Saccharomyces cerevisiae, has been used extensively to develop a functional picture of NHEJ. In this review, we will discuss the current understanding of NHEJ in S. cerevisiae. Topics include canonical end-joining, alternative end-joining, and pathway regulation. Particular attention will be paid to the NHEJ mechanism involving core factors, including Yku70/80, Dnl4, Lif1, and Nej1, as well as the various factors implicated in the processing of the broken ends. The relevance of chromatin dynamics to NHEJ will also be discussed. This review illustrates the use of S. cerevisiae as a powerful system to understand the principles of NHEJ, as well as in pioneering the direction of the field. PMID:27240172

  4. Finding Heavy Paths in Graphs: A Rank Join Approach

    CERN Document Server

    Khabbaz, Mohammad; Lakshmanan, Laks V S

    2011-01-01

    In applications such as playlist recommendation, flow analysis in information networks, and itinerary planning, we face the problem of finding the heaviest path(s) in a graph under a given length constraint. More precisely, in these applications, we are given a graph with non-negative edge weights, and a monotone function such as sum, which aggregates edge weights into a single value that defines a path weight. We are required to find the top-$k$ heaviest simple paths, i.e., the $k$ simple (i.e., cycle-free) paths with the greatest weight, whose length equals a given parameter $\\ell$. We call this the Heavy Path Problem (HPP). The problem is known to be NP-Hard, and in general not approximable. In this work, we develop a practical approach to solve the Heavy Path problem by establishing a strong connection with the well-known Rank Join paradigm. We present an adaptation of the Rank Join algorithm and tailor it to self-joins over the list of edges. We present novel thresholding strategies and develop exact and...

  5. Perfect state transfer, integral circulants and join of graphs

    CERN Document Server

    Angeles-Canul, Ricardo Javier; Opperman, Michael C; Paribello, Christopher C; Russell, Matthew C; Tamon, Christino

    2009-01-01

    We propose new families of graphs which exhibit quantum perfect state transfer. Our constructions are based on the join operator on graphs, its circulant generalizations, and the Cartesian product of graphs. We build upon the results of Ba\\v{s}i\\'{c} et al \\cite{bps09,bp09} and construct new integral circulants and regular graphs with perfect state transfer. More specifically, we show that the integral circulant $\\textsc{ICG}_{n}(\\{2,n/2^{b}\\} \\cup Q)$ has perfect state transfer, where $b \\in \\{1,2\\}$, $n$ is a multiple of 16 and $Q$ is a subset of the odd divisors of $n$. Using the standard join of graphs, we also show a family of double-cone graphs which are non-periodic but exhibit perfect state transfer. This class of graphs is constructed by simply taking the join of the empty two-vertex graph with a specific class of regular graphs. This answers a question posed by Godsil \\cite{godsil08}.

  6. Fabrication of ITER Semi-Prototype Blanket First Wall for the Final Qualification

    Energy Technology Data Exchange (ETDEWEB)

    Choi, Byoung Kwon; Jung, Yang Il; Park, Jeong Yong [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of); Kim, Suk Kwon; Lee, Don Won; Kim, Duck Hoi; Cho, Seung Yon [National Fusion Research Institute, Daejeon (Korea, Republic of)

    2012-05-15

    The ITER semi-prototype was designed to qualify the manufacturing technology for the ITER blanket first wall. According to the design of the semi-prototype, its fabrication is expected to face great difficulty. The blanket first wall consists of three different materials, i.e., beryllium (Be), CuCrZr, and stainless-steel (SS), which are joined into one part. For fabrication of these multi-layered structures, hot isostatic pressing (HIP), which is one of the diffusion bonding methods, has been considered as a promising technology to realize sufficient mechanical integrity of a joint under the anticipated high neutron and stress fields. HIP provides high dimensional accuracy, low residual stress during the joining process, and the joining of three-dimensionally complex structures in comparison with other joining methods. Even though the joining technology for the different materials had been developed in the first stage of the qualification, the joining is still a key issue for the fabrication of the semi-prototype

  7. 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.

  8. Thermoplastic Joining and Assembly of Bulk Metallic Glass Composites Through Capacitive Discharge

    Science.gov (United States)

    Hofmann, Douglas C. (Inventor); Roberts, Scott N. (Inventor); Kozachkov, Henry (Inventor); Demetriou, Marios D. (Inventor); Schramm, Joseph P. (Inventor); Johnson, William L. (Inventor)

    2015-01-01

    Systems and methods for joining BMG Composites are disclosed. Specifically, the joining of BMG Composites is implemented so as to preserve the amorphicity of their matrix phase and the microstructure of their particulate phase. Implementation of the joining method with respect to the construction of modular cellular structures that comprise BMG Composites is also discussed.

  9. The locations and amounts of endogenous ions and elements in the cap and elongating zone of horizontally oriented roots of Zea mays L.: an electron-probe EDS study

    Science.gov (United States)

    Moore, R.; Cameron, I. L.; Hunter, K. E.; Olmos, D.; Smith, N. K.

    1987-01-01

    We used quantitative electron-probe energy-dispersive x-ray microanalysis to localize endogenous Na, Cl, K, P, S, Mg and Ca in cryofixed and freeze-dried cryosections of the cap (i.e. the putative site of graviperception) and elongating zone (i.e. site of gravicurvature) of horizontally oriented roots of Zea mays. Ca, Na, Cl, K and Mg accumulate along the lower side of caps of horizontally oriented roots. The most dramatic asymmetries of these ions occur in the apoplast, especially the mucilage. We could not detect any significant differences in the concentrations of these ions in the central cytoplasm of columella cells along the upper and lower sides of caps of horizontally-oriented roots. However, the increased amounts of Na, Cl, K and Mg in the longitudinal walls of columella cells along the lower side of the cap suggest that these ions may move down through the columella tissue of horizontally-oriented roots. Ca also accumulates (largely in the mucilage) along the lower side of the elongating zone of horizontally-oriented roots, while Na, P, Cl and K tend to accumulate along the upper side of the elongating zone. Of these ions, only K increases in concentration in the cytoplasm and longitudinal walls of cortical cells in the upper vs lower sides of the elongating zone. These results indicate that (1) gravity-induced asymmetries of ions differ significantly in the cap and elongating zone of graviresponding roots, (2) Ca accumulates along the lower side of the cap and elongating zone of graviresponding roots, (3) increased growth of the upper side of the elongating zone of horizontally-oriented roots correlates positively with increased amounts of K in the cytoplasm and longitudinal walls of cortical cells, and (4) the apoplast (especially the mucilage) may be an important component of the pathway via which ions move in graviresponding rots of Zea mays. These results are discussed relative to mechanisms for graviperception and gravicurvature of roots.

  10. 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.

  11. 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.

  12. 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.

  13. 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.

  14. 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...

  15. 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...

  16. 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 ...

  17. 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.

  18. 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.

  19. Thin-walled aluminum alloy tube NC precision bending based on finite element simulation

    Institute of Scientific and Technical Information of China (English)

    GU Rui-jie; YANG He; ZHAN Mei; LI Heng

    2006-01-01

    Elongation and springback are the bottleneck problems of thin-walled aluminum alloy tube NC precision bending. So thin-walled aluminum alloy tube NC precision bending based on finite element simulation is put forward. The finite element model of thin-walled aluminum alloy tube NC bending is established based on the DYNAFORM platform. The process of thin-walled aluminum alloy tube NC precision bending is simulated with the model and the elongation and springback of tube bending can be is put forward and the computing equations of bending angle, bending radius, blanking length and initial bending section based on elongation and springback angle are derived. The bending angle, bending radius, blanking length and initial bending section of tube bending can be gained with these equations based on the elongation and springback angle from the simulation. The study can be used to control the quality of thin-walled aluminum alloy tube NC bending so that precision bending without redundance can be realized.

  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. 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

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

    Science.gov (United States)

    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.

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

    Directory of Open Access Journals (Sweden)

    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.

  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. Gibberellin-Stimulation of Rhizome Elongation and Differential GA-Responsive Proteomic Changes in Two Grass Species

    Science.gov (United States)

    Ma, Xiqing; Huang, Bingru

    2016-01-01

    Rapid and extensive rhizome development is a desirable trait for perennial grass growth and adaptation to environmental stresses. The objective of this study was to determine proteomic changes and associated metabolic pathways of gibberellin (GA) -regulation of rhizome elongation in two perennial grass species differing in rhizome development. Plants of a short-rhizome bunch-type tall fescue (TF; Festuca arundinacea; ‘BR’) and an extensive rhizomatous Kentucky bluegrass (KB; Poa pratensis; ‘Baron’) were treated with 10 μM GA3 in hydroponic culture in growth chambers. The average rhizome length in KB was significantly longer than that in TF regardless of GA3 treatment, and increased significantly with GA3 treatment, to a greater extent than that in TF. Comparative proteomic analysis using two-dimensional electrophoresis and mass spectrometry was performed to further investigate proteins and associated metabolic pathways imparting increased rhizome elongation by GA. A total of 37 and 38 differentially expressed proteins in response to GA3 treatment were identified in TF and KB plants, respectively, which were mainly involved in photosynthesis, energy and amino acid metabolism, protein synthesis, defense and cell development processes. Accelerated rhizome elongation in KB by GA could be mainly associated with the increased abundance of proteins involved in energy metabolism (glyceraldehyde-3-phosphate dehydrogenase, fructose-bisphosphate aldolase, and ATP synthase), amino acid metabolism (S-adenosylmethionine and adenosylhomocysteinase), protein synthesis (HSP90, elongation factor Tu and eukaryotic translation initiation factor 5A), cell-wall development (cell dividion cycle protein, alpha tubulin-2A and actin), and signal transduction (calreticulin). These proteins could be used as candidate proteins for further analysis of molecular mechanisms controlling rhizome growth. PMID:27446135

  6. 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.

  7. 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.

  8. 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.

  9. Comparative study of Trombe wall, water wall and trans wall

    Energy Technology Data Exchange (ETDEWEB)

    Sodha, M.S.; Bansal, N.K.; Singh, S.; Ram, S.; Annamalai, M.; Iyer, M.V.; Nirmala, K.A.; Venkatesh, P.; Prasad, C.R.; Subramani, C.

    1982-01-01

    The thermal performances of three systems viz. Trombe wall: (1) without; and (2) with vents (forced air circulation), water wall and Transwall have been studied analytically interms of heat flux entering the living space (Maintained at 20/sup 0/C) corresponding to the meteriological data on January 19, 1981 at New Delhi (India), a typical cold winter day. Subsequent parametric studies using the simulation indicated that the Transwall system is the more efficient system for the passive heating of buildings.

  10. 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.

  11. High energy electron beam joining of ceramic components

    Energy Technology Data Exchange (ETDEWEB)

    Turman, B.N.; Glass, S.J.; Halbleib, J.A. [and others

    1997-07-01

    High strength, hermetic braze joints between ceramic components have been produced using high energy electron beams. With a penetration depth into a typical ceramic of {approximately}1 cm for a 10 MeV electron beam, this method provides the capability for rapid, transient brazing operations where temperature control of critical components is essential. The method deposits energy directly into a buried joint, allowing otherwise inaccessible interfaces to be brazed. Because of transient heating, higher thermal conductivity, lower heat capacity, and lower melting temperature of braze metals relative to the ceramic materials, a pulsed high power beam can melt a braze metal without producing excessive ceramic temperatures. We have demonstrated the feasibility of this process related to ceramic coupons as well as ceramic and glass tubes. The transient thermal response was predicted, using as input the energy absorption predicted from the coupled electron-photon transport analysis. The joining experiments were conducted with an RF Linac accelerator at 10-13 MV. The repetition rate of the pulsed beam was varied between 8 and 120 Hz, the average beam current was varied between 8 and 120 microamps, and the power was varied up to 1.5 kW. These beam parameters gave a beam power density between 0.2 to 2 kW/cm{sup 2}. The duration of the joining runs varied from 5 to 600 sec. Joining experiments have provided high strength between alumina - alumina and alumina - cermet joints in cylindrical geometry. These joints provided good hermetic seals. A series of tests was conducted to determine the minimum beam power and exposure time for producing, a hermetic seal.

  12. Efficient K-Nearest Neighbor Join Algorithms for High Dimensional Sparse Data

    CERN Document Server

    Wang, Jijie; Huang, Ting; Wang, Jingjing; He, Zengyou

    2010-01-01

    The K-Nearest Neighbor (KNN) join is an expensive but important operation in many data mining algorithms. Several recent applications need to perform KNN join for high dimensional sparse data. Unfortunately, all existing KNN join algorithms are designed for low dimensional data. To fulfill this void, we investigate the KNN join problem for high dimensional sparse data. In this paper, we propose three KNN join algorithms: a brute force (BF) algorithm, an inverted index-based(IIB) algorithm and an improved inverted index-based(IIIB) algorithm. Extensive experiments on both synthetic and real-world datasets were conducted to demonstrate the effectiveness of our algorithms for high dimensional sparse data.

  13. Joining-splitting interaction of non-critical string

    CERN Document Server

    Hadasz, L; Hadasz, Leszek; Jaskolski, Zbigniew

    2003-01-01

    The joining-splitting interaction of non-critical bosonic string is analyzed in the light-cone formulation. The Mandelstam method of constructing tree string amplitudes is extended to the bosonic massive string models of the discrete series. Model independent properties of the dynamics of longitudinal excitations are derived from the requirement of Lorentz covariance of these amplitudes. The properties do not fit the CFT structure usually assumed in the Liouville sector. The results concern in particular the non-critical Nambu-Goto string, leaving open the question of consistent interaction in this model.

  14. Spatio-Temporal Joins on Symbolic Indoor Tracking Data

    DEFF Research Database (Denmark)

    Lu, Hua; Yang, Bin; Jensen, Christian S.

    2011-01-01

    To facilitate a variety of applications, positioning systems are deployed in indoor settings. For example, Bluetooth and RFID positioning are deployed in airports to support real-time monitoring of delays as well as off-line flow and space usage analyses. Such deployments generate large collectio......, an R-tree variant is proposed that facilitates the retrieval of join candidates, and pruning rules are supplied that eliminate candidate pairs that do not qualify. An empirical study on both synthetic and real data shows that the proposed techniques are efficient and scalable....

  15. A new active solder for joining electronic components

    Energy Technology Data Exchange (ETDEWEB)

    SMITH,RONALD W.; VIANCO,PAUL T.; HERNANDEZ,CYNTHIA L.; LUGSCHEIDER,E.; RASS,I.; HILLEN,F.

    2000-05-11

    Electronic components and micro-sensors utilize ceramic substrates, copper and aluminum interconnect and silicon. The joining of these combinations require pre-metallization such that solders with fluxes can wet such combinations of metals and ceramics. The paper will present a new solder alloy that can bond metals, ceramics and composites. The alloy directly wets and bonds in air without the use flux or premetallized layers. The paper will present typical processing steps and joint microstructures in copper, aluminum, aluminum oxide, aluminum nitride, and silicon joints.

