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Sample records for local f-actin assembly

  1. Effect of 0.4 mT power frequency magnetic field on F-actin assembly of CHL cells

    International Nuclear Information System (INIS)

    Chu Keping; Cai Zhiyin; Zhang Yukun; Xia Nuohong

    2007-01-01

    Objective: To investigate the effect of 0.4mT power frequency magnetic field on the microfilament (F- actin) assembly of Chinese hamster lung (CHL) cells. Methods: F-actin were marked with immunohistochemical method, then observed under a confocal microscope. The content of ECFRs in the preparation of the detergent-insoluble cytoskeleton was measured with Western-blotting. Results: The stress fiber's of CHL cells decreased after exposure to 0.4mT power frequency magnetic field for 30min, as well as after treatment with epidermal growth factor (ECF) of 50nM. Filopodias appeared at the periphery after exposure to magnetic field as well as treatment with EGF. The EGF receptor mass associated with the detergent-insoluble cytoskeleton increased after exposure to magnetic field as well as treatment with EGF. Conclusion: 0.4mT power frequency magnetic field induced assembly of F-actin in CHL cells. The change induced by magnetic field would be related to clustering of EGFR induced by magnetic field and passing the signal down. (authors)

  2. RhoA and RhoC are involved in stromal cell-derived factor-1-induced cell migration by regulating F-actin redistribution and assembly.

    Science.gov (United States)

    Luo, Jixian; Li, Dingyun; Wei, Dan; Wang, Xiaoguang; Wang, Lan; Zeng, Xianlu

    2017-12-01

    Stromal cell-derived factor-1 (SDF-1) signaling is important to the maintenance and progression of T-cell acute lymphoblastic leukemia by inducing chemotaxis migration. To identify the mechanism of SDF-1 signaling in the migration of T-ALL, Jurkat acute lymphoblastic leukemia cells were used. Results showed that SDF-1 induces Jurkat cell migration by F-actin redistribution and assembly, which is dependent on Rho activity. SDF-1 induced RhoA and RhoC activation, as well as reactive oxygen species (ROS) production, which was inhibited by Rho inhibitor. The Rho-dependent ROS production led to subsequent cytoskeleton redistribution and assembly in the process of migration. Additionally, RhoA and RhoC were involved in SDF-1-induced Jurkat cell migration. Taken together, we found a SDF-1/CXCR4-RhoA and RhoC-ROS-cytoskeleton pathway that regulates Jurkat cell migration in response to SDF-1. This work will contribute to a clearer insight into the migration mechanism of acute lymphoblastic leukemia.

  3. Cell stress promotes the association of phosphorylated HspB1 with F-actin.

    Directory of Open Access Journals (Sweden)

    Joseph P Clarke

    Full Text Available Previous studies have suggested that the small heat shock protein, HspB1, has a direct influence on the dynamics of cytoskeletal elements, in particular, filamentous actin (F-actin polymerization. In this study we have assessed the influence of HspB1 phosphorylation on its interaction(s with F-actin. We first determined the distribution of endogenous non-phosphorylated HspB1, phosphorylated HspB1 and F-actin in neuroendocrine PC12 cells by immunocytochemistry and confocal microscopy. We then investigated a potential direct interaction between HspB1 with F-actin by precipitating F-actin directly with biotinylated phalloidin followed by Western analyses; the reverse immunoprecipitation of HspB1 was also carried out. The phosphorylation influence of HspB1 in this interaction was investigated by using pharmacologic inhibition of p38 MAPK. In control cells, HspB1 interacts with F-actin as a predominantly non-phosphorylated protein, but subsequent to stress there is a redistribution of HspB1 to the cytoskeletal fraction and a significantly increased association of pHspB1 with F-actin. Our data demonstrate HspB1 is found in a complex with F-actin both in phosphorylated and non-phosphorylated forms, with an increased association of pHspB1 with F-actin after heat stress. Overall, our study combines both cellular and biochemical approaches to show cellular localization and direct demonstration of an interaction between endogenous HspB1 and F-actin using methodolgy that specifically isolates F-actin.

  4. Cooperative and non-cooperative conformational changes of F-actin induced by cofilin

    Energy Technology Data Exchange (ETDEWEB)

    Aihara, Tomoki; Oda, Toshiro, E-mail: toda@spring8.or.jp

    2013-05-31

    Highlights: •Mobility of MTSL attached to C374 in F-actin became high upon addition of cofilin. •Change of motility of MTSL attached to C374 with cofilin-binding was cooperative. •Mobility of MTSL attached to V43C in F-actin became high upon addition of cofilin. •Change of motility of MTSL attached to V43C with cofilin-binding was linear. -- Abstract: Cofilin is an actin-binding protein that promotes F-actin depolymerization. It is well-known that cofilin-coated F-actin is more twisted than naked F-actin, and that the protomer is more tilted. However, the means by which the local changes induced by the binding of individual cofilin proteins proceed to the global conformational changes of the whole F-actin molecule remain unknown. Here we investigated the cofilin-induced changes in several parts of F-actin, through site-directed spin-label electron paramagnetic resonance spectroscopy analyses of recombinant actins containing single reactive cysteines. We found that the global, cooperative conformational changes induced by cofilin-binding, which were detected by the spin-label attached to the Cys374 residue, occurred without the detachment of the D-loop in subdomain 2 from the neighboring protomer. The two processes of local and global changes do not necessarily proceed in sequence.

  5. An F-actin-depleted zone is present at the hyphal tip of invasive hyphae of Neurospora crassa.

    Science.gov (United States)

    Suei, S; Garrill, A

    2008-01-01

    The distribution of filamentous actin (F-actin) in invasive and noninvasive hyphae of the ascomycete Neurospora crassa was investigated. Eighty six percent of noninvasive hyphae had F-actin in the tip region compared to only 9% of invasive hyphae. The remaining 91% of the invasive hyphae had no obvious tip high concentration of F-actin staining; instead they had an F-actin-depleted zone in this region, although some F-actin, possibly associated with the Spitzenkörper, remained at the tip. The size of the F-actin-depleted zone in invasive hyphae increased with an increase in agar concentration. The membrane stain FM 4-64 reveals a slightly larger accumulation of vesicles at the tips of invasive hyphae relative to noninvasive hyphae, although this difference is unlikely to be sufficient to account for the exclusion of F-actin from the depleted zone. Antibodies raised against the actin filament-severing protein cofilin from both yeast and human cells localize to the tips of invasive hyphae. The human cofilin antibody shows a more random distribution in noninvasive hyphae locating primarily at the hyphal periphery but with some diffuse cytoplasmic staining. This antibody also identifies a single band at 21 kDa in immunoblots of whole hyphal fractions. These data suggest that a protein with epitopic similarity to cofilin may function in F-actin dynamics that underlie invasive growth. The F-actin-depleted zone may play a role in the regulation of tip yielding to turgor pressure, thus increasing the protrusive force necessary for invasive growth.

  6. Leading tip drives soma translocation via forward F-actin flow during neuronal migration.

    Science.gov (United States)

    He, Min; Zhang, Zheng-hong; Guan, Chen-bing; Xia, Di; Yuan, Xiao-bing

    2010-08-11

    Neuronal migration involves coordinated extension of the leading process and translocation of the soma, but the relative contribution of different subcellular regions, including the leading process and cell rear, in driving soma translocation remains unclear. By local manipulation of cytoskeletal components in restricted regions of cultured neurons, we examined the molecular machinery underlying the generation of traction force for soma translocation during neuronal migration. In actively migrating cerebellar granule cells in culture, a growth cone (GC)-like structure at the leading tip exhibits high dynamics, and severing the tip or disrupting its dynamics suppressed soma translocation within minutes. Soma translocation was also suppressed by local disruption of F-actin along the leading process but not at the soma, whereas disrupting microtubules along the leading process or at the soma accelerated soma translocation. Fluorescent speckle microscopy using GFP-alpha-actinin showed that a forward F-actin flow along the leading process correlated with and was required for soma translocation, and such F-actin flow depended on myosin II activity. In migrating neurons, myosin II activity was high at the leading tip but low at the soma, and increasing or decreasing this front-to-rear difference accelerated or impeded soma advance. Thus, the tip of the leading process actively pulls the soma forward during neuronal migration through a myosin II-dependent forward F-actin flow along the leading process.

  7. Histones bundle F-actin filaments and affect actin structure.

    Directory of Open Access Journals (Sweden)

    Edna Blotnick

    Full Text Available Histones are small polycationic proteins complexed with DNA located in the cell nucleus. Upon apoptosis they are secreted from the cells and react with extracellular polyanionic compounds. Actin which is a polyanionic protein, is also secreted from necrotic cells and interacts with histones. We showed that both histone mixture (histone type III and the recombinant H2A histone bundles F-actin, increases the viscosity of the F-actin containing solution and polymerizes G-actin. The histone-actin bundles are relatively insensitive to increase of ionic strength, unlike other polycation, histatin, lysozyme, spermine and LL-37 induced F-actin bundles. The histone-actin bundles dissociate completely only in the presence of 300-400 mM NaCl. DNA, which competes with F-actin for histones, disassembles histone induced actin bundles. DNase1, which depolymerizes F- to G-actin, actively unbundles the H2A histone induced but slightly affects the histone mixture induced actin bundles. Cofilin decreases the amount of F-actin sedimented by low speed centrifugation, increases light scattering and viscosity of F-actin-histone mixture containing solutions and forms star like superstructures by copolymerizing G-actin with H2A histone. The results indicate that histones are tightly attached to F-actin by strong electrostatic and hydrophobic forces. Since both histones and F-actin are present in the sputum of patients with cystic fibrosis, therefore, the formation of the stable histone-actin bundles can contribute to the pathology of this disease by increasing the viscosity of the sputum. The actin-histone interaction in the nucleus might affect gene expression.

  8. Histones bundle F-actin filaments and affect actin structure.

    Science.gov (United States)

    Blotnick, Edna; Sol, Asaf; Muhlrad, Andras

    2017-01-01

    Histones are small polycationic proteins complexed with DNA located in the cell nucleus. Upon apoptosis they are secreted from the cells and react with extracellular polyanionic compounds. Actin which is a polyanionic protein, is also secreted from necrotic cells and interacts with histones. We showed that both histone mixture (histone type III) and the recombinant H2A histone bundles F-actin, increases the viscosity of the F-actin containing solution and polymerizes G-actin. The histone-actin bundles are relatively insensitive to increase of ionic strength, unlike other polycation, histatin, lysozyme, spermine and LL-37 induced F-actin bundles. The histone-actin bundles dissociate completely only in the presence of 300-400 mM NaCl. DNA, which competes with F-actin for histones, disassembles histone induced actin bundles. DNase1, which depolymerizes F- to G-actin, actively unbundles the H2A histone induced but slightly affects the histone mixture induced actin bundles. Cofilin decreases the amount of F-actin sedimented by low speed centrifugation, increases light scattering and viscosity of F-actin-histone mixture containing solutions and forms star like superstructures by copolymerizing G-actin with H2A histone. The results indicate that histones are tightly attached to F-actin by strong electrostatic and hydrophobic forces. Since both histones and F-actin are present in the sputum of patients with cystic fibrosis, therefore, the formation of the stable histone-actin bundles can contribute to the pathology of this disease by increasing the viscosity of the sputum. The actin-histone interaction in the nucleus might affect gene expression.

  9. Coronin 3 involvement in F-actin-dependent processes at the cell cortex

    International Nuclear Information System (INIS)

    Rosentreter, Andre; Hofmann, Andreas; Xavier, Charles-Peter; Stumpf, Maria; Noegel, Angelika A.; Clemen, Christoph S.

    2007-01-01

    The actin interaction of coronin 3 has been mainly documented by in vitro experiments. Here, we discuss coronin 3 properties in the light of new structural information and focus on assays that reflect in vivo roles of coronin 3 and its impact on F-actin-associated functions. Using GFP-tagged coronin 3 fusion proteins and RNAi silencing we show that coronin 3 has roles in wound healing, protrusion formation, cell proliferation, cytokinesis, endocytosis, axonal growth, and secretion. During formation of cell protrusions actin accumulation precedes the focal enrichment of coronin 3 suggesting a role for coronin 3 in events that follow the initial F-actin assembly. Moreover, we show that coronin 3 similar to other coronins interacts with the Arp2/3-complex and cofilin indicating that this family in general is involved in regulating Arp2/3-mediated events

  10. A glycolytic metabolon in Saccharomyces cerevisiae is stabilized by F-actin.

    Science.gov (United States)

    Araiza-Olivera, Daniela; Chiquete-Felix, Natalia; Rosas-Lemus, Mónica; Sampedro, José G; Peña, Antonio; Mujica, Adela; Uribe-Carvajal, Salvador

    2013-08-01

    In the Saccharomyces cerevisiae glycolytic pathway, 11 enzymes catalyze the stepwise conversion of glucose to two molecules of ethanol plus two CO₂ molecules. In the highly crowded cytoplasm, this pathway would be very inefficient if it were dependent on substrate/enzyme diffusion. Therefore, the existence of a multi-enzymatic glycolytic complex has been suggested. This complex probably uses the cytoskeleton to stabilize the interaction of the various enzymes. Here, the role of filamentous actin (F-actin) in stabilization of a putative glycolytic metabolon is reported. Experiments were performed in isolated enzyme/actin mixtures, cytoplasmic extracts and permeabilized yeast cells. Polymerization of actin was promoted using phalloidin or inhibited using cytochalasin D or latrunculin. The polymeric filamentous F-actin, but not the monomeric globular G-actin, stabilized both the interaction of isolated glycolytic pathway enzyme mixtures and the whole fermentation pathway, leading to higher fermentation activity. The associated complexes were resistant against inhibition as a result of viscosity (promoted by the disaccharide trehalose) or inactivation (using specific enzyme antibodies). In S. cerevisiae, a glycolytic metabolon appear to assemble in association with F-actin. In this complex, fermentation activity is enhanced and enzymes are partially protected against inhibition by trehalose or by antibodies. © 2013 FEBS.

  11. F-actin distribution and function during sexual differentiation in Schizosaccharomyces pombe

    DEFF Research Database (Denmark)

    Petersen, J; Nielsen, O; Egel, R

    1998-01-01

    Sexual differentiation in Schizosaccharomyces pombe is induced from the G1 phase of the cell cycle by nitrogen starvation and the presence of mating pheromones. We describe the distribution of F-actin during sexual differentiation. Cortical F-actin dots have previously been shown to be restricted...... to one end of the rod shaped cell during the G1 phase of the cell cycle. Within half an hour of nitrogen starvation the distribution of cortical F-actin dots switched from being monopolar to bipolar. This was then reversed as the F-actin cytoskeleton repolarized so that cortical F-actin dots accumulated...

  12. Endophilin, Lamellipodin, and Mena cooperate to regulate F-actin-dependent EGF-receptor endocytosis.

    Science.gov (United States)

    Vehlow, Anne; Soong, Daniel; Vizcay-Barrena, Gema; Bodo, Cristian; Law, Ah-Lai; Perera, Upamali; Krause, Matthias

    2013-10-16

    The epidermal growth factor receptor (EGFR) plays an essential role during development and diseases including cancer. Lamellipodin (Lpd) is known to control lamellipodia protrusion by regulating actin filament elongation via Ena/VASP proteins. However, it is unknown whether this mechanism supports endocytosis of the EGFR. Here, we have identified a novel role for Lpd and Mena in clathrin-mediated endocytosis (CME) of the EGFR. We have discovered that endogenous Lpd is in a complex with the EGFR and Lpd and Mena knockdown impairs EGFR endocytosis. Conversely, overexpressing Lpd substantially increases the EGFR uptake in an F-actin-dependent manner, suggesting that F-actin polymerization is limiting for EGFR uptake. Furthermore, we found that Lpd directly interacts with endophilin, a BAR domain containing protein implicated in vesicle fission. We identified a role for endophilin in EGFR endocytosis, which is mediated by Lpd. Consistently, Lpd localizes to clathrin-coated pits (CCPs) just before vesicle scission and regulates vesicle scission. Our findings suggest a novel mechanism in which Lpd mediates EGFR endocytosis via Mena downstream of endophilin.

  13. Bulkiness or aromatic nature of tyrosine-143 of actin is important for the weak binding between F-actin and myosin-ADP-phosphate

    Energy Technology Data Exchange (ETDEWEB)

    Gomibuchi, Yuki [Graduate School of Science and Engineering, Teikyo University, Toyosatodai 1-1, Utsunomiya 320-8551 (Japan); Uyeda, Taro Q.P. [Biomedical Research Institute, National Institute of Advanced Industrial Science and Technology, AIST Tsukuba Central 4, 1-1-1 Higashi, Tsukuba, Ibaraki 305-8562 (Japan); Wakabayashi, Takeyuki, E-mail: tw007@nasu.bio.teikyo-u.ac.jp [Graduate School of Science and Engineering, Teikyo University, Toyosatodai 1-1, Utsunomiya 320-8551 (Japan); Department of Judo Therapy, Faculty of Medical Technology, Teikyo University, Toyosatodai 1-1, Utsunomiya 320-8551 (Japan)

    2013-11-29

    Highlights: •The effect of mutation of Tyr143 that becomes more exposed on assembly was examined. •Mutation of tyrosine-143 of Dictyostelium actin changed actin polymerizability. •The bulkiness or aromatic nature of Tyr143 is important for the weak binding. •The weak interaction between myosin and actin strengthened by Tyr143Trp mutation. -- Abstract: Actin filaments (F-actin) interact with myosin and activate its ATPase to support force generation. By comparing crystal structures of G-actin and the quasi-atomic model of F-actin based on high-resolution cryo-electron microscopy, the tyrosine-143 was found to be exposed more than 60 Å{sup 2} to the solvent in F-actin. Because tyrosine-143 flanks the hydrophobic cleft near the hydrophobic helix that binds to myosin, the mutant actins, of which the tyrosine-143 was replaced with tryptophan, phenylalanine, or isoleucine, were generated using the Dictyostelium expression system. It polymerized significantly poorly when induced by NaCl, but almost normally by KCl. In the presence of phalloidin and KCl, the extents of the polymerization of all the mutant actins were comparable to that of the wild-type actin so that the actin-activated myosin ATPase activity could be reliably compared. The affinity of skeletal heavy meromyosin to F-actin and the maximum ATPase activity (V{sub max}) were estimated by a double reciprocal plot. The Tyr143Trp-actin showed the higher affinity (smaller K{sub app}) than that of the wild-type actin, with the V{sub max} being almost unchanged. The K{sub app} and V{sub max} of the Tyr143Phe-actin were similar to those of the wild-type actin. However, the activation by Tyr143Ile-actin was much smaller than the wild-type actin and the accurate determination of K{sub app} was difficult. Comparison of the myosin ATPase activated by the various mutant actins at the same concentration of F-actin showed that the extent of activation correlates well with the solvent-accessible surface areas (ASA

  14. The interplay between viscoelastic and thermodynamic properties determines the birefringence of F-actin gels.

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    Helfer, Emmanuèle; Panine, Pierre; Carlier, Marie-France; Davidson, Patrick

    2005-07-01

    F-actin gels of increasing concentrations (25-300 microM) display in vitro a progressive onset of birefringence due to orientational ordering of actin filaments. At F-actin concentrations mechanical stresses stored in the gels. In contrast, at F-actin concentrations > or =100 microM, gels display spontaneous birefringence recovery, at rest, which is the sign of true nematic ordering, in good agreement with statistical physics models of the isotropic/nematic transition. Well-aligned samples of F-actin gels could be produced and their small-angle x-ray scattering patterns are quite anisotropic. These patterns show no sign of filament positional short-range order and could be modeled by averaging the form factor with the Maier-Saupe nematic distribution function. The derived nematic order parameter S of the gels ranged from S = 0.7 at 300 microM to S = 0.4 at 25 microM. Both birefringence and small-angle x-ray scattering data indicate that, even in absence of cross-linking proteins, spontaneous cooperative alignment of actin filaments may arise in motile regions of living cells where F-actin concentrations can reach values of a few 100 microM.

  15. A new F-actin structure in fungi: actin ring formation around the cell nucleus of Cryptococcus neoformans.

    Science.gov (United States)

    Kopecká, Marie; Kawamoto, Susumu; Yamaguchi, Masashi

    2013-04-01

    The F-actin cytoskeleton of Cryptococcus neoformans is known to comprise actin cables, cortical patches and cytokinetic ring. Here, we describe a new F-actin structure in fungi, a perinuclear F-actin collar ring around the cell nucleus, by fluorescent microscopic imaging of rhodamine phalloidin-stained F-actin. Perinuclear F-actin rings form in Cryptococcus neoformans treated with the microtubule inhibitor Nocodazole or with the drug solvent dimethyl sulfoxide (DMSO) or grown in yeast extract peptone dextrose (YEPD) medium, but they are absent in cells treated with Latrunculin A. Perinuclear F-actin rings may function as 'funicular cabin' for the cell nucleus, and actin cables as intracellular 'funicular' suspending nucleus in the central position in the cell and moving nucleus along the polarity axis along actin cables.

  16. F-actin distribution at nodes of Ranvier and Schmidt-Lanterman incisures in mammalian sciatic nerves.

    Science.gov (United States)

    Kun, Alejandra; Canclini, Lucía; Rosso, Gonzalo; Bresque, Mariana; Romeo, Carlos; Hanusz, Alicia; Cal, Karina; Calliari, Aldo; Sotelo Silveira, José; Sotelo, José R

    2012-07-01

    Very little is known about the function of the F-actin cytoskeleton in the regeneration and pathology of peripheral nerve fibers. The actin cytoskeleton has been associated with maintenance of tissue structure, transmission of traction and contraction forces, and an involvement in cell motility. Therefore, the state of the actin cytoskeleton strongly influences the mechanical properties of cells and intracellular transport therein. In this work, we analyze the distribution of F-actin at Schmidt-Lanterman Incisures (SLI) and nodes of Ranvier (NR) domains in normal, regenerating and pathologic Trembler J (TrJ/+) sciatic nerve fibers, of rats and mice. F-actin was quantified and it was found increased in TrJ/+, both in SLI and NR. However, SLI and NR of regenerating rat sciatic nerve did not show significant differences in F-actin, as compared with normal nerves. Cytochalasin-D and Latrunculin-A were used to disrupt the F-actin network in normal and regenerating rat sciatic nerve fibers. Both drugs disrupt F-actin, but in different ways. Cytochalasin-D did not disrupt Schwann cell (SC) F-actin at the NR. Latrunculin-A did not disrupt F-actin at the boundary region between SC and axon at the NR domain. We surmise that the rearrangement of F-actin in neurological disorders, as presented here, is an important feature of TrJ/+ pathology as a Charcot-Marie-Tooth (CMT) model. Copyright © 2012 Wiley Periodicals, Inc.

  17. Interactions between globular proteins and F-actin in isotonic saline solution.

    Science.gov (United States)

    Lakatos, S; Minton, A P

    1991-10-05

    Solutions of each of three different globular proteins (cytochrome c, chromophorically labeled serum albumin, and chromophorically labeled aldolase), mixed with another unlabeled globular protein or with fibrous actin, were prepared in pH 8.0 Tris-HCl buffer containing 0.15 M NaCl. Each solution was centrifuged at low speed, at 5 degrees C, until unassociated globular protein in solution achieved sedimentation equilibrium. Individual absorbance gradients of both macrosolutes in the mixtures subsequent to centrifugation were obtained via optical scans of the centrifuge tubes at two wavelengths. The gradients of each macrosolute in mixtures of two globular proteins revealed no association of globular proteins under the conditions of these experiments, but perturbation of the gradients of serum albumin, aldolase, and cytochrome c in the presence of F-actin indicated association of all three globular proteins with F-actin. Perturbation of actin gradients in the presence of serum albumin and aldolase suggested partial depolymerization of the F-actin by the globular protein. Analysis of the data with a simple phenomenological model relating free globular protein, bound globular protein, and total actin concentration provided estimates of the respective equilibrium constants for association of serum albumin and aldolase with F-actin, under the conditions of these experiments, of the order of 0.1 microM-1.

  18. Vacuole formation in mast cells responding to osmotic stress and to F-actin disassembly

    DEFF Research Database (Denmark)

    Koffer, Anna; Williams, Mark; Johansen, Torben

    2002-01-01

    Fluorescent probes were used to visualize the morphology of membranes and of F-actin in rat peritoneal mast cells, exposed to hyperosmotic medium and consequently reversed to isotonicity. Hypertonicity induced cell shrinkage followed by a regulatory volume increase, and cell alkalinization...

  19. Localization of sarcomeric proteins during myofibril assembly in cultured mouse primary skeletal myotubes

    Science.gov (United States)

    White, Jennifer; Barro, Marietta V.; Makarenkova, Helen P.; Sanger, Joseph W.; Sanger, Jean M.

    2014-01-01

    It is important to understand how muscle forms normally in order to understand muscle diseases that result in abnormal muscle formation. Although the structure of myofibrils is well understood, the process through which the myofibril components form organized contractile units is not clear. Based on the staining of muscle proteins in avian embryonic cardiomyocytes, we previously proposed that myofibrils formation occurred in steps that began with premyofibrils followed by nascent myofibrils and ending with mature myofibrils. The purpose of this study was to determine whether the premyofibril model of myofibrillogenesis developed from studies developed from studies in avian cardiomyocytes was supported by our current studies of myofibril assembly in mouse skeletal muscle. Emphasis was on establishing how the key sarcomeric proteins, F-actin, non-muscle myosin II, muscle myosin II, and α-actinin were organized in the three stages of myofibril assembly. The results also test previous reports that non-muscle myosins II A and B are components of the Z-Bands of mature myofibrils, data that are inconsistent with the premyofibril model. We have also determined that in mouse muscle cells, telethonin is a late assembling protein that is present only in the Z-Bands of mature myofibrils. This result of using specific telethonin antibodies supports the approach of using YFP-tagged proteins to determine where and when these YFP-sarcomeric fusion proteins are localized. The data presented in this study on cultures of primary mouse skeletal myocytes are consistent with the premyofibril model of myofibrillogenesis previously proposed for both avian cardiac and skeletal muscle cells. PMID:25125171

  20. Hyperosmotic stress induces Rho/Rho kinase/LIM kinase-mediated cofilin phosphorylation in tubular cells: key role in the osmotically triggered F-actin response

    DEFF Research Database (Denmark)

    Thirone, Ana C P; Speight, Pam; Zulys, Matthew

    2009-01-01

    Hyperosmotic stress induces cytoskeleton reorganization and a net increase in cellular F-actin, but the underlying mechanisms are incompletely understood. While de novo F-actin polymerization likely contributes to the actin response, the role of F-actin severing is unknown. To address this proble...

  1. Strong Dependence of Hydration State of F-Actin on the Bound Mg(2+)/Ca(2+) Ions.

    Science.gov (United States)

    Suzuki, Makoto; Imao, Asato; Mogami, George; Chishima, Ryotaro; Watanabe, Takahiro; Yamaguchi, Takaya; Morimoto, Nobuyuki; Wazawa, Tetsuichi

    2016-07-21

    Understanding of the hydration state is an important issue in the chemomechanical energetics of versatile biological functions of polymerized actin (F-actin). In this study, hydration-state differences of F-actin by the bound divalent cations are revealed through precision microwave dielectric relaxation (DR) spectroscopy. G- and F-actin in Ca- and Mg-containing buffer solutions exhibit dual hydration components comprising restrained water with DR frequency f2 (fw). The hydration state of F-actin is strongly dependent on the ionic composition. In every buffer tested, the HMW signal Dhyme (≡ (f1 - fw)δ1/(fwδw)) of F-actin is stronger than that of G-actin, where δw is DR-amplitude of bulk solvent and δ1 is that of HMW in a fixed-volume ellipsoid containing an F-actin and surrounding water in solution. Dhyme value of F-actin in Ca2.0-buffer (containing 2 mM Ca(2+)) is markedly higher than in Mg2.0-buffer (containing 2 mM Mg(2+)). Moreover, in the presence of 2 mM Mg(2+), the hydration state of F-actin is changed by adding a small fraction of Ca(2+) (∼0.1 mM) and becomes closer to that of the Ca-bound form in Ca2.0-buffer. This is consistent with the results of the partial specific volume and the Cotton effect around 290 nm in the CD spectra, indicating a change in the tertiary structure and less apparent change in the secondary structure of actin. The number of restrained water molecules per actin (N2) is estimated to be 1600-2100 for Ca2.0- and F-buffer and ∼2500 for Mg2.0-buffer at 10-15 °C. These numbers are comparable to those estimated from the available F-actin atomic structures as in the first water layer. The number of HMW molecules is roughly explained by the volume between the equipotential surface of -kT/2e and the first water layer of the actin surface by solving the Poisson-Boltzmann equation using UCSF Chimera.

  2. Possible interrelationship between changes in F-actin and myosin II, protein phosphorylation, and cell volume regulation in Ehrlich ascites tumor cells

    DEFF Research Database (Denmark)

    Pedersen, S F; Hoffmann, E K

    2002-01-01

    effects on F-actin. The subsequent F-actin depolymerization, however, appeared MLCK- and PKC-dependent, and the initial swelling-induced F-actin depolymerization was MLCK-dependent; both effects were apparently secondary to kinase-mediated effects on cell volume changes. NHE1 in EATC is activated both....... Moreover, Rho kinase inhibition did not significantly affect NHE1 activation, neither by shrinkage nor by CL-A. Implications for the possible interrelationship between changes in F-actin and myosin II, protein phosphorylation, and cell volume regulation are discussed....

  3. Control of Electrostatic Interactions Between F-Actin And Genetically Modified Lysozyme in Aqueous Media

    International Nuclear Information System (INIS)

    Sanders, L.K.; Xian, W.; Guaqueta, C.; Strohman, M.; Vrasich, C.R.; Luijten, E.; Wong, G.C.L.

    2009-01-01

    The aim for deterministic control of the interactions between macroions in aqueous media has motivated widespread experimental and theoretical work. Although it has been well established that like-charged macromolecules can aggregate under the influence of oppositely charged condensing agents, the specific conditions for the stability of such aggregates can only be determined empirically. We examine these conditions, which involve an interplay of electrostatic and osmotic effects, by using a well defined model system composed of F-actin, an anionic rod-like polyelectrolyte, and lysozyme, a cationic globular protein with a charge that can be genetically modified. The structure and stability of actin-lysozyme complexes for different lysozyme charge mutants and salt concentrations are examined by using synchrotron x-ray scattering and molecular dynamics simulations. We provide evidence that supports a structural transition from columnar arrangements of F-actin held together by arrays of lysozyme at the threefold interstitial sites of the actin sublattice to marginally stable complexes in which lysozyme resides at twofold bridging sites between actin. The reduced stability arises from strongly reduced partitioning of salt between the complex and the surrounding solution. Changes in the stability of actin-lysozyme complexes are of biomedical interest because their formation has been reported to contribute to the persistence of airway infections in cystic fibrosis by sequestering antimicrobials such as lysozyme. We present x-ray microscopy results that argue for the existence of actin-lysozyme complexes in cystic fibrosis sputum and demonstrate that, for a wide range of salt conditions, charge-reduced lysozyme is not sequestered in ordered complexes while retaining its bacterial killing activity.

  4. The RhoGAP Stard13 controls insulin secretion through F-actin remodeling

    Directory of Open Access Journals (Sweden)

    Heike Naumann

    2018-02-01

    Full Text Available Objective: Actin cytoskeleton remodeling is necessary for glucose-stimulated insulin secretion in pancreatic β-cells. A mechanistic understanding of actin dynamics in the islet is paramount to a better comprehension of β-cell dysfunction in diabetes. Here, we investigate the Rho GTPase regulator Stard13 and its role in F-actin cytoskeleton organization and islet function in adult mice. Methods: We used Lifeact-EGFP transgenic animals to visualize actin cytoskeleton organization and dynamics in vivo in the mouse islets. Furthermore, we applied this model to study actin cytoskeleton and insulin secretion in mutant mice deleted for Stard13 selectively in pancreatic cells. We isolated transgenic islets for 3D-imaging and perifusion studies to measure insulin secretion dynamics. In parallel, we performed histological and morphometric analyses of the pancreas and used in vivo approaches to study glucose metabolism in the mouse. Results: In this study, we provide the first genetic evidence that Stard13 regulates insulin secretion in response to glucose. Postnatally, Stard13 expression became restricted to the mouse pancreatic islets. We showed that Stard13 deletion results in a marked increase in actin polymerization in islet cells, which is accompanied by severe reduction of insulin secretion in perifusion experiments. Consistently, Stard13-deleted mice displayed impaired glucose tolerance and reduced glucose-stimulated insulin secretion. Conclusions: Taken together, our results suggest a previously unappreciated role for the RhoGAP protein Stard13 in the interplay between actin cytoskeletal remodeling and insulin secretion. Keywords: F-actin, Insulin secretion, Islet, Pancreas, Lifeact, Stard13

  5. Regulation of retinoschisin secretion in Weri-Rb1 cells by the F-actin and microtubule cytoskeleton.

    Directory of Open Access Journals (Sweden)

    Eiko Kitamura

    Full Text Available Retinoschisin is encoded by the gene responsible for X-linked retinoschisis (XLRS, an early onset macular degeneration that results in a splitting of the inner layers of the retina and severe loss in vision. Retinoschisin is predominantly expressed and secreted from photoreceptor cells as a homo-oligomer protein; it then associates with the surface of retinal cells and maintains the retina cellular architecture. Many missense mutations in the XLRS1 gene are known to cause intracellular retention of retinoschisin, indicating that the secretion process of the protein is a critical step for its normal function in the retina. However, the molecular mechanisms underlying retinoschisin's secretion remain to be fully elucidated. In this study, we investigated the role of the F-actin cytoskeleton in the secretion of retinoschisin by treating Weri-Rb1 cells, which are known to secrete retinoschisin, with cytochalasin D, jasplakinolide, Y-27632, and dibutyryl cGMP. Our results show that cytochalasin D and jasplakinolide inhibit retinoschisin secretion, whereas Y-27632 and dibutyryl cGMP enhance secretion causing F-actin alterations. We also demonstrate that high concentrations of taxol, which hyperpolymerizes microtubules, inhibit retinoschisin secretion. Our data suggest that retinoschisin secretion is regulated by the F-actin cytoskeleton, that cGMP or inhibition of ROCK alters F-actin structure enhancing the secretion, and that the microtubule cytoskeleton is also involved in this process.

  6. Regulation of Retinoschisin Secretion in Weri-Rb1 Cells by the F-Actin and Microtubule Cytoskeleton

    Science.gov (United States)

    Kitamura, Eiko; Gribanova, Yekaterina E.; Farber, Debora B.

    2011-01-01

    Retinoschisin is encoded by the gene responsible for X-linked retinoschisis (XLRS), an early onset macular degeneration that results in a splitting of the inner layers of the retina and severe loss in vision. Retinoschisin is predominantly expressed and secreted from photoreceptor cells as a homo-oligomer protein; it then associates with the surface of retinal cells and maintains the retina cellular architecture. Many missense mutations in the XLRS1 gene are known to cause intracellular retention of retinoschisin, indicating that the secretion process of the protein is a critical step for its normal function in the retina. However, the molecular mechanisms underlying retinoschisin's secretion remain to be fully elucidated. In this study, we investigated the role of the F-actin cytoskeleton in the secretion of retinoschisin by treating Weri-Rb1 cells, which are known to secrete retinoschisin, with cytochalasin D, jasplakinolide, Y-27632, and dibutyryl cGMP. Our results show that cytochalasin D and jasplakinolide inhibit retinoschisin secretion, whereas Y-27632 and dibutyryl cGMP enhance secretion causing F-actin alterations. We also demonstrate that high concentrations of taxol, which hyperpolymerizes microtubules, inhibit retinoschisin secretion. Our data suggest that retinoschisin secretion is regulated by the F-actin cytoskeleton, that cGMP or inhibition of ROCK alters F-actin structure enhancing the secretion, and that the microtubule cytoskeleton is also involved in this process. PMID:21738583

  7. The F-actin modifier villin regulates insulin granule dynamics and exocytosis downstream of islet cell autoantigen 512

    Directory of Open Access Journals (Sweden)

    Hassan Mziaut

    2016-08-01

    Full Text Available Objective: Insulin release from pancreatic islet β cells should be tightly controlled to avoid hypoglycemia and insulin resistance. The cortical actin cytoskeleton is a gate for regulated exocytosis of insulin secretory granules (SGs by restricting their mobility and access to the plasma membrane. Prior studies suggest that SGs interact with F-actin through their transmembrane cargo islet cell autoantigen 512 (Ica512 (also known as islet antigen 2/Ptprn. Here we investigated how Ica512 modulates SG trafficking and exocytosis. Methods: Transcriptomic changes in Ica512−/− mouse islets were analyzed. Imaging as well as biophysical and biochemical methods were used to validate if and how the Ica512-regulated gene villin modulates insulin secretion in mouse islets and insulinoma cells. Results: The F-actin modifier villin was consistently downregulated in Ica512−/− mouse islets and in Ica512-depleted insulinoma cells. Villin was enriched at the cell cortex of β cells and dispersed villin−/− islet cells were less round and less deformable. Basal mobility of SGs in villin-depleted cells was enhanced. Moreover, in cells depleted either of villin or Ica512 F-actin cages restraining cortical SGs were enlarged, basal secretion was increased while glucose-stimulated insulin release was blunted. The latter changes were reverted by overexpressing villin in Ica512-depleted cells, but not vice versa. Conclusion: Our findings show that villin controls the size of the F-actin cages restricting SGs and, thus, regulates their dynamics and availability for exocytosis. Evidence that villin acts downstream of Ica512 also indicates that SGs directly influence the remodeling properties of the cortical actin cytoskeleton for tight control of insulin secretion. Keywords: F-actin, Granules, Ica512, Insulin, Secretion, Villin

  8. Protein Kinases Possibly Mediate Hypergravity-Induced Changes in F-Actin Expression by Endothelial Cells

    Science.gov (United States)

    Love, Felisha D.; Melhado, Caroline D.; Bosah, Francis N.; Harris-Hooker, Sandra A.; Sanford, Gary L.

    1998-01-01

    Basic cellular functions such as electrolyte concentration, cell growth rate, glucose utilization, bone formation, response to growth stimulation, and exocytosis are modified in microgravity. These studies indicate that microgravity affects a number of physiological systems and included in this are cell signaling mechanisms. Rijken and coworkers performed growth factor studies that showed PKC signaling and actin microfilament organization appears to be sensitive to microgravity, suggesting that the inhibition of signal transduction by microgravity may be related to alterations in actin microfilament organization. However, similar studies have not been done for vascular cells. Vascular endothelial cells play critical roles in providing nutrients to organ and tissues and in wound repair. The major deterrent to ground-based microgravity studies is that it is impossible to achieved true microgravity for longer than a few minutes on earth. Hence, it has not been possible to conduct prolonged microgravity studies except for two models that simulate certain aspects of microgravity. However, hypergravity is quite easily achieved. Several researchers have shown that hypergravity will increase the proliferation of several different cell lines while decreasing cell motility and slowing liver regeneration following partial hepatectomy, These studies indicate the hypergravity also alters the behavior of most cells. Several investigators have shown that hypergravity affects the activation of several protein kinases (PKs) in cells. In this study, we investigated whether hypergravity alters the expression of f-actin by bovine aortic endothelial cells (BAECs) and the role of PK's (calmodulin 11 dependent, PKA and PKC) as mediators of these effects.

  9. Identification of interfaces involved in weak interactions with application to F-actin-aldolase rafts.

    Science.gov (United States)

    Hu, Guiqing; Taylor, Dianne W; Liu, Jun; Taylor, Kenneth A

    2018-03-01

    Macromolecular interactions occur with widely varying affinities. Strong interactions form well defined interfaces but weak interactions are more dynamic and variable. Weak interactions can collectively lead to large structures such as microvilli via cooperativity and are often the precursors of much stronger interactions, e.g. the initial actin-myosin interaction during muscle contraction. Electron tomography combined with subvolume alignment and classification is an ideal method for the study of weak interactions because a 3-D image is obtained for the individual interactions, which subsequently are characterized collectively. Here we describe a method to characterize heterogeneous F-actin-aldolase interactions in 2-D rafts using electron tomography. By forming separate averages of the two constituents and fitting an atomic structure to each average, together with the alignment information which relates the raw motif to the average, an atomic model of each crosslink is determined and a frequency map of contact residues is computed. The approach should be applicable to any large structure composed of constituents that interact weakly and heterogeneously. Copyright © 2017 Elsevier Inc. All rights reserved.

  10. Dynamics of F-actin prefigure the structure of butterfly wing scales.

    Science.gov (United States)

    Dinwiddie, April; Null, Ryan; Pizzano, Maria; Chuong, Lisa; Leigh Krup, Alexis; Ee Tan, Hwei; Patel, Nipam H

    2014-08-15

    The wings of butterflies and moths consist of dorsal and ventral epidermal surfaces that give rise to overlapping layers of scales and hairs (Lepidoptera, "scale wing"). Wing scales (average length ~200 µm) are homologous to insect bristles (macrochaetes), and their colors create the patterns that characterize lepidopteran wings. The topology and surface sculpture of wing scales vary widely, and this architectural complexity arises from variations in the developmental program of the individual scale cells of the wing epithelium. One of the more striking features of lepidopteran wing scales are the longitudinal ridges that run the length of the mature (dead) cell, gathering the cuticularized scale cell surface into pleats on the sides of each scale. While also present around the periphery of other insect bristles and hairs, longitudinal ridges in lepidopteran wing scales gain new significance for their creation of iridescent color through microribs and lamellae. Here we show the dynamics of the highly organized F-actin filaments during scale cell development, and present experimental manipulations of actin polymerization that reveal the essential role of this cytoskeletal component in wing scale elongation and the positioning of longitudinal ribs. Copyright © 2014 Elsevier Inc. All rights reserved.

  11. Adhesive F-actin Waves: A Novel Integrin-Mediated Adhesion Complex Coupled to Ventral Actin Polymerization

    OpenAIRE

    Case, Lindsay B.; Waterman, Clare M.

    2011-01-01

    At the leading lamellipodium of migrating cells, protrusion of an Arp2/3-nucleated actin network is coupled to formation of integrin-based adhesions, suggesting that Arp2/3-mediated actin polymerization and integrin-dependent adhesion may be mechanistically linked. Arp2/3 also mediates actin polymerization in structures distinct from the lamellipodium, in "ventral F-actin waves" that propagate as spots and wavefronts along the ventral plasma membrane. Here we show that integrins engage the ex...

  12. F-actin-based Ca signaling-a critical comparison with the current concept of Ca signaling.

    Science.gov (United States)

    Lange, Klaus; Gartzke, Joachim

    2006-11-01

    A short comparative survey on the current idea of Ca signaling and the alternative concept of F-actin-based Ca signaling is given. The two hypotheses differ in one central aspect, the mechanism of Ca storage. The current theory rests on the assumption of Ca-accumulating endoplasmic/sarcoplasmic reticulum-derived vesicles equipped with an ATP-dependent Ca pump and IP3- or ryanodine-sensitive channel-receptors for Ca-release. The alternative hypothesis proceeds from the idea of Ca storage at the high-affinity binding sites of actin filaments. Cellular sites of F-actin-based Ca storage are microvilli and the submembrane cytoskeleton. Several specific features of Ca signaling such as store-channel coupling, quantal Ca release, spiking and oscillations, biphasic and "phasic" uptake kinetics, and Ca-induced Ca release (CICR), which are not adequately described by the current concept, are inherent properties of the F-actin system and its dynamic state of treadmilling. Copyright 2006 Wiley-Liss, Inc.

  13. A nanobody targeting the F-actin capping protein CapG restrains breast cancer metastasis.

    Science.gov (United States)

    Van Impe, Katrien; Bethuyne, Jonas; Cool, Steven; Impens, Francis; Ruano-Gallego, David; De Wever, Olivier; Vanloo, Berlinda; Van Troys, Marleen; Lambein, Kathleen; Boucherie, Ciska; Martens, Evelien; Zwaenepoel, Olivier; Hassanzadeh-Ghassabeh, Gholamreza; Vandekerckhove, Joël; Gevaert, Kris; Fernández, Luis Ángel; Sanders, Niek N; Gettemans, Jan

    2013-12-13

    Aberrant turnover of the actin cytoskeleton is intimately associated with cancer cell migration and invasion. Frequently however, evidence is circumstantial, and a reliable assessment of the therapeutic significance of a gene product is offset by lack of inhibitors that target biologic properties of a protein, as most conventional drugs do, instead of the corresponding gene. Proteomic studies have demonstrated overexpression of CapG, a constituent of the actin cytoskeleton, in breast cancer. Indirect evidence suggests that CapG is involved in tumor cell dissemination and metastasis. In this study, we used llama-derived CapG single-domain antibodies or nanobodies in a breast cancer metastasis model to address whether inhibition of CapG activity holds therapeutic merit. We raised single-domain antibodies (nanobodies) against human CapG and used these as intrabodies (immunomodulation) after lentiviral transduction of breast cancer cells. Functional characterization of nanobodies was performed to identify which biochemical properties of CapG are perturbed. Orthotopic and tail vein in vivo models of metastasis in nude mice were used to assess cancer cell spreading. With G-actin and F-actin binding assays, we identified a CapG nanobody that binds with nanomolar affinity to the first CapG domain. Consequently, CapG interaction with actin monomers or actin filaments is blocked. Intracellular delocalization experiments demonstrated that the nanobody interacts with CapG in the cytoplasmic environment. Expression of the nanobody in breast cancer cells restrained cell migration and Matrigel invasion. Notably, the nanobody prevented formation of lung metastatic lesions in orthotopic xenograft and tail-vein models of metastasis in immunodeficient mice. We showed that CapG nanobodies can be delivered into cancer cells by using bacteria harboring a type III protein secretion system (T3SS). CapG inhibition strongly reduces breast cancer metastasis. A nanobody-based approach offers

  14. Plasma Gelsolin Levels Decrease in Diabetic State and Increase upon Treatment with F-Actin Depolymerizing Versions of Gelsolin

    Directory of Open Access Journals (Sweden)

    Neeraj Khatri

    2014-01-01

    Full Text Available The study aims to map plasma gelsolin (pGSN levels in diabetic humans and mice models of type II diabetes and to evaluate the efficacy of gelsolin therapy in improvement of diabetes in mice. We report that pGSN values decrease by a factor of 0.45 to 0.5 in the blood of type II diabetic humans and mice models. Oral glucose tolerance test in mice models showed that subcutaneous administration of recombinant pGSN and its F-actin depolymerizing competent versions brought down blood sugar levels comparable to Sitagliptin, a drug used to manage hyperglycemic condition. Further, daily dose of pGSN or its truncated versions to diabetic mice for a week kept sugar levels close to normal values. Also, diabetic mice treated with Sitagliptin for 7 days, showed increase in their pGSN values with the decrease in blood glucose as compared to their levels at the start of treatment. Gelsolin helped in improving glycemic control in diabetic mice. We propose that gelsolin level monitoring and replacement of F-actin severing capable gelsolin(s should be considered in diabetic care.

  15. The effect of Cytochalasin D on F-Actin behavior of single-cell electroendocytosis using multi-chamber micro cell chip

    KAUST Repository

    Lin, Ran

    2012-03-01

    Electroendocytosis (EED) is a pulsed-electric-field (PEF) induced endocytosis, facilitating cells uptake molecules through nanometer-sized EED vesicles. We herein investigate the effect of a chemical inhibitor, Cytochalasin D (CD) on the actin-filaments (F-Actin) behavior of single-cell EED. The CD concentration (C CD) can control the depolymerization of F-actin. A multi-chamber micro cell chip was fabricated to study the EED under different conditions. Large-scale single-cell data demonstrated EED highly depends on both electric field and C CD. © 2012 IEEE.

  16. The effect of Cytochalasin D on F-Actin behavior of single-cell electroendocytosis using multi-chamber micro cell chip

    KAUST Repository

    Lin, Ran; Chang, Donald C.; Lee, Yi Kuen

    2012-01-01

    Electroendocytosis (EED) is a pulsed-electric-field (PEF) induced endocytosis, facilitating cells uptake molecules through nanometer-sized EED vesicles. We herein investigate the effect of a chemical inhibitor, Cytochalasin D (CD) on the actin-filaments (F-Actin) behavior of single-cell EED. The CD concentration (C CD) can control the depolymerization of F-actin. A multi-chamber micro cell chip was fabricated to study the EED under different conditions. Large-scale single-cell data demonstrated EED highly depends on both electric field and C CD. © 2012 IEEE.

  17. Cell swelling activates cloned Ca(2+)-activated K(+) channels: a role for the F-actin cytoskeleton

    DEFF Research Database (Denmark)

    Jorgensen, Nanna K; Pedersen, Stine F; Rasmussen, Hanne B

    2003-01-01

    Cloned Ca(2+)-activated K(+) channels of intermediate (hIK) or small (rSK3) conductance were expressed in HEK 293 cells, and channel activity was monitored using whole-cell patch clamp. hIK and rSK3 currents already activated by intracellular calcium were further increased by 95% and 125......%, respectively, upon exposure of the cells to a 33% decrease in extracellular osmolarity. hIK and rSK3 currents were inhibited by 46% and 32%, respectively, by a 50% increase in extracellular osmolarity. Cell swelling and channel activation were not associated with detectable increases in [Ca(2+)](i), evidenced...... by population and single-cell measurements. In addition, inhibitors of IK and SK channels significantly reduced the rate of regulatory volume decrease (RVD) in cells expressing these channels. Cell swelling induced a decrease, and cell shrinkage an increase, in net cellular F-actin content. The swelling...

  18. Localized synthesis, assembly and integration of silicon nanowires

    Science.gov (United States)

    Englander, Ongi

    Localized synthesis, assembly and integration of one-dimensional silicon nanowires with MEMS structures is demonstrated and characterized in terms of local synthesis processes, electric-field assisted self-assembly, and a proof-of-concept nanoelectromechanical system (HEMS) demonstration. Emphasis is placed on the ease of integration, process control strategies, characterization techniques and the pursuit of integrated devices. A top-down followed by a bottom-up integration approach is utilized. Simple MEMS heater structures are utilized as the microscale platforms for the localized, bottom-up synthesis of one-dimensional nanostructures. Localized heating confines the high temperature region permitting only localized nanostructure synthesis and allowing the surroundings to remain at room temperature thus enabling CMOS compatible post-processing. The vapor-liquid-solid (VLS) process in the presence of a catalytic nanoparticle, a vapor phase reactant, and a specific temperature environment is successfully employed locally. Experimentally, a 5nm thick gold-palladium layer is used as the catalyst while silane is the vapor phase reactant. The current-voltage behavior of the MEMS structures can be correlated to the approximate temperature range required for the VLS reaction to take place. Silicon nanowires averaging 45nm in diameter and up to 29mum in length synthesized at growth rates of up to 1.5mum/min result. By placing two MEMS structures in close proximity, 4--10mum apart, localized silicon nanowire growth can be used to link together MEMS structures to yield a two-terminal, self-assembled micro-to-nano system. Here, one MEMS structure is designated as the hot growth structure while a nearby structure is designated as the cold secondary structure, whose role is to provide a natural stopping point for the VLS reaction. The application of a localized electric-field, 5 to 13V/mum in strength, during the synthesis process, has been shown to improve nanowire

  19. Mitochondrial Dysfunction, Disruption of F-Actin Polymerization, and Transcriptomic Alterations in Zebrafish Larvae Exposed to Trichloroethylene.

    Science.gov (United States)

    Wirbisky, Sara E; Damayanti, Nur P; Mahapatra, Cecon T; Sepúlveda, Maria S; Irudayaraj, Joseph; Freeman, Jennifer L

    2016-02-15

    Trichloroethylene (TCE) is primarily used as an industrial degreasing agent and has been in use since the 1940s. TCE is released into the soil, surface, and groundwater. From an environmental and regulatory standpoint, more than half of Superfund hazardous waste sites on the National Priority List are contaminated with TCE. Occupational exposure to TCE occurs primarily via inhalation, while environmental TCE exposure also occurs through ingestion of contaminated drinking water. Current literature links TCE exposure to various adverse health effects including cardiovascular toxicity. Current studies aiming to address developmental cardiovascular toxicity utilized rodent and avian models, with the majority of studies using relatively higher parts per million (mg/L) doses. In this study, to further investigate developmental cardiotoxicity of TCE, zebrafish embryos were treated with 0, 10, 100, or 500 parts per billion (ppb; μg/L) TCE during embryogenesis and/or through early larval stages. After the appropriate exposure period, angiogenesis, F-actin, and mitochondrial function were assessed. A significant dose-response decrease in angiogenesis, F-actin, and mitochondrial function was observed. To further complement this data, a transcriptomic profile of zebrafish larvae was completed to identify gene alterations associated with the 10 ppb TCE exposure. Results from the transcriptomic data revealed that embryonic TCE exposure caused significant changes in genes associated with cardiovascular disease, cancer, and organismal injury and abnormalities with a number of targets in the FAK signaling pathway. Overall, results from our study support TCE as a developmental cardiovascular toxicant, provide molecular targets and pathways for investigation in future studies, and indicate a need for continued priority for environmental regulation.

  20. Xijiao Dihuang Decoction combined with Yinqiao Powder reverses influenza virus-induced F-actin reorganization in PMVECs by inhibiting ERM phosphorylation

    Directory of Open Access Journals (Sweden)

    Zinan Xuan

    2016-01-01

    Conclusion: These results show that XDY-CS inhibited influenza-induced F-actin reorganization in PMVECs by down-regulating p-ERM expression via inhibition of the Rho/ROCK, p38 MAPK, and PKC pathways. In conclusion, XDY could reduce the damage to endothelial cytoskeleton induced by IV infection, thus protecting the barriers of PMVECs.

  1. High level of reactive oxygen species impaired mesenchymal stem cell migration via overpolymerization of F-actin cytoskeleton in systemic lupus erythematosus.

    Science.gov (United States)

    Shi, D; Li, X; Chen, H; Che, N; Zhou, S; Lu, Z; Shi, S; Sun, L

    2014-12-01

    Some lines of evidence have demonstrated abnormalities of bone marrow mesenchymal stem cells (MSCs) in systemic lupus erythematosus (SLE) patients, characterized by defective phenotype of MSCs and slower growth with enhanced apoptosis and senescence. However, whether SLE MSCs demonstrate aberrant migration capacity or abnormalities in cytoskeleton are issues that remain poorly understood. In this study, we found that MSCs from SLE patients did show impairment in migration capacity as well as abnormalities in F-actin cytoskeleton, accompanied by a high level of intracellular reactive oxygen species (ROS). When normal MSCs were treated in vitro with H2O2, which increases intracellular ROS level as an oxidant, both reorganization of F-actin cytoskeleton and impairment of migration capability were observed. On the other hand, treatment with N-acetylcysteine (NAC), as an exogenous antioxidant, made F-actin more orderly and increased migration ratio in SLE MSCs. In addition, oral administration of NAC markedly reduced serum autoantibody levels and ameliorated lupus nephritis (LN) in MRL/lpr mice, partially reversing the abnormalities of MSCs. These results indicate that overpolymerization of F-actin cytoskeleton, which may be associated with high levels of ROS, causes impairment in the migration capacity of SLE MSCs and that oral administration of NAC may have potential therapeutic effects on MRL/lpr mice. Copyright © 2014 Elsevier Masson SAS. All rights reserved.

  2. A critical comparison of the current view of Ca signaling with the novel concept of F-actin-based Ca signaling.

    Science.gov (United States)

    Lange, Klaus; Gartzke, Joachim

    2006-01-01

    A detailed comparative survey on the current idea of Ca signaling and the alternative concept of F-actin-based Ca signaling is given. The two hypotheses differ in one central aspect - the mechanism of Ca storage. The current theory rests on the assumption of Ca-accumulating vesicles derived from the endoplasmic/ sarcoplasmic reticulum, which are equipped with an ATP-dependent Ca pump and IP3- or ryanodine-sensitive Ca-release channels/receptors. The alternative hypothesis proceeds from the idea of Ca storage at the high-affinity binding sites of F-actin subunits. Several prominent features of Ca signaling, which are not adequately described by the current concept, are inherent properties of the F-actin system and its dynamic state of treadmilling. F-actin is the only known biological Ca-binding system that has been proven by in vitro experiments to work within the physiological range of Ca concentrations and the only system that meets all necessary conditions to function as receptor-operated Ca store and as a coupling device between the Ca store and the store-operated Ca influx pathway. The most important properties of Ca signaling, such as store-channel coupling, quantal Ca release, spiking and oscillations, biphasic and "phasic" uptake kinetics, and Ca-induced Ca release, turn out to be systematic features of the new concept but remain unexplained by the classical vesicle storage hypothesis. A number of novel findings, specifically recent reports about direct effects of actin-specific toxins on Ca stores, have strengthened the new concept. The concept of F-actin-based Ca signaling combined with the notion of microvillar regulation of ion and substrate fluxes opens new aspects and far-reaching consequences, not only for cellular Ca signaling but also for various other cell functions, and represents an opportunity to connect several fields of cell physiology on the basis of a common mechanism.

  3. Cholesterol modulates the volume-regulated anion current in Ehrlich-Lettre ascites cells via effects on Rho and F-actin

    DEFF Research Database (Denmark)

    Klausen, Thomas Kjaer; Hougaard, Charlotte; Hoffmann, Else K

    2006-01-01

    swollen cells, this reduction was prevented by cholesterol depletion, which also increased isotonic Rho activity. Thrombin, which stimulates Rho and causes actin polymerization, potentiated VRAC in modestly swollen cells. VRAC activity was unaffected by inclusion of a water-soluble PtdIns(4,5)P(2......) analogue or a PtdIns(4,5)P(2)-blocking antibody in the pipette, or neomycin treatment to sequester PtdIns(4,5)P(2). It is suggested that in ELA cells, F-actin and Rho-Rho kinase modulate VRAC magnitude and activation rate, respectively, and that cholesterol depletion potentiates VRAC at least in part......The mechanisms controlling the volume-regulated anion current (VRAC) are incompletely elucidated. Here, we investigate the modulation of VRAC by cellular cholesterol and the potential involvement of F-actin, Rho, Rho kinase, and phosphatidylinositol-(4,5)-bisphosphate [PtdIns(4,5)P(2...

  4. Platelet rich plasma promotes skeletal muscle cell migration in association with up-regulation of FAK, paxillin, and F-Actin formation.

    Science.gov (United States)

    Tsai, Wen-Chung; Yu, Tung-Yang; Lin, Li-Ping; Lin, Mioa-Sui; Tsai, Ting-Ta; Pang, Jong-Hwei S

    2017-11-01

    Platelet rich plasma (PRP) contains various cytokines and growth factors which may be beneficial to the healing process of injured muscle. The aim of this study was to investigate the effect and molecular mechanism of PRP on migration of skeletal muscle cells. Skeletal muscle cells intrinsic to Sprague-Dawley rats were treated with PRP. The cell migration was evaluated by transwell filter migration assay and electric cell-substrate impedance sensing. The spreading of cells was evaluated microscopically. The formation of filamentous actin (F-actin) cytoskeleton was assessed by immunofluorescence staining. The protein expressions of paxillin and focal adhesion kinase (FAK) were assessed by Western blot analysis. Transfection of paxillin small-interfering RNA (siRNAs) to muscle cells was performed to validate the role of paxillin in PRP-mediated promotion of cell migration. Dose-dependently PRP promotes migration of and spreading and muscle cells. Protein expressions of paxillin and FAK were up-regulated dose-dependently. F-actin formation was also enhanced by PRP treatment. Furthermore, the knockdown of paxillin expression impaired the effect of PRP to promote cell migration. It was concluded that PRP promoting migration of muscle cells is associated with up-regulation of proteins expression of paxillin and FAK as well as increasing F-actin formation. © 2017 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 35:2506-2512, 2017. © 2017 Orthopaedic Research Society. Published by Wiley Periodicals, Inc.

  5. Involvement of Gβγ subunits of Gi protein coupled with S1P receptor on multivesicular endosomes in F-actin formation and cargo sorting into exosomes.

    Science.gov (United States)

    Kajimoto, Taketoshi; Mohamed, Nesma Nabil Ibrahim; Badawy, Shaymaa Mohamed Mohamed; Matovelo, Shubi Ambwene; Hirase, Mitsuhiro; Nakamura, Shunsuke; Yoshida, Daisuke; Okada, Taro; Ijuin, Takeshi; Nakamura, Shun-Ichi

    2018-01-05

    Exosomes play a critical role in cell-to-cell communication by delivering cargo molecules to recipient cells. However, the mechanism underlying the generation of the exosomal multivesicular endosome (MVE) is one of the mysteries in the field of endosome research. Although sphingolipid metabolites such as ceramide and sphingosine 1-phosphate (S1P) are known to play important roles in MVE formation and maturation, the detailed molecular mechanisms are still unclear. Here, we show that Rho family GTPases, including Cdc42 and Rac1, are constitutively activated on exosomal MVEs and are regulated by S1P signaling as measured by fluorescence resonance energy transfer (FRET)-based conformational changes. Moreover, we detected S1P signaling-induced filamentous actin (F-actin) formation. A selective inhibitor of Gβγ subunits, M119, strongly inhibited both F-actin formation on MVEs and cargo sorting into exosomal intralumenal vesicles of MVEs, both of which were fully rescued by the simultaneous expression of constitutively active Cdc42 and Rac1. Our results shed light on the mechanism underlying exosomal MVE maturation and inform the understanding of the physiological relevance of continuous activation of the S1P receptor and subsequent downstream G protein signaling to Gβγ subunits/Rho family GTPases-regulated F-actin formation on MVEs for cargo sorting into exosomal intralumenal vesicles. © 2018 by The American Society for Biochemistry and Molecular Biology, Inc.