  16. On the optimality of the neighbor-joining algorithm

    Directory of Open Access Journals (Sweden)

    Pachter Lior

    2008-04-01

    Full Text Available Abstract The popular neighbor-joining (NJ algorithm used in phylogenetics is a greedy algorithm for finding the balanced minimum evolution (BME tree associated to a dissimilarity map. From this point of view, NJ is "optimal" when the algorithm outputs the tree which minimizes the balanced minimum evolution criterion. We use the fact that the NJ tree topology and the BME tree topology are determined by polyhedral subdivisions of the spaces of dissimilarity maps R+(n2 MathType@MTEF@5@5@+=feaafiart1ev1aaatCvAUfKttLearuWrP9MDH5MBPbIqV92AaeXatLxBI9gBaebbnrfifHhDYfgasaacPC6xNi=xH8viVGI8Gi=hEeeu0xXdbba9frFj0xb9qqpG0dXdb9aspeI8k8fiI+fsY=rqGqVepae9pg0db9vqaiVgFr0xfr=xfr=xc9adbaqaaeGaciGaaiaabeqaaeqabiWaaaGcbaWenfgDOvwBHrxAJfwnHbqeg0uy0HwzTfgDPnwy1aaceaGae83gHi1aa0baaSqaaiabgUcaRaqaamaabmaabaqbaeqabiqaaaqaaiabd6gaUbqaaiabikdaYaaaaiaawIcacaGLPaaaaaaaaa@3BA1@ to study the optimality of the neighbor-joining algorithm. In particular, we investigate and compare the polyhedral subdivisions for n ≤ 8. This requires the measurement of volumes of spherical polytopes in high dimension, which we obtain using a combination of Monte Carlo methods and polyhedral algorithms. Our results include a demonstration that highly unrelated trees can be co-optimal in BME reconstruction, and that NJ regions are not convex. We obtain the l2 radius for neighbor-joining for n = 5 and we conjecture that the ability of the neighbor-joining algorithm to recover the BME tree depends on the diameter of the BME tree.

  17. Laser based metal and plastics joining for lightweight design

    Science.gov (United States)

    Kahmann, Max; Quentin, Ulf; Kirchhoff, Marc; Brockmann, Rüdiger; Löffler, Klaus

    2015-03-01

    One of the most important issues in automotive industry is lightweight design, especially since the CO2 emission of new cars has to be reduced by 2020. Plastic and fiber reinforced plastics (e.g. CFRP and GFRP) receive besides new manufacturing methods and the employment of high-strength steels or non-ferrous metals increasing interest. Especially the combination of different materials such as metals and plastics to single components exhausts the entire potential on weight reduction. This article presents an approach based on short laser pulses to join such dissimilar materials in industrial applications.

  18. FRESNO State joins exploration of new frontiers in physics

    CERN Multimedia

    2008-01-01

    California State University, Fresno has joined a prestigious collaboration of top physicists, giving the Department of Physics' students, faculty and staff access to the most up-to-date information possible on new frontiers in the science for the next 15 years or longer. The program is the ATLAS (an acronym for A Toroidal LHC ApparatuS) Experiment, which makes use of the Large Hadron Collider (LHC) under construction at the European Organization for Nuclear Research (CERN) near Geneva, Switzerland. (CERN also gave birth to the World Wide Web.)

  19. Ultrapulse welding: A new joining technique. [for automotive industry

    Science.gov (United States)

    Anderson, D. G.

    1972-01-01

    The ultrapulse process is a resistance welding process that utilizes unidirectional current of high magnitude for a very short time with a precisely controlled dynamic force pulse. Peak currents of up to 220,000 amperes for two to ten milliseconds are used with synchronized force pulses of up to nine thousand pounds. The welding current passing through the relatively high resistance of the interface between the parts that are being joined results in highly localized heating. Described is the UPW process as it applies to the automotive industry.

  20. TOMORROW: EPA Administrator to Attend Wall Street Journals ECO:nomics Conference

    Science.gov (United States)

    WASHINGTON - Tomorrow, EPA Administrator Gina McCarthy will join the Wall Street Journal's ECO:nomics conference for an interview with Editor in Chief Gerard Baker on the economic need for acting on climate change. Administrator McCarthy will speak

  1. TODAY: EPA Administrator to Attend Wall Street Journals ECO:nomics Conference

    Science.gov (United States)

    WASHINGTON - Today, EPA Administrator Gina McCarthy will join the Wall Street Journal's ECO:nomics conference for an interview with Editor in Chief Gerard Baker on the economic need for acting on climate change. Administrator McCarthy will speak abo

  2. Mirror, mirror on the wall

    CERN Multimedia

    2005-01-01

    RICH 2, one of the two Ring Imaging Cherenkov detectors of the LHCb experiment, is being prepared to join the other detector elements ready for the first proton-proton collisions at LHC. The mirrors of the RICH2 detector are meticulously assembled in a clean room.In a large dark room, men in white move around an immense structure some 7 metres high, 10 metres wide and nearly 2.5 metres deep. Apparently effortlessly, they are installing the two large high-precision spherical mirrors. These mirrors will focus Cherenkov light, created by the charged particles that will traverse this detector, onto the photon detectors. Each spherical mirror wall is made up of facets like a fly's eye. Twenty-eight individual thin glass mirrors will all point to the same point in space to within a few micro-radians. The development of these mirrors has been technically demanding : Ideally they should be massless, sturdy, precise and have high reflectivity. In practice, though not massless, they are made from a mere 6 mm thin gl...

  3. High Temperature Joining and Characterization of Joint Properties in Silicon Carbide-Based Composite Materials

    Science.gov (United States)

    Halbig, Michael C.; Singh, Mrityunjay

    2015-01-01

    Advanced silicon carbide-based ceramics and composites are being developed for a wide variety of high temperature extreme environment applications. Robust high temperature joining and integration technologies are enabling for the fabrication and manufacturing of large and complex shaped components. The development of a new joining approach called SET (Single-step Elevated Temperature) joining will be described along with the overview of previously developed joining approaches including high temperature brazing, ARCJoinT (Affordable, Robust Ceramic Joining Technology), diffusion bonding, and REABOND (Refractory Eutectic Assisted Bonding). Unlike other approaches, SET joining does not have any lower temperature phases and will therefore have a use temperature above 1315C. Optimization of the composition for full conversion to silicon carbide will be discussed. The goal is to find a composition with no remaining carbon or free silicon. Green tape interlayers were developed for joining. Microstructural analysis and preliminary mechanical tests of the joints will be presented.

  4. Cooperativity of peptidoglycan synthases active in bacterial cell elongation.

    NARCIS (Netherlands)

    Banzhaf, M.; van den Berg van Saparoea, B.; Terrak, M.; Fraipont, C.; Egan, A.; Philippe, J.; Zapun, A.; Breukink, E.; Nguyen-Distèche, M.; den Blaauwen, T.; Vollmer, W.

    2012-01-01

    Growth of the bacterial cell wall peptidoglycan sacculus requires the co-ordinated activities of peptidoglycan synthases, hydrolases and cell morphogenesis proteins, but the details of these interactions are largely unknown. We now show that the Escherichia coli peptidoglycan

  5. Domain Walls on Singularities

    CERN Document Server

    Halyo, Edi

    2009-01-01

    We describe domain walls that live on $A_2$ and $A_3$ singularities. The walls are BPS if the singularity is resolved and non--BPS if it is deformed and fibered. We show that these domain walls may interpolate between vacua that support monopoles and/or vortices.

  6. The Lamportian cell wall

    Energy Technology Data Exchange (ETDEWEB)

    Keiliszewski, M.; Lamport, D. (Michigan State Univ. Plant Research Lab., East Lansing (United States))

    1991-05-01

    The Lamportian Warp-Weft hypothesis suggests a cellulose-extensin interpenetrating network where extensin mechanically couples the load-bearing cellulose microfibrils in a wall matrix that is best described as a microcomposite. This model is based on data gathered from the extensin-rich walls of tomato and sycamore cell suspension culture, wherein extensin precursors are insolubilized into the wall by undefined crosslinks. The authors recent work with cell walls isolated from intact tissue as well as walls from suspension cultured cells of the graminaceous monocots maize and rice, the non-graminaceous monocot asparagus, the primitive herbaceous dicot sugar beet, and the gymnosperm Douglas Fir indicate that although extensins are ubiquitous to all plant species examined, they are not the major structural protein component of most walls examined. Amino acid analyses of intact and HF-treated walls shows a major component neither an HRGP, nor directly comparable to the glycine-rich wall proteins such as those associated with seed coat walls or the 67 mole% glycine-rich proteins cloned from petunia and soybean. Clearly, structural wall protein alternatives to extensin exist and any cell wall model must take that into account. If we assume that extracellular matrices are a priori network structures, then new Hypless' structural proteins in the maize cell wall raise questions about the sort of network these proteins create: the kinds of crosslinks involved; how they are formed; and the roles played by the small amounts of HRGPs.

  7. Halogenation of microcapsule walls

    Science.gov (United States)

    Davis, T. R.; Schaab, C. K.; Scott, J. C.

    1972-01-01

    Procedure for halogenation of confining walls of both gelatin and gelatin-phenolic resin capsules is similar to that used for microencapsulation. Ten percent halogen content renders capsule wall nonburning; any higher content enhances flame-retardant properties of selected internal phase material. Halogenation decreases permeability of wall material to encapsulated materials.

  8. Temperature Controlled Laser Joining of Aluminum to Galvanized Steel

    Science.gov (United States)

    Weller, Daniel; Simon, Jörg; Stritt, Peter; Weber, Rudolf; Graf, Thomas; Bezençon, Cyrille; Bassi, Corrado

    Reliable joining of 6000 series aluminum alloy to galvanized steel is a challenge for current manufacturing technologies. To control and limit the formation of brittle intermetallic phases, mixing of both metals in liquid state has to be avoided. It has been shown that laser weld-brazing is a possible process. Thereby the aluminum and zinc layer of the galvanized steel are molten and the steel remains solid during the process. In addition, to avoid zinc degassing, the aluminum melt bath temperature has to be below zinc boiling temperature of 907°C. To meet these requirements a temperature controlled laser process was developed, allowing to join the two materials without flux and filler material. The thickness of the intermetallic layer shows a dependency on the set temperature used to control the process. At optimum set temperature the thickness of intermetallic phases can be limited to about 5 μm. Tensile strengths of the joints of up to 75% of the aluminum base material were achieved.

  9. Electric Propulsion Concepts for an Inverted Joined Wing Airplane Demonstrator

    Directory of Open Access Journals (Sweden)

    Cezary Galinski

    2017-05-01

    Full Text Available One of the airplane design concepts that potentially allows for significantly increased efficiency, but has not yet been investigated thoroughly, is the inverted joined wing configuration, where the upper wing is positioned in front of the lower one. We performed wind tunnel and flight testing of a demonstrator of this concept, first by applying electrical propulsion to simplify wind tunnel testing, and then the same electrical-propulsion demonstrator performed several flights. As the chosen propulsion method proved to be too cumbersome for an intensive flight campaign and significant loss of battery performance was also observed, the electrical propulsion was then replaced by internal combustion propulsion in the second phase, involving longer-duration flight testing. Next we identified and analyzed two potentially beneficial modifications to the design tested: one involved shifting the center of gravity towards the aft, the other involved modifying the thrust vector position, both with the assumption that electric motors can be applied for propulsion. On this basis, the paper finishes with some conclusions concerning a new concept of electrical propulsion for an inverted joined wing design, combining two ideas: hybridization and distribution along the aft wing leading edge.

  10. Feasibility of ceramic joining with high energy electron beams

    Energy Technology Data Exchange (ETDEWEB)

    Turman, B.N.; Glass, S.J.; Halbleib, J.A.; Helmich, D.R.; Loehman, R.E. [Sandia National Labs., Albuquerque, NM (United States); Clifford, J.R. [Titan Corp., Albuquerque, NM (United States)

    1995-01-01

    Joining structural ceramics is possible using high melting point metals such as Mo and Pt that are heated with a high energy electron beam, with the potential for producing joints with high temperature capability. A 10 MeV electron beam can penetrate through 1 cm of ceramic, offering the possibility of buried interface joining. Because of transient heating and the lower heat capacity of the metal relative to the ceramic, a pulsed high power beam has the potential for melting the metal without decomposing or melting the adjacent ceramic. The authors have demonstrated the feasibility of the process with a series of 10 MeV, 1 kW electron beam experiments. Shear strengths up to 28 NTa have been measured for Si{sub 3}N{sub 4}-Mo-Si{sub 3}N{sub 4}. These modest strengths are due to beam non-uniformity and the limited area of bonding. The bonding mechanism appears to be a thin silicide reaction layer. Si{sub 3}N{sub 4}-Si{sub 3}N{sub 4} joints with no metal layer were also produced, apparently bonded an yttrium apatite grain boundary phase.

  11. 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.

  12. Phosphorylation of the Peptidoglycan Synthase PonA1 Governs the Rate of Polar Elongation in Mycobacteria.

    Science.gov (United States)

    Kieser, Karen J; Boutte, Cara C; Kester, Jemila C; Baer, Christina E; Barczak, Amy K; Meniche, Xavier; Chao, Michael C; Rego, E Hesper; Sassetti, Christopher M; Fortune, Sarah M; Rubin, Eric J

    2015-06-01

    Cell growth and division are required for the progression of bacterial infections. Most rod-shaped bacteria grow by inserting new cell wall along their mid-section. However, mycobacteria, including the human pathogen Mycobacterium tuberculosis, produce new cell wall material at their poles. How mycobacteria control this different mode of growth is incompletely understood. Here we find that PonA1, a penicillin binding protein (PBP) capable of transglycosylation and transpeptidation of cell wall peptidoglycan (PG), is a major governor of polar growth in mycobacteria. PonA1 is required for growth of Mycobacterium smegmatis and is critical for M. tuberculosis during infection. In both cases, PonA1's catalytic activities are both required for normal cell length, though loss of transglycosylase activity has a more pronounced effect than transpeptidation. Mutations that alter the amount or the activity of PonA1 result in abnormal formation of cell poles and changes in cell length. Moreover, altered PonA1 activity results in dramatic differences in antibiotic susceptibility, suggesting that a balance between the two enzymatic activities of PonA1 is critical for survival. We also find that phosphorylation of a cytoplasmic region of PonA1 is required for normal activity. Mutations in a critical phosphorylated residue affect transglycosylase activity and result in abnormal rates of cell elongation. Together, our data indicate that PonA1 is a central determinant of polar growth in mycobacteria, and its governance of cell elongation is required for robust cell fitness during both host-induced and antibiotic stress.

  13. Phosphorylation of the Peptidoglycan Synthase PonA1 Governs the Rate of Polar Elongation in Mycobacteria.

    Directory of Open Access Journals (Sweden)

    Karen J Kieser

    2015-06-01

    Full Text Available Cell growth and division are required for the progression of bacterial infections. Most rod-shaped bacteria grow by inserting new cell wall along their mid-section. However, mycobacteria, including the human pathogen Mycobacterium tuberculosis, produce new cell wall material at their poles. How mycobacteria control this different mode of growth is incompletely understood. Here we find that PonA1, a penicillin binding protein (PBP capable of transglycosylation and transpeptidation of cell wall peptidoglycan (PG, is a major governor of polar growth in mycobacteria. PonA1 is required for growth of Mycobacterium smegmatis and is critical for M. tuberculosis during infection. In both cases, PonA1's catalytic activities are both required for normal cell length, though loss of transglycosylase activity has a more pronounced effect than transpeptidation. Mutations that alter the amount or the activity of PonA1 result in abnormal formation of cell poles and changes in cell length. Moreover, altered PonA1 activity results in dramatic differences in antibiotic susceptibility, suggesting that a balance between the two enzymatic activities of PonA1 is critical for survival. We also find that phosphorylation of a cytoplasmic region of PonA1 is required for normal activity. Mutations in a critical phosphorylated residue affect transglycosylase activity and result in abnormal rates of cell elongation. Together, our data indicate that PonA1 is a central determinant of polar growth in mycobacteria, and its governance of cell elongation is required for robust cell fitness during both host-induced and antibiotic stress.

  14. 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.

  15. 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.

  16. 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...

  17. 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

  18. 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.

  19. 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...

  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...... 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...

  1. 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...

  2. 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....