  6. Calmodulin-Dependent Protein Kinase mediates Hypergravity-Induced Changes in F-Actin Expression by Endothelial Cells

    Science.gov (United States)

    Love, Felisha D.; Melhado, Caroline; Bosah, Francis; Harris-Hooker, Sandra A.; Sanford, Gary L.

    1997-01-01

    A number of basic cellular functions, e.g., electrolyte concentration cell growth rate, glucose utilization, bone formation, response to growth stimulation and exocytosis are modified by microgravity or during spaceflight. Studies with intact animal during spaceflights have found lipid accumulations within the lumen of the vasculature and degeneration of the vascular wall. Capillary alterations with extensive endothelial invaginations were also seen. Hemodynamic studies have shown that there is a redistribution of blood from the lower extremities to the upper part of the body; this will alter vascular permeability, resulting in leakage into surrounding tissues. These studies indicate that changes in gravity will affect a number of physiological systems, including the vasculature. However, few studies have addressed the effect of microgravity on vascular cell function and metabolism. A major problem with ground based studies is that achieving a true microgravity hand, environment for prolonged period is not possible. On the other increasing gravity (i.e., hypergravity) is easily achieved. Several researchers have shown that hypergravity will increase the proliferation of several different cell limes (e.g., chick embryo fibroblasts) while decreasing cell motility and slowing liver regeneration following partial hepatectomy. These studies suggest that hypergravity will alter the behavior of most cells. Several investigators have shown that hypergravity affects the expression of the early response genes (c-fos and c-myc) and the activation of several protein kinases (PK's) in cells (10,11). In this study we investigated whether hypergravity alters the expression of f-actin by aortic endothelial cells, and the possible role of protein kinases (calmodulin(II)-dependent and PKA) as mediators of these effects.

  7. The F-Actin Binding Protein Cortactin Regulates the Dynamics of the Exocytotic Fusion Pore through its SH3 Domain

    Science.gov (United States)

    González-Jamett, Arlek M.; Guerra, María J.; Olivares, María J.; Haro-Acuña, Valentina; Baéz-Matus, Ximena; Vásquez-Navarrete, Jacqueline; Momboisse, Fanny; Martinez-Quiles, Narcisa; Cárdenas, Ana M.

    2017-01-01

    Upon cell stimulation, the network of cortical actin filaments is rearranged to facilitate the neurosecretory process. This actin rearrangement includes both disruption of the preexisting actin network and de novo actin polymerization. However, the mechanism by which a Ca2+ signal elicits the formation of new actin filaments remains uncertain. Cortactin, an actin-binding protein that promotes actin polymerization in synergy with the nucleation promoting factor N-WASP, could play a key role in this mechanism. We addressed this hypothesis by analyzing de novo actin polymerization and exocytosis in bovine adrenal chromaffin cells expressing different cortactin or N-WASP domains, or cortactin mutants that fail to interact with proline-rich domain (PRD)-containing proteins, including N-WASP, or to be phosphorylated by Ca2+-dependent kinases, such as ERK1/2 and Src. Our results show that the activation of nicotinic receptors in chromaffin cells promotes cortactin translocation to the cell cortex, where it colocalizes with actin filaments. We further found that, in association with PRD-containing proteins, cortactin contributes to the Ca2+-dependent formation of F-actin, and regulates fusion pore dynamics and the number of exocytotic events induced by activation of nicotinic receptors. However, whereas the actions of cortactin on the fusion pore dynamics seems to depend on the availability of monomeric actin and its phosphorylation by ERK1/2 and Src kinases, cortactin regulates the extent of exocytosis by a mechanism independent of actin polymerization. Together our findings point out a role for cortactin as a critical modulator of actin filament formation and exocytosis in neuroendocrine cells. PMID:28522963

  8. Dual effect of F-actin targeted carrier combined with antimitotic drug on aggressive colorectal cancer cytoskeleton: Allying dissimilar cell cytoskeleton disrupting mechanisms.

    Science.gov (United States)

    Taranejoo, Shahrouz; Janmaleki, Mohsen; Pachenari, Mohammad; Seyedpour, Seyed Morteza; Chandrasekaran, Ramya; Cheng, Wenlong; Hourigan, Kerry

    2016-11-20

    A recent approach to colon cancer therapy is to employ selective drugs with specific extra/intracellular sites of action. Alteration of cytoskeletal protein reorganization and, subsequently, to cellular biomechanical behaviour during cancer progression highly affects the cancer cell progress. Hence, cytoskeleton targeted drugs are an important class of cancer therapy agents. We have studied viscoelastic alteration of the human colon adenocarcinoma cell line, SW48, after treatment with a drug delivery system comprising chitosan as the carrier and albendazole as the microtubule-targeting agent (MTA). For the first time, we have evaluated the biomechanical characteristics of the cell line, using the micropipette aspiration (MA) method after treatment with drug delivery systems. Surprisingly, employing a chitosan-albendazole pair, in comparison with both neat materials, resulted in more significant change in the viscoelastic parameters of cells, including the elastic constants (K 1 and K 2 ) and the coefficient of viscosity (μ). This difference was more pronounced for cancer cells after 48h of the treatment. Microtubule and actin microfilament (F-actin) contents in the cell line were studied by immunofluorescent staining. Good agreement was observed between the mechanical characteristics results and microtubule/F-actin contents of the treated SW48 cell line, which declined after treatment. The results showed that chitosan affected F-actin more, while MTA was more effective for microtubules. Toxicity studies were performed against two cancer cell lines (SW48 and MCF10CA1h) and compared to normal cells, MCF10A. The results showed cancer selectiveness, safety of formulation, and enhanced anticancer efficacy of the CS/ABZ conjugate. This study suggests that employing such a suitable pair of drug-carriers with dissimilar sites of action, thus allying the different cell cytoskeleton disrupting mechanisms, may provide a more efficient cancer therapy approach. Copyright

  9. The connection between galaxy formation and the assembly of stellar halos in the Local Group

    NARCIS (Netherlands)

    Helmi, Amina

    I will review our current understanding of the assembly of stellar halos from a theoretical perspective. I will place particular emphasis on how observations of Local Group galaxies can be used to constrain the assembly history of both their stellar and dark matter halos. Finally I will focus on

  10. Nuclear localization of Schizosaccharomyces pombe Mcm2/Cdc19p requires MCM complex assembly.

    Science.gov (United States)

    Pasion, S G; Forsburg, S L

    1999-12-01

    The minichromosome maintenance (MCM) proteins MCM2-MCM7 are conserved eukaryotic replication factors that assemble in a heterohexameric complex. In fission yeast, these proteins are nuclear throughout the cell cycle. In studying the mechanism that regulates assembly of the MCM complex, we analyzed the cis and trans elements required for nuclear localization of a single subunit, Mcm2p. Mutation of any single mcm gene leads to redistribution of wild-type MCM subunits to the cytoplasm, and this redistribution depends on an active nuclear export system. We identified the nuclear localization signal sequences of Mcm2p and showed that these are required for nuclear targeting of other MCM subunits. In turn, Mcm2p must associate with other MCM proteins for its proper localization; nuclear localization of MCM proteins thus requires assembly of MCM proteins in a complex. We suggest that coupling complex assembly to nuclear targeting and retention ensures that only intact heterohexameric MCM complexes remain nuclear.

  11. WWER-440 control assembly local power peaking investigation on LR-0 reactor

    International Nuclear Information System (INIS)

    Mikus, J.

    2002-01-01

    This paper presents information concerning the local power peaking problem induced by the WWER-440 control assembly and the investigation possibilities on the light water, zero power reactor LR-0 at the Nuclear Research Institute (NRI) Rez plc. A brief description is given about the disposable control assembly model, experimental arrangement and conditions on the LR-0 reactor with regard to the earlier performed investigations as well as to the relevant measurements to be realized in the near future.(abstract)

  12. [Alterations in expression of F-actin and DNA of fluid shear stress treated-mesenchymal stem cells affected by titanium particles loading].

    Science.gov (United States)

    Wu, Jiang; Chen, Huiqing; Cao, Hui; Zhou, Jiang; Zhang, Li; Sung, K L

    2004-02-01

    Particulate wear debris within the bone-prosthesis microenvironment generated by normal wear and corrosion of orthopaedic implants is considered to be one of the main factors responsible for chronic aseptic inflammation and development of osteolysis in the long-term instability and failure of total joint arthroplasty. While the decrease in bone volume caused by wear debris-induced osteolysis could have been compensated by enough new bone matrix secreted by osteoblasts. Actually, the normal osteoblastic population depend on the regular differentiation and proliferation of their progenitor cells--bone marrow mesenchymal stem cells (MSCs). This study aims to investigate the potential mechanism for the rat MSCs cytotoxicity upon exposure to Titanium (Ti) particles. Rat mesenchymal stem cells (rMSCs) isolated from 3-month-old male Sprague-Dawley rats by Percoll intensity gradient method were cultured in DMEM medium (low glucose) supplemented with 10% fetal bovine serum, 100 U/ml penicillin, and 100 micrograms/ml streptomycin in a humidified incubator with 5% CO2 at 37 degrees C. In order to gain the homogenous cell population, rMSCs were passaged to 3-4th subpassage which were used in all the experiment groups. Then rMSCs were seeded in the 6 well culture plates and exposed to three different circle diameters (mean size, TD1: 0.9 micron, TD2: 2.7 microns, TD3: 6.9 microns) with three different concentrations (0.1 wt%, 0.05 wt%, 0.01 wt%, W/V) at different durations (8 h, 16 h, 24 h,), respectively. Unexposed rMSCs were used as control. In the given periods of Ti loading, fluid shear stress (FSS) was applied to each group cells. The expression of F-actin and DNA of the rMSCs at the indicated time were determined with laser confocal scanning microscopy and image analysis software. The results showed that there was up-regulation expression of F-actin in the rMSCs without Ti particles loading but in the presence of FSS. Ti particles loading can suppress the expression of F

  13. Primary assembly of soil communities: disentangling the effect of dispersal and local environment.

    Science.gov (United States)

    Ingimarsdóttir, María; Caruso, Tancredi; Ripa, Jörgen; Magnúsdóttir, Olöf Birna; Migliorini, Massimo; Hedlund, Katarina

    2012-11-01

    It has long been recognised that dispersal abilities and environmental factors are important in shaping invertebrate communities, but their relative importance for primary soil community assembly has not yet been disentangled. By studying soil communities along chronosequences on four recently emerged nunataks (ice-free land in glacial areas) in Iceland, we replicated environmental conditions spatially at various geographical distances. This allowed us to determine the underlying factors of primary community assembly with the help of metacommunity theories that predict different levels of dispersal constraints and effects of the local environment. Comparing community assembly of the nunataks with that of non-isolated deglaciated areas indicated that isolation of a few kilometres did not affect the colonisation of the soil invertebrates. When accounting for effects of geographical distances, soil age and plant richness explained a significant part of the variance observed in the distribution of the oribatid mites and collembola communities, respectively. Furthermore, null model analyses revealed less co-occurrence than expected by chance and also convergence in the body size ratio of co-occurring oribatids, which is consistent with species sorting. Geographical distances influenced species composition, indicating that the community is also assembled by dispersal, e.g. mass effect. When all the results are linked together, they demonstrate that local environmental factors are important in structuring the soil community assembly, but are accompanied with effects of dispersal that may "override" the visible effect of the local environment.

  14. Calculation of local characteristics of velocity field in turbulent coolant flow in fast reactor fuel assembly

    International Nuclear Information System (INIS)

    Muehlbauer, P.

    1981-08-01

    Experience is described gained with the application of computer code VELASCO in calculating the velocity field in fast reactor fuel assemblies taking into account configuration disturbances due to fuel pin displacement. Theoretical results are compared with the results of experiments conducted by UJV on aerodynamic models HEM-1 (model of the fuel assembly central part) and HEM-2 (model of the fuel assembly peripheral part). The results are reported of calculating the distribution of shear stress in wetted rod surfaces and in the assembly wall (model HEM-2) and the corresponding experimental results are shown. The shear stress distribution in wetted surfaces obtained using the VELASCO code allowed forming an opinion on the code capability of comprising local parameters of turbulent flow through a fuel rod bundle. The applicability was also tested of the code for calculating mean velocities in the individual zones, eg., in elementary cells. (B.S.)

  15. Involvement of F-Actin in Chaperonin-Containing t-Complex 1 Beta Regulating Mouse Mesangial Cell Functions in a Glucose-Induction Cell Model

    Directory of Open Access Journals (Sweden)

    Jin-Shuen Chen

    2011-01-01

    Full Text Available The aim of this study is to investigate the role of chaperonin-containing t-complex polypeptide 1 beta (CCT2 in the regulation of mouse mesangial cell (mMC contraction, proliferation, and migration with filamentous/globular-(F/G- actin ratio under high glucose induction. A low CCT2 mMC model induced by treatment of small interference RNA was established. Groups with and without low CCT2 induction examined in normal and high (H glucose conditions revealed the following major results: (1 low CCT2 or H glucose showed the ability to attenuate F/G-actin ratio; (2 groups with low F/G-actin ratio all showed less cell contraction; (3 suppression of CCT2 may reduce the proliferation and migration which were originally induced by H glucose. In conclusion, CCT2 can be used as a specific regulator for mMC contraction, proliferation, and migration affected by glucose, which mechanism may involve the alteration of F-actin, particularly for cell contraction.

  16. Role of local assembly in the hierarchical crystallization of associating colloidal hard hemispheres

    Science.gov (United States)

    Lei, Qun-li; Hadinoto, Kunn; Ni, Ran

    2017-10-01

    Hierarchical self-assembly consisting of local associations of simple building blocks for the formation of complex structures widely exists in nature, while the essential role of local assembly remains unknown. In this work, by using computer simulations, we study a simple model system consisting of associating colloidal hemispheres crystallizing into face-centered-cubic crystals comprised of spherical dimers of hemispheres, focusing on the effect of dimer formation on the hierarchical crystallization. We found that besides assisting the crystal nucleation because of increasing the symmetry of building blocks, the association between hemispheres can also induce both reentrant melting and reentrant crystallization depending on the range of interaction. Especially when the interaction is highly sticky, we observe a novel reentrant crystallization of identical crystals, which melt only in a certain temperature range. This offers another axis in fabricating responsive crystalline materials by tuning the fluctuation of local association.

  17. BAUM: Improving genome assembly by adaptive unique mapping and local overlap-layout-consensus approach.

    Science.gov (United States)

    Wang, Anqi; Wang, Zhanyu; Li, Zheng; Li, Lei M

    2018-01-15

    It is highly desirable to assemble genomes of high continuity and consistency at low cost. The current bottleneck of draft genome continuity using the Second Generation Sequencing (SGS) reads is primarily caused by uncertainty among repetitive sequences. Even though the Single-Molecule Real-Time sequencing technology is very promising to overcome the uncertainty issue, its relatively high cost and error rate add burden on budget or computation. Many long-read assemblers take the overlap-layout-consensus (OLC) paradigm, which is less sensitive to sequencing errors, heterozygosity and variability of coverage. However, current assemblers of SGS data do not sufficiently take advantage of the OLC approach. Aiming at minimizing uncertainty, the proposed method BAUM, breaks the whole genome into regions by adaptive unique mapping; then the local OLC is used to assemble each region in parallel. BAUM can: (1) perform reference-assisted assembly based on the genome of a close species; (2) or improve the results of existing assemblies that are obtained based on short or long sequencing reads. The tests on two eukaryote genomes, a wild rice Oryza longistaminata and a parrot Melopsittacus undulatus, show that BAUM achieved substantial improvement on genome size and continuity. Besides, BAUM reconstructed a considerable amount of repetitive regions that failed to be assembled by existing short read assemblers. We also propose statistical approaches to control the uncertainty in different steps of BAUM. http://www.zhanyuwang.xin/wordpress/index.php/2017/07/21/baum. lilei@amss.ac.cn. Supplementary data are available at Bioinformatics online. © The Author (2018). Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com

  18. System for determining the local power in the fuel assembly of a nuclear reactor

    International Nuclear Information System (INIS)

    Rolstad, Erik; Korpas, T.-H.; Leyse, R.H.; Smith, R.D.

    1979-01-01

    System for determining the local power in the fuel assembly of a nuclear reactor which includes a rod conducting the heat and electricity, along which axial areas act as a gamma radiation thermometer. Each area includes a thermal bridge, a cold source and a pair of junctions acting as thermocouples so placed that they measure the temperature difference between the thermal bridge and the cold source. The power created by the fuel assembly near each area acting as gamma thermometer is found from this difference in temperature [fr

  19. Dissecting the sequential assembly and localization of intraflagellar transport particle complex B in Chlamydomonas.

    Directory of Open Access Journals (Sweden)

    Elizabeth A Richey

    Full Text Available Intraflagellar transport (IFT, the key mechanism for ciliogenesis, involves large protein particles moving bi-directionally along the entire ciliary length. IFT particles contain two large protein complexes, A and B, which are constructed with proteins in a core and several peripheral proteins. Prior studies have shown that in Chlamydomonas reinhardtii, IFT46, IFT52, and IFT88 directly interact with each other and are in a subcomplex of the IFT B core. However, ift46, bld1, and ift88 mutants differ in phenotype as ift46 mutants are able to form short flagella, while the other two lack flagella completely. In this study, we investigated the functional differences of these individual IFT proteins contributing to complex B assembly, stability, and basal body localization. We found that complex B is completely disrupted in bld1 mutant, indicating an essential role of IFT52 for complex B core assembly. Ift46 mutant cells are capable of assembling a relatively intact complex B, but such complex is highly unstable and prone to degradation. In contrast, in ift88 mutant cells the complex B core still assembles and remains stable, but the peripheral proteins no longer attach to the B core. Moreover, in ift88 mutant cells, while complex A and the anterograde IFT motor FLA10 are localized normally to the transition fibers, complex B proteins instead are accumulated at the proximal ends of the basal bodies. In addition, in bld2 mutant, the IFT complex B proteins still localize to the proximal ends of defective centrioles which completely lack transition fibers. Taken together, these results revealed a step-wise assembly process for complex B, and showed that the complex first localizes to the proximal end of the centrioles and then translocates onto the transition fibers via an IFT88-dependent mechanism.

  20. Characterization of f-actin tryptophan phosphorescence in the presence and absence of tryptophan-free myosin motor domain.

    Science.gov (United States)

    Bódis, Emöke; Strambini, Giovanni B; Gonnelli, Margherita; Málnási-Csizmadia, András; Somogyi, Béla

    2004-08-01

    The effect of binding the Trp-free motor domain mutant of Dictyostelium discoideum, rabbit skeletal muscle myosin S1, and tropomyosin on the dynamics and conformation of actin filaments was characterized by an analysis of steady-state tryptophan phosphorescence spectra and phosphorescence decay kinetics over a temperature range of 140-293 K. The binding of the Trp-free motor domain mutant of D. discoideum to actin caused red shifts in the phosphorescence spectrum of two internal Trp residues of actin and affected the intrinsic lifetime of each emitter, decreasing by roughly twofold the short phosphorescence lifetime components (tau(1) and tau(2)) and increasing by approximately 20% the longest component (tau(3)). The alteration of actin phosphorescence by the motor protein suggests that i), structural changes occur deep down in the core of actin and that ii), subtle changes in conformation appear also on the surface but in regions distant from the motor domain binding site. When actin formed complexes with skeletal S1, an extra phosphorescence lifetime component appeared (tau(4), twice as long as tau(3)) in the phosphorescence decay that is absent in the isolated proteins. The lack of this extra component in the analogous actin-Trp-free motor domain mutant of D. discoideum complex suggests that it should be assigned to Trps in S1 that in the complex attain a more compact local structure. Our data indicated that the binding of tropomyosin to actin filaments had no effect on the structure or flexibility of actin observable by this technique.

  1. Chemical similarity and local community assembly in the species rich tropical genus Piper.

    Science.gov (United States)

    Salazar, Diego; Jaramillo, M Alejandra; Marquis, Robert J

    2016-11-01

    Community ecologists have strived to find mechanisms that mediate the assembly of natural communities. Recent evidence suggests that natural enemies could play an important role in the assembly of hyper-diverse tropical plant systems. Classic ecological theory predicts that in order for coexistence to occur, species differences must be maximized across biologically important niche dimensions. For plant-herbivore interactions, it has been recently suggested that, within a particular community, plant species that maximize the difference in chemical defense profiles compared to neighboring taxa will have a relative competitive advantage. Here we tested the hypothesis that plant chemical diversity can affect local community composition in the hyper-diverse genus Piper at a lowland wet forest location in Costa Rica. We first characterized the chemical composition of 27 of the most locally abundant species of Piper. We then tested whether species with different chemical compositions were more likely to coexist. Finally, we assessed the degree to which Piper phylogenetic relationships are related to differences in secondary chemical composition and community assembly. We found that, on average, co-occurring species were more likely to differ in chemical composition than expected by chance. Contrary to expectations, there was no phylogenetic signal for overall secondary chemical composition. In addition we found that species in local communities were, on average, more phylogenetically closely related than expected by chance, suggesting that functional traits other than those measured here also influence local assembly. We propose that selection by herbivores for divergent chemistries between closely related species facilitates the coexistence of a high diversity of congeneric taxa via apparent competition. © 2016 by the Ecological Society of America.

  2. Halo assembly bias and the tidal anisotropy of the local halo environment

    Science.gov (United States)

    Paranjape, Aseem; Hahn, Oliver; Sheth, Ravi K.

    2018-05-01

    We study the role of the local tidal environment in determining the assembly bias of dark matter haloes. Previous results suggest that the anisotropy of a halo's environment (i.e. whether it lies in a filament or in a more isotropic region) can play a significant role in determining the eventual mass and age of the halo. We statistically isolate this effect, using correlations between the large-scale and small-scale environments of simulated haloes at z = 0 with masses between 1011.6 ≲ (m/h-1 M⊙) ≲ 1014.9. We probe the large-scale environment, using a novel halo-by-halo estimator of linear bias. For the small-scale environment, we identify a variable αR that captures the tidal anisotropy in a region of radius R = 4R200b around the halo and correlates strongly with halo bias at fixed mass. Segregating haloes by αR reveals two distinct populations. Haloes in highly isotropic local environments (αR ≲ 0.2) behave as expected from the simplest, spherically averaged analytical models of structure formation, showing a negative correlation between their concentration and large-scale bias at all masses. In contrast, haloes in anisotropic, filament-like environments (αR ≳ 0.5) tend to show a positive correlation between bias and concentration at any mass. Our multiscale analysis cleanly demonstrates how the overall assembly bias trend across halo mass emerges as an average over these different halo populations, and provides valuable insights towards building analytical models that correctly incorporate assembly bias. We also discuss potential implications for the nature and detectability of galaxy assembly bias.

  3. Local Government Finance in Ghana: Disbursement and Utilisation of the MPs share of the District Assemblies Common Fund

    OpenAIRE

    Nana Nimo Appiah-Agyekum

    2013-01-01

    The establishment of the District Assembly Common Fund (DACF) in 1993 and concomitant percentage set aside for Members of Parliament (MPs) in 2004 aims to support local governments and legislators in pro-poor development activities in their communities and constituencies. In spite of the importance of the MPs’ share of the District Assemblies Common Fund (MPsCF) in financing local level development in Ghana, very little is known about monitoring systems and procedures on the disbursement and ...

  4. Analysis of Co-assembly and Co-localization of Ameloblastin and Amelogenin

    Directory of Open Access Journals (Sweden)

    Prichita eMazumder

    2014-07-01

    Full Text Available Epithelially-derived ameloblasts secrete extracellular matrix proteins including amelogenin, enamelin and ameloblastin. Complex intermolecular interactions among these proteins are believed to be important in controlling enamel formation. Here we provide in vitro and in vivo evidence of co-assembly and co-localization of ameloblastin with amelogenin using both biophysical and immunohistochemical methods. We performed co-localization studies using immunofluorescence confocal microscopy with paraffin-embedded tissue sections from mandibular molars of mice at 1, 5 and 8 days of age. Commercially-available ameloblastin antibody (M300 against mouse ameloblastin residues 107-407 and an antibody against full-length recombinant mouse (rM179 amelogenin were used. Ameloblastin-M300 clearly reacted along the secretory face of ameloblasts from days 1-8. Quantitative co-localization was analyzed (QCA in several configurations by choosing appropriate regions of interest (ROIs. Analysis of ROIs along the secretory face of ameloblasts revealed that at day 1, very high percentages of both the ameloblastin and amelogenin co-localized. At day 8 along the ameloblast cells the percentage of co-localization remained high for the ameloblastin whereas co-localization percentage was reduced for amelogenin. Analysis of the entire thickness on day 8 revealed no significant co-localization of amelogenin and ameloblastin. With the progress of amelogenesis and ameloblastin degradation, there was a segregation of ameloblastin and co-localization with the C-terminal region decreased. CD spectra indicated that structural changes in ameloblastin occurred upon addition of amelogenin. Our data suggest that amelogenin-ameloblastin complexes may be the functional entities at the early stage of enamel mineralization.

  5. Documentation and localization of force-mediated filamin A domain perturbations in moving cells

    Science.gov (United States)

    Nakamura, Fumihiko; Song, Mia; Hartwig, John H.; Stossel, Thomas P.

    2014-08-01

    Endogenously and externally generated mechanical forces influence diverse cellular activities, a phenomenon defined as mechanotransduction. Deformation of protein domains by application of stress, previously documented to alter macromolecular interactions in vitro, could mediate these effects. We engineered a photon-emitting system responsive to unfolding of two repeat domains of the actin filament (F-actin) crosslinker protein filamin A (FLNA) that binds multiple partners involved in cell signalling reactions and validated the system using F-actin networks subjected to myosin-based contraction. Expressed in cultured cells, the sensor-containing FLNA construct reproducibly reported FLNA domain unfolding strikingly localized to dynamic, actively protruding, leading cell edges. The unfolding signal depends upon coherence of F-actin-FLNA networks and is enhanced by stimulating cell contractility. The results establish protein domain distortion as a bona fide mechanism for mechanotransduction in vivo.

  6. Fabrication of Localized Surface Plasmon Resonance Fiber Probes Using Ionic Self-Assembled Gold Nanoparticles

    Directory of Open Access Journals (Sweden)

    Miao Wan

    2010-07-01

    Full Text Available An nm-thickness composite gold thin film consisting of gold nanoparticles and polyelectrolytes is fabricated through ionic self-assembled multilayers (ISAM technique and is deposited on end-faces of optical fibers to construct localized surface plasmon resonance (LSPR fiber probes. We demonstrate that the LSPR spectrum induced by ISAM gold films can be fine-tuned through the ISAM procedure. We investigate variations of reflection spectra of the probe with respect to the layer-by-layer adsorption of ISAMs onto end-faces of fibers, and study the spectral variation mechanism. Finally, we demonstrated using this fiber probe to detect the biotin-streptavidin bioconjugate pair. ISAM adsorbed on optical fibers potentially provides a simple, fast, robust, and low-cost, platform for LSPR biosensing applications.

  7. Self-Assembled Local Artificial Substrates of GaAs on Si Substrate

    Directory of Open Access Journals (Sweden)

    Frigeri C

    2010-01-01

    Full Text Available Abstract We propose a self-assembling procedure for the fabrication of GaAs islands by Droplet Epitaxy on silicon substrate. Controlling substrate temperature and amount of supplied gallium is possible to tune the base size of the islands from 70 up to 250 nm and the density from 107 to 109 cm−2. The islands show a standard deviation of base size distribution below 10% and their shape evolves changing the aspect ratio from 0.3 to 0.5 as size increases. Due to their characteristics, these islands are suitable to be used as local artificial substrates for the integration of III–V quantum nanostructures directly on silicon substrate.

  8. Interaction of nucleosome assembly proteins abolishes nuclear localization of DGKζ by attenuating its association with importins

    International Nuclear Information System (INIS)

    Okada, Masashi; Hozumi, Yasukazu; Ichimura, Tohru; Tanaka, Toshiaki; Hasegawa, Hiroshi; Yamamoto, Masakazu; Takahashi, Nobuya; Iseki, Ken; Yagisawa, Hitoshi; Shinkawa, Takashi; Isobe, Toshiaki; Goto, Kaoru

    2011-01-01

    Diacylglycerol kinase (DGK) is involved in the regulation of lipid-mediated signal transduction through the metabolism of a second messenger diacylglycerol. Of the DGK family, DGKζ, which contains a nuclear localization signal, localizes mainly to the nucleus but translocates to the cytoplasm under pathological conditions. However, the detailed mechanism of translocation and its functional significance remain unclear. To elucidate these issues, we used a proteomic approach to search for protein targets that interact with DGKζ. Results show that nucleosome assembly protein (NAP) 1-like 1 (NAP1L1) and NAP1-like 4 (NAP1L4) are identified as novel DGKζ binding partners. NAP1Ls constitutively shuttle between the nucleus and the cytoplasm in transfected HEK293 cells. The molecular interaction of DGKζ and NAP1Ls prohibits nuclear import of DGKζ because binding of NAP1Ls to DGKζ blocks import carrier proteins, Qip1 and NPI1, to interact with DGKζ, leading to cytoplasmic tethering of DGKζ. In addition, overexpression of NAP1Ls exerts a protective effect against doxorubicin-induced cytotoxicity. These findings suggest that NAP1Ls are involved in a novel molecular basis for the regulation of nucleocytoplasmic shuttling of DGKζ and provide a clue to examine functional significance of its translocation under pathological conditions.

  9. ATLAS (Automatic Tool for Local Assembly Structures) - A Comprehensive Infrastructure for Assembly, Annotation, and Genomic Binning of Metagenomic and Metaranscripomic Data

    Energy Technology Data Exchange (ETDEWEB)

    White, Richard A.; Brown, Joseph M.; Colby, Sean M.; Overall, Christopher C.; Lee, Joon-Yong; Zucker, Jeremy D.; Glaesemann, Kurt R.; Jansson, Georg C.; Jansson, Janet K.