  3. Thermal stability of catalytically grown multi-walled carbon nanotubes observed in transmission electron microscopy

    DEFF Research Database (Denmark)

    Wang, Cheng-Yu; Liu, Chuan-Pu; Boothroyd, Chris

    2009-01-01

    The thermal stability of multi-walled carbon nanotubes (MWCNTs) was assessed in situ by transmission electron microscopy. Upon heating, Ni catalysts in MWC-NTs containing bamboo structures shrank from the tail due to evaporation, leading to additional bamboo formation and tube elongation at 800...

  4. Abdominal wall fat pad biopsy

    Science.gov (United States)

    Amyloidosis - abdominal wall fat pad biopsy; Abdominal wall biopsy; Biopsy - abdominal wall fat pad ... method of taking an abdominal wall fat pad biopsy . The health care provider cleans the skin on ...

  5. 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.

  6. 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

  7. 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.

  8. 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.

  9. 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.

  10. 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.

  11. 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.

  12. 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.

  13. 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.

  14. 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

  15. 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.

  16. 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.

  17. 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.

  18. 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.

  19. Liquid Wall Chambers

    Energy Technology Data Exchange (ETDEWEB)

    Meier, W R

    2011-02-24

    The key feature of liquid wall chambers is the use of a renewable liquid layer to protect chamber structures from target emissions. Two primary options have been proposed and studied: wetted wall chambers and thick liquid wall (TLW) chambers. With wetted wall designs, a thin layer of liquid shields the structural first wall from short ranged target emissions (x-rays, ions and debris) but not neutrons. Various schemes have been proposed to establish and renew the liquid layer between shots including flow-guiding porous fabrics (e.g., Osiris, HIBALL), porous rigid structures (Prometheus) and thin film flows (KOYO). The thin liquid layer can be the tritium breeding material (e.g., flibe, PbLi, or Li) or another liquid metal such as Pb. TLWs use liquid jets injected by stationary or oscillating nozzles to form a neutronically thick layer (typically with an effective thickness of {approx}50 cm) of liquid between the target and first structural wall. In addition to absorbing short ranged emissions, the thick liquid layer degrades the neutron flux and energy reaching the first wall, typically by {approx}10 x x, so that steel walls can survive for the life of the plant ({approx}30-60 yrs). The thick liquid serves as the primary coolant and tritium breeding material (most recent designs use flibe, but the earliest concepts used Li). In essence, the TLW places the fusion blanket inside the first wall instead of behind the first wall.

  20. Adaptive scheduling for shared window joins over data streams

    Institute of Scientific and Technical Information of China (English)

    JIN Cheqing; ZHOU Aoying; Jeffrey Xu Yu; Joshua Zhexue Huang; CAO Feng

    2007-01-01

    Recently a few Continuous Query systems have been developed to cope with applications involving continuous data streams.At the same time,numerous algorithms are proposed for better performance.A recent work on this subject was to define scheduling strategies on shared window joins over data streams from multiple query expressions.In these strategies,a tuple with the highest priority is selected to process from multiple candidates.However,the performance of these static strategies is deeply influenced when data are bursting,because the priority is determined only by static information,such as the query windows,arriving order,etc.In this paper,we propose a novel adaptive strategy where the priority of a tuple is integrated with realtime information.A thorough experimental evaluation has demonstrated that this new strategy can outperform the existing strategies.

  1. Genome rearrangement by the double cut and join operation.

    Science.gov (United States)

    Friedberg, Richard; Darling, Aaron E; Yancopoulos, Sophia

    2008-01-01

    The Double Cut and Join is an operation acting locally at four chromosomal positions without regard to chromosomal context. This chapter discusses its application and the resulting menu of operations for genomes consisting of arbitrary numbers of circular chromosomes, as well as for a general mix of linear and circular chromosomes. In the general case the menu includes: inversion, translocation, transposition, formation and absorption of circular intermediates, conversion between linear and circular chromosomes, block interchange, fission, and fusion. This chapter discusses the well-known edge graph and its dual, the adjacency graph, recently introduced by Bergeron et al. Step-by-step procedures are given for constructing and manipulating these graphs. Simple algorithms are given in the adjacency graph for computing the minimal DCJ distance between two genomes and finding a minimal sorting; and use of an online tool (Mauve) to generate synteny blocks and apply DCJ is described.

  2. Analysis of Gene Targeting & Nonhomologous End-joining. Final Report

    Energy Technology Data Exchange (ETDEWEB)

    Haber, J. E.

    2002-11-30

    Overall, we identified a number of new proteins that participate in nonhomologous end-joining and also in telomere addition to the ends of broken chromosomes. We showed that NHEJ is severely reduced in cells expressing both yeast mating-type genes and then went on to identify the NEJ1 gene that was under this control. We showed the epistasis relations among a set of mutations that impair telomere addition and we showed that there are in fact two pathways to repair broken chromosomes in the absence of telomerase. We characterized the DNA damage checkpoint pathway in response to a single broken chromosome and characterized especially the adaptation of cells arrested by an unrepaired DSB. We demonstrated that the DNA damage response is nuclear-limited. We showed adaptation defects for Tid1and Srs2 proteins and showed that Srs2 was also recovery-defective, even when DNA was repaired.

  3. Joining of Silicon Carbide Through the Diffusion Bonding Approach

    Science.gov (United States)

    Halbig, Michael .; Singh, Mrityunjay

    2009-01-01

    In order for ceramics to be fully utilized as components for high-temperature and structural applications, joining and integration methods are needed. Such methods will allow for the fabrication the complex shapes and also allow for insertion of the ceramic component into a system that may have different adjacent materials. Monolithic silicon carbide (SiC) is a ceramic material of focus due to its high temperature strength and stability. Titanium foils were used as an interlayer to form diffusion bonds between chemical vapor deposited (CVD) SiC ceramics with the aid of hot pressing. The influence of such variables as interlayer thickness and processing time were investigated to see which conditions contributed to bonds that were well adhered and crack free. Optical microscopy, scanning electron microscopy, and electron microprobe analysis were used to characterize the bonds and to identify the reaction formed phases.

  4. The endless tale of non-homologous end-joining.

    Science.gov (United States)

    Weterings, Eric; Chen, David J

    2008-01-01

    DNA double-strand breaks (DSBs) are introduced in cells by ionizing radiation and reactive oxygen species. In addition, they are commonly generated during V(D)J recombination, an essential aspect of the developing immune system. Failure to effectively repair these DSBs can result in chromosome breakage, cell death, onset of cancer, and defects in the immune system of higher vertebrates. Fortunately, all mammalian cells possess two enzymatic pathways that mediate the repair of DSBs: homologous recombination and non-homologous end-joining (NHEJ). The NHEJ process utilizes enzymes that capture both ends of the broken DNA molecule, bring them together in a synaptic DNA-protein complex, and finally repair the DNA break. In this review, all the known enzymes that play a role in the NHEJ process are discussed and a working model for the co-operation of these enzymes during DSB repair is presented.

  5. The endless tale of non-homologous end-joining

    Institute of Scientific and Technical Information of China (English)

    Eric Weterings; David J Chen

    2008-01-01

    DNA double-strand breaks (DSBs) are introduced in cells by ionizing radiation and reactive oxygen species. In addi-tion, they are commonly generated during V(D)J recombination, an essential aspect of the developing immune system. Failure to effectively repair these DSBs can result in chromosome breakage, cell death, onset of cancer, and defects in the immune system of higher vertebrates. Fortunately, all mammalian cells possess two enzymatic pathways that mediate the repair of DSBs: homologous recombination and non-homologous end-joining (NHEJ). The NHEJ process utilizes enzymes that capture both ends of the broken DNA molecule, bring them together in a synaptic DNA-protein complex, and finally repair the DNA break. In this review, all the known enzymes that play a role in the NHEJ process are discussed and a working model for the co-operation of these enzymes during DSB repair is presented.

  6. Combustion based technique for synthesis and joining of refractory materials

    Science.gov (United States)

    White, Jeremiah David Edward

    Gasless combustion systems offer features that make them attractive tools for a variety of potential applications. Among them are rapid heating rates, high exothermicity, and high maximum temperatures. These characteristics were exploited to accomplish three separate concepts including the joining of refractory materials, synthesis of a pore-free composite, and the study of thermal explosion in mechanically activated powders. Honeywell Aerospace is a leading producer of carbon brakes for commercial aircraft. The manufacturing process involves chemical vapor infiltration (CVI) to form a carbon matrix around a carbon fiber preform. A major disadvantage of this approach is the time required to form a fully dense preform, which is on the order of 140 days. In addition, after the brakes are in service, they have to be discarded while there is a relatively thick amount of friction material still available. There is a profit motive for reusing these discs which are out of spec. One such example would be to perform a refurbishment by bonding a new thin C/C element onto a used "core" to produce a brake that meets performance specifications. Unfortunately, joining C/C composites is not a simple task, as carbon does not lend itself to welding, and other means (e.g. mechanical or adhesives) would not hold up to the harsh operational conditions. A novel apparatus was designed, built, and proven to join C/C using so-called reactive resistance welding (RRW). It is shown that a joint stronger than the original material can be achieved using moderate electrical current and mechanical force. Additionally, joining layers of similar thickness and microstructure were obtained with different reactive media, ranging from pellets of pressed powders (˜1-2 mm) to thin metal foils (˜25 micron). By modifying the schematic of the RRW apparatus, porous C/C was infiltrated with liquid silicon in order to form a new pore-free C/C-SiC composite. It is shown that using such a process, the silicon

  7. Pulsed Joining Of Body-In-White Components

    Energy Technology Data Exchange (ETDEWEB)

    Bonnen, John [Ford Motor Company, Dearborn, MI (United States)

    2014-09-30

    The objective of this project was to develop cost efficient high quality pulsed welding (PW) technology for joining 6xxx Aluminum and High Strength Steel (with tensile strength above 580MPa) components enabling broad usage of hydroformed parts and leading to substantial weight reduction of cars and trucks to reduce US demand on petroleum, lower carbon emissions and energy expenditures. In general, pulsed welding is a form of impact welding where two dissimilar metal pieces are joined by accelerating one to velocities exceeding 300m/s at which point the first piece strikes the second and forms a weld. In this work, two methods were used to accelerate the flyer material: Electro-Magnetic (EM) pulse and Electro-Hydraulic (EH) pulse launching. The advantage of pulsed welding techniques is that welds can be formed between two materials that cannot otherwise be welded: high strength aluminum and high strength steel. The technical objectives of the project included: 1) developing cost affordable production feasible tooling design for PW of 6xxx aluminum to High Strength steel with strengths above 580MPa; 2) demonstrating that fabricated joints can exceed the required service load strength initially at the coupon level and then at the component level; 3) developing fundamental understanding of the mechanisms of joint formation and conditions leading to formation of high quality PW joint; and 4) creating a numerical model predicting the tooling and electric discharge parameters necessary for the joint formation and that satisfy the targeted strength parameters. The project successfully developed: 1) EM and EH pulsed welds between high strength aluminum with tensile strengths exceeding 240MPa and steels exceeding 580MPa; 2) pulsed welds of extrusions with strengths exceeding project requirements; 3) EM and EH flyer launch models and 4) weld interface formation models. However, the grant holder, Ford Motor Company, could see no path to commercialization and the work was

  8. Rod-shaped silica particles derivatized with elongated silver nanoparticles immobilized within mesopores

    Science.gov (United States)

    Mnasri, Najib; Charnay, Clarence; de Ménorval, Louis-Charles; Elaloui, Elimame; Zajac, Jerzy

    2016-11-01

    Silver-derivatized silica particles possessing a non-spherical morphology and surface plasmon resonance properties have been achieved. Nanometer-sized silica rods with uniformly sized mesopore channels were prepared first making use of alkyltrimethyl ammonium surfactants as porogens and the 1:0.10 tetraethyl orthosilicate (TEOS) : 3-aminopropyltriethoxysilane (APTES) mixture as a silicon source. Silica rods were subsequently functionalized by introducing elongated silver nanoparticles within the intra-particle mesopores thanks to the AgNO3 reduction procedure based on the action of hemiaminal groups previously located on the mesopore walls. The textural and structural features of the samples were inferred from the combined characterization studies including SEM and TEM microscopy, nitrogen adsorption-desorption at 77 K, powder XRD in the small- and wide-angle region, as well as UV-visible spectroscopy. 129Xe NMR spectroscopy appeared particularly useful to obtain a correct information about the porous structure of rod-shaped silica particles and the silver incorporation within their intra-particle mesopores.

  9. Joining of Different Melting-Point Materials by Charging with Electromagnetic Energy

    Science.gov (United States)

    Haneji, Tatsushi; Sueyoshi, Toshiyasu; Makabe, Chobin; Miyagi, Kiyohiro

    An electrical resistance welding method was applied under atmospheric conditions by using a metal powder medium or media mixture which was sandwiched in the space between two metal bars which were compressed longitudinally, and simultaneously, current was conducted to generate Joule thermal heat. In the joining, aluminum was used as a base material and was joined to another aluminum, or one of four other metal bars with different melting points, by using resistance-welding apparatus. In the experiments, the specimens used as metal bars were aluminum, stainless steel, carbon steel, titanium and copper; and the powder media were aluminum, nickel and silicon. The reliability of the joined specimens was confirmed by their mechanical properties. In the present study, qualitative results are shown, but the best joining conditions are unknown, yet. However, it is concluded that the present method is useful for the joining of different metals, and it is of value to continue the investigation of joining by generated Joule thermal heat.

  10. Finite element thermal analysis for PMMA/st.st.304 laser direct joining

    Science.gov (United States)

    Hussein, Furat I.; Salloomi, Kareem N.; Akman, E.; Hajim, K. I.; Demir, A.

    2017-01-01

    This work is concerned with building a three-dimensional (3D) ab-initio models that is capable of predicting the thermal distribution of laser direct joining processes between Polymethylmethacrylate (PMMA) and stainless steel 304(st.st.304). ANSYS® simulation based on finite element analysis (FEA) was implemented for materials joining in two modes; laser transmission joining (LTJ) and conduction joining (CJ). ANSYS® simulator was used to explore the thermal environment of the joints during joining (heating time) and after joining (cooling time). For both modes, the investigation is carried out when the laser spot is at the middle of the joint width, at 15 mm from the commencement point (joint edge) at traveling time of 3.75 s. Process parameters involving peak power (Pp=3 kW), pulse duration (τ=5 ms), pulse repetition rate (PRR=20 Hz) and scanning speed (v=4 mm/s) are applied for both modes.

  11. Growth regulation mechanisms in higher plants under microgravity conditions - changes in cell wall metabolism.

    Science.gov (United States)

    Hoson, T; Kamisaka, S; Wakabayashi, K; Soga, K; Tabuchi, A; Tokumoto, H; Okamura, K; Nakamura, Y; Mori, R; Tanimoto, E; Takeba, G; Nishitani, K; Izumi, R; Ishioka, N; Kamigaichi, S; Aizawa, S; Yoshizaki, I; Shimazu, T; Fukui, K

    2000-06-01

    During Space Shuttle STS-95 mission, we cultivated seedlings of rice (Oryza sativa L. cv. Koshihikari and cv. Tan-ginbozu) and Arabidopsis (Arabidopsis thaliana L. cv. Columbia and cv. etr1-1) for 68.5, 91.5, and 136 hr on board, and then analyzed changes in the nature of their cell walls, growth, and morphogenesis under microgravity conditions. In space, elongation growth of both rice coleoptiles and Arabidopsis hypocotyls was stimulated. Also, the increase in the cell wall extensibility, especially that in the irreversible extensibility, was observed for such materials. The analyses of the amounts, the structure, and the physicochemical properties of the cell wall constituents indicated that the decreases in levels and molecular masses of cell wall polysaccharides were induced under microgravity conditions, which appeared to contribute to the increase in the wall extensibility. The activity of certain wall enzymes responsible for the metabolic turnover of the wall polysaccharides was increased in space. By the space flight, we also confirmed the occurrence of automorphogenesis of both seedlings under microgravity conditions; rice coleoptiles showed an adaxial bending, whereas Arabidopsis hypocotyls elongated in random directions. Furthermore, it was shown that spontaneous curvatures of rice coleoptiles in space were brought about uneven modifications of cell wall properties between the convex and the concave sides.

  12. Solar heating wall

    Energy Technology Data Exchange (ETDEWEB)

    Schoenfelder, J.L.

    1983-08-16

    A solar heating wall is disclosed including a water pipe circulation system having a plurality of separate tubes, each formed as a loop, connected between a water supply and a return. The separate tubes are arranged in a single vertical plane at the approximate center of the wall. The wall is formed within a frame which is packed with a material suited for use as a thERMAL RESERVOIR, SUCH AS concrete. The frame provides extra support by having a series of horizontally disposed cross supports on one surface of the wall and a series of vertically disposed cross supports on the opposite surface A pressure relief valve may be provided between the water supply to the separate tubes and the water supply to the building or structure containing the solar wall, so that the solar wall can be adapted for use with a city water system.

  13. An Efficient Group Key Management Using Code for Key Calculation for Simultaneous Join/Leave: CKCS

    OpenAIRE

    Melisa Hajyvahabzadeh; Elina Eidkhani; S. Anahita Mortazavi; Alireza Nemaney Pour

    2012-01-01

    This paper presents an efficient group key management protocol, CKCS (Code for Key Calculation in Simultaneous join/leave) for simultaneous join/leave in secure multicast. This protocol is based on logical key hierarchy. In this protocol, when new members join the group simultaneously, server sends only thegroup key for those new members. Then, current members and new members calculate the necessary keys by node codes and one-way hash function. A node code is a random number which is assigned...

  14. Comparative analysis of the practice of China and Russia joining the WTO

    OpenAIRE

    Anastasia Sergeyevna Loginova; Liliya Andreevna Travina

    2015-01-01

    Objective to examine the positive and negative experience of China39s joining the World Trade Organization WTO that joined it on terms similar to the Russian ones for the best understanding of the advantages and disadvantages of joining and building the appropriate policy. Methods the objective of the work has been achieved through the application of both general and specific scientific methods. In particular the analysis and synthesis allowed to study the social and economic context...

  15. 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.

  16. Cell Wall Proteome

    OpenAIRE

    Boudart, Georges; Minic, Zoran; Albenne, Cécile; Canut, Hervé; Jamet, Elisabeth; Pont-Lezica, Rafael F

    2007-01-01

    In this chapter, we will focus on the contribution of proteomics to the identification and determination of the structure and function of CWPs as well as discussing new perspectives in this area. The great variety of proteins found in the plant cell wall is described. Some families, such as glycoside hydrolases, proteases, lectins, and inhibitors of cell wall modifying enzymes, are discussed in detail. Examples of the use of proteomic techniques to elucidate the structure of various cell wall...

  17. Staggered domain wall fermions

    CERN Document Server

    Hoelbling, Christian

    2016-01-01

    We construct domain wall fermions with a staggered kernel and investigate their spectral and chiral properties numerically in the Schwinger model. In some relevant cases we see an improvement of chirality by more than an order of magnitude as compared to usual domain wall fermions. Moreover, we present first results for four-dimensional quantum chromodynamics, where we also observe significant reductions of chiral symmetry violations for staggered domain wall fermions.

  18. Green walls in Vancouver

    Energy Technology Data Exchange (ETDEWEB)

    Sharp, R. [Sharp and Diamond Landscape Architecture Inc., Vancouver, BC (Canada)

    2007-07-01

    With the renewed interest in design for microclimate control and energy conservation, many cities are implementing clean air initiatives and sustainable planning policies to mitigate the effects of urban climate and the urban heat island effect. Green roofs, sky courts and green walls must be thoughtfully designed to withstand severe conditions such as moisture stress, extremes in temperature, tropical storms and strong desiccating winds. This paper focused on the installation of green wall systems. There are 2 general types of green walls systems, namely facade greening and living walls. Green facades are trellis systems where climbing plants can grow vertically without attaching to the surface of the building. Living walls are part of a building envelope system where plants are actually planted and grown in a wall system. A modular G-SKY Green Wall Panel was installed at the Aquaquest Learning Centre at the Vancouver Aquarium in Stanley Park in September 2006. This green wall panel, which was originally developed in Japan, incorporates many innovative features in the building envelope. It provides an exterior wall covered with 8 species of plants native to the Coastal Temperate Rain Forest. The living wall is irrigated by rainwater collected from the roof, stored in an underground cistern and fed through a drip irrigation system. From a habitat perspective, the building imitates an escarpment. Installation, support systems, irrigation, replacement of modules and maintenance are included in the complete wall system. Living walls reduce the surface temperature of buildings by as much as 10 degrees C when covered with vegetation and a growing medium. The project team is anticipating LEED gold certification under the United States-Canada Green Building Council. It was concluded that this technology of vegetated building envelopes is applicable for acoustical control at airports, biofiltration of indoor air, greywater treatment, and urban agriculture and vertical

  19. Lossless Join Decomposition for Extended Possibility-Based Fuzzy Relational Databases

    National Research Council Canada - National Science Library

    Liu, Julie Yu-Chih

    2014-01-01

    .... However, the problem of achieving lossless join decomposition occurs when employing the fuzzy functional dependencies to database normalization in an extended possibility-based fuzzy data models...

  20. AMJoin: An Advanced Join Algorithm for Multiple Data Streams Using a Bit-Vector Hash Table

    Science.gov (United States)

    Kwon, Tae-Hyung; Kim, Hyeon-Gyu; Kim, Myoung-Ho; Son, Jin-Hyun

    A multiple stream join is one of the most important but high cost operations in ubiquitous streaming services. In this paper, we propose a newly improved and practical algorithm for joining multiple streams called AMJoin, which improves the multiple join performance by guaranteeing the detection of join failures in constant time. To achieve this goal, we first design a new data structure called BiHT (Bit-vector Hash Table) and present the overall behavior of AMJoin in detail. In addition, we show various experimental results and their analyses for clarifying its efficiency and practicability.

  1. Joining of Ion Transport Membranes Using a Novel Transient Liquid Phase Process

    Energy Technology Data Exchange (ETDEWEB)

    Darryl P. Butt

    2006-08-30

    The feasibility of a novel transient liquid phase (TLP) joining method has been demonstrated in joining La{sub 0.9}Ca{sub 0.1}FeO{sub 3} materials. Metal oxide powders were processed to form the TLP compositions which were used in the joining process. The method has been successful in producing joint interfaces that effectively disappear, as they are the same material and have the same properties as the joined parts. The feasibility of the method has been demonstrated for a single system, but many systems where the method can potentially be applied have been identified.

  2. Efficient string similarity join in multi-core and distributed systems.

    Science.gov (United States)

    Yan, Cairong; Zhao, Xue; Zhang, Qinglong; Huang, Yongfeng

    2017-01-01

    In big data area a significant challenge about string similarity join is to find all similar pairs more efficiently. In this paper, we propose a parallel processing framework for efficient string similarity join. First, the input is split into some disjoint small subsets according to the joint frequency distribution and the interval distribution of strings. Then the filter-verification strategy is adopted in the computation of string similarity for each subset so that the number of candidate pairs is reduced before an effective pruning strategy is used to improve the performance. Finally, the operation of string join is executed in parallel. Para-Join algorithm based on the multi-threading technique is proposed to implement the framework in a multi-core system while Pada-Join algorithm based on Spark platform is proposed to implement the framework in a cluster system. We prove that Para-Join and Pada-Join cannot only avoid reduplicate computation but also ensure the completeness of the result. Experimental results show that Para-Join can achieve high efficiency and significantly outperform than state-of-the-art approaches, meanwhile, Pada-Join can work on large datasets.

  3. Wall Conditioning and Impurity Measurements in the PEGASUS Experiment

    Science.gov (United States)

    Ono, M.; Fonck, R.; Toonen, R.; Thorson, T.; Tritz, K.; Winz, G.

    1999-11-01

    Wall conditioning and impurity effects on plasma evolution are increasingly relevant to the PEGASUS program. Surface conditioning consists of hydrogen glow discharge cleaning (GDC) to remove water and oxides, followed by He GDC to reduce the hydrogen inventory. Isotope exchange measurements indicate that periodic He GDC almost eliminates uncontrolled fueling from gas desorbed from the limiting surfaces. Additional wall conditioning will include Ti gettering and/or boronization. Impurity monitoring is provided by the recent installation of a SPRED multichannel VUV spectrometer (wavelength range = 10-110 nm; 1 msec time resolution), several interference filter (IF) monochromators, and a multichannel Ross-filter SXR diode assembly (for CV, CVI, OVII, and OVIII). The IF monitors indicate increased C radiation upon contact of the plasma with the upper and lower limiters for highly elongated plasmas. This radiation appears correlated with a subsequent rollover in the plasma current, and motivates an upgrade to the poloidal limiters to provide better plasma-wall interaction control.

  4. 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.

  5. 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.

  6. 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.

  7. 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.

  8. 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].

  9. 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.

  10. 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

  11. Neural network analyses of infrared spectra for classifying cell wall architectures.

    Science.gov (United States)

    McCann, Maureen C; Defernez, Marianne; Urbanowicz, Breeanna R; Tewari, Jagdish C; Langewisch, Tiffany; Olek, Anna; Wells, Brian; Wilson, Reginald H; Carpita, Nicholas C

    2007-03-01

    About 10% of plant genomes are devoted to cell wall biogenesis. Our goal is to establish methodologies that identify and classify cell wall phenotypes of mutants on a genome-wide scale. Toward this goal, we have used a model system, the elongating maize (Zea mays) coleoptile system, in which cell wall changes are well characterized, to develop a paradigm for classification of a comprehensive range of cell wall architectures altered during development, by environmental perturbation, or by mutation. Dynamic changes in cell walls of etiolated maize coleoptiles, sampled at one-half-d intervals of growth, were analyzed by chemical and enzymatic assays and Fourier transform infrared spectroscopy. The primary walls of grasses are composed of cellulose microfibrils, glucuronoarabinoxylans, and mixed-linkage (1 --> 3),(1 --> 4)-beta-D-glucans, together with smaller amounts of glucomannans, xyloglucans, pectins, and a network of polyphenolic substances. During coleoptile development, changes in cell wall composition included a transient appearance of the (1 --> 3),(1 --> 4)-beta-D-glucans, a gradual loss of arabinose from glucuronoarabinoxylans, and an increase in the relative proportion of cellulose. Infrared spectra reflected these dynamic changes in composition. Although infrared spectra of walls from embryonic, elongating, and senescent coleoptiles were broadly discriminated from each other by exploratory principal components analysis, neural network algorithms (both genetic and Kohonen) could correctly classify infrared spectra from cell walls harvested from individuals differing at one-half-d interval of growth. We tested the predictive capabilities of the model with a maize inbred line, Wisconsin 22, and found it to be accurate in classifying cell walls representing developmental stage. The ability of artificial neural networks to classify infrared spectra from cell walls provides a means to identify many possible classes of cell wall phenotypes. This classification

  12. 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.

  13. 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.

  14. 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

  15. Acoustic Emission Analysis of Damage during Compressive Deformation of Amorphous Zr-Based Foams with Aligned, Elongated Pores

    Science.gov (United States)

    Cox, Marie E.; Dunand, David C.

    2013-07-01

    Acoustic emission methods are used to investigate the evolution of internal microfractural damage during uniaxial compression of amorphous Zr-based foams with aligned, elongated pores. The foams are fabricated by means of densifying a blend of crystalline W powders and amorphous Zr-based powders with two oxygen contents (0.078 and 0.144 wt pct) by warm equal channel angular extrusion, followed by dissolution of the elongated W phase from the fully densified amorphous matrix. For the high-oxygen foams, prior powder boundaries in the amorphous struts promote damage that accumulates during compression, resulting in energy-absorbing properties comparable with the low-oxygen foams without stress-concentrating powder boundaries. The influence of pore orientation on the evolution of microfracture damage and the ability of the foams to accumulate damage without catastrophic failure is also investigated: pores oriented from 24 to 68 deg to the loading direction promote wall bending, resulting in foams with more diffuse damage and better energy-absorbing properties.

  16. 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

  17. Changes in growth and cell wall extensibility of maize silks following pollination

    Science.gov (United States)

    Sella Kapu, Nuwan U.; Cosgrove, Daniel J.

    2010-01-01

    In response to pollination maize silks undergo an accelerated process of senescence which involves an inhibition of elongation. To gain insight into the mechanism underlying this growth response, the relationships among silk elongation kinetics, cell wall biophysical properties, pollen tube growth, and expansin protein abundance were investigated. The inhibition of silk elongation became apparent beyond 12 h after pollination. Pollinated walls were less responsive in assays of extension induced by pollen β-expansin. Expansin protein abundance and endogenous expansin activity were not considerably reduced after pollination. Silk wall plastic compliance was significantly reduced 6 h post-pollination and beyond, suggesting that the wall undergoes structural modifications leading to its rigidification in response to pollination. The reduction in the plastic compliance occurred locally and progressively, shortly after pollen tubes traversed through a region of silk. Though numerous pollen grains germinated and initiated pollen tubes at the silk tip, the density of pollen tubes gradually declined along the length of the silk and only 1–2 reached the ovary even 24 h after pollination. These results support the notion that pollination-induced cell wall rigidification plays multiple roles in maize reproduction, including inhibition of silk growth and prevention of polyspermy. PMID:20656797

  18. Joining the UN global compact in Spain: an institutional approach

    Directory of Open Access Journals (Sweden)

    Ainhoa Garayar Erro

    2012-12-01

    Full Text Available The aim of this study is to analyse the incentives for Spanish organisations that have adopted a voluntary code of conduct such as the United Nations Global Compact – GC. In the light of the sociological approach of neoinstitutional theory, we sought to determine the main isomorphic processes that result from joining the GC and factors of the institutional field that might undermine the legitimacy of organisations participating in this voluntary initiative.On the one hand, the main results, while not conclusive, showed that Spanish participants in the GC have more than one reason for joining the initiative. The study’s findings suggest that both institutional processes of mimetic isomorphism and normative isomorphism explain participation in the GC, which emphasizes the improvement in employee satisfaction, an improvement in customer satisfaction and also the fact of being part of sustainable development efforts.On the other hand, it can be asserted that the respondent organisations do not perceive major threats from the institutional environment that might undermine the legitimacy gained by joining the GC. Nonetheless, the Spanish organisations participating in the GC highlight the fact that the main institutional factor that might undermine the organization’s legitimacy is weak governance and corruption.RESUMENEl presente trabajo examina la incidencia que la adopción del Pacto Mundial de Naciones Unidas –PM– ha tenido en organizaciones españolas. En concreto, el objetivo es aportar evidencia sobre las motivaciones que impulsan a un grupo de entidades a participar en esta iniciativa voluntaria. Basándonos en el enfoque sociológico de la teoría neoinstitucional, analizamos los principales procesos de isomorfismo resultantes del proceso de adhesión, así como aquellos factores del entorno institucional que pueden llegar a mermar su legitimidad.Los resultados, aunque no concluyentes, muestran que las organizaciones espa

  19. Stochastic behavior of nanoscale dielectric wall buckling

    Science.gov (United States)

    Friedman, Lawrence H.; Levin, Igor; Cook, Robert F.