    2017-03-02

    ATLAS (Automatic Tool for Local Assembly Structures) is a comprehensive multiomics data analysis pipeline that is massively parallel and scalable. ATLAS contains a modular analysis pipeline for assembly, annotation, quantification and genome binning of metagenomics and metatranscriptomics data and a framework for reference metaproteomic database construction. ATLAS transforms raw sequence data into functional and taxonomic data at the microbial population level and provides genome-centric resolution through genome binning. ATLAS provides robust taxonomy based on majority voting of protein coding open reading frames rolled-up at the contig level using modified lowest common ancestor (LCA) analysis. ATLAS provides robust taxonomy based on majority voting of protein coding open reading frames rolled-up at the contig level using modified lowest common ancestor (LCA) analysis. ATLAS is user-friendly, easy install through bioconda maintained as open-source on GitHub, and is implemented in Snakemake for modular customizable workflows.

  10. Self-assembled nanoformulation of methylprednisolone succinate with carboxylated block copolymer for local glucocorticoid therapy.

    Science.gov (United States)

    Kamalov, Marat I; Đặng, Trinh; Petrova, Natalia V; Laikov, Alexander V; Luong, Duong; Akhmadishina, Rezeda A; Lukashkin, Andrei N; Abdullin, Timur I

    2018-04-01

    A new self-assembled formulation of methylprednisolone succinate (MPS) based on a carboxylated trifunctional block copolymer of ethylene oxide and propylene oxide (TBC-COOH) was developed. TBC-COOH and MPS associated spontaneously at increased concentrations in aqueous solutions to form almost monodisperse mixed micelles (TBC-COOH/MPS) with a hydrodynamic diameter of 19.6 nm, zeta potential of -27.8 mV and optimal weight ratio ∼1:6.3. Conditions for the effective formation of TBC-COOH/MPS were elucidated by comparing copolymers and glucocorticoids with different structure. The micellar structure of TBC-COOH/MPS persisted upon dilution, temperature fluctuations and interaction with blood serum components. TBC-COOH increased antiradical activity of MPS and promoted its intrinsic cytotoxicity in vitro attributed to enhanced cellular availability of the mixed micelles. Intracellular transportation and hydrolysis of MPS were analyzed using optimized liquid chromatography tandem mass spectrometry with multiple reaction monitoring which showed increased level of both MPS and methylprednisolone in neuronal cells treated with the formulated glucocorticoid. Our results identify TBC-COOH/MPS as an advanced in situ prepared nanoformulation and encourage its further investigation for a potential local glucocorticoid therapy. Copyright © 2018 Elsevier B.V. All rights reserved.

  11. ACTH-induced caveolin-1 tyrosine phosphorylation is related to podosome assembly in Y1 adrenal cells

    International Nuclear Information System (INIS)

    Colonna, Cecilia; Podesta, Ernesto J.

    2005-01-01

    Y1 adrenocortical cells respond to ACTH with a characteristic rounding-up that facilitates cAMP signaling, critical for transport of cholesterol to the mitochondria and increase in steroid secretion. We here demonstrate that caveolin-1 participates in coupling activation of protein kinase A (PKA) to the control of cell shape. ACTH/8-Br-cAMP induced reorganization of caveolin-1-positive structures in correlation with the cellular rounding-up. Concomitant with this change, there was an increase in the phosphorylation of caveolin-1 (Tyr-14) localized at focal adhesions (FA) with reorganization of FA to rounded, ringlike structures. Colocalization with phalloidin showed that phosphocaveolin is present at the edge of actin filaments and that after ACTH stimulation F-actin dots at the cell periphery become surrounded by phosphocaveolin-1. These observations along with electron microscopy studies revealed these structures as podosomes. Podosome assembly was dependent on both PKA and tyrosine kinase activities because their formation was impaired after treatment with specific inhibitors [myristoylated PKI (mPKI) or PP2, respectively] previous to ACTH/8-Br-cAMP stimulation. These results show for the first time that ACTH induces caveolin-1 phosphorylation and podosome assembly in Y1 cells and support the view that the morphological and functional responses to PKA activation in steroidogenic cells are related to cytoskeleton dynamics

  12. Feedbacks between community assembly and habitat selection shape variation in local colonization

    Science.gov (United States)

    Kraus, J.M.; Vonesh, J.R.

    2010-01-01

    1. Non-consumptive effects of predators are increasingly recognized as important drivers of community assembly and structure. Specifically, habitat selection responses to top predators during colonization and oviposition can lead to large differences in aquatic community structure, composition and diversity. 2. These differences among communities due to predators may develop as communities assemble, potentially altering the relative quality of predator vs. predator-free habitats through time. If so, community assembly would be expected to modify the subsequent behavioural responses of colonists to habitats containing top predators. Here, we test this hypothesis by manipulating community assembly and the presence of fish in experimental ponds and measuring their independent and combined effects on patterns of colonization by insects and amphibians. 3. Assembly modified habitat selection of dytscid beetles and hylid frogs by decreasing or even reversing avoidance of pools containing blue-spotted sunfish (Enneacanthus gloriosus). However, not all habitat selection responses to fish depended on assembly history. Hydrophilid beetles and mosquitoes avoided fish while chironomids were attracted to fish pools, regardless of assembly history. 4. Our results show that community assembly causes taxa-dependent feedbacks that can modify avoidance of habitats containing a top predator. Thus, non-consumptive effects of a top predator on community structure change as communities assemble and effects of competitors and other predators combine with the direct effects of top predators to shape colonization. 5. This work reinforces the importance of habitat selection for community assembly in aquatic systems, while illustrating the range of factors that may influence colonization rates and resulting community structure. Directly manipulating communities both during colonization and post-colonization is critical for elucidating how sequential processes interact to shape communities.

  13. Local Government Finance in Ghana: Disbursement and Utilisation of the MPs share of the District Assemblies Common Fund

    Directory of Open Access Journals (Sweden)

    Nana Nimo Appiah-Agyekum

    2013-05-01

    Full Text Available The establishment of the District Assembly Common Fund (DACF in 1993 and concomitant percentage set aside for Members of Parliament (MPs in 2004 aims to support local governments and legislators in pro-poor development activities in their communities and constituencies. In spite of the importance of the MPs’ share of the District Assemblies Common Fund (MPsCF in financing local level development in Ghana, very little is known about monitoring systems and procedures on the disbursement and utilization of the funds. The study therefore assessed qualitative data derived from interviews with officials from selected Local Government Authorities (LGAs as well as other key stakeholders in the disbursement and utilization of the fund. The study findings point to the absence of legislative instrument on the management of the MPsCF. Further, monitoring of the fund was a responsibility shared by the LGAs and other external stakeholders. Finally, the effectiveness of monitoring the disbursement and utilization of the MPsCF was strongly influenced by the relationship between the Chief Executive of the Local Government Authority (LGCE and MPs in the local government area.

  14. EXPERIMENTAL STUDY OF LOCAL HYDRODYNAMICS AND MASS EXCHANGE PROCESSES OF COOLANT IN FUEL ASSEMBLIES OF PRESSURIZED WATER REACTORS

    Directory of Open Access Journals (Sweden)

    S. M. Dmitriev

    2016-01-01

    Full Text Available The results of experimental studies of local hydrodynamics and mass exchange of coolant flow behind spacer and mixing grids of different structural versions that were developed for fuel assemblies of domestic and foreign nuclear reactors are presented in the article. In order to carry out the study the models of the following fuel assemblies have been fabricated: FA for VVER and VBER, FA-KVADRAT for PWR-reactor and FA for KLT-40C reactor. All the models have been fabricated with a full geometrical similarity with full-scale fuel assemblies. The study was carried out by simulating the flow of coolant in a core by air on an aerodynamic test rig. In order to measure local hydrodynamic characteristics of coolant flow five-channel Pitot probes were used that enable to measure the velocity vector in a point by its three components. The tracerpropane method was used for studying mass transfer processes. Flow hydrodynamics was studied by measuring cross-section velocities of coolant flow and coolant rates according to the model cells. The investigation of mass exchange processes consisted of a study of concentration distribution for tracer in experimental model, in determination of attenuation lengths of mass transfer processes behind mixing grids, in calculating of inter-cellar mass exchange coefficient. The database on coolant flow in fuel assemblies for different types of reactors had been accumulated that formed the basis of the engineering substantiation of reactor cores designs. The recommendations on choice of optimal versions of mixing grids have been taken into consideration by implementers of the JSC “OKBM Afrikantov” when creating commissioned fuel assemblies. The results of the study are used for verification of CFD-codes and CFD programs of detailed cell-by-cell calculation of reactor cores in order to decrease conservatism for substantiation of thermal-mechanical reliability.

  15. Calculation of the local power peaking near WWER-440 control assemblies with Hf plates

    International Nuclear Information System (INIS)

    Hegyi, Gy.; Hordosy, G.; Kereszturi, A.; Maraszy, Cs.; Temesvari, E.

    2003-01-01

    The original coupler design of the WWER-440 assemblies had the following well known deficiency: The relatively large amount of water in the coupler between the absorber and fuel port of the control assembly can cause undesirably sharp power peaking in the fuel rods next to the coupler. The power peaking can be especially high after control rod withdrawal when the coupler reached low burnup level region of the adjacent assembly. The modernized coupler design overcomes the original problem by applying a thin Hf plate in the critical region. The very complicated structure of the coupler requires the verification of the core design methods by high precision 3D Monte Carlo calculations. The paper presents an MCNP reference calculation on the control rod coupler benchmark with Hf absorber plates. The benchmark solution with the KARATE-440 code system is also presented. The need for treating the Hf burnout in the reflector region is investigated (Authors)

  16. Methodology for local verification of flow regimes in fuel assemblies charts

    International Nuclear Information System (INIS)

    Igor, Sharaevsky; Elena, Sharaevskaya; Domashev, E.D.; Alexander, Arkhypov; Vladimir, Kolochko

    2003-01-01

    The best estimate thermal hydraulic codes describe adequately two-phase flows in nuclear energy facilities if there is proper system of closed relations. It could be obtained from the reliable information on structure forms of two-phase flows, its boundaries and reliable regime charts. In the paper the methodology of automatic recognition of the boundaries of the main types of two phase flows for rod fuel assemblies is presented. The methodology is based on definition of thermal hydraulic parameters distribution in experimental fuel assembly. The measurements were carried out using ASD signals of acoustic noise. In the paper data on two-phase flow regimes boundaries recognition especially low boundaries of bubble flow are summarized for experimental fuel assembly. The methodology of flow regimes charts applied to recognition of upper boundaries of boiling crisis regime was verificated. The satisfactory coincidence with experimental results have been shown. (author)

  17. A synthetic mechano-growth factor E peptide promotes rat tenocyte migration by lessening cell stiffness and increasing F-actin formation via the FAK-ERK1/2 signaling pathway

    International Nuclear Information System (INIS)

    Zhang, Bingyu; Luo, Qing; Mao, Xinjian; Xu, Baiyao; Yang, Li; Ju, Yang; Song, Guanbin

    2014-01-01

    Tendon injuries are common in sports and are frequent reasons for orthopedic consultations. The management of damaged tendons is one of the most challenging problems in orthopedics. Mechano-growth factor (MGF), a recently discovered growth repair factor, plays positive roles in tissue repair through the improvement of cell proliferation and migration and the protection of cells against injury-induced apoptosis. However, it remains unclear whether MGF has the potential to accelerate tendon repair. We used a scratch wound assay in this study to demonstrate that MGF-C25E (a synthetic mechano-growth factor E peptide) promotes the migration of rat tenocytes and that this promotion is accompanied by an elevation in the expression of the following signaling molecules: focal adhesion kinase (FAK) and extracellular signal regulated kinase1/2 (ERK1/2). Inhibitors of the FAK and ERK1/2 pathways inhibited the MGF-C25E-induced tenocyte migration, indicating that MGF-C25E promotes tenocyte migration through the FAK-ERK1/2 signaling pathway. The analysis of the mechanical properties showed that the Young's modulus of tenocytes was decreased through treatment of MGF-C25E, and an obvious formation of pseudopodia and F-actin was observed in MGF-C25E-treated tenocytes. The inhibition of the FAK or ERK1/2 signals restored the decrease in Young's modulus and inhibited the formation of pseudopodia and F-actin. Overall, our study demonstrated that MGF-C25E promotes rat tenocyte migration by lessening cell stiffness and increasing pseudopodia formation via the FAK-ERK1/2 signaling pathway. - Highlights: • Mechano-growth factor E peptide (MGF-C25E) promotes migration of rat tenocytes. • MGF-C25E activates the FAK-ERK1/2 pathway in rat tenocytes. • MGF-C25E induces the actin remodeling and the formation of pseudopodia, and decreases the stiffness in rat tenocytes. • MGF-C25E promotes tenocyte migration via altering stiffness and forming pseudopodia by the activation of the

  18. A synthetic mechano-growth factor E peptide promotes rat tenocyte migration by lessening cell stiffness and increasing F-actin formation via the FAK-ERK1/2 signaling pathway

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Bingyu [Key Laboratory of Biorheological Science and Technology, Ministry of Education, College of Bioengineering, Chongqing University, Chongqing 400044 (China); Luo, Qing, E-mail: qing.luo@cqu.edu.cn [Key Laboratory of Biorheological Science and Technology, Ministry of Education, College of Bioengineering, Chongqing University, Chongqing 400044 (China); Mao, Xinjian [Key Laboratory of Biorheological Science and Technology, Ministry of Education, College of Bioengineering, Chongqing University, Chongqing 400044 (China); Xu, Baiyao [Department of Mechanical Science and Engineering, Nagoya University, Nagoya 464-8603 (Japan); Yang, Li [Key Laboratory of Biorheological Science and Technology, Ministry of Education, College of Bioengineering, Chongqing University, Chongqing 400044 (China); Ju, Yang [Department of Mechanical Science and Engineering, Nagoya University, Nagoya 464-8603 (Japan); Song, Guanbin, E-mail: song@cqu.edu.cn [Key Laboratory of Biorheological Science and Technology, Ministry of Education, College of Bioengineering, Chongqing University, Chongqing 400044 (China)

    2014-03-10

    Tendon injuries are common in sports and are frequent reasons for orthopedic consultations. The management of damaged tendons is one of the most challenging problems in orthopedics. Mechano-growth factor (MGF), a recently discovered growth repair factor, plays positive roles in tissue repair through the improvement of cell proliferation and migration and the protection of cells against injury-induced apoptosis. However, it remains unclear whether MGF has the potential to accelerate tendon repair. We used a scratch wound assay in this study to demonstrate that MGF-C25E (a synthetic mechano-growth factor E peptide) promotes the migration of rat tenocytes and that this promotion is accompanied by an elevation in the expression of the following signaling molecules: focal adhesion kinase (FAK) and extracellular signal regulated kinase1/2 (ERK1/2). Inhibitors of the FAK and ERK1/2 pathways inhibited the MGF-C25E-induced tenocyte migration, indicating that MGF-C25E promotes tenocyte migration through the FAK-ERK1/2 signaling pathway. The analysis of the mechanical properties showed that the Young's modulus of tenocytes was decreased through treatment of MGF-C25E, and an obvious formation of pseudopodia and F-actin was observed in MGF-C25E-treated tenocytes. The inhibition of the FAK or ERK1/2 signals restored the decrease in Young's modulus and inhibited the formation of pseudopodia and F-actin. Overall, our study demonstrated that MGF-C25E promotes rat tenocyte migration by lessening cell stiffness and increasing pseudopodia formation via the FAK-ERK1/2 signaling pathway. - Highlights: • Mechano-growth factor E peptide (MGF-C25E) promotes migration of rat tenocytes. • MGF-C25E activates the FAK-ERK1/2 pathway in rat tenocytes. • MGF-C25E induces the actin remodeling and the formation of pseudopodia, and decreases the stiffness in rat tenocytes. • MGF-C25E promotes tenocyte migration via altering stiffness and forming pseudopodia by the activation of the

  19. Playing hide and seek with repeats in local and global de novo transcriptome assembly of short RNA-seq reads.

    Science.gov (United States)

    Lima, Leandro; Sinaimeri, Blerina; Sacomoto, Gustavo; Lopez-Maestre, Helene; Marchet, Camille; Miele, Vincent; Sagot, Marie-France; Lacroix, Vincent

    2017-01-01

    The main challenge in de novo genome assembly of DNA-seq data is certainly to deal with repeats that are longer than the reads. In de novo transcriptome assembly of RNA-seq reads, on the other hand, this problem has been underestimated so far. Even though we have fewer and shorter repeated sequences in transcriptomics, they do create ambiguities and confuse assemblers if not addressed properly. Most transcriptome assemblers of short reads are based on de Bruijn graphs (DBG) and have no clear and explicit model for repeats in RNA-seq data, relying instead on heuristics to deal with them. The results of this work are threefold. First, we introduce a formal model for representing high copy-number and low-divergence repeats in RNA-seq data and exploit its properties to infer a combinatorial characteristic of repeat-associated subgraphs. We show that the problem of identifying such subgraphs in a DBG is NP-complete. Second, we show that in the specific case of local assembly of alternative splicing (AS) events, we can implicitly avoid such subgraphs, and we present an efficient algorithm to enumerate AS events that are not included in repeats. Using simulated data, we show that this strategy is significantly more sensitive and precise than the previous version of KisSplice (Sacomoto et al. in WABI, pp 99-111, 1), Trinity (Grabherr et al. in Nat Biotechnol 29(7):644-652, 2), and Oases (Schulz et al. in Bioinformatics 28(8):1086-1092, 3), for the specific task of calling AS events. Third, we turn our focus to full-length transcriptome assembly, and we show that exploring the topology of DBGs can improve de novo transcriptome evaluation methods. Based on the observation that repeats create complicated regions in a DBG, and when assemblers try to traverse these regions, they can infer erroneous transcripts, we propose a measure to flag transcripts traversing such troublesome regions, thereby giving a confidence level for each transcript. The originality of our work when

  20. Design local exhaust ventilation on sieve machine at PT.Perkebunan Nusantara VIII Ciater using design for assembly (DFA) approach with Boothroyd and Dewhurst method

    Science.gov (United States)

    Khalqihi, K. I.; Rahayu, M.; Rendra, M.

    2017-12-01

    PT Perkebunan Nusantara VIII Ciater is a company produced black tea orthodox more or less 4 tons every day. At the production section, PT Perkebunan Nusantara VIII will use local exhaust ventilation specially at sortation area on sieve machine. To maintain the quality of the black tea orthodox, all machine must be scheduled for maintenance every once a month and takes time 2 hours in workhours, with additional local exhaust ventilation, it will increase time for maintenance process, if maintenance takes time more than 2 hours it will caused production process delayed. To support maintenance process in PT Perkebunan Nusantara VIII Ciater, designing local exhaust ventilation using design for assembly approach with Boothroyd and Dewhurst method, design for assembly approach is choosen to simplify maintenance process which required assembly process. There are 2 LEV designs for this research. Design 1 with 94 components, assembly time 647.88 seconds and assembly efficiency level 23.62%. Design 2 with 82 components, assembly time 567.84 seconds and assembly efficiency level 24.83%. Design 2 is choosen for this research based on DFA goals, minimum total part that use, optimization assembly time, and assembly efficiency level.

  1. Structural and optical studies of local disorder sensitivity in natural organic-inorganic self-assembled semiconductors

    Energy Technology Data Exchange (ETDEWEB)

    Vijaya Prakash, G; Pradeesh, K [Nanophotonics Lab, Department of Physics, Indian Institute of Technology Delhi, New Delhi (India); Ratnani, R; Saraswat, K [Department of Pure and Applied Chemistry, MDS University, Ajmer (India); Light, M E [School of Chemistry, University of Southampton, Southampton (United Kingdom); Baumberg, J J, E-mail: prakash@physics.iitd.ac.i [Nanophotonic Centre, Cavendish Laboratory, University Cambridge, Cambridge CB3 OHE (United Kingdom)

    2009-09-21

    The structural and optical spectra of two related lead iodide (PbI) based self-assembled hybrid organic-inorganic semiconductors are compared. During the synthesis, depending on the bridging of organic moiety intercalated between the PbI two-dimensional planes, different crystal structures are produced. These entirely different networks show different structural and optical features, including excitonic bandgaps. In particular, the modified organic environment of the excitons is sensitive to the local disorder both in single crystal and thin film forms. Such information is vital for incorporating these semiconductors into photonic device architectures.

  2. A local bottom-gate structure with low parasitic capacitance for dielectrophoresis assembly and electrical characterization of suspended nanomaterials

    International Nuclear Information System (INIS)

    Wang, Tun; Liu, Bin; Jiang, Shusen; Rong, Hao; Lu, Miao

    2014-01-01

    A device including a pair of top electrodes and a local gate in the bottom of an SU-8 trench was fabricated on a glass substrate for dielectrophoresis assembly and electrical characterization of suspended nanomaterials. The three terminals were made of gold electrodes and electrically isolated from each other by an air gap. Compared to the widely used global back-gate silicon device, the parasitic capacitance between the three terminals was significantly reduced and an individual gate was assigned to each device. In addition, the spacing from the bottom-gate to either the source or drain was larger than twice the source-drain gap, which guaranteed that the electric field between the source and drain in the dielectrophoresis assembly was not distinguished by the bottom-gate. To prove the feasibility and versatility of the device, a suspended carbon nanotube and graphene film were assembled by dielectrophoresis and characterized successfully. Accordingly, the proposed device holds promise for the electrical characterization of suspended nanomaterials, especially in a high frequency resonator or transistor configuration. (paper)

  3. An Arabidopsis E3 Ligase, SHOOT GRAVITROPISM9, Modulates the Interaction between Statoliths and F-Actin in Gravity Sensing[W][OA

    Science.gov (United States)

    Nakamura, Moritaka; Toyota, Masatsugu; Tasaka, Masao; Morita, Miyo Terao

    2011-01-01

    Higher plants use the sedimentation of amyloplasts in statocytes as statolith to sense the direction of gravity during gravitropism. In Arabidopsis thaliana inflorescence stem statocyte, amyloplasts are in complex movement; some show jumping-like saltatory movement and some tend to sediment toward the gravity direction. Here, we report that a RING-type E3 ligase SHOOT GRAVITROPISM9 (SGR9) localized to amyloplasts modulates amyloplast dynamics. In the sgr9 mutant, which exhibits reduced gravitropism, amyloplasts did not sediment but exhibited increased saltatory movement. Amyloplasts sometimes formed a cluster that is abnormally entangled with actin filaments (AFs) in sgr9. By contrast, in the fiz1 mutant, an ACT8 semidominant mutant that induces fragmentation of AFs, amyloplasts, lost saltatory movement and sedimented with nearly statically. Both treatment with Latrunculin B, an inhibitor of AF polymerization, and the fiz1 mutation rescued the gravitropic defect of sgr9. In addition, fiz1 decreased saltatory movement and induced amyloplast sedimentation even in sgr9. Our results suggest that amyloplasts are in equilibrium between sedimentation and saltatory movement in wild-type endodermal cells. Furthermore, this equilibrium is the result of the interaction between amyloplasts and AFs modulated by the SGR9. SGR9 may promote detachment of amyloplasts from AFs, allowing the amyloplasts to sediment in the AFs-dependent equilibrium of amyloplast dynamics. PMID:21602290

  4. Heterogeneous local order in self-assembled nanoparticle films revealed by X-ray cross-correlations

    Directory of Open Access Journals (Sweden)

    Felix Lehmkühler

    2018-05-01

    Full Text Available We report on the self-assembly of gold nanoparticles coated with a soft poly(ethylene glycol shell studied by X-ray cross-correlation analysis. Depending on the initial concentration of gold nanoparticles used, structurally heterogeneous films were formed. The films feature hot spots of dominating four- and sixfold local order with patch sizes of a few micrometres, containing 104–105 particles. The amplitude of the order parameters suggested that a minimum sample amount was necessary to form well ordered local structures. Furthermore, the increasing variation in order parameters with sample thickness demonstrated a high degree of structural heterogeneity. This wealth of information cannot be obtained by the conventional microscopy techniques that are commonly used to study nanocrystal superstructures, as illustrated by complementary scanning electron microscopy measurements.

  5. Measurement of molecular length of self-assembled monolayer probed by localized surface plasmon resonance

    Science.gov (United States)

    Ito, Juri; Kajikawa, Kotaro

    2016-02-01

    We propose a method to measure the variation of the molecular length of self-assembled monolayers (SAMs) when it is exposed to solutions at different pH conditions. The surface immobilized gold nanospheres (SIGNs) shows strong absorption peak at the wavelengths of 600-800 nm when p-polarized light is illuminated. The peak wavelength depends on the length of the gap distance between the SIGNs and the substrate. The gap is supported by the SAM molecules. According to the analytical calculation based on multiple expansion, the relation between the peak wavelength of the SIGN structures and the gap distance is calculated, to evaluate the molecular length of the SAM through the optical absorption spectroscopy for the SIGN structures. The molecular length of the SIGN structure was measured in air, water, acidic, and basic solutions. It was found that the molecular lengths are longer in acidic solutions.

  6. Creating periodic local strain in monolayer graphene with nanopillars patterned by self-assembled block copolymer

    Energy Technology Data Exchange (ETDEWEB)

    Mi, Hongyi; Mikael, Solomon; Seo, Jung-Hun; Gui, Gui; Ma, Alice L.; Ma, Zhenqiang, E-mail: nealey@uchicago.edu, E-mail: mazq@engr.wisc.edu [Department of Electrical and Computer Engineering, University of Wisconsin–Madison, Madison, Wisconsin 53706 (United States); Liu, Chi-Chun; Nealey, Paul F., E-mail: nealey@uchicago.edu, E-mail: mazq@engr.wisc.edu [Department of Chemical and Biological Engineering, University of Wisconsin–Madison, Madison, Wisconsin 53706 (United States)

    2015-10-05

    A simple and viable method was developed to produce biaxial strain in monolayer graphene on an array of SiO{sub 2} nanopillars. The array of SiO{sub 2} nanopillars (1 cm{sup 2} in area, 80 nm in height, and 40 nm in pitch) was fabricated by employing self-assembled block copolymer through simple dry etching and deposition processes. According to high resolution micro-Raman spectroscopy and atomic force microscopy analyses, 0.9% of maximum biaxial tensile strain and 0.17% of averaged biaxial tensile strain in graphene were created. This technique provides a simple and viable method to form biaxial tensile strain in graphene and offers a practical platform for future studies in graphene strain engineering.

  7. Lenalidomide induces lipid raft assembly to enhance erythropoietin receptor signaling in myelodysplastic syndrome progenitors.

    Science.gov (United States)

    McGraw, Kathy L; Basiorka, Ashley A; Johnson, Joseph O; Clark, Justine; Caceres, Gisela; Padron, Eric; Heaton, Ruth; Ozawa, Yukiyasu; Wei, Sheng; Sokol, Lubomir; List, Alan F

    2014-01-01

    Anemia remains the principal management challenge for patients with lower risk Myelodysplastic Syndromes (MDS). Despite appropriate cytokine production and cellular receptor display, erythropoietin receptor (EpoR) signaling is impaired. We reported that EpoR signaling is dependent upon receptor localization within lipid raft microdomains, and that disruption of raft integrity abolishes signaling capacity. Here, we show that MDS erythroid progenitors display markedly diminished raft assembly and smaller raft aggregates compared to normal controls (p = 0.005, raft number; p = 0.023, raft size). Because lenalidomide triggers raft coalescence in T-lymphocytes promoting immune synapse formation, we assessed effects of lenalidomide on raft assembly in MDS erythroid precursors and UT7 cells. Lenalidomide treatment rapidly induced lipid raft formation accompanied by EpoR recruitment into raft fractions together with STAT5, JAK2, and Lyn kinase. The JAK2 phosphatase, CD45, a key negative regulator of EpoR signaling, was displaced from raft fractions. Lenalidomide treatment prior to Epo stimulation enhanced both JAK2 and STAT5 phosphorylation in UT7 and primary MDS erythroid progenitors, accompanied by increased STAT5 DNA binding in UT7 cells, and increased erythroid colony forming capacity in both UT7 and primary cells. Raft induction was associated with F-actin polymerization, which was blocked by Rho kinase inhibition. These data indicate that deficient raft integrity impairs EpoR signaling, and provides a novel strategy to enhance EpoR signal fidelity in non-del(5q) MDS.

  8. Phylogenetic isolation of host trees affects assembly of local Heteroptera communities

    NARCIS (Netherlands)

    Vialatte, A.; Bailey, R.; Vasseur, C.; Matocq, A.; Gossner, M.; Everhart, D.; Vitrac, X.; Belhadj, A.; Ernoult, A.; Prinzing, A.

    2010-01-01

    A host may be physically isolated in space and then may correspond to a geographical island, but it may also be separated from its local neighbours by hundreds of millions of years of evolutionary history, and may form in this case an evolutionarily distinct island. We test how this affects the

  9. Localized Surface Plasmon-Enhanced Electroluminescence in OLEDs by Self-Assembly Ag Nanoparticle Film

    Science.gov (United States)

    He, Xiaoxiao; Wang, Wenjun; Li, Shuhong; Wang, Qingru; Zheng, Wanquan; Shi, Qiang; Liu, Yunlong

    2015-12-01

    We fabricated Ag nanoparticle (NP) film in organic light emission diodes (OLEDs), and a 23 times increase in electroluminescence (EL) at 518 nm was probed by time-resolved EL measurement. The luminance and relative external quantum efficiency (REQE) were increased by 5.4 and 3.7 times, respectively. There comes a new energy transport way that localized surface plasmons (LSPs) would absorb energy that corresponds to the electron-hole pair before recombination, promoting the formation of electron-hole pair and exciting local surface plasmon resonance (LSPR). The extended lifetime of Alq3 indicates the existence of strong interaction between LSPR and exciton, which decreases the nonradiative decay rate of OLEDs.

  10. Control of cell division and the spatial localization of assembled gene products in Caulobacter crescentus

    International Nuclear Information System (INIS)

    Nathan, P.D.

    1988-01-01

    Experiments are described that examine the role of penicillin-binding proteins (PBPs) in the regulation of cell division in Caulobacter crescentus; and the spatial localization of methyl-accepting chemotaxis proteins (MCPs) in C. crescentus swarmer and predivisional cells. In the analysis of PBP function, in vivo and in vitro assays are used to directly label C. crescentus PBPs with [ 3 H] penicillin G in wild type strain CB15, in a series of conditional cell division mutants and in new temperature sensitive cephalosporin C resistant mutants PC8002 and PC8003. 14 PBPs are characterized and a high molecular weight PBP (PBP 1B) that is required for cell division is identified. PBP 1B competes for β-lactams that induce filament formation and may be a high affinity binding protein. A second high molecular weight PBP (PBP 1C) is also associated with defective cell division. The examination of PBP patterns in synchronous swarmer cells reveals that the in vivo activity of PBP 1B and PBP 1C increases at the time that the cell division pathway is initiated. None of the PBPs, however, appear to be differentially localized in the C. crescentus cell. In the analysis of MCP localization, in vivo and in vitro assays are used to directly label C. crescentus MCPs with methyl- 3 H. MCPs are examined in flagellated and non-flagellated vesicles prepared from cells by immunoaffinity chromatography

  11. Dynamic assembly, localization and proteolysis of the Bacillus subtilis SMC complex

    Directory of Open Access Journals (Sweden)

    Rinn Cornelia

    2005-06-01

    Full Text Available Abstract Background SMC proteins are key components of several protein complexes that perform vital tasks in different chromosome dynamics. Bacterial SMC forms a complex with ScpA and ScpB that is essential for chromosome arrangement and segregation. The complex localizes to discrete centres on the nucleoids that during most of the time of the cell cycle localize in a bipolar manner. The complex binds to DNA and condenses DNA in an as yet unknown manner. Results We show that in vitro, ScpA and ScpB form different complexes with each other, among which the level of the putative 2 ScpA/4 ScpB complex showed a pronounced decrease in level upon addition of SMC protein. Different mutations of the ATPase-binding pocket of SMC reduced, but did not abolish interaction of mutant SMC with ScpA and ScpB. The loss of SMC ATPase activity led to a loss of function in vivo, and abolished proper localization of the SMC complex. The formation of bipolar SMC centres was also lost after repression of gyrase activity, and was abnormal during inhibition of replication, resulting in single central clusters. Resumption of replication quickly re-established bipolar SMC centres, showing that proper localization depends on ongoing replication. We also found that the SMC protein is subject to induced proteolysis, most strikingly as cells enter stationary phase, which is partly achieved by ClpX and LonA proteases. Atomic force microscopy revealed the existence of high order rosette-like SMC structures in vitro, which might explain the formation of the SMC centres in vivo. Conclusion Our data suggest that a ScpA/ScpB sub-complex is directly recruited into the SMC complex. This process does not require SMC ATPase activity, which, however, appears to facilitate loading of ScpA and ScpB. Thus, the activity of SMC could be regulated through binding and release of ScpA and ScpB, which has been shown to affect SMC ATPase activity. The proper bipolar localization of the SMC

  12. Interaction of nucleosome assembly proteins abolishes nuclear localization of DGK{zeta} by attenuating its association with importins

    Energy Technology Data Exchange (ETDEWEB)

    Okada, Masashi; Hozumi, Yasukazu [Department of Anatomy and Cell Biology, Yamagata University School of Medicine, Yamagata 990-9585 (Japan); Ichimura, Tohru [Department of Chemistry, Graduate School of Sciences and Engineering, Tokyo Metropolitan University, Hachioji 192-0397 (Japan); Tanaka, Toshiaki; Hasegawa, Hiroshi; Yamamoto, Masakazu; Takahashi, Nobuya [Department of Anatomy and Cell Biology, Yamagata University School of Medicine, Yamagata 990-9585 (Japan); Iseki, Ken [Department of Emergency and Critical Care Medicine, Yamagata University School of Medicine, Yamagata 990-9585 (Japan); Yagisawa, Hitoshi [Laboratory of Biological Signaling, Graduate School of Life Science, University of Hyogo, Hyogo 678-1297 (Japan); Shinkawa, Takashi; Isobe, Toshiaki [Department of Chemistry, Graduate School of Sciences and Engineering, Tokyo Metropolitan University, Hachioji 192-0397 (Japan); Goto, Kaoru, E-mail: kgoto@med.id.yamagata-u.ac.jp [Department of Anatomy and Cell Biology, Yamagata University School of Medicine, Yamagata 990-9585 (Japan)

    2011-12-10

    Diacylglycerol kinase (DGK) is involved in the regulation of lipid-mediated signal transduction through the metabolism of a second messenger diacylglycerol. Of the DGK family, DGK{zeta}, which contains a nuclear localization signal, localizes mainly to the nucleus but translocates to the cytoplasm under pathological conditions. However, the detailed mechanism of translocation and its functional significance remain unclear. To elucidate these issues, we used a proteomic approach to search for protein targets that interact with DGK{zeta}. Results show that nucleosome assembly protein (NAP) 1-like 1 (NAP1L1) and NAP1-like 4 (NAP1L4) are identified as novel DGK{zeta} binding partners. NAP1Ls constitutively shuttle between the nucleus and the cytoplasm in transfected HEK293 cells. The molecular interaction of DGK{zeta} and NAP1Ls prohibits nuclear import of DGK{zeta} because binding of NAP1Ls to DGK{zeta} blocks import carrier proteins, Qip1 and NPI1, to interact with DGK{zeta}, leading to cytoplasmic tethering of DGK{zeta}. In addition, overexpression of NAP1Ls exerts a protective effect against doxorubicin-induced cytotoxicity. These findings suggest that NAP1Ls are involved in a novel molecular basis for the regulation of nucleocytoplasmic shuttling of DGK{zeta} and provide a clue to examine functional significance of its translocation under pathological conditions.

  13. Thermal hydraulic behavior of sub-assembly local blockage in China experiment fast reactor

    International Nuclear Information System (INIS)

    Yang Zhimin

    2000-01-01

    The geometrical parameter ratio of pitch to diameter of China Experiment Fast Reactor (CEFR) subassembly is 1,167. To address the thermal hydraulic behavior of subassembly local blockage which may be caused by deformation of cladding due to severe swelling and thermal stresses and by space swirl loosening etc., the porous numerical model and SIMPLE-P code used to solve Navier-Stokes and energy equations in porous medium was developed, and the bundle experiment with 19 pins with 24 subchannels blocked in the sodium coolant was carried on in China Institute of Atomic Energy (CIAE). The comparison of code predictions against experiments (including non-blockage and ten blockage conditions) seems well. The thermal hydraulic behavior of fuel subassembly with 61 fuel pins blockage of CEFR is calculated with SIMPLE-P code. The results indicate that the maximum temperature is 815 deg. C when the blockage area is about 37% (54 central subchannels are blocked). In this case the cladding won't be damaged and no sodium coolant boiling takes place. (author)

  14. Application of a local linearization technique for the solution of a system of stiff differential equations associated with the simulation of a magnetic bearing assembly

    Science.gov (United States)

    Kibler, K. S.; Mcdaniel, G. A.

    1981-01-01

    A digital local linearization technique was used to solve a system of stiff differential equations which simulate a magnetic bearing assembly. The results prove the technique to be accurate, stable, and efficient when compared to a general purpose variable order Adams method with a stiff option.

  15. Experimental investigation of local hydrodynamic characteristics of the peripheral area of a fast reactor fuel assembly. 2

    International Nuclear Information System (INIS)

    Hejna, J.; Vosahlo, L.; Cervenka, J.; Smid, J.

    Aerodynamic model HEM-2 was used for the first stage of experiments aimed at obtaining data allowing to determine the effect of assembly configuration changes on hydrodynamic conditions. The results are given of measuring tangential stresses and velocity fields. (Ha)

  16. Definition of the local fields of velocity, temperature and turbulent characteristics for axial stabilized fluid in arbitrary formed rod bundle assemblies

    International Nuclear Information System (INIS)

    Sedov, A.A.; Gagin, V.L.

    1995-01-01

    For the temperature fields in rod clads of experimental assemblies a good agreement have been got with use of prior calculations by subchannel code COBRA-IV-I, from results of which an additional information about δt/δX 3 distribution was taken. The method of definition the local fields of velocity, turbulent kinetic energy, temperature and eddy diffusivities for one-phase axial stabilized fluids in arbitrary formed rod bundle assemblies with invariable upward geometry was developed. According to this model the AGURA code was worked out to calculate local thermal hydraulic problems in combination with temperature fields in fuel rods and constructive elements of fuel assemblies. The method does not use any prior geometric scales and is based only on invariant local flow parameters: turbulent kinetic energy, velocity field deformation tensor and specific work of inner friction. Verification of this method by available experimental data showed a good agreement of calculation data and findings of velocity and t.k.e. fields, when the secondary flows have not a substantial influence to a balance of axial momentum and turbulent kinetic energy. (author)

  17. Reduced-order computational model in nonlinear structural dynamics for structures having numerous local elastic modes in the low-frequency range. Application to fuel assemblies

    International Nuclear Information System (INIS)

    Batou, A.; Soize, C.; Brie, N.

    2013-01-01

    Highlights: • A ROM of a nonlinear dynamical structure is built with a global displacements basis. • The reduced order model of fuel assemblies is accurate and of very small size. • The shocks between grids of a row of seven fuel assemblies are computed. -- Abstract: We are interested in the construction of a reduced-order computational model for nonlinear complex dynamical structures which are characterized by the presence of numerous local elastic modes in the low-frequency band. This high modal density makes the use of the classical modal analysis method not suitable. Therefore the reduced-order computational model is constructed using a basis of a space of global displacements, which is constructed a priori and which allows the nonlinear dynamical response of the structure observed on the stiff part to be predicted with a good accuracy. The methodology is applied to a complex industrial structure which is made up of a row of seven fuel assemblies with possibility of collisions between grids and which is submitted to a seismic loading

  18. Reduced-order computational model in nonlinear structural dynamics for structures having numerous local elastic modes in the low-frequency range. Application to fuel assemblies

    Energy Technology Data Exchange (ETDEWEB)

    Batou, A., E-mail: anas.batou@univ-paris-est.fr [Université Paris-Est, Laboratoire Modélisation et Simulation Multi Echelle, MSME UMR 8208 CNRS, 5 bd Descartes, 77454 Marne-la-Vallee (France); Soize, C., E-mail: christian.soize@univ-paris-est.fr [Université Paris-Est, Laboratoire Modélisation et Simulation Multi Echelle, MSME UMR 8208 CNRS, 5 bd Descartes, 77454 Marne-la-Vallee (France); Brie, N., E-mail: nicolas.brie@edf.fr [EDF R and D, Département AMA, 1 avenue du général De Gaulle, 92140 Clamart (France)

    2013-09-15

    Highlights: • A ROM of a nonlinear dynamical structure is built with a global displacements basis. • The reduced order model of fuel assemblies is accurate and of very small size. • The shocks between grids of a row of seven fuel assemblies are computed. -- Abstract: We are interested in the construction of a reduced-order computational model for nonlinear complex dynamical structures which are characterized by the presence of numerous local elastic modes in the low-frequency band. This high modal density makes the use of the classical modal analysis method not suitable. Therefore the reduced-order computational model is constructed using a basis of a space of global displacements, which is constructed a priori and which allows the nonlinear dynamical response of the structure observed on the stiff part to be predicted with a good accuracy. The methodology is applied to a complex industrial structure which is made up of a row of seven fuel assemblies with possibility of collisions between grids and which is submitted to a seismic loading.

  19. Requirement of subunit co-assembly and ankyrin-G for M-channel localization at the axon initial segment

    DEFF Research Database (Denmark)

    Rasmussen, Hanne B; Frøkjaer-Jensen, Christian; Jensen, Camilla Stampe

    2007-01-01

    The potassium channel subunits KCNQ2 and KCNQ3 are believed to underlie the M current of hippocampal neurons. The M-type potassium current plays a key role in the regulation of neuronal excitability; however, the subcellular location of the ion channels underlying this regulation has been...... controversial. We report here that KCNQ2 and KCNQ3 subunits are localized to the axon initial segment of pyramidal neurons of adult rat hippocampus and in cultured hippocampal neurons. We demonstrate that the localization of the KCNQ2/3 channel complex to the axon initial segment is favored by co...

  20. Fuel assembly

    International Nuclear Information System (INIS)

    Watanabe, Shoichi; Hirano, Yasushi.

    1998-01-01

    A one-half or more of entire fuel rods in a fuel assembly comprises MOX fuel rods containing less than 1wt% of burnable poisons, and at least a portion of the burnable poisons comprises gadolinium. Then, surplus reactivity at an initial stage of operation cycle is controlled to eliminate burnable poisons remained unburnt at a final stage, as well as increase thermal reactivity. In addition, the content of fission plutonium is determined to greater than the content of uranium 235, and fuel rods at corner portions are made not to incorporate burnable poisons. Fuel rods not containing burnable poisons are disposed at positions in adjacent with fuel rods facing to a water rod at one or two directions. Local power at radial center of the fuel assembly is increased to flatten the distortion of radial power distribution. (N.H.)

  1. MLL/WDR5 Complex Regulates Kif2A Localization to Ensure Chromosome Congression and Proper Spindle Assembly during Mitosis.

    Science.gov (United States)

    Ali, Aamir; Veeranki, Sailaja Naga; Chinchole, Akash; Tyagi, Shweta

    2017-06-19

    Mixed-lineage leukemia (MLL), along with multisubunit (WDR5, RbBP5, ASH2L, and DPY30) complex catalyzes the trimethylation of H3K4, leading to gene activation. Here, we characterize a chromatin-independent role for MLL during mitosis. MLL and WDR5 localize to the mitotic spindle apparatus, and loss of function of MLL complex by RNAi results in defects in chromosome congression and compromised spindle formation. We report interaction of MLL complex with several kinesin and dynein motors. We further show that the MLL complex associates with Kif2A, a member of the Kinesin-13 family of microtubule depolymerase, and regulates the spindle localization of Kif2A during mitosis. We have identified a conserved WDR5 interaction (Win) motif, so far unique to the MLL family, in Kif2A. The Win motif of Kif2A engages in direct interactions with WDR5 for its spindle localization. Our findings highlight a non-canonical mitotic function of MLL complex, which may have a direct impact on chromosomal stability, frequently compromised in cancer. Copyright © 2017 Elsevier Inc. All rights reserved.

  2. local

    Directory of Open Access Journals (Sweden)

    Abílio Amiguinho

    2005-01-01

    Full Text Available The process of socio-educational territorialisation in rural contexts is the topic of this text. The theme corresponds to a challenge to address it having as main axis of discussion either the problem of social exclusion or that of local development. The reasons to locate the discussion in this last field of analysis are discussed in the first part of the text. Theoretical and political reasons are there articulated because the question is about projects whose intentions and practices call for the political both in the theoretical debate and in the choices that anticipate intervention. From research conducted for several years, I use contributions that aim at discuss and enlighten how school can be a potential locus of local development. Its identification and recognition as local institution (either because of those that work and live in it or because of those that act in the surrounding context are crucial steps to progressively constitute school as a partner for development. The promotion of the local values and roots, the reconstruction of socio-personal and local identities, the production of sociabilities and the equation and solution of shared problems were the dimensions of a socio-educative intervention, markedly globalising. This scenario, as it is argued, was also, intentionally, one of transformation and of deliberate change of school and of the administration of the educative territoires.

  3. The assembly of MreB, a prokaryotic homolog of actin.

    Science.gov (United States)

    Esue, Osigwe; Cordero, Maria; Wirtz, Denis; Tseng, Yiider

    2005-01-28

    MreB, a major component of the bacterial cytoskeleton, exhibits high structural homology to its eukaryotic counterpart actin. Live cell microscopy studies suggest that MreB molecules organize into large filamentous spirals that support the cell membrane and play a key shape-determining function. However, the basic properties of MreB filament assembly remain unknown. Here, we studied the assembly of Thermotoga maritima MreB triggered by ATP in vitro and compared it to the well-studied assembly of actin. These studies show that MreB filament ultrastructure and polymerization depend crucially on temperature as well as the ions present on solution. At the optimal growth temperature of T. maritima, MreB assembly proceeded much faster than that of actin, without nucleation (or nucleation is highly favorable and fast) and with little or no contribution from filament end-to-end annealing. MreB exhibited rates of ATP hydrolysis and phosphate release similar to that of F-actin, however, with a critical concentration of approximately 3 nm, which is approximately 100-fold lower than that of actin. Furthermore, MreB assembled into filamentous bundles that have the ability to spontaneously form ring-like structures without auxiliary proteins. These findings suggest that despite high structural homology, MreB and actin display significantly different assembly properties.

  4. Experimental data and calculation studies of critical heat fluxes at local disturbances of geometry of WWER fuel assemblies

    International Nuclear Information System (INIS)

    Kobzar, L.L.; Oleksyuk, D.A.

    2001-01-01

    The results of experiments executed in RRC 'Kurchatov Institute on the thermal-physical critical facility SVD are presented herein. The experiments modeled the drawing of two fuel rods to each other till touching WWER-1000 reactor in FA. The experimental model is a 7-rod bundle with the heated length of 1 m. The primary goal of experiments was to acquire the quantitative factors of the reduction in the critical heat fluxes as contrasted to the basic model (without disturbances of FA geometry) at the expense of local disturbance of a rod bundle geometry. As it follows from the experiment, the effect of decrease of the critical heat rate depends on combination of regime parameters and it makes 15% in the most unfavorable case (Authors)

  5. Localization of adenovirus morphogenesis players, together with visualization of assembly intermediates and failed products, favor a model where assembly and packaging occur concurrently at the periphery of the replication center.

    Directory of Open Access Journals (Sweden)

    Gabriela N Condezo

    2017-04-01

    Full Text Available Adenovirus (AdV morphogenesis is a complex process, many aspects of which remain unclear. In particular, it is not settled where in the nucleus assembly and packaging occur, and whether these processes occur in a sequential or a concerted manner. Here we use immunofluorescence and immunoelectron microscopy (immunoEM to trace packaging factors and structural proteins at late times post infection by either wildtype virus or a delayed packaging mutant. We show that representatives of all assembly factors are present in the previously recognized peripheral replicative zone, which therefore is the AdV assembly factory. Assembly intermediates and abortive products observed in this region favor a concurrent assembly and packaging model comprising two pathways, one for capsid proteins and another one for core components. Only when both pathways are coupled by correct interaction between packaging proteins and the genome is the viral particle produced. Decoupling generates accumulation of empty capsids and unpackaged cores.

  6. Bacteriophage Assembly

    Directory of Open Access Journals (Sweden)

    Anastasia A. Aksyuk

    2011-02-01

    Full Text Available Bacteriophages have been a model system to study assembly processes for over half a century. Formation of infectious phage particles involves specific protein-protein and protein-nucleic acid interactions, as well as large conformational changes of assembly precursors. The sequence and molecular mechanisms of phage assembly have been elucidated by a variety of methods. Differences and similarities of assembly processes in several different groups of bacteriophages are discussed in this review. The general principles of phage assembly are applicable to many macromolecular complexes.

  7. Fuel assemblies

    International Nuclear Information System (INIS)

    Nakatsuka, Masafumi.

    1979-01-01

    Purpose: To prevent scattering of gaseous fission products released from fuel assemblies stored in an fbr type reactor. Constitution; A cap provided with means capable of storing gas is adapted to amount to the assembly handling head, for example, by way of threading in a storage rack of spent fuel assemblies consisting of a bottom plate, a top plate and an assembly support mechanism. By previously eliminating the gas inside of the assembly and the cap in the storage rack, gaseous fission products upon loading, if released from fuel rods during storage, are stored in the cap and do not scatter in the storage rack. (Horiuchi, T.)

  8. Sequence assembly

    DEFF Research Database (Denmark)

    Scheibye-Alsing, Karsten; Hoffmann, S.; Frankel, Annett Maria

    2009-01-01

    Despite the rapidly increasing number of sequenced and re-sequenced genomes, many issues regarding the computational assembly of large-scale sequencing data have remain unresolved. Computational assembly is crucial in large genome projects as well for the evolving high-throughput technologies and...... in genomic DNA, highly expressed genes and alternative transcripts in EST sequences. We summarize existing comparisons of different assemblers and provide a detailed descriptions and directions for download of assembly programs at: http://genome.ku.dk/resources/assembly/methods.html....

  9. Origin of localized states in zinc-blende ZnCdSe thin films and the influence on carrier relaxation of self-assembled ZnTe/ZnCdSe quantum dots

    International Nuclear Information System (INIS)

    Lee, Ling; Dai, Yue-Ru; Yang, Chu-Shou; Fan, Wen-Chung; Chou, Wu-Ching

    2015-01-01

    Highlights: • The localized emission in zinc-blende ZnCdSe is induced by excess selenium. • An optimized growth is demonstrated as the VI/II ratio approaches unity. • Size-independent lifetimes are observed in ZnTe/ZnCdSe quantum dots. • Localized electrons in the capping layer dominate size-independent lifetimes. - Abstract: This study discovered the origin of deep level emission in zinc-blende ZnCdSe thin films grown by molecular beam epitaxy, in which a localization behavior was noticed. Pronounced deep level emission observed in films grown under a VI/II ratio of 1.74 (Se-accumulated regime) could be suppressed by a lower VI/II ratio of 1.04 (intermediate regime) and 0.74 (metal-rich regime). Hence the localized states could be correlated to excess selenium accumulated at the growth surface. The localized states also influence the carrier relaxation process of self-assembled ZnTe quantum dots embedded in a ZnCdSe matrix. Once quantum dots surmount the wetting layer, localized electrons in the capping layer dominate the type-II transition and exhibit size-independent lifetimes

  10. Self-assembly of a double-helical complex of sodium.

    Science.gov (United States)

    Bell, T W; Jousselin, H

    1994-02-03

    Spontaneous self-organization of helical and multiple-helical molecular structures occurs on several levels in living organisms. Key examples are alpha-helical polypeptides, double-helical nucleic acids and helical protein structures, including F-actin, microtubules and the protein sheath of the tobacco mosaic virus. Although the self-assembly of double-helical transition-metal complexes bears some resemblance to the molecular organization of double-stranded DNA, selection between monohelical, double-helical and triple-helical structures is determined largely by the size and geometrical preference of the tightly bound metal. Here we present an example of double-helical assembly induced by the weaker and non-directional interactions of an alkali-metal ion with an organic ligand that is pre-organized into a coil. We have characterized the resulting complex by two-dimensional NMR and fast-atom-bombardment mass spectrometry. These results provide a step toward the creation of molecular tubes or ion channels consisting of intertwined coils.

  11. Direct imaging by atomic force microscopy of surface-localized self-assembled monolayers on a cuprate superconductor and surface X-ray scattering analysis of analogous monolayers on the surface of water

    DEFF Research Database (Denmark)

    Schougaard, Steen B.; Reitzel, Niels; Bjørnholm, Thomas

    2007-01-01

    A self-assembled monolayer of CF3(CF2)(3)(CH2)(11)NH2 atop the (001) surface of the high-temperature superconductor YBa2Cu3O7-x was imaged by atomic force microscopy (AFM). The AFM images provide direct 2D-structural evidence for the epitaxial 5.5 angstrom square root 2 x root 2R45 degrees unit...... was studied by grazing-incidence X-ray diffraction and specular X-ray reflectivity. Structural differences and similarities between the water-supported and superconductor-localized monolayers are discussed....

  12. Fuel assembly

    International Nuclear Information System (INIS)

    Abe, Hideaki; Sakai, Takao; Ishida, Tomio; Yokota, Norikatsu.

    1992-01-01

    The lower ends of a plurality of plate-like shape memory alloys are secured at the periphery of the upper inside of the handling head of a fuel assembly. As the shape memory alloy, a Cu-Zn alloy, a Ti-Pd alloy or a Fe-Ni alloy is used. When high temperature coolants flow out to the handling head, the shape memory alloy deforms by warping to the outer side more greatly toward the upper portion thereof with the temperature increase of the coolants. As the result, the shape of the flow channel of the coolants is changed so as to enlarge at the exit of the upper end of the fuel assembly. Then, the pressure loss of the coolants in the fuel assembly is decreased by the enlargement. Accordingly, the flow rate of the coolants in the fuel assembly is increased to lower the temperature of the coolants. Further, high temperature coolants and low temperature coolants are mixed sufficiently just above the fuel assembly. This can suppress the temperature fluctuation of the mixed coolants in the upper portion of the reactor core, thereby enabling to decrease a fatigue and failures of the structural components in the upper portion of the reactor core. (I.N.)

  13. Fuel assembly

    International Nuclear Information System (INIS)

    Nakatsuka, Masafumi; Matsuzuka, Ryuji.

    1976-01-01

    Object: To provide a fuel assembly which can decrease pressure loss of coolant to uniform temperature. Structure: A sectional area of a flow passage in the vicinity of an inner peripheral surface of a wrapper tube is limited over the entire length to prevent the temperature of a fuel element in the outermost peripheral portion from being excessively decreased to thereby flatten temperature distribution. To this end, a plurality of pincture-frame-like sheet metals constituting a spacer for supporting a fuel assembly, which has a plurality of fuel elements planted lengthwise and in given spaced relation within the wrapper tube, is disposed in longitudinal grooves and in stacked fashion to form a substantially honeycomb-like space in cross section. The fuel elements are inserted and supported in the space to form a fuel assembly. (Kamimura, M.)

  14. Fuel assemblies

    International Nuclear Information System (INIS)

    Nagano, Mamoru; Yoshioka, Ritsuo

    1983-01-01

    Purpose: To effectively utilize nuclear fuels by increasing the reactivity of a fuel assembly and reduce the concentration at the central region thereof upon completion of the burning. Constitution: A fuel assembly is bisected into a central region and a peripheral region by disposing an inner channel box within a channel box. The flow rate of coolants passing through the central region is made greater than that in the peripheral region. The concentration of uranium 235 of the fuel rods in the central region is made higher. In such a structure, since the moderating effect in the central region is improved, the reactivity of the fuel assembly is increased and the uranium concentration in the central region upon completion of the burning can be reduced, fuel economy and effective utilization of uranium can be attained. (Kamimura, M.)

  15. Royal jelly-like protein localization reveals differences in hypopharyngeal glands buildup and conserved expression pattern in brains of bumblebees and honeybees

    Directory of Open Access Journals (Sweden)

    Štefan Albert

    2014-03-01

    Full Text Available Royal jelly proteins (MRJPs of the honeybee bear several open questions. One of them is their expression in tissues other than the hypopharyngeal glands (HGs, the site of royal jelly production. The sole MRJP-like gene of the bumblebee, Bombus terrestris (BtRJPL, represents a pre-diversification stage of the MRJP gene evolution in bees. Here we investigate the expression of BtRJPL in the HGs and the brain of bumblebees. Comparison of the HGs of bumblebees and honeybees revealed striking differences in their morphology with respect to sex- and caste-specific appearance, number of cells per acinus, and filamentous actin (F-actin rings. At the cellular level, we found a temporary F-actin-covered meshwork in the secretory cells, which suggests a role for actin in the biogenesis of the end apparatus in HGs. Using immunohistochemical localization, we show that BtRJPL is expressed in the bumblebee brain, predominantly in the Kenyon cells of the mushroom bodies, the site of sensory integration in insects, and in the optic lobes. Our data suggest that a dual gland-brain function preceded the multiplication of MRJPs in the honeybee lineage. In the course of the honeybee evolution, HGs dramatically changed their morphology in order to serve a food-producing function.

  16. Valve assembly

    International Nuclear Information System (INIS)

    Sandling, M.

    1981-01-01

    An improved valve assembly, used for controlling the flow of radioactive slurry, is described. Radioactive contamination of the air during removal or replacement of the valve is prevented by sucking air from the atmosphere through a portion of the structure above the valve housing. (U.K.)

  17. Fuel assembly

    International Nuclear Information System (INIS)

    Gjertsen, R.K.; Bassler, E.A.; Huckestein, E.A.; Salton, R.B.; Tower, S.N.

    1988-01-01

    A fuel assembly adapted for use with a pressurized water nuclear reactor having capabilities for fluid moderator spectral shift control is described comprising: parallel arranged elongated nuclear fuel elements; means for providing for axial support of the fuel elements and for arranging the fuel elements in a spaced array; thimbles interspersed among the fuel elements adapted for insertion of a rod control cluster therewithin; means for structurally joining the fuel elements and the guide thimbles; fluid moderator control means for providing a volume of low neutron absorbing fluid within the fuel assembly and for removing a substantially equivalent volume of reactor coolant water therefrom, a first flow manifold at one end of the fuel assembly sealingly connected to a first end of the moderator control tubes whereby the first ends are commonly flow connected; and a second flow manifold, having an inlet passage and an outlet passage therein, sealingly connected to a second end of the moderator control tubes at a second end of the fuel assembly

  18. Profilin connects actin assembly with microtubule dynamics

    Czech Academy of Sciences Publication Activity Database

    Nejedla, M.; Sadi, S.; Sulimenko, Vadym; de Almeida, F.N.; Blom, H.; Dráber, Pavel; Aspenstrom, P.; Karlsson, R.

    2016-01-01

    Roč. 27, č. 15 (2016), s. 2381-2393 ISSN 1059-1524 R&D Projects: GA ČR GA16-25159S Institutional support: RVO:68378050 Keywords : cross-linked profilin * arp2/3 complex * f-actin * microfilament system * migrating cells * focal adhesions * cultured-cells * messenger-rna * living cells * protein Subject RIV: EB - Genetics ; Molecular Biology Impact factor: 3.685, year: 2016

  19. Rapid localized deactivation of self-assembled monolayers by propagation-controlled laser-induced plasma and its application to self-patterning of electronics and biosensors

    Science.gov (United States)

    Kim, Jongsu; Kwon, Seung-Gab; Back, Seunghyun; Kang, Bongchul

    2018-03-01

    We present a novel laser-induced surface treatment process to rapidly control the spatial wettabilities of various functional solutions with submicron to micron resolutions. Ultrathin hydrophobic self-assembled monolayers (SAMs) that little absorb typical laser lights due to short penetration depth were selectively deactivated by instantaneous interaction with laser-induced metallic plasmas. The spatial region of the deactivated SAM, which corresponds to process resolution, is adjustable by controlling the spatial propagation of the plasma. This method leads to the parallel formation of hydrophilic functional solutions on glass substrates with a minimum resolution on the submicron scale. To show its feasibility in device engineering fields, this method was applied to the cost-effective fabrication of electronics and biosensors. Rapid self-patterning of electronic and biological functional solutions (silver nanoparticle solution and streptavidin protein solution) was successfully realized by selective deactivation of two different SAMs (tridecafluoro-1,1,2,2-tetrahydrooctyltrichlorosilane (FOTS) for electronics and the hetero-hybrid SAM (octadecyltrichlorosilane (OTS)/2-[methoxy(polyethyleneoxy)propyl] trichlorosilane (PEG)) for biosensors). As a result, this method can be exploited for the rapid and low-cost fabrication of various thin film devices such as electronics, biosensors, energy, displays, and photonics.

  20. ReseqChip: Automated integration of multiple local context probe data from the MitoChip array in mitochondrial DNA sequence assembly

    Directory of Open Access Journals (Sweden)

    Spang Rainer

    2009-12-01

    Full Text Available Abstract Background The Affymetrix MitoChip v2.0 is an oligonucleotide tiling array for the resequencing of the human mitochondrial (mt genome. For each of 16,569 nucleotide positions of the mt genome it holds two sets of four 25-mer probes each that match the heavy and the light strand of a reference mt genome and vary only at their central position to interrogate all four possible alleles. In addition, the MitoChip v2.0 carries alternative local context probes to account for known mtDNA variants. These probes have been neglected in most studies due to the lack of software for their automated analysis. Results We provide ReseqChip, a free software that automates the process of resequencing mtDNA using multiple local context probes on the MitoChip v2.0. ReseqChip significantly improves base call rate and sequence accuracy. ReseqChip is available at http://code.open-bio.org/svnweb/index.cgi/bioperl/browse/bioperl-live/trunk/Bio/Microarray/Tools/. Conclusions ReseqChip allows for the automated consolidation of base calls from alternative local mt genome context probes. It thereby improves the accuracy of resequencing, while reducing the number of non-called bases.