    2016-01-01

    The random buckling patterns of nanoscale dielectric walls are analyzed using a nonlinear multi-scale stochastic method that combines experimental measurements with simulations. The dielectric walls, approximately 200 nm tall and 20 nm wide, consist of compliant, low dielectric constant (low-k) fins capped with stiff, compressively stressed TiN lines that provide the driving force for buckling. The deflections of the buckled lines exhibit sinusoidal pseudoperiodicity with amplitude fluctuation and phase decorrelation arising from stochastic variations in wall geometry, properties, and stress state at length scales shorter than the characteristic deflection wavelength of about 1000 nm. The buckling patterns are analyzed and modeled at two length scales: a longer scale (up to 5000 nm) that treats randomness as a longer-scale measurable quantity, and a shorter-scale (down to 20 nm) that treats buckling as a deterministic phenomenon. Statistical simulation is used to join the two length scales. Through this approach, the buckling model is validated and material properties and stress states are inferred. In particular, the stress state of TiN lines in three different systems is determined, along with the elastic moduli of low-k fins and the amplitudes of the small-scale random fluctuations in wall properties—all in the as-processed state. The important case of stochastic effects giving rise to buckling in a deterministically sub-critical buckling state is demonstrated. The nonlinear multiscale stochastic analysis provides guidance for design of low-k structures with acceptable buckling behavior and serves as a template for how randomness that is common to nanoscale phenomena might be measured and analyzed in other contexts. PMID:27330220

  20. International Divider Walls

    NARCIS (Netherlands)

    Kruis, A.; Sneller, A.C.W.(L.)

    2013-01-01

    The subject of this teaching case is the Enterprise Resource Planning (ERP) system implementation at International Divider Walls, the world market leader in design, production, and sales of divider walls. The implementation in one of the divisions of this multinational company had been successful, a

  1. Domain wall filters

    CERN Document Server

    Bär, O; Neuberger, H; Witzel, O; Baer, Oliver; Narayanan, Rajamani; Neuberger, Herbert; Witzel, Oliver

    2007-01-01

    We propose using the extra dimension separating the domain walls carrying lattice quarks of opposite handedness to gradually filter out the ultraviolet fluctuations of the gauge fields that are felt by the fermionic excitations living in the bulk. This generalization of the homogeneous domain wall construction has some theoretical features that seem nontrivial.

  2. Thin Wall Iron Castings

    Energy Technology Data Exchange (ETDEWEB)

    J.F. Cuttino; D.M. Stefanescu; T.S. Piwonka

    2001-10-31

    Results of an investigation made to develop methods of making iron castings having wall thicknesses as small as 2.5 mm in green sand molds are presented. It was found that thin wall ductile and compacted graphite iron castings can be made and have properties consistent with heavier castings. Green sand molding variables that affect casting dimensions were also identified.

  3. International Divider Walls

    NARCIS (Netherlands)

    Kruis, A.; Sneller, A.C.W.(L.)

    2013-01-01

    The subject of this teaching case is the Enterprise Resource Planning (ERP) system implementation at International Divider Walls, the world market leader in design, production, and sales of divider walls. The implementation in one of the divisions of this multinational company had been successful,

  4. Hard and soft walls

    CERN Document Server

    Milton, Kimball A

    2011-01-01

    In a continuing effort to understand divergences which occur when quantum fields are confined by bounding surfaces, we investigate local energy densities (and the local energy-momentum tensor) in the vicinity of a wall. In this paper, attention is largely confined to a scalar field. If the wall is an infinite Dirichlet plane, well known volume and surface divergences are found, which are regulated by a temporal point-splitting parameter. If the wall is represented by a linear potential in one coordinate $z$, the divergences are softened. The case of a general wall, described by a potential of the form $z^\\alpha$ for $z>0$ is considered. If $\\alpha>2$, there are no surface divergences, which in any case vanish if the conformal stress tensor is employed. Divergences within the wall are also considered.

  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. 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.

  7. Ultrastructure of the Epidermal Cell Wall and Cuticle of Tomato Fruit (Solanum lycopersicum L.) during Development.

    Science.gov (United States)

    Segado, Patricia; Domínguez, Eva; Heredia, Antonio

    2016-02-01

    The epidermis plays a pivotal role in plant development and interaction with the environment. However, it is still poorly understood, especially its outer epidermal wall: a singular wall covered by a cuticle. Changes in the cuticle and cell wall structures are important to fully understand their functions. In this work, an ultrastructure and immunocytochemical approach was taken to identify changes in the cuticle and the main components of the epidermal cell wall during tomato fruit development. A thin and uniform procuticle was already present before fruit set. During cell division, the inner side of the procuticle showed a globular structure with vesicle-like particles in the cell wall close to the cuticle. Transition between cell division and elongation was accompanied by a dramatic increase in cuticle thickness, which represented more than half of the outer epidermal wall, and the lamellate arrangement of the non-cutinized cell wall. Changes in this non-cutinized outer wall during development showed specific features not shared with other cell walls. The coordinated nature of the changes observed in the cuticle and the epidermal cell wall indicate a deep interaction between these two supramolecular structures. Hence, the cuticle should be interpreted within the context of the outer epidermal wall. © 2016 American Society of Plant Biologists. All Rights Reserved.

  8. Meet and Join Matrices in the Poset of Exponential Divisors

    Indian Academy of Sciences (India)

    Ismo Korkee; Pentti Haukkanen

    2009-06-01

    It is well-known that $(\\mathbb{Z}_+,|)=(\\mathbb{Z}_+,GCD,LCM)$ is a lattice, where $|$ is the usual divisibility relation and $GCD$ and $LCM$ stand for the greatest common divisor and the least common multiple of positive integers. The number $d=\\prod^r_{k=1}p^{d^{(k)}}_k$ is said to be an exponential divisor or an -divisor of $n=\\prod^r_{k=1}p^{n^{(k)}}_k(n >1)$, written as $d|_e n$, if $d^{(k)}|n^{(k)}$ for all prime divisors $p_k$ of . It is easy to see that $(\\mathbb{Z}_+\\backslash\\{1\\},|_e)$ is a poset under the exponential divisibility relation but not a lattice, since the greatest common exponential divisor $(GCED)$ and the least common exponential multiple $(LCEM)$ do not always exist. In this paper we embed this poset in a lattice. As an application we study the $GCED$ and $LCEM$ matrices, analogues of $GCD$ and $LCM$ matrices, which are both special cases of meet and join matrices on lattices.

  9. Joining characteristics of orthodontic wires with laser welding.

    Science.gov (United States)

    Iijima, Masahiro; Brantley, William A; Yuasa, Toshihiro; Muguruma, Takeshi; Kawashima, Isao; Mizoguchi, Itaru

    2008-01-01

    Laser welding 0.016 x 0.022 in. beta-Ti, Ni-Ti, and Co-Cr-Ni orthodontic wires was investigated by measuring joint tensile strength, measuring laser penetration depth, determining metallurgical phases using micro X-ray diffraction (micro-XRD), and examining microstructures with an scanning electron microscope (SEM). Welding was performed from 150 to 230 V. Mean tensile strength for Ni-Ti groups was significantly lower (p laser-welded specimens. Although mean tensile strength for beta-Ti and Co-Cr-Ni was significantly lower than for control specimens joined by silver soldering, it was sufficient for clinical use. The beta-Ti orthodontic wire showed deeper penetration depth from laser welding than the Ni-Ti and Co-Cr-Ni orthodontic wires. Micro-XRD patterns of laser-welded beta-Ti and Ni-Ti obtained 2 mm from the boundary were similar to as-received specimens, indicating that original microstructures were maintained. When output voltages of 190 V and higher were used, most peaks from joint areas disappeared or were much weaker, perhaps because of a directional solidification effect, evidenced by SEM observation of fine striations in welded beta-Ti. Laser welding beta-Ti and Co-Cr-Ni wires may be acceptable clinically, since joints had sufficient strength and metallurgical phases in the original wires were not greatly altered.

  10. Structure-Property Correlations in Microwave Joining of Inconel 718

    Science.gov (United States)

    Bansal, Amit; Sharma, Apurbba Kumar; Kumar, Pradeep; Das, Shantanu

    2015-09-01

    The butt joining of Inconel 718 plates at 981°C solution treated and aged (981STA) condition was carried out using the microwave hybrid heating technique with Inconel 718 powder as a filler material. The developed joints were free from any microfissures (cracks) and were metallurgically bonded through complete melting of the powder particles. The as-welded joints were subjected to postweld heat treatments, including direct-aged, 981STA and 1080STA. The microstructural features of the welded joints were investigated using a field emission-scanning electron microscope equipped with x-ray elemental analysis. Microhardness and room-temperature tensile properties of the welded joints were evaluated. The postweld heat-treated specimens exhibited higher microhardness and tensile strength than the as-welded specimens due to the formation of strengthening precipitates in the microstructure after postweld heat treatments. The microhardness of the fusion zone of the joint in 1080STA condition was higher than all welded conditions due to the complete dissolution of Laves phase after 1080STA treatment. However, the tensile strength of the welded specimen in 981STA condition was higher than all welded conditions. The tensile strength in 1080STA condition was lower than that in 981STA condition because of the grain coarsening that took place after 1080STA condition. The fractography of the fractured surfaces was carried out to determine the structure-property-fracture correlation.

  11. Joining Forces: The Chemical Biology-Medicinal Chemistry Continuum.

    Science.gov (United States)

    Plowright, Alleyn T; Ottmann, Christian; Arkin, Michelle; Auberson, Yves P; Timmerman, Henk; Waldmann, Herbert

    2017-09-21

    The scientific advances being made across all disciplines are creating ever-increasing opportunities to enhance our knowledge of biological systems and how they relate to human disease. One of the central driving forces in discovering new medicines is medicinal chemistry, where the design and synthesis of novel compounds has led to multiple drugs. Chemical biology, sitting at the interface of many disciplines, has now emerged as a major contributor to the understanding of biological systems and is becoming an integral part of drug discovery. Bringing chemistry and biology much closer and blurring the boundaries between disciplines is creating new opportunities to probe and understand biology; both disciplines play key roles and need to join forces and work together effectively to synergize their impact. The power of chemical biology will then reach its full potential and drive innovation, leading to the discovery of transformative medicines to treat patients. Advances in cancer biology and drug discovery highlight this potential. Copyright © 2017 Elsevier Ltd. All rights reserved.

  12. Asian international students' barriers to joining group counseling.

    Science.gov (United States)

    Lee, Ji-Yeon

    2014-10-01

    This cross-sectional study examined anticipated reactions to group participation among Asian international students (ISs). Structural equation modeling confirmed that Asian ISs' (n = 180) level of acculturation was associated with their attitude toward joining group counseling, which is partially mediated by their stigma toward help-seeking. The results of multiple regression analyses indicated that ISs who reported higher place dependence, stigma toward help-seeking, and fear of negative evaluation reported more fear about disclosing emotional parts of themselves to other group members in the presence of a group member from the same country of origin. The results showed that ISs' perceived difficulties in providing feedback to a group member in the presence of an IS from the same country of origin were predicted by low place identity, high place dependence, and more stigma. International students' willingness to disclose and provide feedback in a group counseling setting was compared in three different hypothetical situations based on other group members' demographics, and the results showed that ISs are more afraid of self-disclosure in the presence of an international student from the same country.

  13. Predictive modeling of reactive wetting and metal joining.

    Energy Technology Data Exchange (ETDEWEB)

    van Swol, Frank B.

    2013-09-01

    The performance, reproducibility and reliability of metal joints are complex functions of the detailed history of physical processes involved in their creation. Prediction and control of these processes constitutes an intrinsically challenging multi-physics problem involving heating and melting a metal alloy and reactive wetting. Understanding this process requires coupling strong molecularscale chemistry at the interface with microscopic (diffusion) and macroscopic mass transport (flow) inside the liquid followed by subsequent cooling and solidification of the new metal mixture. The final joint displays compositional heterogeneity and its resulting microstructure largely determines the success or failure of the entire component. At present there exists no computational tool at Sandia that can predict the formation and success of a braze joint, as current capabilities lack the ability to capture surface/interface reactions and their effect on interface properties. This situation precludes us from implementing a proactive strategy to deal with joining problems. Here, we describe what is needed to arrive at a predictive modeling and simulation capability for multicomponent metals with complicated phase diagrams for melting and solidification, incorporating dissolutive and composition-dependent wetting.

  14. Involvement of artemis in nonhomologous end-joining during immunoglobulin class switch recombination

    NARCIS (Netherlands)

    L. Du (Likun); M.D. van Burg; S.W. Popov (Sergey); A. Kotnis (Ashwin); J.J.M. van Dongen (Jacques); A.R. Gennery (Andrew); Q. Pan-Hammarström (Qiang)

    2008-01-01

    textabstractDNA double-strand breaks (DSBs) introduced in the switch (S) regions are intermediates during immunoglobulin class switch recombination (CSR). These breaks are subsequently recognized, processed, and joined, leading to recombination of the two S regions. Nonho- mologous end-joining (NHEJ

  15. Realizing joined-up government: Dynamic capabilities and stage models for transformation

    NARCIS (Netherlands)

    Klievink, B.; Janssen, M.

    2009-01-01

    Joining up remains a high priority on the e-government agenda and requires extensive transformation. Stage models are predictable patterns which exist in the growth of organizations and unfold as discrete time periods that result in discontinuity and can help e-government development towards joined-

  16. Combustion Synthesis of NiAl and In-situ Joining to Ni-based Superalloy

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    Combustion synthesis is used as a joining technology to join Ni-based superalloys with in-situ synthesized NiAl filler. The synthesis mechanism is discussed. The microstructure of the joints is investigated and the joint strength is also evaluated by tensile testing.

  17. Involvement of artemis in nonhomologous end-joining during immunoglobulin class switch recombination

    NARCIS (Netherlands)

    L. Du (Likun); M.D. van Burg; S.W. Popov (Sergey); A. Kotnis (Ashwin); J.J.M. van Dongen (Jacques); A.R. Gennery (Andrew); Q. Pan-Hammarström (Qiang)

    2008-01-01

    textabstractDNA double-strand breaks (DSBs) introduced in the switch (S) regions are intermediates during immunoglobulin class switch recombination (CSR). These breaks are subsequently recognized, processed, and joined, leading to recombination of the two S regions. Nonho- mologous end-joining

  18. The Joining-Up Process: Issues in Effective Human Resource Development

    Science.gov (United States)

    Frohman, Alan L.; Kotter, John P.

    1975-01-01

    Four specific problems associated with ineffective and expensive joining-up which are examined in the article are: (1) mismatched expectations; (2) stifling creativity and challenge; (3) lack of managerial awareness and sensitivity to joining-up issues; and (4) using inappropriate or incomplete screening criteria. Solutions are suggested; a table…

  19. 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.

  20. 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...

  1. 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.

  2. 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...

  3. Microstructure and properties of ceramics and composites joined by plastic deformation.

    Energy Technology Data Exchange (ETDEWEB)

    Goretta, K. C.; Singh, D.; Chen, N.; Gutierrez-Mora, F.; Lorenzo-Martin, M. de la, Cinta; Dominguez-Rodriguez, A.; Routbort, J. L.; Energy Systems; Univ. of Seville

    2008-12-01

    A review is presented of the design of suitable materials systems for joining by high-temperature plastic deformation, details of the joining techniques, microstructures and properties of the resulting composite bodies, and prospects and limitation for this type of joining technology. Joining parameters and resulting forms are discussed for Al{sub 2}O{sub 3}/mullite particulate composites, Y{sub 2}O{sub 3}-stabilized ZrO{sub 2} particulate/Al{sub 2}O{sub 3} particulate and whisker-reinforced composites, hydroxyapatite bioceramics, La{sub 0.85}Sr{sub 0.15}MnO{sub 3} electronic ceramics, MgF{sub 2} optical ceramics, and Ni{sub 3}Al intermetallics. Results are contrasted with those obtained by other methods of joining brittle, high-temperature materials, with special focus on durability and mechanical properties.

  4. Microstructure and properties of ceramics and composites joined by plastic deformation

    Energy Technology Data Exchange (ETDEWEB)

    Goretta, K.C. [Argonne National Laboratory, Argonne, IL 60439-4838 (United States)], E-mail: ken.goretta@aoard.af.mil; Singh, D.; Chen Nan [Argonne National Laboratory, Argonne, IL 60439-4838 (United States); Gutierrez-Mora, F.; Cinta Lorenzo-Martin, M. de la [Argonne National Laboratory, Argonne, IL 60439-4838 (United States); University of Seville, Seville 41080 (Spain); Dominguez-Rodriguez, A. [University of Seville, Seville 41080 (Spain); Routbort, J.L. [Argonne National Laboratory, Argonne, IL 60439-4838 (United States)

    2008-12-20

    A review is presented of the design of suitable materials systems for joining by high-temperature plastic deformation, details of the joining techniques, microstructures and properties of the resulting composite bodies, and prospects and limitation for this type of joining technology. Joining parameters and resulting forms are discussed for Al{sub 2}O{sub 3}/mullite particulate composites, Y{sub 2}O{sub 3}-stabilized ZrO{sub 2} particulate/Al{sub 2}O{sub 3} particulate and whisker-reinforced composites, hydroxyapatite bioceramics, La{sub 0.85}Sr{sub 0.15}MnO{sub 3} electronic ceramics, MgF{sub 2} optical ceramics, and Ni{sub 3}Al intermetallics. Results are contrasted with those obtained by other methods of joining brittle, high-temperature materials, with special focus on durability and mechanical properties.

  5. Robust Joining and Assembly of Ceramic Matrix Composites for High Temperature Applications

    Science.gov (United States)

    Singh, Mrityunjay

    2003-01-01

    Advanced ceramic matrix composites (CMCs) are under active consideration for use in a wide variety of high temperature applications within the aerospace, energy, and nuclear industries. The engineering designs of CMC components require fabrication and manufacturing of large and complex shaped parts of various thicknesses. In many instances, it is more economical to build up complex shapes by joining simple geometrical shapes. Thus, joining and attachment have been recognized as enabling technologies for successful utilization of ceramic components in various demanding applications. In this presentation, various challenges and opportunities in design, fabrication, and testing of high temperature joints in ceramic matrix composites will be presented. A wide variety of ceramic composites, in different shapes and sizes, have been joined using an affordable, robust ceramic joining technology (ARCJoinT). Microstructure and mechanical properties of joints in melt infiltrated and CVI Sic matrix composites will be reported. Various joint design philosophies and design issues in joining of composites will be discussed.

  6. Can joined-up data lead to joined-up thinking? The Western Australian developmental pathways project.

    Science.gov (United States)

    Stanley, Fiona; Glauert, Rebecca; McKenzie, Anne; O'Donnell, Melissa

    2011-01-01

    Modern societies are challenged by "wicked problems" - by definition, those that are difficult to define, multi-causal and hard to treat. Problems such as low birth weight, obesity, mental ill health, teenage pregnancy, educational difficulties and juvenile crime fit this category. Given the complex nature of these problems, they require the best data in order to measure them, guide policy frameworks and evaluate whether the steps taken to address them are actually making a difference. What such problems really require are joined-up approaches to enable effective solutions. In this paper, we describe a unique initiative to encourage a more preventive, whole-of-government approach to these problems - the Developmental Pathways Project, which has enabled the linkage of a large number of de-identified administrative databases in order to explore the pathways into and out of the negative outcomes affecting our children and youth. This project has not only enabled the linkage of agency data, but also of agency personnel, in order to improve and promote cross-agency research, policy and preventive solutions. Through the use of these linkages we are attempting to shift the paradigm to encourage agencies to appreciate that these "wicked problems" demand a preventive approach, as well as the provision of effective services for those already affected.

  7. "I Climbed the Great Wall"

    Institute of Scientific and Technical Information of China (English)

    1996-01-01

    I finally climbed the Great Wall, A dream of my childhood; my heart is filled with pleasure at the indescribable beauty of the Wall. China’s ancient civilization is best documented by the grandeur of the Wall.

  8. Gossypium herbaceum Negative Mutant for Fiber Elongation a Useful Isoline for Identification of Genes for Fiber Elongation

    Institute of Scientific and Technical Information of China (English)

    KATAGERI I S; KHADI B M; ANANDKUMA P; REDDY V S; VAMADEVAAH H M

    2008-01-01

    @@ Actin cytoskeleton plays an important role in cell morphogenesis in plants as demonstrated by pharmacological,biochemical,and genetic studies.The actin cytoskeleton may be involved in the transportation of organelles and vesicles carrying membranes and cell wall components to the site of cell growth as in root hairs,trichome cells,and pollen tubes.Actins in plants are encoded by a multigene family that comprises dozens or even hundreds of actin genes.

  9. 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.

  10. 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.

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

    Science.gov (United States)

    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.

  12. 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.

  13. 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.

  14. 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 ...

  15. 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.

  16. 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.

  17. 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.

  18. 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.

  19. 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.

  20. 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.

  1. 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.

  2. 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.

  3. Join the NASA Science Mission Directorate Scientist Speaker's Bureau!

    Science.gov (United States)

    Dalton, H.; Shupla, C. B.; Buxner, S.; Shipp, S. S.

    2013-12-01

    Join the new NASA SMD Scientist Speaker's Bureau, an online portal to connect scientists interested in getting involved in E/PO projects (e.g., giving public talks, classroom visits, and virtual connections) with audiences! The Scientist Speaker's Bureau helps educators and institutions connect with NASA scientists who are interested in giving presentations, based upon the topic, logistics, and audience. Aside from name, organization, location, bio, and (optional) photo and website, the information that scientists enter into this database will not be made public; instead, it will be used to help match scientists with the requests being placed. One of the most common ways for scientists to interact with students, adults, and general public audiences is to give presentations about or related to their science. However, most educators do not have a simple way to connect with those planetary scientists, Earth scientists, heliophysicists, and astronomers who are interested and available to speak with their audiences. This system is designed to help meet the need for connecting potential audiences to interested scientists. The information input into the database (availability to travel, willingness to present online or in person, interest in presenting to different age groups and sizes of audience, topics, and more) will be used to help match scientists (you!) with the requests being placed by educators. All NASA-funded Earth and space scientists engaged in active research are invited to fill out the short registration form, including those who are involved in missions, institutes, grants, and those who are using NASA science data in their research, and more. There is particular need for young scientists, such as graduate students and post-doctoral researchers, and women and people of diverse backgrounds. Submit your information at http://www.lpi.usra.edu/education/speaker.

  4. 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.

  5. Advanced walling systems

    CSIR Research Space (South Africa)

    De Villiers, A

    2010-01-01

    Full Text Available The question addressed by this chapter is: How should advanced walling systems be planned, designed, built, refurbished, and end their useful lives, to classify as smart, sustainable, green or eco-building environments?...

  6. Smectic Layer Deformation of Ferroelectric Liquid Crystal Sandwiched between Polymer Walls with Anchoring Effects

    Science.gov (United States)

    Murashige, Takeshi; Fujikake, Hideo; Ikehata, Seiichiro; Sato, Fumio

    2002-05-01

    We studied smectic layer structures of ferroelectric liquid crystal (FLC) formed in elongated small spaces surrounded by molecule-aligned polymer walls and rubbed polyimide alignment layers. The polymer walls, which are parallel to the rubbing direction and vertical to the alignment layers, were formed by the photopolymerization of an aligned monomer under patterned ultraviolet light irradiation. From the observation of the alignment textures of the FLC between the polymer walls with a polarizing microscope, it was found that the smectic layer structure was changed from vertical plane bending alignment (chevron structure), as observed with a conventional surface-stabilized FLC, into horizontal plane bending, as the interval between the polymer walls decreased. It is thought that the smectic layer structure is governed by the competition between the anchoring effects of the alignment polyimide layers and the molecule-aligned polymer walls.

  7. False ring formation in eastern hemlock branches: impacts of hemlock woolly adelgid and elongate hemlock scale.

    Science.gov (United States)

    Gonda-King, Liahna; Radville, Laura; Preisser, Evan L

    2012-06-01

    Herbivores can alter plant physiology through the induction of abnormal wood formation. Feeding by some insects induces the formation of false rings, a band of thick-walled latewood cells within the earlywood portion of the tree ring that reduces water transport. Hemlock woolly adelgid (Adelges tsugae Annand) and elongate hemlock scale (Fiorinia externa Ferris) are invasive insects that both feed on eastern hemlock [Tsuga canadensis (L.) Carrière]. Adelges tsugae has a greater effect on tree health than F. externa, but the mechanism underlying their differential effect is unknown. We explored the effects of these herbivores by assessing growth ring formation in branches of trees that had been experimentally infested for 4 yr with A. tsugae, F. externa, or neither insect. We measured false ring density, ring growth, and earlywood: latewood ratios in the two most recently deposited growth rings. Branches from A. tsugae-infested trees had 30% more false rings than branches from F. externa-infested trees and 50% more than branches from uninfested trees. In contrast, branches from F. externa-infested trees and control trees did not differ in false ring formation. Radial growth and earlywood: latewood ratios did not differ among treatments. Our results show that two invasive herbivores with piercing-sucking mouth parts have differing effects on false ring formation in eastern hemlock. These false rings may be the product of a systemic plant hypersensitive response to feeding by A. tsugae on hemlock stems. If false rings are responsible for or symptomatic of hemlock water stress, this may provide a potential explanation for the relatively large effect of A. tsugae infestations on tree health.

  8. Conducting Wall Hall Thrusters

    Science.gov (United States)

    Goebel, Dan M.; Hofer, Richard R.; Mikellides, Ioannis G.; Katz, Ira; Polk, James E.; Dotson, Brandon

    2013-01-01

    A unique configuration of the magnetic field near the wall of Hall thrusters, called Magnetic Shielding, has recently demonstrated the ability to significantly reduce the erosion of the boron nitride (BN) walls and extend the life of Hall thrusters by orders of magnitude. The ability of magnetic shielding to minimize interactions between the plasma and the discharge chamber walls has for the first time enabled the replacement of insulating walls with conducting materials without loss in thruster performance. The boron nitride rings in the 6 kW H6 Hall thruster were replaced with graphite that self-biased to near the anode potential. The thruster efficiency remained over 60% (within two percent of the baseline BN configuration) with a small decrease in thrust and increase in Isp typical of magnetically shielded Hall thrusters. The graphite wall temperatures decreased significantly compared to both shielded and unshielded BN configurations, leading to the potential for higher power operation. Eliminating ceramic walls makes it simpler and less expensive to fabricate a thruster to survive launch loads, and the graphite discharge chamber radiates more efficiently which increases the power capability of the thruster compared to conventional Hall thruster designs.

  9. Limitation of Cell Elongation in Barley (Hordeum vulgare L.) Leaves Through Mechanical and Tissue-Hydraulic Properties.

    Science.gov (United States)

    Touati, Mostefa; Knipfer, Thorsten; Visnovitz, Tamás; Kameli, Abdelkrim; Fricke, Wieland

    2015-07-01

    The aim of the present study was to assess the mechanical and hydraulic limitation of growth in leaf epidermal cells of barley (Hordeum vulgare L.) in response to agents which affect cellular water (mercuric chloride, HgCl(2)) and potassium (cesium chloride, CsCl; tetraethylammonium, TEA) transport, pump activity of plasma membrane H(+)-ATPase and wall acidification (fusicoccin, FC). Cell turgor (P) was measured with the cell pressure probe, and cell osmotic pressure (π) was analyzed through picoliter osmometry of single-cell extracts. A wall extensibility coefficient (M) and tissue hydraulic conductance coefficient (L) were derived using the Lockhart equation. There was a significant positive linear relationship between relative elemental growth rate and P, which fit all treatments, with an overall apparent yield threshold of 0.368 MPa. Differences in growth between treatments could be explained through differences in P. A comparison of L and M showed that growth in all except the FC treatment was co-limited through hydraulic and mechanical properties, though to various extents. This was accompanied by significant (0.17-0.24 MPa) differences in water potential (ΔΨ) between xylem and epidermal cells in the leaf elongation zone. In contrast, FC-treated leaves showed ΔΨ close to zero and a 10-fold increase in L. © The Author 2015. Published by Oxford University Press on behalf of Japanese Society of Plant Physiologists. All rights reserved. For permissions, please email: journals.permissions@oup.com.

  10. Mechanical Elongation of the Small Intestine: Evaluation of Techniques for Optimal Screw Placement in a Rodent Model

    Directory of Open Access Journals (Sweden)

    P. A. Hausbrandt

    2013-01-01

    Full Text Available Introduction. The aim of this study was to evaluate techniques and establish an optimal method for mechanical elongation of small intestine (MESI using screws in a rodent model in order to develop a potential therapy for short bowel syndrome (SBS. Material and Methods. Adult female Sprague Dawley rats (n=24 with body weight from 250 to 300 g (Σ=283 were evaluated using 5 different groups in which the basic denominator for the technique involved the fixation of a blind loop of the intestine on the abdominal wall with the placement of a screw in the lumen secured to the abdominal wall. Results. In all groups with accessible screws, the rodents removed the implants despite the use of washers or suits to prevent removal. Subcutaneous placement of the screw combined with antibiotic treatment and dietary modifications was finally successful. In two animals autologous transplantation of the lengthened intestinal segment was successful. Discussion. While the rodent model may provide useful basic information on mechanical intestinal lengthening, further investigations should be performed in larger animals to make use of the translational nature of MESI in human SBS treatment.

  11. Radiation-tolerant joining technologies for silicon carbide ceramics and composites

    Energy Technology Data Exchange (ETDEWEB)

    Katoh, Yutai, E-mail: katohy@ornl.gov [Oak Ridge National Laboratory, P.O. Box 2008, Oak Ridge, Tennessee 37831 (United States); Snead, Lance L.; Cheng, Ting; Shih, Chunghao; Lewis, W. Daniel [Oak Ridge National Laboratory, P.O. Box 2008, Oak Ridge, Tennessee 37831 (United States); Koyanagi, Takaaki; Hinoki, Tatsuya [Institute of Advanced Energy, Kyoto University, Uji, Kyoto 611-0011 (Japan); Henager, Charles H. [Pacific Northwest National Laboratory, 902 Battelle Blvd., Richland, WA 99352 (United States); Ferraris, Monica [Department of Applied Science and Technology, Politecnico di Torino, Corso Duca degli Abruzzi 24, I-10129 Torino (Italy)

    2014-05-01

    Silicon carbide (SiC) for nuclear structural applications, whether in the monolithic ceramic or composite form, will require a robust joining technology capable of withstanding the harsh nuclear environment. This paper presents significant progress made towards identifying and processing irradiation-tolerant joining methods for nuclear-grade SiC. In doing so, a standardized methodology for carrying out joint testing has been established consistent with the small volume samples mandated by neutron irradiation testing. Candidate joining technologies were limited to those that provide low induced radioactivity and included titanium diffusion bonding, Ti–Si–C MAX-phase joining, calcia–alumina glass–ceramic joining, and transient eutectic-phase SiC joining. Samples of these joints were irradiated in the Oak Ridge National Laboratory High Flux Isotope Reactor at 500 or 800 °C, and their microstructure and mechanical properties were compared to pre-irradiation conditions. Within the limitations of statistics, all joining methodologies presented retained their joint mechanical strength to ∼3 dpa at 500 °C, thus indicating the first results obtained on irradiation-stable SiC joints. Under the more aggressive irradiation conditions (800 °C, ∼5 dpa), some joint materials exhibited significant irradiation-induced microstructural evolution; however, the effect of irradiation on joint strength appeared rather limited.