  1. Actin-interacting protein 1 controls assembly and permeability of intestinal epithelial apical junctions.

    Science.gov (United States)

    Lechuga, Susana; Baranwal, Somesh; Ivanov, Andrei I

    2015-05-01

    Adherens junctions (AJs) and tight junctions (TJs) are crucial regulators of the integrity and restitution of the intestinal epithelial barrier. The structure and function of epithelial junctions depend on their association with the cortical actin cytoskeleton that, in polarized epithelial cells, is represented by a prominent perijunctional actomyosin belt. The assembly and stability of the perijunctional cytoskeleton is controlled by constant turnover (disassembly and reassembly) of actin filaments. Actin-interacting protein (Aip) 1 is an emerging regulator of the actin cytoskeleton, playing a critical role in filament disassembly. In this study, we examined the roles of Aip1 in regulating the structure and remodeling of AJs and TJs in human intestinal epithelium. Aip1 was enriched at apical junctions in polarized human intestinal epithelial cells and normal mouse colonic mucosa. Knockdown of Aip1 by RNA interference increased the paracellular permeability of epithelial cell monolayers, decreased recruitment of AJ/TJ proteins to steady-state intercellular contacts, and attenuated junctional reassembly in a calcium-switch model. The observed defects of AJ/TJ structure and functions were accompanied by abnormal organization and dynamics of the perijunctional F-actin cytoskeleton. Moreover, loss of Aip1 impaired the apico-basal polarity of intestinal epithelial cell monolayers and inhibited formation of polarized epithelial cysts in 3-D Matrigel. Our findings demonstrate a previously unanticipated role of Aip1 in regulating the structure and remodeling of intestinal epithelial junctions and early steps of epithelial morphogenesis. Copyright © 2015 the American Physiological Society.

  2. Fuel assembly

    International Nuclear Information System (INIS)

    Yokota, Tokunobu.

    1990-01-01

    A fuel assembly used in a FBR type nuclear reactor comprises a plurality of fuel rods and a moderator guide member (water rod). A moderator exit opening/closing mechanism is formed at the upper portion of the moderator guide member for opening and closing a moderator exit. In the initial fuel charging operation cycle to the reactor, the moderator exit is closed by the moderator exit opening/closing mechanism. Then, voids are accumulated at the inner upper portion of the moderator guide member to harden spectrum and a great amount of plutonium is generated and accumulated in the fuel assembly. Further, in the fuel re-charging operation cycle, the moderator guide member is used having the moderator exit opened. In this case, voids are discharged from the moderator guide member to decrease the ratio, and the plutonium accumulated in the initial charging operation cycle is burnt. In this way, the fuel economy can be improved. (I.N.)

  3. Fuel assemblies

    International Nuclear Information System (INIS)

    Echigoya, Hironori; Nomata, Terumitsu.

    1983-01-01

    Purpose: To render the axial distribution relatively flat. Constitution: First nuclear element comprises a fuel can made of zircalloy i.e., the metal with less neutron absorption, which is filled with a plurality of UO 2 pellets and sealed by using a lower end plug, a plenum spring and an upper end plug by means of welding. Second fuel element is formed by substituting a part of the UO 2 pellets with a water tube which is sealed with water and has a space for allowing the heat expansion. The nuclear fuel assembly is constituted by using the first and second fuel elements together. In such a structure, since water reflects neutrons and decrease their leakage to increase the temperature, reactivity is added at the upper portion of the fuel assembly to thereby flatten the axial power distribution. Accordingly, stable operation is possible only by means of deep control rods while requiring no shallow control rods. (Sekiya, K.)

  4. Fuel assembly

    International Nuclear Information System (INIS)

    Kawai, Mitsuo.

    1988-01-01

    Purpose: To reduce the corrosion rate and suppress the increase of radioactive corrosion products in reactor water of nuclear fuel assemblies for use in BWR type reactors having spacer springs made of nickel based deposition reinforced type alloys. Constitution: Spacer rings made of nickel based deposition reinforced type alloy are incorporated and used as fuel assemblies after applying treatment of dipping and maintaining at high temperature water followed by heating in steams. Since this can remove the nickel leaching into reactor water at the initial stage, Co-58 as the radioactive corrosion products in the reactor water can be reduced, and the operation at in-service inspection or repairement can be facilitated to improve the working efficiency of the nuclear power plant. The dipping time is desirably more than 10 hours and more desirably more than 30 hours. (Horiuchi, T. )

  5. General Assembly

    CERN Multimedia

    Staff Association

    2016-01-01

    5th April, 2016 – Ordinary General Assembly of the Staff Association! In the first semester of each year, the Staff Association (SA) invites its members to attend and participate in the Ordinary General Assembly (OGA). This year the OGA will be held on Tuesday, April 5th 2016 from 11:00 to 12:00 in BE Auditorium, Meyrin (6-2-024). During the Ordinary General Assembly, the activity and financial reports of the SA are presented and submitted for approval to the members. This is the occasion to get a global view on the activities of the SA, its financial management, and an opportunity to express one’s opinion, including taking part in the votes. Other points are listed on the agenda, as proposed by the Staff Council. Who can vote? Only “ordinary” members (MPE) of the SA can vote. Associated members (MPA) of the SA and/or affiliated pensioners have a right to vote on those topics that are of direct interest to them. Who can give his/her opinion? The Ordinary General Asse...

  6. Fuel assembly

    International Nuclear Information System (INIS)

    Ueda, Sei; Ando, Ryohei; Mitsutake, Toru.

    1995-01-01

    The present invention concerns a fuel assembly suitable to a BWR-type reactor and improved especially with the nuclear characteristic, heat performance, hydraulic performance, dismantling or assembling performance and economical property. A part of poison rods are formed as a large-diameter/multi-region poison rods having a larger diameter than a fuel rod. A large number of fuel rods are disposed surrounding a large diameter water rod and a group of the large-diameter/multi-region poison rods in adjacent with the water rod. The large-diameter water rod has a burnable poison at the tube wall portion. At least a portion of the large-diameter poison rods has a coolant circulation portion allowing coolants to circulate therethrough. Since the large-diameter poison rods are disposed at a position of high neutron fluxes, a large neutron multiplication factor suppression effect can be provided, thereby enabling to reduce the number of burnable poison rods relative to fuels. As a result, power peaking in the fuel assembly is moderated and a greater amount of plutonium can be loaded. In addition the flow of cooling water which tends to gather around the large diameter water rod can be controlled to improve cooling performance of fuels. (N.H.)

  7. Myosin IIA interacts with the spectrin-actin membrane skeleton to control red blood cell membrane curvature and deformability.

    Science.gov (United States)

    Smith, Alyson S; Nowak, Roberta B; Zhou, Sitong; Giannetto, Michael; Gokhin, David S; Papoin, Julien; Ghiran, Ionita C; Blanc, Lionel; Wan, Jiandi; Fowler, Velia M

    2018-05-08

    The biconcave disk shape and deformability of mammalian RBCs rely on the membrane skeleton, a viscoelastic network of short, membrane-associated actin filaments (F-actin) cross-linked by long, flexible spectrin tetramers. Nonmuscle myosin II (NMII) motors exert force on diverse F-actin networks to control cell shapes, but a function for NMII contractility in the 2D spectrin-F-actin network of RBCs has not been tested. Here, we show that RBCs contain membrane skeleton-associated NMIIA puncta, identified as bipolar filaments by superresolution fluorescence microscopy. MgATP disrupts NMIIA association with the membrane skeleton, consistent with NMIIA motor domains binding to membrane skeleton F-actin and contributing to membrane mechanical properties. In addition, the phosphorylation of the RBC NMIIA heavy and light chains in vivo indicates active regulation of NMIIA motor activity and filament assembly, while reduced heavy chain phosphorylation of membrane skeleton-associated NMIIA indicates assembly of stable filaments at the membrane. Treatment of RBCs with blebbistatin, an inhibitor of NMII motor activity, decreases the number of NMIIA filaments associated with the membrane and enhances local, nanoscale membrane oscillations, suggesting decreased membrane tension. Blebbistatin-treated RBCs also exhibit elongated shapes, loss of membrane curvature, and enhanced deformability, indicating a role for NMIIA contractility in promoting membrane stiffness and maintaining RBC biconcave disk cell shape. As structures similar to the RBC membrane skeleton exist in many metazoan cell types, these data demonstrate a general function for NMII in controlling specialized membrane morphology and mechanical properties through contractile interactions with short F-actin in spectrin-F-actin networks.

  8. Fuel assembly

    International Nuclear Information System (INIS)

    Fujibayashi, Toru.

    1970-01-01

    Herein disclosed is a fuel assembly in which a fuel rod bundle is easily detachable by rotating a fuel rod fastener rotatably mounted to the upper surface of an upper tie-plate supporting a fuel bundle therebelow. A locking portion at the leading end of each fuel rod protrudes through the upper tie-plate and is engaged with or separated from the tie-plate by the rotation of the fastener. The removal of a desired fuel rod can therefore be remotely accomplished without the necessity of handling pawls, locking washers and nuts. (Owens, K.J.)

  9. Assembling consumption

    DEFF Research Database (Denmark)

    Assembling Consumption marks a definitive step in the institutionalisation of qualitative business research. By gathering leading scholars and educators who study markets, marketing and consumption through the lenses of philosophy, sociology and anthropology, this book clarifies and applies...... the investigative tools offered by assemblage theory, actor-network theory and non-representational theory. Clear theoretical explanation and methodological innovation, alongside empirical applications of these emerging frameworks will offer readers new and refreshing perspectives on consumer culture and market...... societies. This is an essential reading for both seasoned scholars and advanced students of markets, economies and social forms of consumption....

  10. Fuel assembly

    International Nuclear Information System (INIS)

    Kurihara, Kunitoshi; Azekura, Kazuo.

    1992-01-01

    In a reactor core of a heavy water moderated light water cooled pressure tube type reactor, no sufficient effects have been obtained for the transfer width to a negative side of void reactivity change in a region of a great void coefficient. Then, a moderation region divided into upper and lower two regions is disposed at the central portion of a fuel assembly. Coolants flown into the lower region can be discharged to the cooling region from an opening disposed at the upper end portion of the lower region. Light water flows from the lower region of the moderator region to the cooling region of the reactor core upper portion, to lower the void coefficient. As a result, the reactivity performance at low void coefficient, i.e., a void reaction rate is transferred to the negative side. Thus, this flattens the power distribution in the fuel assembly, increases the thermal margin and enables rapid operaiton and control of the reactor core, as well as contributes to the increase of fuel burnup ratio and reduction of the fuel cycle cost. (N.H.)

  11. Fuel assembly

    International Nuclear Information System (INIS)

    Chaki, Masao; Nishida, Koji; Karasawa, Hidetoshi; Kanazawa, Toru; Orii, Akihito; Nagayoshi, Takuji; Kashiwai, Shin-ichi; Masuhara, Yasuhiro

    1998-01-01

    The present invention concerns a fuel assembly, for a BWR type nuclear reactor, comprising fuel rods in 9 x 9 matrix. The inner width of the channel box is about 132mm and the length of the fuel rods which are not short fuel rods is about 4m. Two water rods having a circular cross section are arranged on a diagonal line in a portion of 3 x 3 matrix at the center of the fuel assembly, and two fuel rods are disposed at vacant spaces, and the number of fuel rods is 74. Eight fuel rods are determined as short fuel rods among 74 fuel rods. Assuming the fuel inventory in the short fuel rod as X(kg), and the fuel inventory in the fuel rods other than the short fuel rods as Y(kg), X and Y satisfy the relation: X + Y ≥ 173m, Y ≤ - 9.7X + 292, Y ≤ - 0.3X + 203 and X > 0. Then, even when the short fuel rods are used, the fuel inventory is increased and fuel economy can be improved. (I.N.)

  12. Fuel assembly

    International Nuclear Information System (INIS)

    Fushimi, Atsushi; Shimada, Hidemitsu; Aoyama, Motoo; Nakajima, Junjiro

    1998-01-01

    In a fuel assembly for an n x n lattice-like BWR type reactor, n is determined to 9 or greater, and the enrichment degree of plutonium is determined to 4.4% by weight or less. Alternatively, n is determined to 10 or greater, and the enrichment degree of plutonium is determined to 5.2% by weight or less. An average take-out burnup degree is determined to 39GWd/t or less, and the matrix is determined to 9 x 9 or more, or the average take-out burnup degree is determined to 51GWd/t, and the matrix is determined to 10 x 10 or more and the increase of the margin of the maximum power density obtained thereby is utilized for the compensation of the increase of distortion of power distribution due to decrease of the kinds of plutonium enrichment degree, thereby enabling to reduce the kind of the enrichment degree of MOX fuel rods to one. As a result, the manufacturing step for fuel pellets can be simplified to reduce the manufacturing cost for MOX fuel assemblies. (N.H.)

  13. General Assembly

    CERN Multimedia

    Staff Association

    2015-01-01

    Mardi 5 mai à 11 h 00 Salle 13-2-005 Conformément aux statuts de l’Association du personnel, une Assemblée générale ordinaire est organisée une fois par année (article IV.2.1). Projet d’ordre du jour : 1- Adoption de l’ordre du jour. 2- Approbation du procès-verbal de l’Assemblée générale ordinaire du 22 mai 2014. 3- Présentation et approbation du rapport d’activités 2014. 4- Présentation et approbation du rapport financier 2014. 5- Présentation et approbation du rapport des vérificateurs aux comptes pour 2014. 6- Programme 2015. 7- Présentation et approbation du projet de budget 2015 et taux de cotisation pour 2015. 8- Pas de modifications aux Statuts de l'Association du personnel proposée. 9- Élections des membres de la Commission é...

  14. General Assembly

    CERN Multimedia

    Staff Association

    2017-01-01

    Conformément aux statuts de l’Association du personnel, une Assemblée générale ordinaire est organisée une fois par année (article IV.2.1). Projet d’ordre du jour : Adoption de l’ordre du jour. Approbation du procès-verbal de l’Assemblée générale ordinaire du 5 avril 2016. Présentation et approbation du rapport d’activités 2016. Présentation et approbation du rapport financier 2016. Présentation et approbation du rapport des vérificateurs aux comptes pour 2016. Programme de travail 2017. Présentation et approbation du projet de budget 2017 Approbation du taux de cotisation pour 2018. Modifications aux Statuts de l'Association du personnel proposées. Élections des membres de la Commission électorale. Élections des vérifica...

  15. General Assembly

    CERN Multimedia

    Staff Association

    2016-01-01

    Mardi 5 avril à 11 h 00 BE Auditorium Meyrin (6-2-024) Conformément aux statuts de l’Association du personnel, une Assemblée générale ordinaire est organisée une fois par année (article IV.2.1). Projet d’ordre du jour : Adoption de l’ordre du jour. Approbation du procès-verbal de l’Assemblée générale ordinaire du 5 mai 2015. Présentation et approbation du rapport d’activités 2015. Présentation et approbation du rapport financier 2015. Présentation et approbation du rapport des vérificateurs aux comptes pour 2015. Programme de travail 2016. Présentation et approbation du projet de budget 2016 Approbation du taux de cotisation pour 2017. Modifications aux Statuts de l'Association du personnel proposée. Élections des membres de la Commissio...

  16. General assembly

    CERN Multimedia

    Staff Association

    2015-01-01

    Mardi 5 mai à 11 h 00 Salle 13-2-005 Conformément aux statuts de l’Association du personnel, une Assemblée générale ordinaire est organisée une fois par année (article IV.2.1). Projet d’ordre du jour : Adoption de l’ordre du jour. Approbation du procès-verbal de l’Assemblée générale ordinaire du 22 mai 2014. Présentation et approbation du rapport d’activités 2014. Présentation et approbation du rapport financier 2014. Présentation et approbation du rapport des vérificateurs aux comptes pour 2014. Programme 2015. Présentation et approbation du projet de budget 2015 et taux de cotisation pour 2015. Pas de modifications aux Statuts de l'Association du personnel proposée. Élections des membres de la Commission électorale. &am...

  17. Fuel assembly

    International Nuclear Information System (INIS)

    Nomata, Terumitsu.

    1993-01-01

    Among fuel pellets to be loaded to fuel cans of a fuel assembly, fuel pellets having a small thermal power are charged in a region from the end of each of spacers up to about 50mm on the upstream of coolants that flow vertically at the periphery of fuel rods. Coolants at the periphery of fuel rods are heated by the heat generation, to result in voids. However, since cooling effect on the upstream of the spacers is low due to influences of the spacers. Further, since the fuel pellets disposed in the upstream region have small thermal power, a void coefficient is not increased. Even if a thermal power exceeding cooling performance should be generated, there is no worry of causing burnout in the upstream region. Even if burnout should be caused, safety margin and reliability relative to burnout are improved, to increase an allowable thermal power, thereby enabling to improve integrity and reliability of fuel rods and fuel assemblies. (N.H.)

  18. Fuel assembly

    International Nuclear Information System (INIS)

    Ueda, Makoto; Ogiya, Shunsuke.

    1989-01-01

    For improving the economy of a BWR type reactor by making the operation cycle longer, the fuel enrichment degree has to be increased further. However, this makes the subcriticality shallower in the upper portion of the reactor core, to bring about a possibility that the reactor shutdown becomes impossible. In the present invention, a portion of fuel rod is constituted as partial length fuel rods (P-fuel rods) in which the entire stack length in the effective portion is made shorter by reducing the concentration of fissionable materials in the axial portion. A plurality of moderator rods are disposed at least on one diagonal line of a fuel assembly and P-fuel rods are arranged at a position put between the moderator rods. This makes it possible to reactor shutdown and makes the axial power distribution satisfactory even if the fuel enrichment degree is increased. (T.M.)

  19. Fuel assembly

    International Nuclear Information System (INIS)

    Bando, Masaru.

    1993-01-01

    As neutron irradiation progresses on a fuel assembly of an FBR type reactor, a strong force is exerted to cause ruptures if the arrangement of fuel elements is not displaced, whereas the fuel elements may be brought into direct contact with each other not by way of spacers to cause burning damages if the arrangement is displaced. In the present invention, the circumference of fuel elements arranged in a normal triangle lattice is surrounded by a wrapper tube having a hexagonal cross section, wire spacers are wound therearound, and deformable spacers are distributed to optional positions for fuel elements in the wrapper tube. Interaction between the fuel elements caused by irradiation is effectively absorbed, thereby enabling to delay the occurrence of the rupture and burning damages of the elements. (N.H.)

  20. Fuel assembly

    International Nuclear Information System (INIS)

    Ueda, Makoto.

    1991-01-01

    In a fuel assembly in which spectral shift type moderator guide members are arranged, the moderator guide member has a flow channel resistance member, that provides flow resistance against the moderators, in the upstream of a moderator flowing channel, by which the ratio of removing coolants is set greater at the upstream than downstream. With such a constitution, the void distribution increasing upward in the channel box except for the portion of the moderator guide member is moderated by the increase of the area of the void region that expands downward in the guide member. Accordingly, the axial power distribution is flattened throughout the operation cycle and excess distortion is eliminated to improve the fuel integrity. (T.M.)

  1. Fuel assembly

    International Nuclear Information System (INIS)

    Wataumi, Kazutoshi; Tajiri, Hiroshi.

    1992-01-01

    In a fuel assembly of a BWR type reactor, a pellet to be loaded comprises an external layer of fissile materials containing burnable poisons and an internal layer of fissile materials not containing burnable poison. For example, there is provided a dual type pellet comprising an external layer made of UO 2 incorporated with Gd 2 O 3 at a predetermined concentration as the burnable poisons and an internal layer made of UO 2 not containing Gd 2 O 3 . The amount of the burnable poisons required for predetermined places is controlled by the thickness of the ring of the external layer. This can dissipate an unnecessary poisoning effect at the final stage of the combustion cycle. Further, since only one or a few kinds of powder mixture of the burnable poisons and the fissile materials is necessary, production and product control can be facilitated. (I.N.)

  2. Fuel assembly

    International Nuclear Information System (INIS)

    Ishibashi, Yoko; Aoyama, Motoo; Oyama, Jun-ichi.

    1995-01-01

    Burnable poison-incorporating fuel rods of a first group are disposed in a region in adjacent with a water rod having a large diameter (neutron moderator rod) disposed to the central portion of a fuel assembly. Burnable poison-incorporating fuel rods of a second group are disposed to a region other than peripheral zone in adjacent with a channel box and corners positioned at an inner zone, in adjacent with the channel box. The average concentration of burnable poisons of the burnable poison-incorporating fuel rods of the first group is made greater than that of the second group. With such a constitution, when the burnable poisons of the first group are burnt out, the burnable poisons of the second group are also burnt out at the same time. Accordingly, an amount of burnable poisons left unburnt at the final stage of the operation cycle is reduced, to improve the reactivity. This can improve the economical property. (I.N.)

  3. Fuel assemblies

    International Nuclear Information System (INIS)

    Yoshioka, Ritsuo.

    1983-01-01

    Purpose: To improve the operation performance of a BWR type reactor by improving the distribution of the uranium enrichment and the incorporation amount of burnable poisons in fuel assemblies. Constitution: The average enrichment of uranium 235 is increased in the upper portion as compared with that in the lower portion, while the incorporation amount of burnable poisons is increased in an upper portion as compared with that in the lower portion. The difference in the incorporation amount of the burnable poisons between the upper and lower portions is attained by charging two kinds of fuel rods; the ones incorporated with the burnable poisons over the entire length and the others incorporated with the burnable poisons only in the upper portions. (Seki, T.)

  4. Onset of self-assembly

    International Nuclear Information System (INIS)

    Chitanvis, S.M.

    1998-01-01

    We have formulated a theory of self-assembly based on the notion of local gauge invariance at the mesoscale. Local gauge invariance at the mesoscale generates the required long-range entropic forces responsible for self-assembly in binary systems. Our theory was applied to study the onset of mesostructure formation above a critical temperature in estane, a diblock copolymer. We used diagrammatic methods to transcend the Gaussian approximation and obtain a correlation length ξ∼(c-c * ) -γ , where c * is the minimum concentration below which self-assembly is impossible, c is the current concentration, and γ was found numerically to be fairly close to 2/3. The renormalized diffusion constant vanishes as the critical concentration is approached, indicating the occurrence of critical slowing down, while the correlation function remains finite at the transition point. copyright 1998 The American Physical Society

  5. Coupling Considerations in Assembly Language

    Science.gov (United States)

    2018-01-05

    done in assembly languages—just write a command that modifies the opcode of another command. A module modifying (or referring to) local data in...178C.) 3. Martin Fowler. Last accessed 6 November 2017, http://martinfowler.com. Email is fowler@acm.org. 4. “Thoughts on Coupling in Software

  6. Fuel assembly

    International Nuclear Information System (INIS)

    Hirukawa, Koji; Sakurada, Koichi.

    1992-01-01

    In a fuel assembly for a BWR type reactor, water rods or water crosses are disposed between fuel rods, and a value with a spring is disposed at the top of the coolant flow channel thereof, which opens a discharge port when pressure is increased to greater than a predetermined value. Further, a control element for the amount of coolant flow rate is inserted retractable to a control element guide tube formed at the lower portion of the water rod or the water cross. When the amount of control elements inserted to the control element guide tube is small and the inflown coolant flow rate is great, the void coefficient at the inside of the water rod is less than 5%. On the other hand, when the control elements are inserted, the flow resistance is increased, so that the void coefficient in the water rod is greater than 80%. When the pressure in the water rod is increased, the valve with the spring is raised to escape water or steams. Then, since the variation range of the change of the void coefficient can be controlled reliably by the amount of the control elements inserted, and nuclear fuel materials can be utilized effectively. (N.H.)

  7. Fuel assembly

    International Nuclear Information System (INIS)

    Hiraiwa, Koji; Ueda, Makoto

    1989-01-01

    In a fuel assembly used for a light water cooled reactor such as a BWR type reactor, a water rod is divided axially into an upper outer tube and a lower outer tube by means of a plug disposed from the lower end of a water rod to a position 1/4 - 1/2 of the entire length for the water rod. Inlet apertures and exit apertures for moderators are respectively perforated for the divided outer tube and upper and lower portions. Further, an upper inner tube with less neutron irradiation growing amount than the outer tube is perforated on the plug in the outer tube, while a lower inner tube with greater neutron irradiation growing amount than the outer tube is suspended from the lower surface of the plug in the outer tube. Then, the opening area for the exit apertures disposed to the upper outer tube and the lower outer tube is controlled depending on the difference of the neutron irradiation growing amount between the upper inner tube and the upper outer tube, and the difference of the neutron irradiation growing amount between the lower inner tube and the lower outer tube. This enables effective spectral shift operation and improve the fuel economy. (T.M.)

  8. Fuel assembly

    International Nuclear Information System (INIS)

    Yamazaki, Hajime.

    1995-01-01

    In a fuel assembly having fuel rods of different length, fuel pellets of mixed oxides of uranium and plutonium are loaded to a short fuel rod. The volume ratio of a pellet-loaded portion to a plenum portion of the short fuel rod is made greater than the volume ratio of a fuel rod to which uranium fuel pellets are loaded. In addition, the volume of the plenum portion of the short fuel rod is set greater depending on the plutonium content in the loaded fuel pellets. MOX fuel pellets are loaded on the short fuel rods having a greater degree of freedom relevant to the setting for the volume of the plenum portion compared with that of a long rod fuel, and the volume of the plenum portion is ensured greater depending on the plutonium content. Even if a large amount of FP gas and He gas are discharged from the MOX fuels compared with that from the uranium fuels, the internal pressure of the MOX fuel rod during operation is maintained substantially identical with that of the uranium fuel rod, so that a risk of generating excess stresses applied to the fuel cladding tubes and rupture of fuels are greatly reduced. (N.H.)

  9. Fuel assembly

    International Nuclear Information System (INIS)

    Nakajima, Akiyoshi; Bessho, Yasunori; Aoyama, Motoo; Koyama, Jun-ichi; Hirakawa, Hiromasa; Yamashita, Jun-ichi; Hayashi, Tatsuo

    1998-01-01

    In a fuel assembly of a BWR type reactor in which a water rod of a large diameter is disposed at the central portion, the cross sectional area perpendicular to the axial direction comprises a region a of a fuel rod group facing to a wide gap water region to which a control rod is inserted, a region b of a fuel rod group disposed on the side of the wide gap water region other than the region a, a region d of a fuel rod group facing to a narrow gap water region and a region c of a fuel rod group disposed on the side of the narrow gap water region other than the region d. When comparing an amount of fission products contained in the four regions relative to that in the entire regions and average enrichment degrees of fuel rods for the four regions, the relative amount and the average enrichment degree of the fuel rod group of the region a is minimized, and the relative amount and the average enrichment degree of the fuel rod group in the region b is maximized. Then, reactor shut down margin during cold operation can be improved while flattening the power in the cross section perpendicular to the axial direction. (N.H.)

  10. Regulation of myosin IIA and filamentous actin during insulin-stimulated glucose uptake in 3T3-L1 adipocytes

    International Nuclear Information System (INIS)

    Stall, Richard; Ramos, Joseph; Kent Fulcher, F.; Patel, Yashomati M.

    2014-01-01

    Insulin stimulated glucose uptake requires the colocalization of myosin IIA (MyoIIA) and the insulin-responsive glucose transporter 4 (GLUT4) at the plasma membrane for proper GLUT4 fusion. MyoIIA facilitates filamentous actin (F-actin) reorganization in various cell types. In adipocytes F-actin reorganization is required for insulin-stimulated glucose uptake. What is not known is whether MyoIIA interacts with F-actin to regulate insulin-induced GLUT4 fusion at the plasma membrane. To elucidate the relationship between MyoIIA and F-actin, we examined the colocalization of MyoIIA and F-actin at the plasma membrane upon insulin stimulation as well as the regulation of this interaction. Our findings demonstrated that MyoIIA and F-actin colocalized at the site of GLUT4 fusion with the plasma membrane upon insulin stimulation. Furthermore, inhibition of MyoII with blebbistatin impaired F-actin localization at the plasma membrane. Next we examined the regulatory role of calcium in MyoIIA-F-actin colocalization. Reduced calcium or calmodulin levels decreased colocalization of MyoIIA and F-actin at the plasma membrane. While calcium alone can translocate MyoIIA it did not stimulate F-actin accumulation at the plasma membrane. Taken together, we established that while MyoIIA activity is required for F-actin localization at the plasma membrane, it alone is insufficient to localize F-actin to the plasma membrane. - Highlights: • Insulin induces colocalization of MyoIIA and F-actin at the cortex in adipocytes. • MyoIIA is necessary but not sufficient to localize F-actin at the cell cortex. • MyoIIA-F-actin colocalization is regulated by calcium and calmodulin

  11. Self-assembly of cyclodextrins

    DEFF Research Database (Denmark)

    Fülöp, Z.; Kurkov, S.V.; Nielsen, T.T.

    2012-01-01

    The design of functional cyclodextrin (CD) nanoparticles is a developing area in the field of nanomedicine. CDs can not only help in the formation of drug carriers but also increase the local concentration of drugs at the site of action. CD monomers form aggregates by self-assembly, a tendency...... that increases upon formation of inclusion complexes with lipophilic drugs. However, the stability of such aggregates is not sufficient for parenteral administration. In this review CD polymers and CD containing nanoparticles are categorized, with focus on self-assembled CD nanoparticles. It is described how...

  12. Newnes electronics assembly handbook

    CERN Document Server

    Brindley, Keith

    2013-01-01

    Newnes Electronics Assembly Handbook: Techniques, Standards and Quality Assurance focuses on the aspects of electronic assembling. The handbook first looks at the printed circuit board (PCB). Base materials, basic mechanical properties, cleaning of assemblies, design, and PCB manufacturing processes are then explained. The text also discusses surface mounted assemblies and packaging of electromechanical assemblies, as well as the soldering process. Requirements for the soldering process; solderability and protective coatings; cleaning of PCBs; and mass solder/component reflow soldering are des

  13. Nuclear fuel assembly

    International Nuclear Information System (INIS)

    Domoto, Noboru; Masuda, Hiroyuki

    1989-01-01

    In a nuclear fuel assembly loaded with a plurality of fuel rods, the inside of a fuel rod disposed at a high neutron flux region is divided into an inner region and an outer region, and more burnable poisons are mixed in the inner region than in the outer region. Alternatively, the central portion of a pellet disposed in a high neutron flux region is made hollow, in which burnable poisons are charged. This can prevent neutron infinite multiplication factor from decreasing extremely at the initial burning stage. Further, the burnable poisons are not rapidly burnt completely and local peaking coefficient can be controlled. Accordingly, in a case of suppressing a predetermined excess reactivity by using a fuel rod incorporated with the burnable poison, the fuel economy can be improved more and the reactor core controllability can also be improved as compared with the usual case. (T.M.)