  12. Radiation-tolerant joining technologies for silicon carbide ceramics and composites

    Energy Technology Data Exchange (ETDEWEB)

    Katoh, Yutai; Snead, Lance L.; Cheng, Ting; Shih, Chunghao; Lewis, W. Daniel; Koyanagi, Takaaki; Hinoki, Tatsuya; Henager, Charles H.; Ferraris, Monica

    2014-05-01

    Silicon carbide (SiC) for nuclear structural applications, whether in the monolithic ceramic or composite form, will require a robust joining technology capable of withstanding the harsh nuclear environment. This paper presents significant progress made towards identifying and processing irradiation-tolerant joining methods for nuclear-grade SiC. In doing so, a standardized methodology for carrying out joint testing has been established consistent with the small volume samples mandated by neutron irradiation testing. Candidate joining technologies were limited to those that provide low induced radioactivity and included titanium diffusion bonding, Ti–Si–C MAX-phase joining, calcia–alumina glass–ceramic joining, and transient eutectic-phase SiC joining. Samples of these joints were irradiated in the Oak Ridge National Laboratory High Flux Isotope Reactor at 500 or 800 °C, and their microstructure and mechanical properties were compared to pre-irradiation conditions. Within the limitations of statistics, all joining methodologies presented retained their joint mechanical strength to ~3 dpa at 500 °C, thus indicating the first results obtained on irradiation-stable SiC joints. Finally, under the more aggressive irradiation conditions (800 °C, ~5 dpa), some joint materials exhibited significant irradiation-induced microstructural evolution; however, the effect of irradiation on joint strength appeared rather limited.

  13. 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.

  14. 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.

  15. 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...

  16. 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

  17. 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...

  18. 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

  19. 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.

  20. 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...

  1. 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

  2. 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.

  3. Rapid changes in leaf elongation, ABA and water status during the recovery phase following application of water stress in two durum wheat varieties differing in drought tolerance.

    Science.gov (United States)

    Mahdid, Mohamed; Kameli, Abdelkrim; Ehlert, Christina; Simonneau, Thierry

    2011-10-01

    This study aims to investigate the role of Abscisic acid (ABA) in water potential and turgor variations as well as growth recovery during the first phase of a rapid water stress induced by PEG6000. Two wheat varieties (Triticum durum L.), MBB (more tolerant) and OZ (less productive under drought), were grown in aerated nutrient solutions. Leaf elongation kinetics of the growing leaf 3 was estimated using LVDT. Water potential was measured using a pressure chamber; osmotic potential was estimated from expressed sap of elongation zone, turgor pressure of the same zone of leaf three was estimated directly by pressure probe. Growth rapidly ceased for a period of about one hour after the addition of PEG, gradual recovery was then observed for about 2 h. A significant difference was found in the % recovery of Leaf Elongation Rate (LER) and ABA between the two varieties, leading to better water status in MBB compared to OZ. The results of this study showed the possible role of ABA on growth resumption by the increase of relative water content and turgor via osmotic adjustment during the stress period in the leaves, which indicates the importance of OA in the resumption of LER even in the short term under conditions of water deficit. Full recovery of turgor but not of LER at the end stress period suggested the possible effect on cell wall extensibility (hardening) even at short term resulting from the rapid accumulation of ABA.

  4. Plant cell walls: New insights from ancient species

    DEFF Research Database (Denmark)

    Sørensen, Iben; Willats, William George Tycho

    2008-01-01

    Cell walls are a defining feature of plants and have numerous crucial roles in growth and development. They are also the largest source of terrestrial biomass and have many important industrial applications - ranging from bulk products to functional food ingredients. There is considerable interest......¿4)-linked ß-D-Glcp are joined by occasional (1¿3)-linkages. This mixed linkage glucan (MLG) has been the subject of extensive research because of the economic importance of several Poales species including rice, barley and wheat and because MLG has proven health benefits. The recent discovery of MLG......-D-glucan is not unique to the Poales and is an abundant component of Equisetum arvense cell walls. Plant J 2008; 54:510-21....

  5. 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.

  6. 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.

  7. 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.

  8. 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.

  9. Optimization of Multi—Join Queries in Shared—Nothing Systems

    Institute of Scientific and Technical Information of China (English)

    Kian-LeeTan

    1995-01-01

    This paper proposes a semi-greedy framework for optimizing multi-join queries in shared-nothing systems.The plan generated by the framework comprises several pipelines,each performing several joins.The framework determines the “optimal” number of joins to be performed in each pipeline.The decisions are made based on the cost estimation of the entire processing plan.Two existing optimization algorithms are extended under the framework.An analytical model is presented and used to compare the quality of plans produced by each optimization algorithm.Our study shows that the new algorithms outperform their counterparts that are not extended.

  10. Joining Movement Sequences: Modified Dynamic Movement Primitives for Robotics Applications Exemplified on Handwriting

    DEFF Research Database (Denmark)

    Kulvicius, Tomas; Ning, K.; Tamosiunaite, M.

    2012-01-01

    The generation of complex movement patterns, in particular, in cases where one needs to smoothly and accurately join trajectories in a dynamic way, is an important problem in robotics. This paper presents a novel joining method that is based on the modification of the original dynamic movement...... to simulated handwriting generation, which are also shown on a robot, where an adaptive algorithm is used to learn trajectories from human demonstration. These results demonstrate that the new method is a feasible alternative for joining of movement sequences, which has a high potential for all robotics...

  11. Thermal-Fatigue Analysis of W-joined Ferritic-Martensitic Steel Mockup for Fusion Reactor Components

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Dong Won; Jin, Hyung Gon; Lee, Eo Hwak; Yoon, Jae Sung; Kim, Suk Kwon; Park, Seong Dae [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of); Shin, Kyu In [Gentec Co., Daejeon (Korea, Republic of); Moon, Se Yeon; Hong, Bong Guen [Chonbuk National University, Chonbuk (Korea, Republic of)

    2015-10-15

    Through the ITER blanket first wall (BFW) development project in Korea, the joining methods were developed with a beryllium (Be) layer as a plasma-facing material, a copper alloy (CuCrZr) layer as a heat sink, and type 316L austenitic stainless steel (SS316L) as a structural material. And joining methods were developed such as Be as an armor and FMS as a structural material, or W as an armor and FMS as a structural material were developed through the test blanket module (TBM) program. As a candidate of PFC for DEMO, W/FMS joining methods have been developed and a new Ti interlayer was applied differently from the previous work. In the present study, the W/FMS PFC development was introduced with the following procedure to apply to the PFCs for a fusion reactor: (1) Three W/FMS mockups were fabricated using the developed HIP followed by a post-HIP heat treatment (PHHT). (2) Because the High Heat Flux (HHF) test should be performed over the thermal lifetime of the mockup under the proper test conditions to confirm the joint's integrity, the test conditions were determined through a preliminary analysis. In this study, commercial ANSYS-CFX for thermalhydraulic analysis and ANSYS-mechanical for the thermo-mechanical analysis are used to evaluate the thermal-lifetime of the mockup to determine the test conditions. Also, the Korea Heat Load Test facility with an Electron Beam (KoHLT-EB) will be used and its water cooling system is considered to perform the thermal-hydraulic analysis especially for considering the two-phase analysis with a higher heat flux conditions. From the analysis, the heating and the cooling conditions were determined for 0.5- and 1.0-MW/m{sup 2} heat fluxes, respectively. Elastic-plastic analysis is performed to determine the lifetime and finally, the 1.0 MW/m{sup 2} heat flux conditions are determined up to 4,306 cycles. The test will be done in the near future and the measured temperatures will be compared with the present simulation results.

  12. Phenylalanine ammonia-lyase and cell wall peroxidase are cooperatively involved in the extensive formation of ferulate network in cell walls of developing rice shoots.

    Science.gov (United States)

    Wakabayashi, Kazuyuki; Soga, Kouichi; Hoson, Takayuki

    2012-02-15

    The relationship between the formation of cell wall-bound ferulic acid (FA) and diferulic acid (DFA) and the change in activities of phenylalanine ammonia-lyase (PAL) and cell wall-bound peroxidase (CW-PRX) was studied in rice shoots. The length and the fresh mass of shoots increased during the growth period from day 4 to 6, while coleoptiles ceased elongation growth on day 5. The amounts of FA and DFA isomers as well as cell wall polysaccharides continued to increase during the whole period. The activities of PAL and CW-PRX greatly increased in the same manner during the period. There were close correlations between the PAL activity and ferulate content or between the CW-PRX activity and DFA content. The expression levels of investigated genes for PAL and putative CW-PRX showed good accordance with the activities of these enzymes. These results suggest that increases in PAL and CW-PRX activities are cooperatively involved in the formation of ferulate network in cell walls of rice shoots and that investigated genes may be, at least in part, associated with the enzyme activities. The substantial increase in such network probably causes the maturation of cell walls and thus the cessation of elongation growth of coleoptiles.

  13. Evaluation of Steel Shear Walls Behavior with Sinusoidal and Trapezoidal Corrugated Plates

    Directory of Open Access Journals (Sweden)

    Emad Hosseinpour

    2015-01-01

    Full Text Available Reinforcement of structures aims to control the input energy of unnatural and natural forces. In the past four decades, steel shear walls are utilized in huge constructions in some seismic countries such as Japan, United States, and Canada to lessen the risk of destructive forces. The steel shear walls are divided into two types: unstiffened and stiffened. In the former, a series of plates (sinusoidal and trapezoidal corrugated with light thickness are used that have the postbuckling field property under overall buckling. In the latter, steel profile belt series are employed as stiffeners with different arrangement: horizontal, vertical, or diagonal in one side or both sides of wall. In the unstiffened walls, increasing the thickness causes an increase in the wall capacity under large forces in tall structures. In the stiffened walls, joining the stiffeners to the wall is costly and time consuming. The ANSYS software was used to analyze the different models of unstiffened one-story steel walls with sinusoidal and trapezoidal corrugated plates under lateral load. The obtained results demonstrated that, in the walls with the same dimensions, the trapezoidal corrugated plates showed higher ductility and ultimate bearing compared to the sinusoidal corrugated plates.

  14. Where are the Walls?

    CERN Document Server

    Olive, Keith A; Peterson, Adam J

    2012-01-01

    The reported spatial variation in the fine-structure constant at high redshift, if physical, could be due to the presence of dilatonic domains, and one or more domain walls inside our horizon. An absorption spectrum of an object in a different domain from our own would be characterized by a different value of alpha. We show that while a single wall solution is statically comparable to a dipole fit, and is a big improvement over a weighted mean (despite adding 3 parameters), a two-wall solution is a far better fit (despite adding 3 parameters over the single wall solution). We derive a simple model accounting for the two-domain wall solution. The goodness of these fits is however dependent on the extra random error which was argued to account for the large scatter in most of the data. When this error is omitted, all the above solutions are poor fits to the data. When included, the solutions that exhibit a spatial dependence agree with the data much more significantly than the Standard Model; however, the Stand...

  15. EPA, USDA Join to Set Nations First Food Waste Reduction Goals with Charities and Private Companies

    Science.gov (United States)

    WASHINGTON -- On Wednesday, September 16, U.S. Environmental Protection Agency (EPA) Acting Deputy Administrator Stan Meiberg will join U.S. Agriculture Secretary Tom Vilsack as well as private industry and charitable organizations to announce the U

  16. Summary of Dissimilar Metal Joining Trials Conducted by Edison Welding Institute

    Energy Technology Data Exchange (ETDEWEB)

    MJ Lambert

    2005-11-18

    Under the direction of the NASA-Glenn Research Center, the Edison Welding Institute (EWI) in Columbus, OH performed a series of non-fusion joining experiments to determine the feasibility of joining refractory metals or refractory metal alloys to Ni-based superalloys. Results, as reported by EWI, can be found in the project report for EWI Project 48819GTH (Attachment A, at the end of this document), dated October 10, 2005. The three joining methods used in this investigation were inertia welding, magnetic pulse welding, and electro-spark deposition joining. Five materials were used in these experiments: Mo-47Re, T-111, Hastelloy X, Mar M-247 (coarse-grained, 0.5 mm to several millimeter average grain size), and Mar M-247 (fine-grained, approximately 50 {micro}m average grain size). Several iterative trials of each material combination with each joining method were performed to determine the best practice joining method. Mo-47Re was found to be joined easily to Hastelloy X via inertia welding, but inertia welding of the Mo-alloy to both Mar M-247 alloys resulted in inconsistent joint strength and large reaction layers between the two metals. T-111 was found to join well to Hastelloy X and coarse-grained Mar M-247 via inertia welding, but joining to fine-grained Mar M-247 resulted in low joint strength. Magnetic pulse welding (MPW) was only successful in joining T-111 tubing to Hastelloy X bar stock. The joint integrity and reaction layer between the metals were found to be acceptable. This single joining trial, however, caused damage to the electromagnetic concentrators used in this process. Subsequent design efforts to eliminate the problem resulted in a loss of power imparted to the accelerating work piece, and results could not be reproduced. Welding trials of Mar M-247 to T-111 resulted in catastrophic failure of the bar stock, even at lower power. Electro-spark deposition joining of Mo-47Re, in which the deposited material was Hastelloy X, did not have a

  17. Recombination, transcription, and diversity of a partially germline-joined VH in a mammal.

    Science.gov (United States)

    Wang, Xinxin; Miller, Robert D

    2012-09-01

    Full or partially germline-joined V genes have been described in a number of different vertebrate lineages where they can contribute to the expressed antibody repertoire through different mechanisms. Here we demonstrate that VH3.1, a partially germline-joined VH gene in the opossum Monodelphis domestica, can undergo V(D)J recombination to generate productive IgH transcripts. VH3.1 is fused to a DH gene segment in the germline DNA and is the only known example of a germline-joined VH in a mammal. B cells that have recombined VH3.1 were not detected until nearly 2 months of age, around the time of weaning, and much later than B cells using the conventional VH. Compared to opossum IgH transcripts using the conventional VH genes, those with VH3.1 have unusually long CDR3 due to the length of the germline-joined DH.

  18. Parcels and Land Ownership, had to join to cama database, Published in 2008, Campbell County Government.

    Data.gov (United States)

    NSGIC GIS Inventory (aka Ramona) — This Parcels and Land Ownership dataset as of 2008. It is described as 'had to join to cama database'. The extent of these data is generally Campbell County, WY....

  19. Human transcriptional coactivator PC4 stimulates DNA end joining and activates DSB repair activity.

    Science.gov (United States)

    Batta, Kiran; Yokokawa, Masatoshi; Takeyasu, Kunio; Kundu, Tapas K

    2009-01-23

    Human transcriptional coactivator PC4 is a highly abundant nuclear protein that is involved in diverse cellular processes ranging from transcription to chromatin organization. Earlier, we have shown that PC4, a positive activator of p53, overexpresses upon genotoxic insult in a p53-dependent manner. In the present study, we show that PC4 stimulates ligase-mediated DNA end joining irrespective of the source of DNA ligase. Pull-down assays reveal that PC4 helps in the association of DNA ends through its C-terminal domain. In vitro nonhomologous end-joining assays with cell-free extracts show that PC4 enhances the joining of noncomplementary DNA ends. Interestingly, we found that PC4 activates double-strand break (DSB) repair activity through stimulation of DSB rejoining in vivo. Together, these findings demonstrate PC4 as an activator of nonhomologous end joining and DSB repair activity.

  20. Simulation of a Novel Joining Process for Fiber-Reinforced Thermoplastic Composites and Metallic Components

    Science.gov (United States)

    Gude, M.; Freund, A.; Vogel, C.; Kupfer, R.