  14. Faucet: streaming de novo assembly graph construction.

    Science.gov (United States)

    Rozov, Roye; Goldshlager, Gil; Halperin, Eran; Shamir, Ron

    2018-01-01

    We present Faucet, a two-pass streaming algorithm for assembly graph construction. Faucet builds an assembly graph incrementally as each read is processed. Thus, reads need not be stored locally, as they can be processed while downloading data and then discarded. We demonstrate this functionality by performing streaming graph assembly of publicly available data, and observe that the ratio of disk use to raw data size decreases as coverage is increased. Faucet pairs the de Bruijn graph obtained from the reads with additional meta-data derived from them. We show these metadata-coverage counts collected at junction k-mers and connections bridging between junction pairs-contain most salient information needed for assembly, and demonstrate they enable cleaning of metagenome assembly graphs, greatly improving contiguity while maintaining accuracy. We compared Fauceted resource use and assembly quality to state of the art metagenome assemblers, as well as leading resource-efficient genome assemblers. Faucet used orders of magnitude less time and disk space than the specialized metagenome assemblers MetaSPAdes and Megahit, while also improving on their memory use; this broadly matched performance of other assemblers optimizing resource efficiency-namely, Minia and LightAssembler. However, on metagenomes tested, Faucet,o outputs had 14-110% higher mean NGA50 lengths compared with Minia, and 2- to 11-fold higher mean NGA50 lengths compared with LightAssembler, the only other streaming assembler available. Faucet is available at https://github.com/Shamir-Lab/Faucet. rshamir@tau.ac.il or eranhalperin@gmail.com. Supplementary data are available at Bioinformatics online. © The Author 2017. Published by Oxford University Press.

  15. Leading-process actomyosin coordinates organelle positioning and adhesion receptor dynamics in radially migrating cerebellar granule neurons.

    Science.gov (United States)

    Trivedi, Niraj; Ramahi, Joseph S; Karakaya, Mahmut; Howell, Danielle; Kerekes, Ryan A; Solecki, David J

    2014-12-02

    During brain development, neurons migrate from germinal zones to their final positions to assemble neural circuits. A unique saltatory cadence involving cyclical organelle movement (e.g., centrosome motility) and leading-process actomyosin enrichment prior to nucleokinesis organizes neuronal migration. While functional evidence suggests that leading-process actomyosin is essential for centrosome motility, the role of the actin-enriched leading process in globally organizing organelle transport or traction forces remains unexplored. We show that myosin ii motors and F-actin dynamics are required for Golgi apparatus positioning before nucleokinesis in cerebellar granule neurons (CGNs) migrating along glial fibers. Moreover, we show that primary cilia are motile organelles, localized to the leading-process F-actin-rich domain and immobilized by pharmacological inhibition of myosin ii and F-actin dynamics. Finally, leading process adhesion dynamics are dependent on myosin ii and F-actin. We propose that actomyosin coordinates the overall polarity of migrating CGNs by controlling asymmetric organelle positioning and cell-cell contacts as these cells move along their glial guides.

  16. Fuel assembly guide tube

    International Nuclear Information System (INIS)

    Jabsen, F.S.

    1979-01-01

    This invention is directed toward a nuclear fuel assembly guide tube arrangement which restrains spacer grid movement due to coolant flow and which offers secondary means for supporting a fuel assembly during handling and transfer operations

  17. Design of a nanocomposite substrate inducing adult stem cell assembly and progression toward an Epiblast-like or Primitive Endoderm-like phenotype via mechanotransduction.

    Science.gov (United States)

    Morena, Francesco; Armentano, Ilaria; Montanucci, Pia; Argentati, Chiara; Fortunati, Elena; Montesano, Simona; Bicchi, Ilaria; Pescara, Teresa; Pennoni, Ilaria; Mattioli, Samantha; Torre, Luigi; Latterini, Loredana; Emiliani, Carla; Basta, Giuseppe; Calafiore, Riccardo; Kenny, Josè Maria; Martino, Sabata

    2017-11-01

    This work shows that the active interaction between human umbilical cord matrix stem cells and Poly (l-lactide)acid (PLLA) and PLLA/Multi Walled Carbon Nanotubes (MWCNTs) nanocomposite films results in the stem cell assembly as a spheroid conformation and affects the stem cell fate transition. We demonstrated that spheroids directly respond to a tunable surface and the bulk properties (electric, dielectric and thermal) of plain and nanocomposite PLLA films by triggering a mechanotransduction axis. This stepwise process starts from tethering of the cells' focal adhesion proteins to the surface, together with the adherens junctions between cells. Both complexes transmit traction forces to F-Actin stress fibres that link Filamin-A and Myosin-IIA proteins, generating a biological scaffold, with increased stiffening conformation from PLLA to PLLA/MWCNTs, and enable the nucleoskeleton proteins to boost chromatin reprogramming processes. Herein, the opposite expression of NANOG and GATA6 transcription factors, together with other lineage specification related proteins, steer spheroids toward an Epiblast-like or Primitive Endoderm-like lineage commitment, depending on the absence or presence of 1 wt% MWCNTs, respectively. This work represents a pioneering effort to create a stem cell/material interface that can model the stem cell fate transition under growth culture conditions. Copyright © 2017 Elsevier Ltd. All rights reserved.

  18. Polymer Directed Protein Assemblies

    NARCIS (Netherlands)

    van Rijn, Patrick

    2013-01-01

    Protein aggregation and protein self-assembly is an important occurrence in natural systems, and is in some form or other dictated by biopolymers. Very obvious influences of biopolymers on protein assemblies are, e. g., virus particles. Viruses are a multi-protein assembly of which the morphology is

  19. Nuclear reactor fuel assembly

    International Nuclear Information System (INIS)

    Sasaki, Y.; Tashima, J.

    1975-01-01

    A description is given of nuclear reactor fuel assemblies arranged in the form of a lattice wherein there is attached to the interface of one of two adjacent fuel assemblies a plate spring having a concave portion curved toward said interface and to the interface of the other fuel assembly a plate spring having a convex portion curved away from said interface

  20. Improved localization of cellular membrane receptors using combined fluorescence microscopy and simultaneous topography and recognition imaging

    International Nuclear Information System (INIS)

    Duman, M; Pfleger, M; Chtcheglova, L A; Neundlinger, I; Bozna, B L; Ebner, A; Schuetz, G J; Hinterdorfer, P; Zhu, R; Mayer, B; Rankl, C; Moertelmaier, M; Kada, G; Kienberger, F; Salio, M; Shepherd, D; Polzella, P; Cerundolo, V; Dieudonne, M

    2010-01-01

    The combination of fluorescence microscopy and atomic force microscopy has a great potential in single-molecule-detection applications, overcoming many of the limitations coming from each individual technique. Here we present a new platform of combined fluorescence and simultaneous topography and recognition imaging (TREC) for improved localization of cellular receptors. Green fluorescent protein (GFP) labeled human sodium-glucose cotransporter (hSGLT1) expressed Chinese Hamster Ovary (CHO) cells and endothelial cells (MyEnd) from mouse myocardium stained with phalloidin-rhodamine were used as cell systems to study AFM topography and fluorescence microscopy on the same surface area. Topographical AFM images revealed membrane features such as lamellipodia, cytoskeleton fibers, F-actin filaments and small globular structures with heights ranging from 20 to 30 nm. Combined fluorescence and TREC imaging was applied to detect density, distribution and localization of YFP-labeled CD1d molecules on α-galactosylceramide (αGalCer)-loaded THP1 cells. While the expression level, distribution and localization of CD1d molecules on THP1 cells were detected with fluorescence microscopy, the nanoscale distribution of binding sites was investigated with molecular recognition imaging by using a chemically modified AFM tip. Using TREC on the inverted light microscope, the recognition sites of cell receptors were detected in recognition images with domain sizes ranging from ∼ 25 to ∼ 160 nm, with the smaller domains corresponding to a single CD1d molecule.

  1. Improved localization of cellular membrane receptors using combined fluorescence microscopy and simultaneous topography and recognition imaging

    Energy Technology Data Exchange (ETDEWEB)

    Duman, M; Pfleger, M; Chtcheglova, L A; Neundlinger, I; Bozna, B L; Ebner, A; Schuetz, G J; Hinterdorfer, P [Institute for Biophysics, University of Linz, Altenbergerstrasse 69, A-4040 Linz (Austria); Zhu, R; Mayer, B [Christian Doppler Laboratory for Nanoscopic Methods in Biophysics, Institute for Biophysics, University of Linz, Altenbergerstrasse 69, A-4040 Linz (Austria); Rankl, C; Moertelmaier, M; Kada, G; Kienberger, F [Agilent Technologies Austria GmbH, Aubrunnerweg 11, A-4040 Linz (Austria); Salio, M; Shepherd, D; Polzella, P; Cerundolo, V [Cancer Research UK Tumor Immunology Group, Weatherall Institute of Molecular Medicine, Nuffield Department of Medicine, University of Oxford, Oxford OX3 9DS (United Kingdom); Dieudonne, M, E-mail: ferry_kienberger@agilent.com [Agilent Technologies Belgium, Wingepark 51, Rotselaar, AN B-3110 (Belgium)

    2010-03-19

    The combination of fluorescence microscopy and atomic force microscopy has a great potential in single-molecule-detection applications, overcoming many of the limitations coming from each individual technique. Here we present a new platform of combined fluorescence and simultaneous topography and recognition imaging (TREC) for improved localization of cellular receptors. Green fluorescent protein (GFP) labeled human sodium-glucose cotransporter (hSGLT1) expressed Chinese Hamster Ovary (CHO) cells and endothelial cells (MyEnd) from mouse myocardium stained with phalloidin-rhodamine were used as cell systems to study AFM topography and fluorescence microscopy on the same surface area. Topographical AFM images revealed membrane features such as lamellipodia, cytoskeleton fibers, F-actin filaments and small globular structures with heights ranging from 20 to 30 nm. Combined fluorescence and TREC imaging was applied to detect density, distribution and localization of YFP-labeled CD1d molecules on {alpha}-galactosylceramide ({alpha}GalCer)-loaded THP1 cells. While the expression level, distribution and localization of CD1d molecules on THP1 cells were detected with fluorescence microscopy, the nanoscale distribution of binding sites was investigated with molecular recognition imaging by using a chemically modified AFM tip. Using TREC on the inverted light microscope, the recognition sites of cell receptors were detected in recognition images with domain sizes ranging from {approx} 25 to {approx} 160 nm, with the smaller domains corresponding to a single CD1d molecule.

  2. Sensor mount assemblies and sensor assemblies

    Science.gov (United States)

    Miller, David H [Redondo Beach, CA

    2012-04-10

    Sensor mount assemblies and sensor assemblies are provided. In an embodiment, by way of example only, a sensor mount assembly includes a busbar, a main body, a backing surface, and a first finger. The busbar has a first end and a second end. The main body is overmolded onto the busbar. The backing surface extends radially outwardly relative to the main body. The first finger extends axially from the backing surface, and the first finger has a first end, a second end, and a tooth. The first end of the first finger is disposed on the backing surface, and the tooth is formed on the second end of the first finger.

  3. Soldering in electronics assembly

    CERN Document Server

    Judd, Mike

    2013-01-01

    Soldering in Electronics Assembly discusses several concerns in soldering of electronic assemblies. The book is comprised of nine chapters that tackle different areas in electronic assembly soldering. Chapter 1 discusses the soldering process itself, while Chapter 2 covers the electronic assemblies. Chapter 3 talks about solders and Chapter 4 deals with flux. The text also tackles the CS and SC soldering process. The cleaning of soldered assemblies, solder quality, and standards and specifications are also discussed. The book will be of great use to professionals who deal with electronic assem

  4. Nuclear fuel string assembly

    International Nuclear Information System (INIS)

    Ip, A.K.; Koyanagi, K.; Tarasuk, W.R.

    1976-01-01

    A method of fabricating rodded fuels suitable for use in pressure tube type reactors and in pressure vessel type reactors is described. Fuel rods are secured as an inner and an outer sub-assembly, each rod attached between mounting rings secured to the rod ends. The two sub-assemblies are telescoped together and positioned by spaced thimbles located between them to provide precise positioning while permittng differential axial movement between the sub-assemblies. Such sub-assemblies are particularly suited for mounting as bundle strings. The method provides particular advantages in the assembly of annular-section fuel pins, which includes booster fuel containing enriched fuel material. (LL)

  5. Nuclear reactor fuel assembly

    International Nuclear Information System (INIS)

    Marmonier, Pierre; Mesnage, Bernard; Nervi, J.C.

    1975-01-01

    This invention refers to fuel assemblies for a liquid metal cooled fast neutron reactor. Each assembly is composed of a hollow vertical casing, of regular polygonal section, containing a bundle of clad pins filled with a fissile or fertile substance. The casing is open at its upper end and has a cylindrical foot at its lower end for positioning the assembly in a housing provided in the horizontal diagrid, on which the core assembly rests. A set of flat bars located on the external surface of the casing enables it to be correctly orientated in its housing among the other core assemblies [fr

  6. Interdependence of Pes1, Bop1, and WDR12 controls nucleolar localization and assembly of the PeBoW complex required for maturation of the 60S ribosomal subunit.

    Science.gov (United States)

    Rohrmoser, Michaela; Hölzel, Michael; Grimm, Thomas; Malamoussi, Anastassia; Harasim, Thomas; Orban, Mathias; Pfisterer, Iris; Gruber-Eber, Anita; Kremmer, Elisabeth; Eick, Dirk

    2007-05-01

    The PeBoW complex is essential for cell proliferation and maturation of the large ribosomal subunit in mammalian cells. Here we examined the role of PeBoW-specific proteins Pes1, Bop1, and WDR12 in complex assembly and stability, nucleolar transport, and pre-ribosome association. Recombinant expression of the three subunits is sufficient for complex formation. The stability of all three subunits strongly increases upon incorporation into the complex. Only overexpression of Bop1 inhibits cell proliferation and rRNA processing, and its negative effects could be rescued by coexpression of WDR12, but not Pes1. Elevated levels of Bop1 induce Bop1/WDR12 and Bop1/Pes1 subcomplexes. Knockdown of Bop1 abolishes the copurification of Pes1 with WDR12, demonstrating Bop1 as the integral component of the complex. Overexpressed Bop1 substitutes for endogenous Bop1 in PeBoW complex assembly, leading to the instability of endogenous Bop1. Finally, indirect immunofluorescence, cell fractionation, and sucrose gradient centrifugation experiments indicate that transport of Bop1 from the cytoplasm to the nucleolus is Pes1 dependent, while Pes1 can migrate to the nucleolus and bind to preribosomal particles independently of Bop1. We conclude that the assembly and integrity of the PeBoW complex are highly sensitive to changes in Bop1 protein levels.

  7. Assembly tool design

    International Nuclear Information System (INIS)

    Kanamori, Naokazu; Nakahira, Masataka; Ohkawa, Yoshinao; Tada, Eisuke; Seki, Masahiro

    1996-06-01

    The reactor core of the International Thermonuclear Experimental Reactor (ITER) is assembled with a number of large and asymmetric components within a tight tolerance in order to assure the structural integrity for various loads and to provide the tritium confinement. In addition, the assembly procedure should be compatible with remote operation since the core structures will be activated by 14-MeV neutrons once it starts operation and thus personal access will be prohibited. Accordingly, the assembly procedure and tool design are quite essential and should be designed from the beginning to facilitate remote operation. According to the ITER Design Task Agreement, the Japan Atomic Energy Research Institute (JAERI) has performed design study to develop the assembly procedures and associated tool design for the ITER tokamak assembly. This report describes outlines of the assembly tools and the remaining issues obtained in this design study. (author)

  8. Fuel assembly storage pool

    International Nuclear Information System (INIS)

    Hiranuma, Hiroshi.

    1976-01-01

    Object: To remove limitation of the number of storage of fuel assemblies to increase the number of storage thereof so as to relatively reduce the water depth required for shielding radioactive rays. Structure: Fuel assembly storage rack containers for receiving a plurality of spent fuel assembly racks are stacked in multi-layer fashion within a storage pool filled with water for shielding radioactive rays and removing heat. (Furukawa, Y.)

  9. Target Assembly Facility

    Data.gov (United States)

    Federal Laboratory Consortium — The Target Assembly Facility integrates new armor concepts into actual armored vehicles. Featuring the capability ofmachining and cutting radioactive materials, it...

  10. Composite turbine bucket assembly

    Science.gov (United States)

    Liotta, Gary Charles; Garcia-Crespo, Andres

    2014-05-20

    A composite turbine blade assembly includes a ceramic blade including an airfoil portion, a shank portion and an attachment portion; and a transition assembly adapted to attach the ceramic blade to a turbine disk or rotor, the transition assembly including first and second transition components clamped together, trapping said ceramic airfoil therebetween. Interior surfaces of the first and second transition portions are formed to mate with the shank portion and the attachment portion of the ceramic blade, and exterior surfaces of said first and second transition components are formed to include an attachment feature enabling the transition assembly to be attached to the turbine rotor or disk.

  11. Antibodies to filamentous actin (F-actin) in type 1 autoimmune hepatitis.

    Science.gov (United States)

    Granito, A; Muratori, L; Muratori, P; Pappas, G; Guidi, M; Cassani, F; Volta, U; Ferri, A; Lenzi, M; Bianchi, F B

    2006-03-01

    To evaluate the diagnostic significance of anti-filamentous actin antibodies (A-FAA) assessed with a commercial ELISA in comparison with immunofluorescence reactivity and patterns of anti-smooth muscle antibodies (SMA); and to correlate A-FAA positivity with clinical, immunogenetic, laboratory, and histological features in patients with autoimmune hepatitis type 1 (AIH-1). We studied 78 consecutive untreated AIH-1 patients and 160 controls: 22 with autoimmune hepatitis type 2 (AIH-2), 51 with hepatitis C, 17 with coeliac disease (CD), 20 with primary biliary cirrhosis (PBC) and 50 blood donors. SMA was evaluated by indirect immunofluorescence (IIF) on frozen sections of rat tissues, and A-FAA with a modified commercial ELISA. SMA was detected by IIF in 61 (78%) of 78 AIH-1 patients, of whom 47 (60%) had the SMA-T/G and 14 (18%) the SMA-V pattern. Of the pathological controls, 32 (20%) had the SMA-V pattern (25 with hepatitis C, 2 with AIH-2, 2 with PBC, 3 with CD). A-FAA were present in 55 AIH-1 patients (70.5%; 46 with SMA-T/G, 7 with SMA-V, and 2 SMA-negative), and in 10 controls (6%), of whom five had hepatitis C, two AIH-2, two PBC and one CD. The association between A-FAA and the SMA-T/G pattern was statistically significant (p<0.0001). A-FAA levels were higher in SMA-T/G positive than SMA-V positive AIH-1 patients and controls (p<0.0001). A-FAA positivity was significantly associated with higher gamma-globulin and IgG levels, but did not correlate with other considered parameters. The modified A-FAA ELISA strictly correlates with the SMA-T/G pattern and is a reliable and operator independent assay for AIH-1. Detection of A-FAA, even if devoid of prognostic relevance, may be useful when interpretative doubts of standard IIF arise.

  12. Cofilin phosphorylation is elevated after F-actin disassembly induced by Rac1 depletion.

    Science.gov (United States)

    Liu, Linna; Li, Jing; Zhang, Liwang; Zhang, Feng; Zhang, Rong; Chen, Xiang; Brakebusch, Cord; Wang, Zhipeng; Liu, Xinyou

    2015-01-01

    Cytoskeletal reorganization is essential to keratinocyte function. Rac1 regulates cytoskeletal reorganization through signaling pathways such as the cofilin cascade. Cofilin severs actin filaments after activation by dephosphorylation. Rac1 was knocked out in mouse keratinocytes and it was found that actin filaments disassembled. In the epidermis of mice in which Rac1 was knocked out only in keratinocytes, cofilin phosphorylation was aberrantly elevated, corresponding to repression of the phosphatase slingshot1 (SSH1). These effects were independent of the signaling pathways for p21-activated kinase/LIM kinase (Pak/LIMK), protein kinase C, or protein kinase D or generation of reactive oxygen species. Similarly, when actin polymerization was specifically inhibited or Rac1 was knocked down, cofilin phosphorylation was enhanced and SSH1 was repressed. Repression of SSH1 partially blocked actin depolymerization induced by Rac1 depletion. Therefore, aberrant cofilin phosphorylation that induces actin polymerization might be a consequence of actin disassembly induced by the absence of Rac1. © 2015 International Union of Biochemistry and Molecular Biology.

  13. Total Synthesis of (-)-Doliculide, Structure-Activity Relationship Studies and Its Binding to F-Actin

    NARCIS (Netherlands)

    Matcha, Kiran; Madduri, Ashoka V. R.; Roy, Sayantani; Ziegler, Slava; Waldmann, Herbert; Hirsch, Anna K. H.; Minnaard, Adriaan J.

    2012-01-01

    Actin, an abundant protein in most eukaryotic cells, is one of the targets in cancer research. Recently, a great deal of attention has been paid to the synthesis and function of actin-targeting compounds and their use as effective molecular probes in chemical biology. In this study, we have

  14. Reversibility and Viscoelastic Properties of Micropillar Supported and Oriented Magnesium Bundled F-Actin.

    Directory of Open Access Journals (Sweden)

    Timo Maier

    Full Text Available Filamentous actin is one of the most important cytoskeletal elements. Not only is it responsible for the elastic properties of many cell types, but it also plays a vital role in cellular adhesion and motility. Understanding the bundling kinetics of actin filaments is important in the formation of various cytoskeletal structures, such as filopodia and stress fibers. Utilizing a unique pillar-structured microfluidic device, we investigated the time dependence of bundling kinetics of pillar supported free-standing actin filaments. Microparticles attached to the filaments allowed the measurement of thermal motion, and we found that bundling takes place at lower concentrations than previously found in 3-dimensional actin gels, i.e. actin filaments formed bundles in the presence of 5-12 mM of magnesium chloride in a time-dependent manner. The filaments also displayed long term stability for up to hours after removing the magnesium ions from the buffer, which suggests that there is an extensive hysteresis between cation induced crosslinking and decrosslinking.

  15. Drosophila Imp iCLIP identifies an RNA assemblage coordinating F-actin formation

    DEFF Research Database (Denmark)

    Hansen, Heidi Theil; Rasmussen, Simon Horskjær; Adolph, Sidsel Kramshøj

    2015-01-01

    BACKGROUND: Post-transcriptional RNA regulons ensure co-ordinated expression of monocistronic mRNAs encoding functionally related proteins. In this study, we employ a combination of RIP-seq and short- and long-wave individual-nucleotide resolution crosslinking and immunoprecipitation (iCLIP...

  16. F-actin-like filaments formed by plasmid segregation protein ParM

    DEFF Research Database (Denmark)

    van den Ent, Fusinita; Møller-Jensen, Jakob; Amos, Linda A.

    2002-01-01

    It was the general belief that DNA partitioning in prokaryotes is independent of a cytoskeletal structure, which in eukaryotic cells is indispensable for DNA segregation. Recently, however, immunofluorescence microscopy revealed highly dynamic, filamentous structures along the longitudinal axis...

  17. Cofilin phosphorylation is elevated after F-actin disassembly induced by Rac1 depletion

    DEFF Research Database (Denmark)

    Liu, Linna; Li, Jing; Zhang, Liwang

    2015-01-01

    Cytoskeletal reorganization is essential to keratinocyte function. Rac1 regulates cytoskeletal reorganization through signaling pathways such as the cofilin cascade. Cofilin severs actin filaments after activation by dephosphorylation. Rac1 was knocked out in mouse keratinocytes and it was found...... that actin filaments disassembled. In the epidermis of mice in which Rac1 was knocked out only in keratinocytes, cofilin phosphorylation was aberrantly elevated, corresponding to repression of the phosphatase slingshot1 (SSH1). These effects were independent of the signaling pathways for p21-activated kinase....../LIM kinase (Pak/LIMK), protein kinase C, or protein kinase D or generation of reactive oxygen species. Similarly, when actin polymerization was specifically inhibited or Rac1 was knocked down, cofilin phosphorylation was enhanced and SSH1 was repressed. Repression of SSH1 partially blocked actin...

  18. Scaling of F-actin network rheology to probe single filament elasticity and dynamics.

    Science.gov (United States)

    Gardel, M L; Shin, J H; MacKintosh, F C; Mahadevan, L; Matsudaira, P A; Weitz, D A

    2004-10-29

    The linear and nonlinear viscoelastic response of networks of cross-linked and bundled cytoskeletal filaments demonstrates remarkable scaling with both frequency and applied prestress, which helps elucidate the origins of the viscoelasticity. The frequency dependence of the shear modulus reflects the underlying single-filament relaxation dynamics for 0.1-10 rad/sec. Moreover, the nonlinear strain stiffening of such networks exhibits a universal form as a function of prestress; this is quantitatively explained by the full force-extension relation of single semiflexible filaments.

  19. Targeted assembly of short sequence reads.

    Directory of Open Access Journals (Sweden)

    René L Warren

    Full Text Available As next-generation sequence (NGS production continues to increase, analysis is becoming a significant bottleneck. However, in situations where information is required only for specific sequence variants, it is not necessary to assemble or align whole genome data sets in their entirety. Rather, NGS data sets can be mined for the presence of sequence variants of interest by localized assembly, which is a faster, easier, and more accurate approach. We present TASR, a streamlined assembler that interrogates very large NGS data sets for the presence of specific variants by only considering reads within the sequence space of input target sequences provided by the user. The NGS data set is searched for reads with an exact match to all possible short words within the target sequence, and these reads are then assembled stringently to generate a consensus of the target and flanking sequence. Typically, variants of a particular locus are provided as different target sequences, and the presence of the variant in the data set being interrogated is revealed by a successful assembly outcome. However, TASR can also be used to find unknown sequences that flank a given target. We demonstrate that TASR has utility in finding or confirming genomic mutations, polymorphisms, fusions and integration events. Targeted assembly is a powerful method for interrogating large data sets for the presence of sequence variants of interest. TASR is a fast, flexible and easy to use tool for targeted assembly.

  20. Nuclear fuel assembly

    International Nuclear Information System (INIS)

    Delafosse, Jacques.

    1977-01-01

    This invention relates to a nuclear fuel assembly for a light or heavy water reactor, or for a fast reactor of the kind with a bundle of cladded pins, maintained parallel to each other in a regular network by an assembly of separate supporting grids, fitted with elastic bearing surfaces on these pins [fr

  1. Assembling Transgender Moments

    Science.gov (United States)

    Greteman, Adam J.

    2017-01-01

    In this article, the author seeks to assemble moments--scholarly, popular, and aesthetic--in order to explore the possibilities that emerge as moments collect in education's encounters with the needs, struggles, and possibilities of transgender lives and practices. Assembling moments, the author argues, illustrates the value of "moments"…

  2. Vertical pump assembly

    International Nuclear Information System (INIS)

    Dohnal, M.; Rosel, J.; Skarka, V.

    1988-01-01

    The mounting is described of the drive assembly of a vertical pump for nuclear power plants in areas with seismic risk. The assembly is attached to the building floor using flexible and damping elements. The design allows producing seismically resistant pumps without major design changes in the existing types of vertical pumps. (E.S.). 1 fig

  3. Fuel Assembly Damping Summary

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Kanghee; Kang, Heungseok; Oh, Dongseok; Yoon, Kyungho; Kim, Hyungkyu; Kim, Jaeyong [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)

    2013-10-15

    This paper summary the fuel assembly damping data in air/in still water/under flow, released from foreign fuel vendors, compared our data with the published data. Some technical issues in fuel assembly damping measurement testing are also briefly discussed. Understanding of each fuel assembly damping mechanisms according to the surrounding medium and flow velocity can support the fuel design improvement in fuel assembly dynamics and structural integrity aspect. Because the upgraded requirements of the newly-developed advanced reactor system will demands to minimize fuel design margin in integrity evaluation, reduction in conservatism of fuel assembly damping can contribute to alleviate the fuel design margin for sure. Damping is an energy dissipation mechanism in a vibrating mechanical structure and prevents a resonant structure from having infinite vibration amplitudes. The sources of fuel assembly damping are various from support friction to flow contribution, and it can be increased by the viscosity or drag of surrounding fluid medium or the average velocity of water flowing. Fuel licensing requires fuel design evaluation in transient or accidental condition. Dynamic response analysis of fuel assembly is to show fuel integrity and requires information on assembly-wise damping in dry condition and under wet or water flowing condition. However, damping measurement test for the full-scale fuel assembly prototype is not easy to carry out because of the scale (fuel prototype, test facility), unsteadiness of test data (scattering, random sampling and processing), instrumentation under water flowing (water-proof response measurement), and noise. LWR fuel technology division in KAERI is preparing the infra structure for damping measurement test of full-scale fuel assembly, to support fuel industries and related research activities. Here is a preliminary summary of fuel assembly damping, published in the literature. Some technical issues in fuel assembly damping

  4. Self-assembled nanostructures

    CERN Document Server

    Zhang, Jin Z; Liu, Jun; Chen, Shaowei; Liu, Gang-yu

    2003-01-01

    Nanostructures refer to materials that have relevant dimensions on the nanometer length scales and reside in the mesoscopic regime between isolated atoms and molecules in bulk matter. These materials have unique physical properties that are distinctly different from bulk materials. Self-Assembled Nanostructures provides systematic coverage of basic nanomaterials science including materials assembly and synthesis, characterization, and application. Suitable for both beginners and experts, it balances the chemistry aspects of nanomaterials with physical principles. It also highlights nanomaterial-based architectures including assembled or self-assembled systems. Filled with in-depth discussion of important applications of nano-architectures as well as potential applications ranging from physical to chemical and biological systems, Self-Assembled Nanostructures is the essential reference or text for scientists involved with nanostructures.

  5. Dia-Interacting Protein (DIP) Imposes Migratory Plasticity in mDia2-Dependent Tumor Cells in Three-Dimensional Matrices

    Science.gov (United States)

    Wyse, Meghan M.; Lei, Jun; Nestor-Kalinoski, Andrea L.; Eisenmann, Kathryn M.