    2017-01-01

    In this study, a new joining technology to produce hybrid structures with continuous-fiber-reinforced thermoplastics and metallic components is presented adapting the concept of classical clinching for thermoplastic composites. To demonstrate the capability of the thermoclinching process, prototypic joints were manufactured using an experimental joining installation developed. Nondestructive and destructive analyses of the thermoclinched joints showed that a relocation of the reinforcement into the neck and head area of the joining zone could be achieved. For a first estimation of the maximum load-carrying capacity of the joints, single-lap specimens with both reinforced and nonreinforced thermoplastics were manufactured and tested, revealing up to 50% higher failure loads of the reinforced joints. To understand the local material configuration and to achieve a defined and adjustable fabric structure in the head area of the joint, further analyses with regard to material- and tool-side conditions of the joining zone are necessary.

  1. Joining mechanism of field-assisted diffusion bonding of solid electrolyte ceramic to metals

    Institute of Scientific and Technical Information of China (English)

    孟庆森; 薛锦

    2003-01-01

    Field-assisted diffusion bonding applied in the joining of solid electrolyte borosilicate glass, β″-Al2O3, Y2O-ZrO2 to monocrystal silicate and aluminum were proceeded with bonding machine in the assistance of static electric field. TEM, SEM, XRD and other means were applied to investigate and analyze microstructure of interface. It is supposed that the interfacial area is a model of metal-oxides-ceramic, and the joining mechanism is solid diffusion joining and static electric bonding. The process of ions migration and accumulation under electric field is the most essential factor for the anodic oxidation and interfacial joining. Temperature and voltage are the basic factors of the solid diffusion bonding of interfacial oxidation. And voltage, temperature, pressure and the condition of surface are the most important factors that govern the bonding process.

  2. A review of semi-solid aluminium-steel joining processes

    Science.gov (United States)

    Obeidi, Muhannad; McCarthy, Éanna; Brabazon, Dermot

    2016-10-01

    The semi-solid metal (SSM) forming process can be applied to achieve near net shape forming of metal alloys, and provides superior component properties compared to those achievable with conventional casting methods. The technique, also commonly called thixoforming, relies on achieving a spheroidal microstructure within the metal alloy so that its fluidity can be adjusted to achieve a controlled laminar filling of the die. Despite the better quality and the higher mechanical properties of an SSM product, thixoforming still represents only 1% of the total aluminium production, which can be explained by the higher premium cost of the processing equipment compared to conventional die casting. The method has also proven successful as a joining method, for joining similar and dissimilar materials. This paper reviews semisolid forming as a forming method and as a joining method, in particular the joining of dissimilar materials such as stainless steel to aluminium.

  3. The impact of joining the European Union on the Romanian capital market

    Directory of Open Access Journals (Sweden)

    Elena Lidia MELNIC

    2015-12-01

    Full Text Available This paper approach the theme of the development of the Romanian Stock Exchange Market (BVB during the process of joining the European Union. The first goal is to illustrate the stage of the BVB in the years before the accession to the Union and what were the perspectives of joining the EU at that time. The second goal is to highlight the effects the accession had on the neighboring markets: the Polish, the Hungarian and the Czech markets who joined EU in 2004 and to analyze the correlation between the indexes from these stock markets and the Romanian stock index. The last goal is to show the impact of joining the European Union on the Romanian Stock Exchange Market.

  4. Mouse bladder wall injection.

    Science.gov (United States)

    Fu, Chi-Ling; Apelo, Charity A; Torres, Baldemar; Thai, Kim H; Hsieh, Michael H

    2011-07-12

    Mouse bladder wall injection is a useful technique to orthotopically study bladder phenomena, including stem cell, smooth muscle, and cancer biology. Before starting injections, the surgical area must be cleaned with soap and water and antiseptic solution. Surgical equipment must be sterilized before use and between each animal. Each mouse is placed under inhaled isoflurane anesthesia (2-5% for induction, 1-3% for maintenance) and its bladder exposed by making a midline abdominal incision with scissors. If the bladder is full, it is partially decompressed by gentle squeezing between two fingers. The cell suspension of interest is intramurally injected into the wall of the bladder dome using a 29 or 30 gauge needle and 1 cc or smaller syringe. The wound is then closed using wound clips and the mouse allowed to recover on a warming pad. Bladder wall injection is a delicate microsurgical technique that can be mastered with practice.

  5. Axion domain wall baryogenesis

    Energy Technology Data Exchange (ETDEWEB)

    Daido, Ryuji; Kitajima, Naoya [Department of Physics, Tohoku University,Sendai 980-8578 (Japan); Takahashi, Fuminobu [Department of Physics, Tohoku University,Sendai 980-8578 (Japan); Kavli IPMU, TODIAS, University of Tokyo,Kashiwa 277-8583 (Japan)

    2015-07-28

    We propose a new scenario of baryogenesis, in which annihilation of axion domain walls generates a sizable baryon asymmetry. Successful baryogenesis is possible for a wide range of the axion mass and decay constant, m≃10{sup 8}–10{sup 13} GeV and f≃10{sup 13}–10{sup 16} GeV. Baryonic isocurvature perturbations are significantly suppressed in our model, in contrast to various spontaneous baryogenesis scenarios in the slow-roll regime. In particular, the axion domain wall baryogenesis is consistent with high-scale inflation which generates a large tensor-to-scalar ratio within the reach of future CMB B-mode experiments. We also discuss the gravitational waves produced by the domain wall annihilation and its implications for the future gravitational wave experiments.

  6. Manufacturing Systems Demonstration: Bimetallic Friction STIR Joining of AA6061 and High Hardness Steel

    Science.gov (United States)

    2013-05-31

    tool’s first use. In all tools made of alloy having hafnium carbide, we’ve commonly seen small voids (0.0-1.0 mm dia.) on the surface of machined...distribution unlimited 13. SUPPLEMENTARY NOTES 14. ABSTRACT Focus: HOPE (FH) has developed the process parameters to successfully join AA6061 aluminum alloy ...to successfully join AA6061 aluminum alloy and High Hardness Armor (HHA) steel using the friction stir process (FSP). Metallographic analysis

  7. Investigation into the joining of MoSi{sub 2} to 316L stainless steel

    Energy Technology Data Exchange (ETDEWEB)

    Vaidya, R.U.; Bartlett, A.H.; Conzone, S.D.; Butt, D.P.

    1996-10-01

    Partial transient liquid phase joining and low temperature brazing were applied in joining MoSi{sub 2} to 316L ss. Exploratory studies were carried out on various interlayer materials. Mechanical, physical, and chemical compatibilities between various interlayers, brazing material, and substrate materials were investigated. Effect of thermal expansion mismatch between various components of the joint on the overall joint integrity was also studied. Preliminary findings are outlined.

  8. Kyrgyz Republic - The Garment Sector : Impact of Joining the Customs Union and Options to Increase Competitiveness

    OpenAIRE

    World Bank

    2014-01-01

    This note analyzes the impact that joining the Eurasian Customs Union will have on the Kyrgyz Republic s garment sector and options for improving the sector s competitiveness. The paper finds that joining the Eurasian Customs Union will lead to higher prices for the textiles and cloth used in garment production. This will increase the cost of producing garments in the Kyrgyz Republic and w...

  9. When and Whom to Join: The Expansion of Ongoing Violent Interstate Conflicts

    OpenAIRE

    Bayer, Reşat; Joyce, Kyle A.; Ghosn, Faten

    2014-01-01

    The opportunity and willingness framework has received much attention in research on interstate conflict expansion. This framework is extended here by examining when and what side third parties join during ongoing conflicts. It is maintained that without examining both timing and side selection, understanding of conflict expansion is limited. The timing and side joined in interstate disputes between 1816 and 2001 are analysed using a competing risks duration model. The findings contribute nov...

  10. Congenital Abdominal Wall Defects

    DEFF Research Database (Denmark)

    Risby, Kirsten; Jakobsen, Marianne Skytte; Qvist, Niels

    2016-01-01

    complications were seen in five (15%) children: four had detachment of the mesh and one patient developed abdominal compartment syndrome. Mesh related clinical infection was observed in five children. In hospital mortality occurred in four cases (2 gastroschisis and 2 omphalocele) and was not procedure......OBJECTIVE: To evaluate the clinical utility of GORE® DUALMESH (GDM) in the staged closure of large congenital abdominal wall defects. MATERIALS AND METHODS: Data of patients with congenital abdominal wall defects managed with GDM was analyzed for outcome regarding complete fascial closure; mesh...

  11. Timber frame walls

    DEFF Research Database (Denmark)

    Hansen, Ernst Jan de Place; Brandt, Erik

    2010-01-01

    A ventilated cavity is usually considered good practice for removing moisture behind the cladding of timber framed walls. Timber frame walls with no cavity are a logical alternative as they are slimmer and less expensive to produce and besides the risk of a two-sided fire behind the cladding....... It was found that the specific damages made to the vapour barrier as part of the test did not have any provable effect on the moisture content. In general elements with an intact vapour barrier did not show a critical moisture content at the wind barrier after four years of exposure....

  12. 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.

  13. 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.

  14. Europlanet - Joining the European Planetary Research Information Service

    Science.gov (United States)

    Capria, M. T.; Chanteur, G.; Schmidt, W.

    2009-04-01

    The "Europlanet Research Infrastructure - Europlanet RI", supported by the European Commission's Framework Program 7, aims at integrating major parts of the distributed European Planetary Research infrastructure with as diverse components as space exploration, ground-based observations, laboratory experiments and numerical model-ling teams. A central part of Europlanet RI is the "Integrated and Distributed Information Service" or Europlanet-IDIS which intends to provide easy Web-based access to information about scientists and teams working in related fields, observatories or laboratories with capabilities possibly beneficial to planetary research, modelling expertise useful for planetary science and observations from space-based, ground-based or laboratory measurements. As far as the type of data and their access methods allow, IDIS will provide Virtual Observatory (VO) like access to a variety of data from distributed sources and tools to compare and integrate this information to further data analysis and re-search. IDIS itself is providing a platform for information and data sharing and for data mining. It is structured as a network of thematic nodes each concentrating on a sub-set of research areas in planetary sciences. But the most important elements of IDIS and the whole Europlanet RI are the single scientists, institutes, laboratories, observatories and mission project teams. Without them the whole effort would remain an empty shell. How can an interested individual or team join this activity and what are the benefits to be expected from the related effort? The poster gives detailed answers to these questions. Here some highlights: 1. Locate from the Europlanet web pages (addresses see below) the thematic node best related to the own field of expertise. This might be more than one. 2. Define which services you want to offer to the community: just the contact address, field of competence, off-line access to data on request or even on-line searchable access

  15. Stability of the flow in a plane microchannel with one or two superhydrophobic walls

    Science.gov (United States)

    Pralits, Jan O.; Alinovi, Edoardo; Bottaro, Alessandro

    2017-01-01

    The modal and nonmodal linear stability of the flow in a microchannel with either one or both walls coated with a superhydrophobic material is studied. The topography of the bounding wall(s) has the shape of elongated microridges with arbitrary alignment with respect to the direction of the mean pressure gradient. The superhydrophobic walls are modeled using the Navier slip condition through a slip tensor, and the results depend parametrically on the slip length and orientation angle of the ridges. The stability analysis is carried out in the temporal framework; the modal analysis is performed by solving a generalized eigenvalue problem, and the nonmodal, optimal perturbation analysis is done with an adjoint optimization approach. We show theoretically and verify numerically that Squire's theorem does not apply in the present settings, despite the fact that Squire modes are found to be always damped. The most notable result is the appearance of a streamwise wall-vortex mode at very low Reynolds numbers when the ridges are sufficiently inclined with respect to the mean pressure gradient, in the case of a single superhydrophobic wall. When two walls are rendered water repellent, the exponential growth of the instability results from either a two-dimensional or a three-dimensional Orr-Sommerfeld mode, depending on the ridges' orientation and amplitude. Nonmodal results for either one or two superhydrophobic wall(s) display but a mild modification of the no-slip case.

  16. A Review of Similar and Dissimilar Micro-joining of Nitinol

    Science.gov (United States)

    Deepan Bharathi Kannan, T.; Ramesh, T.; Sathiya, P.

    2016-04-01

    NiTinol belongs to a class of smart materials which has a wide range of applications in the field of automotive, aerospace, biomedical, robotics, etc., owing to the growing trend in miniaturization of components. Micro-joining is becoming one of the important and familiar processes in the fabrication of miniaturized components. Recently, effective micro-joining of thin sheets has been gaining a lot of interest among researchers. In this article, the research and progress in micro-joining of NiTinol to itself and other metals are reviewed at different aspects. To date, laser welding, tungsten inert gas welding, and resistance welding have been used to a large extent in investigating the weldability of NiTinol alloys. Some important welding parameters used in micro joining by various researchers and their effects on weld qualities are detailed in this review. Metallurgical aspects, mechanical properties and corrosion aspects of micro-joined NiTinol sheets/wires are discussed. The aim of this report is to review the recent progress in micro-joining of NiTinol and to provide a basis for follow-on research.

  17. 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

  18. Evolution and allometry of calcaneal elongation in living and extinct primates.

    Science.gov (United States)

    Boyer, Doug M; Seiffert, Erik R; Gladman, Justin T; Bloch, Jonathan I

    2013-01-01

    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 increases in calcaneal

  19. Morphological evidence for a change in the pattern of aortic wall shear stress with age.

    Science.gov (United States)

    Bond, Andrew R; Iftikhar, Saadia; Bharath, Anil A; Weinberg, Peter D

    2011-03-01

    The distribution of atherosclerosis around branch sites changes with age in human and rabbit aortas. We tested whether that reflects a change in the pattern of wall shear stress by examining shear-dependent morphological features of endothelial cells. Endothelial cells and their nuclei align and elongate with applied shear. These parameters were examined in the descending thoracic aorta of immature and mature rabbits. The use of Häutchen preparations, fluorescent stains, and automated image analysis allowed nuclear morphology to be mapped reliably at high resolution over large areas. Cells and their nuclei were most elongated downstream of branch ostia in immature aortas but upstream of them in mature aortas. Elongation was generally greater in mature animals, and nuclei aligned toward the ostia more in these animals, consistent with a greater flow into the branch. Morphology away from branches was indicative of helical flow in the aorta, with greatest shear on the dorsal wall, at both ages. The data are consistent with age-related changes in the pattern of shear around aortic branches. Maps of nuclear elongation closely resembled maps of lesion frequency. The association was positive, implying that lesions occur at sites of high shear stress at both ages.

  20. TIG and HIP joining of Reduced Activation Ferrite/Martensitic steel for the Korean ITER-TBM

    Energy Technology Data Exchange (ETDEWEB)

    Ku, Duck Young [ITER Korea, National Fusion Research Institute, Gwahangno 113, Yuseong-gu, Daejeon 305-333 (Korea, Republic of); Oh, Seungjin, E-mail: osj0423@gmail.com [Nuclear Engineering and Technology Institute, KHNP, 508 Keumbyeong-ro, Yuseong-gu, Daejeon 305-343 (Korea, Republic of); Ahn, Mu-Young; Yu, In-Keun; Kim, Duck-Hoi; Cho, Seungyon [ITER Korea, National Fusion Research Institute, Gwahangno 113, Yuseong-gu, Daejeon 305-333 (Korea, Republic of); Choi, Im-Sub; Kwon, Ki-Bum [Soles Co. LTD., 9-1 Horim-dong, Dalseo-gu, Daegu 704-249 (Korea, Republic of)

    2011-10-01

    Korea is developing a Helium Cooled Solid Breeder Test Blanket Module for ITER. The primary candidate structural material is a Reduced Activation Ferritic/Martensitic steel. The complex TBM structure requires developing joining technologies for successful fabrication. The characteristics of Tungsten Inert Gas welding and Hot Isostatic Pressing joining of RAFM steel were investigated. Metallurgical examinations showed that the steel grain size was increased after HIP joining and recovered by post joining heat treatment. Both TIG welding and HIP joining are found to be acceptable for ITER TBM based on mechanical tests and microstructure examination.