    2012-01-01

    Tumor cells rely upon membrane pliancy to escape primary lesions and invade secondary metastatic sites. This process relies upon localized assembly and disassembly cycles of F-actin that support and underlie the plasma membrane. Dynamic actin generates both spear-like and bleb structures respectively characterizing mesenchymal and amoeboid motility programs utilized by metastatic cells in three-dimensional matrices. The molecular mechanism and physiological trigger(s) driving membrane plasticity are poorly understood. mDia formins are F-actin assembly factors directing membrane pliancy in motile cells. mDia2 is functionally coupled with its binding partner DIP, regulating cortical actin and inducing membrane blebbing in amoeboid cells. Here we show that mDia2 and DIP co-tether to nascent blebs and this linkage is required for bleb formation. DIP controls mesenchymal/amoeboid cell interconvertability, while CXCL12 induces assembly of mDia2:DIP complexes to bleb cortices in 3D matrices. These results demonstrate how DIP-directed mDia2-dependent F-actin dynamics regulate morphological plasticity in motile cancer cells. PMID:23024796

  6. Dia-interacting protein (DIP imposes migratory plasticity in mDia2-dependent tumor cells in three-dimensional matrices.

    Directory of Open Access Journals (Sweden)

    Meghan M Wyse

    Full Text Available Tumor cells rely upon membrane pliancy to escape primary lesions and invade secondary metastatic sites. This process relies upon localized assembly and disassembly cycles of F-actin that support and underlie the plasma membrane. Dynamic actin generates both spear-like and bleb structures respectively characterizing mesenchymal and amoeboid motility programs utilized by metastatic cells in three-dimensional matrices. The molecular mechanism and physiological trigger(s driving membrane plasticity are poorly understood. mDia formins are F-actin assembly factors directing membrane pliancy in motile cells. mDia2 is functionally coupled with its binding partner DIP, regulating cortical actin and inducing membrane blebbing in amoeboid cells. Here we show that mDia2 and DIP co-tether to nascent blebs and this linkage is required for bleb formation. DIP controls mesenchymal/amoeboid cell interconvertability, while CXCL12 induces assembly of mDia2:DIP complexes to bleb cortices in 3D matrices. These results demonstrate how DIP-directed mDia2-dependent F-actin dynamics regulate morphological plasticity in motile cancer cells.

  7. Chaperoning 5S RNA assembly.

    Science.gov (United States)

    Madru, Clément; Lebaron, Simon; Blaud, Magali; Delbos, Lila; Pipoli, Juliana; Pasmant, Eric; Réty, Stéphane; Leulliot, Nicolas

    2015-07-01

    In eukaryotes, three of the four ribosomal RNAs (rRNAs)—the 5.8S, 18S, and 25S/28S rRNAs—are processed from a single pre-rRNA transcript and assembled into ribosomes. The fourth rRNA, the 5S rRNA, is transcribed by RNA polymerase III and is assembled into the 5S ribonucleoprotein particle (RNP), containing ribosomal proteins Rpl5/uL18 and Rpl11/uL5, prior to its incorporation into preribosomes. In mammals, the 5S RNP is also a central regulator of the homeostasis of the tumor suppressor p53. The nucleolar localization of the 5S RNP and its assembly into preribosomes are performed by a specialized complex composed of Rpf2 and Rrs1 in yeast or Bxdc1 and hRrs1 in humans. Here we report the structural and functional characterization of the Rpf2-Rrs1 complex alone, in complex with the 5S RNA, and within pre-60S ribosomes. We show that the Rpf2-Rrs1 complex contains a specialized 5S RNA E-loop-binding module, contacts the Rpl5 protein, and also contacts the ribosome assembly factor Rsa4 and the 25S RNA. We propose that the Rpf2-Rrs1 complex establishes a network of interactions that guide the incorporation of the 5S RNP in preribosomes in the initial conformation prior to its rotation to form the central protuberance found in the mature large ribosomal subunit. © 2015 Madru et al.; Published by Cold Spring Harbor Laboratory Press.

  8. Assembly of finite element methods on graphics processors

    KAUST Repository

    Cecka, Cris; Lew, Adrian J.; Darve, E.

    2010-01-01

    in assembling and solving sparse linear systems with NVIDIA GPUs and the Compute Unified Device Architecture (CUDA) are created and analyzed. Multiple strategies for efficient use of global, shared, and local memory, methods to achieve memory coalescing

  9. TPX assembly plan

    International Nuclear Information System (INIS)

    Knutson, D.

    1993-01-01

    The TPX machine will be assembled in the TFTR Test Cell at the Plasma Physics Laboratory, utilizing the existing TFTR machine foundation. Preparation of the area for assembly will begin after completion of the decontamination and decommissioning phase on TFTR and certification that the radiation levels remaining, if any, are consistent with the types of operations planned. Assembly operations begin with the arrival of the first components, and conclude, approximately 24 months later, with the successful completion of the integrated systems tests and the achievement of a first plasma

  10. Nuclear reactor control assembly

    International Nuclear Information System (INIS)

    Negron, S.B.

    1991-01-01

    This patent describes an assembly for providing global power control in a nuclear reactor having the core split into two halves. It comprises a disk assembly formed from at least two disks each machined with an identical surface hole pattern such that rotation of one disk relative to the other causes the hole pattern to open or close, the disk assembly being positioned substantially at the longitudinal center of and coaxial with the core halves; and means for rotating at least one of the disks relative to the other

  11. Fuel assemblies for use in nuclear reactors

    International Nuclear Information System (INIS)

    Mochida, Takaaki.

    1987-01-01

    Purpose: To increase the plutonium utilization amount and improve the uranium-saving effect in the fuel assemblies of PWR type reactor using mixed uranium-plutonium oxides. Constitution: MOX fuel rods comprising mixed plutonium-uranium oxides are disposed to the outer circumference of a fuel assembly and uranium fuel rods only composed of uranium oxides are disposed to the central portion thereof. In such a fuel assembly, since the uranium fuel rods are present at the periphery of the control rod, the control rod worth is the same as that of the uranium fuel assembly in the prior art. Further, since about 25 % of the entire fuel rods is composed of the MOX fuel rods, the plutonium utilization amount is increased. Further, since the MOX fuel rods at low enrichment degree are present at the outer circumferential portion, mismatching at the boundary to the adjacent MOX fuel assembly is reduced and the problem of local power peaking increase in the MOX fuel assembly is neither present. (Kamimura, M.)

  12. Reference: 198 [Arabidopsis Phenome Database[Archive

    Lifescience Database Archive (English)

    Full Text Available etion of either RIC4 or RIC3 causes tip growth defects that are rescued by overproduction or depletion...C4. RIC4 promotes F-actin assembly, whereas RIC3 activates Ca(2+) signaling that leads to F-actin disassembly. Overproduction or depl

  13. Nonlinear Modeling by Assembling Piecewise Linear Models

    Science.gov (United States)

    Yao, Weigang; Liou, Meng-Sing

    2013-01-01

    To preserve nonlinearity of a full order system over a parameters range of interest, we propose a simple modeling approach by assembling a set of piecewise local solutions, including the first-order Taylor series terms expanded about some sampling states. The work by Rewienski and White inspired our use of piecewise linear local solutions. The assembly of these local approximations is accomplished by assigning nonlinear weights, through radial basis functions in this study. The efficacy of the proposed procedure is validated for a two-dimensional airfoil moving at different Mach numbers and pitching motions, under which the flow exhibits prominent nonlinear behaviors. All results confirm that our nonlinear model is accurate and stable for predicting not only aerodynamic forces but also detailed flowfields. Moreover, the model is robustness-accurate for inputs considerably different from the base trajectory in form and magnitude. This modeling preserves nonlinearity of the problems considered in a rather simple and accurate manner.

  14. Nuclear fuel assembly

    International Nuclear Information System (INIS)

    Anthony, A.J.

    1980-01-01

    A bimetallic spacer means is cooperatively associated with a nuclear fuel assembly and operative to resist the occurrence of in-reactor bowing of the nuclear fuel assembly. The bimetallic spacer means in one embodiment of the invention includes a space grid formed, at least principally, of zircaloy to the external surface of which are attached a plurality of stainless steel strips. In another embodiment the strips are attached to fuel pins. In each of the embodiments, the stainless steel strips during power production expand outwardly to a greater extent than do the members to which the stainless steel strips are attached, thereby forming stiff springs which abut against like bimetallic spacer means with which the other nuclear fuel assemblies are provided in a given nuclear reactor core to thus prevent the occurrence of in-reactor bowing of the nuclear fuel assemblies. (author)

  15. Fuel assembly spacer

    International Nuclear Information System (INIS)

    Shirakawa, Ken-etsu.

    1988-01-01

    Purpose: To reduce the pressure loss of coolants by fuel assembly spacers. Constitution: Spacers for supporting a fuel assembly are attached by means of a plurality of wires to an outer frame. The outer frame is made of shape memory alloy such that the wires are caused to slacken at normal temperature and the slacking of the wires is eliminated in excess of the transition temperature. Since the wires slacken at the normal temperature, fuel rods can be inserted easily. After the insertion of the fuel rods, when the entire portion or the outer frame is heated by water or gas at a predetermined temperature, the outer frame resumes its previously memorized shape to tighten the wires and, accordingly, the fuel rods can be supported firmly. In this way, since the fuel rods are inserted in the slacken state of the wires and, after the assembling, the outer frame resumes its memorized shape, the assembling work can be conducted efficiently. (Kamimura, M.)

  16. Nuclear reactor spacer assembly

    International Nuclear Information System (INIS)

    Anthony, A.J.; Groves, M.D.

    1979-01-01

    A fuel assembly for a nuclear reactor is disclosed wherein the fuel element receiving and supporting grid is comprised of a first metal, the guide tubes which pass through the grid assembly are comprised of a second metal and the grid is supported on the guide tubes by means of expanded sleeves located intermediate the grid and guide tubes. The fuel assembly is fabricated by inserting the sleeves, of initial outer diameter commensurate with the guide tube outer diameters, through the holes in the grid assembly provided for the guide tubes and thereafter expanding the sleeves radially outwardly along their entire length such that the guide tubes can subsequently be passed through the sleeves. The step of radial expansion, as a result of windows provided in the sleeves having dimensions commensurate with the geometry of the grid, mechanically captures the grid and simultaneously preloads the sleeve against the grid whereby relative motion between the grid and guide tube will be precluded

  17. Nuclear reactor fuel assembly

    International Nuclear Information System (INIS)

    Vikhorev, Yu.V.; Biryukov, G.I.; Kirilyuk, N.A.; Lobanov, V.N.

    1977-01-01

    A fuel assembly is proposed for nuclear reactors allowing remote replacement of control rod bundles or their shifting from one assembly to another, i.e., their multipurpose use. This leads to a significant increase in fuel assembly usability. In the fuel assembly the control rod bundle is placed in guide tube channels to which baffles are attached for fuel element spacing. The remote handling of control rods is provided by a hollow cylinder with openings in its lower bottom through which the control rods pass. All control rods in a bundle are mounted to a cross beam which in turn is mounted in the cylinder and is designed for grasping the whole rod bundle by a remotely controlled telescopic mechanism in bundle replacement or shifting. (Z.M.)

  18. Nuclear fuel assembly

    International Nuclear Information System (INIS)

    Betten, P.R.

    1976-01-01

    Under the invention the fuel assembly is particularly suitable for liquid metal cooled fast neutron breeder reactors. Hence, according to the invention a fuel assembly cladding includes inward corrugations with respect to the remainder of the cladding according to a recurring pattern determined by the pitch of the metal wire helically wound round the fuel rods of the assembly. The parts of the cladding pressed inwards correspond to the areas in which the wire encircling the peripheral fuel rods is generally located apart from the cladding, thereby reducing the play between the cladding and the peripheral fuel rods situated in these areas. The reduction in the play in turn improves the coolant flow in the internal secondary channels of the fuel assembly to the detriment of the flow in the peripheral secondary channels and thereby establishes a better coolant fluid temperature profile [fr

  19. Nuclear reactor fuel assembly

    International Nuclear Information System (INIS)

    Sakurai, Shungo; Ogiya, Shunsuke.

    1990-01-01

    In a fuel assembly, if the entire fuels comprise mixed oxide fuels, reactivity change in cold temperature-power operation is increased to worsen the reactor shutdown margin. The reactor shutdown margin has been improved by increasing the burnable poison concentration thereby reducing the reactivity of the fuel assembly. However, since unburnt poisons are present at the completion of the reactor operation, the reactivity can not be utilized effectively to bring about economical disadvantage. In view of the above, the reactivity change between lower temperature-power operations is reduced by providing a non-boiling range with more than 9.1% of cross sectional area at the inside of a channel at the central portion of the fuel assembly. As a result, the amount of the unburnt burnable poisons is decreased, the economy of fuel assembly is improved and the reactor shutdown margin can be increase. (N.H.)

  20. Fuel assembly reconstitution

    International Nuclear Information System (INIS)

    Morgado, Mario M.; Oliveira, Monica G.N.; Ferreira Junior, Decio B.M.; Santos, Barbara O. dos; Santos, Jorge E. dos

    2009-01-01

    Fuel failures have been happened in Nuclear Power Plants worldwide, without lost of integrity and safety, mainly for the public, environment and power plants workers. The most common causes of these events are corrosion (CRUD), fretting and pellet cladding interaction. These failures are identified by increasing the activity of fission products, verified by chemical analyses of reactor coolant. Through these analyses, during the fourth operation cycle of Angra 2 Nuclear Power Plant, was possible to observe fuel failure indication. This indication was confirmed in the end of the cycle during the unloading of reactor core through leakage tests of fuel assembly, using the equipment called 'In Mast Sipping' and 'Box Sipping'. After confirmed, the fuel assembly reconstitution was scheduled, and happened in April, 2007, where was identified the cause and the fuel rod failure, which was substitute by dummy rods (zircaloy). The cause was fretting by 'debris'. The actions to avoid and prevent fuel assemblies failures are important. The goals of this work are to describe the methodology of fuel assembly reconstitution using the FARE (Fuel Assembly Reconstitution Equipment) system, to describe the results of this task in economic and security factors of the company and show how the fuel assembly failures are identified during operation and during the outage. (author)

  1. Polymer Directed Protein Assemblies

    Directory of Open Access Journals (Sweden)

    Patrick van Rijn

    2013-05-01

    Full Text Available Protein aggregation and protein self-assembly is an important occurrence in natural systems, and is in some form or other dictated by biopolymers. Very obvious influences of biopolymers on protein assemblies are, e.g., virus particles. Viruses are a multi-protein assembly of which the morphology is dictated by poly-nucleotides namely RNA or DNA. This “biopolymer” directs the proteins and imposes limitations on the structure like the length or diameter of the particle. Not only do these bionanoparticles use polymer-directed self-assembly, also processes like amyloid formation are in a way a result of directed protein assembly by partial unfolded/misfolded biopolymers namely, polypeptides. The combination of proteins and synthetic polymers, inspired by the natural processes, are therefore regarded as a highly promising area of research. Directed protein assembly is versatile with respect to the possible interactions which brings together the protein and polymer, e.g., electrostatic, v.d. Waals forces or covalent conjugation, and possible combinations are numerous due to the large amounts of different polymers and proteins available. The protein-polymer interacting behavior and overall morphology is envisioned to aid in clarifying protein-protein interactions and are thought to entail some interesting new functions and properties which will ultimately lead to novel bio-hybrid materials.

  2. Construction method of pre assembled unit of bolt sphere grid

    Science.gov (United States)

    Hu, L. W.; Guo, F. L.; Wang, J. L.; Bu, F. M.

    2018-03-01

    The traditional construction of bolt sphere grid has many disadvantages, such as high cost, large amount of work at high altitude and long construction period, in order to make up for these shortcomings, in this paper, a new and applicable construction method is explored: setting up local scaffolding, installing the bolt sphere grid starting frame on the local scaffolding, then the pre assembled unit of bolt sphere grid is assembled on the ground, using small hoisting equipment to lift pre assembled unit to high altitude and install. Compared with the traditional installation method, the construction method has strong practicability and high economic efficiency, and has achieved good social and economic benefits.

  3. Human Assisted Assembly Processes

    Energy Technology Data Exchange (ETDEWEB)

    CALTON,TERRI L.; PETERS,RALPH R.

    2000-01-01

    Automatic assembly sequencing and visualization tools are valuable in determining the best assembly sequences, but without Human Factors and Figure Models (HFFMs) it is difficult to evaluate or visualize human interaction. In industry, accelerating technological advances and shorter market windows have forced companies to turn to an agile manufacturing paradigm. This trend has promoted computerized automation of product design and manufacturing processes, such as automated assembly planning. However, all automated assembly planning software tools assume that the individual components fly into their assembled configuration and generate what appear to be a perfectly valid operations, but in reality the operations cannot physically be carried out by a human. Similarly, human figure modeling algorithms may indicate that assembly operations are not feasible and consequently force design modifications; however, if they had the capability to quickly generate alternative assembly sequences, they might have identified a feasible solution. To solve this problem HFFMs must be integrated with automated assembly planning to allow engineers to verify that assembly operations are possible and to see ways to make the designs even better. Factories will very likely put humans and robots together in cooperative environments to meet the demands for customized products, for purposes including robotic and automated assembly. For robots to work harmoniously within an integrated environment with humans the robots must have cooperative operational skills. For example, in a human only environment, humans may tolerate collisions with one another if they did not cause much pain. This level of tolerance may or may not apply to robot-human environments. Humans expect that robots will be able to operate and navigate in their environments without collisions or interference. The ability to accomplish this is linked to the sensing capabilities available. Current work in the field of cooperative

  4. WHO: World Health Assembly.

    Science.gov (United States)

    McGregor, A

    1992-05-23

    1200 delegates from 175 member countries attended the 45th World Health Assembly in Geneva. Everyone at the Assembly ratified measures to prevent and control AIDS. 12 countries intended to do long term planning for community based care for AIDS patients. Further the Assembly denounced instances where countries and individuals denied the gravity of the AIDS pandemic. In fact, it expressed the importance for urgent and intensive action against HIV/AIDS. The assembly backed proposals to prevent and control sexually transmitted diseases that affect AIDS patients, especially hepatitis B. For example, in countries with hepatitis B prevalence 8% (many countries in Sub-Sahara Africa, Asia, the Pacific region, and South America), health officials should introduce hepatitis B vaccine into their existing immunization programs by 1995. By 1997, this vaccine should be part of all immunization programs. The Assembly was aware of the obstacles of establishing reliable cold chains for nationwide distribution, however. Delegates in Committee A objected to the fact that 50% of the populations of developing countries continued to have limited access to essential drugs. They also expressed disapproval in implementation of WHO's 1988 ethical criteria for promotion of drugs which WHO entrusted to the Council for International Organisations of Medical Sciences (CIOMS). CIOMS lacked WHO's status and thus could not effectively monitor drug advertising. In fact, the pharmaceutical industry as well as WHO provided the funds for a meeting of 25 experts to discuss principles included in the ethical criteria. At least 4 countries insisted that WHO have the ultimate authority in monitoring drug advertising. Delegates did adopt a compromise resolution on this topic which required that industry promotion methods be reported to the 1994 Assembly via the Executive Board. The Assembly requested WHO to establish an international advisory committee on nursing and midwifery and to improve the network of

  5. Thermal Aspects Related to Power Assemblies

    Directory of Open Access Journals (Sweden)

    PLESCA, A.

    2010-02-01

    Full Text Available In many cases when a power assembly based on power semiconductors is used, catastrophic failure is the result of steep temperature gradient in the localized temperature distribution. Hence, an optimal heatsink design for certain industrial applications has become a real necessity. In this paper, the Pro/ENGINEER software with the thermal simulation integrated tool, Pro/MECHANICA, has been used for thermal study of a specific power semiconductor assembly. A series of steady-state and transient thermal simulations have been performed. The experimental tests have confirmed the simulation results. Therefore, the use of specific 3D modeling and simulation software allows to design special power semiconductor assemblies with a better thermal transfer between its heatsink and power electronic components at given operating conditions.

  6. Dynamic behaviour of diagnostic assemblies

    International Nuclear Information System (INIS)

    Pecinka, L.

    1980-01-01

    The methodology is shown of calculating the frequency spectrum of a diagnostic assembly. The oscillations of the assembly as a whole, of a fuel rod bundle, the assembly jacket and of the individual rods in the bundle were considered. The manufacture is suggested of a model assembly which would be used for testing forced vibrations using an experimental water loop. (M.S.)

  7. Fuel assembly inspection device

    International Nuclear Information System (INIS)

    Yaginuma, Yoshitaka

    1998-01-01

    The present invention provides a device suitable to inspect appearance of fuel assemblies by photographing the appearance of fuel assemblies. Namely, the inspection device of the present invention measures bowing of fuel assembly or each of fuel rods or both of them based on the partially photographed images of fuel assembly. In this case, there is disposed a means which flashily projects images in the form of horizontal line from a direction intersecting obliquely relative to a horizontal cross section of the fuel assembly. A first image processing means separates the projected image pictures including projected images and calculates bowing. A second image processing means replaces the projected image pictures of the projected images based on projected images just before and after the photographing. Then, images for the measurement of bowing and images for inspection can be obtained simultaneously. As a result, the time required for the photographing can be shortened, the time for inspection can be shortened and an effect of preventing deterioration of photographing means by radiation rays can be provided. (I.S.)

  8. Sincronia interespecífica de uma assembléia local de anuros no Brasil Central: efeitos da filogenia e padrões reprodutivos - DOI: 10.4025/actascibiolsci.v25i1.2114 Interspecific synchrony in a local assemblage of anurans in Central Brazil: effects of phylogeny and reproductive patterns - DOI: 10.4025/actascibiolsci.v25i1.2114

    Directory of Open Access Journals (Sweden)

    Thiago Fernando L. Valle de Britto Rangel

    2003-04-01

    Full Text Available O padrão de ocorrência temporal de 15 espécies de anfíbios que coexistem em uma unidade de conservação brasileira foi estudado de junho de 1995 a maio de 1998. Utilizando a matriz de dados binários, uma matriz de associação interespecífica (coeficiente de Jaccard foi calcudala. Como uma única assembléia local foi temporalmente monitorada, esta matriz demonstra como os pares de espécies estão temporalmente associados (sincronia interespecífica. Duas matrizes explanatórias, uma baseada nas relações taxonômicas entre as espécies e a outra baseada nas características reprodutivas das espécies foram também analisadas. Os testes de Mantel indicaram que a matriz de sincronia interespecífica foi significativamente relacionada com a matriz de taxonomia, mas não com a matriz de padrões reprodutivos. Assim, espécies de anfíbios taxonomicamente relacionadas flutuam mais sincronicamente do que o esperado ao acaso. Extrapolando esse resultado para outras assembléias, inferimos que o número de espécies de anfíbios que estão em declínio é provavelmente subestimado. Em outras palavras, se as espécies de uma assembléia estão temporalmente associadas (sincronicamente associadas, além das espécies monitoradas (que reconhecidamente estão em declínio, aquelas espécies taxonomicamente relacionadas da assembléia (que não estão sendo monitoradas também podem apresentar populações em declínioWe studied the pattern of temporal occurrence of 15 amphibians species that coexist in a Brazilian conservation unit from June 1995 to May 1998. Using the resultant binary data matrix, an interspecific association matrix (Jaccard coefficient was calculated. As a unique local assemblage was temporally surveyed, this matrix represents how pairs of species are temporally associated (interspecific synchrony. Two symmetrical explanatory matrices, one based on taxonomic relationships amongst species and the other based on reproductive

  9. Sequencing and de novo assembly of 150 genomes from Denmark as a population reference

    DEFF Research Database (Denmark)

    Maretty, Lasse; Jensen, Jacob Malte; Petersen, Bent

    2017-01-01

    or by performing local assembly. However, these approaches are biased against discovery of structural variants and variation in the more complex parts of the genome. Hence, large-scale de novo assembly is needed. Here we show that it is possible to construct excellent de novo assemblies from high......-coverage sequencing with mate-pair libraries extending up to 20 kilobases. We report de novo assemblies of 150 individuals (50 trios) from the GenomeDenmark project. The quality of these assemblies is similar to those obtained using the more expensive long-read technology. We use the assemblies to identify a rich set...

  10. Blade attachment assembly

    Science.gov (United States)

    Garcia-Crespo, Andres Jose; Delvaux, John McConnell; Miller, Diane Patricia

    2016-05-03

    An assembly and method for affixing a turbomachine rotor blade to a rotor wheel are disclosed. In an embodiment, an adaptor member is provided disposed between the blade and the rotor wheel, the adaptor member including an adaptor attachment slot that is complementary to the blade attachment member, and an adaptor attachment member that is complementary to the rotor wheel attachment slot. A coverplate is provided, having a coverplate attachment member that is complementary to the rotor wheel attachment slot, and a hook for engaging the adaptor member. When assembled, the coverplate member matingly engages with the adaptor member, and retains the blade in the adaptor member, and the assembly in the rotor wheel.

  11. Reactor and fuel assembly

    International Nuclear Information System (INIS)

    Ishii, Yoshihiko; Bessho, Yasunori; Sano, Hiroki; Yokomizo, Osamu; Yamashita, Jun-ichi.

    1990-01-01

    The present invention realizes an effective spectral operation by applying an optimum pressure loss coefficient while taking the characteristics of a lower tie plate into consideration. That is, the pressure loss coefficient of the lower tie plate is optimized by varying the cross sectional area of a fuel assembly flow channel in the lower tie plate or varying the surface roughness of a coolant flow channel in the lower tie plate. Since there is a pressure loss coefficient to optimize the moderator density over a flow rate change region, the effect of spectral shift rods can be improved by setting the optimum pressure loss coefficient of the lower tie plate. According to the present invention, existent fuel assemblies can easily be changed successively to fuel assemblies having spectral shift rods of a great spectral shift effect by using existent reactor facilities as they are. (I.S.)

  12. Power module assembly

    Science.gov (United States)

    Campbell, Jeremy B [Torrance, CA; Newson, Steve [Redondo Beach, CA

    2011-11-15

    A power module assembly of the type suitable for deployment in a vehicular power inverter, wherein the power inverter has a grounded chassis, is provided. The power module assembly comprises a conductive base layer electrically coupled to the chassis, an insulating layer disposed on the conductive base layer, a first conductive node disposed on the insulating layer, a second conductive node disposed on the insulating layer, wherein the first and second conductive nodes are electrically isolated from each other. The power module assembly also comprises a first capacitor having a first electrode electrically connected to the conductive base layer, and a second electrode electrically connected to the first conductive node, and further comprises a second capacitor having a first electrode electrically connected to the conductive base layer, and a second electrode electrically connected to the second conductive node.

  13. Magnetic nanoparticle assemblies

    CERN Document Server

    Trohidou, Kalliopi N

    2014-01-01

    Magnetic nanoparticles with diameters in the range of a few nanometers are today at the cutting edge of modern technology and innovation because of their use in numerous applications ranging from engineering to biomedicine. A great deal of scientific interest has been focused on the functionalization of magnetic nanoparticle assemblies. The understanding of interparticle interactions is necessary to clarify the physics of these assemblies and their use in the development of high-performance magnetic materials. This book reviews prominent research studies on the static and dynamic magnetic properties of nanoparticle assemblies, gathering together experimental and computational techniques in an effort to reveal their optimized magnetic properties for biomedical use and as ultra-high magnetic recording media.

  14. Reactor fuel assembly

    International Nuclear Information System (INIS)

    Anthony, A.J.; Groves, M.D.

    1980-01-01

    A nuclear reactor fuel assembly having a lower end fitting and actuating means interacting therewith for holding the assembly down on the core support stand against the upward flow of coolant. Locking means for interacting with projections on the support stand are carried by the lower end fitting and are actuated by the movement of an actuating rod operated from above the top of the assembly. In one embodiment of the invention the downward movement of the actuating rod forces a latched spring to move outward into locking engagement with a shoulder on the support stand projections. In another embodiment, the actuating rod is rotated to effect the locking between the end fitting and the projection. (author)

  15. Nuclear fuel assembly

    International Nuclear Information System (INIS)

    Hayashi, Hiroshi; Watari, Yoshio; Hizahara, Hiroshi; Masuoka, Ryuzo.

    1970-01-01

    When exchanging nuclear fuel assemblies during the operation of a nuclear reactor, melting of fuel bodies, and severence of tubular claddings is halted at the time of insertion by furnishing a neutron absorbing material such as B 10 , Cd, Gd or the like at the forward end of the fuel assembly to thereby lower the power peak at the forward ends of the fuel elements to within tolerable levels and thus prevent both fuel liquification and excessive expansion. The neutron absorbing material may be attached in the form of a plate to the fuel assembly forward tie plate, or may be inserted as a pellet into the front end of the tubular cladding. (Owens, K.J.)

  16. Liaison based assembly design

    Energy Technology Data Exchange (ETDEWEB)

    Ames, A.; Kholwadwala, D.; Wilson, R.H.

    1996-12-01

    Liaison Based Assembly Design extends the current information infrastructure to support design in terms of kinematic relationships between parts, or liaisons. These liaisons capture information regarding contact, degrees-of-freedom constraints and containment relationships between parts in an assembly. The project involved defining a useful collection of liaison representations, investigating their properties, and providing for maximum use of the data in downstream applications. We tested our ideas by implementing a prototype system involving extensions to Pro/Engineer and the Archimedes assembly planner. With an expanded product model, the design system is more able to capture design intent. When a product update is attempted, increased knowledge availability improves our ability to understand the effect of design changes. Manufacturing and analysis disciplines benefit from having liaison information available, so less time is wasted arguing over incomplete design specifications and our enterprise can be more completely integrated.

  17. Integrated magnetic transformer assembly

    DEFF Research Database (Denmark)

    2014-01-01

    The present invention relates to an integrated magnetics transformer assembly comprising a first magnetically permeable core forming a first substantially closed magnetic flux path and a second magnetically permeable core forming a second substantially closed magnetic flux path. A first input...... inductor winding is wound around a first predetermined segment of the first magnetically permeable core and a second input inductor winding is wound around a first predetermined segment of the second magnetically permeable core. The integrated magnetics transformer assembly further comprises a first output......-winding of the first output inductor winding and the first half-winding of the second output inductor winding are configured to produce aligned, i.e. in the same direction, magnetic fluxes through the first substantially closed magnetic flux path. The integrated magnetics transformer assembly is well- suited for use...

  18. Transfer of fuel assemblies

    International Nuclear Information System (INIS)

    Vuckovich, M.; Burkett, J. P.; Sallustio, J.

    1984-01-01

    Fuel assemblies of a nuclear reactor are transferred during fueling or refueling or the like by a crane. The work-engaging fixture of the crane picks up an assembly, removes it from this slot, transfers it to the deposit site and deposits it in its slot at the deposit site. The control for the crane includes a strain gauge connected to the crane line which raises and lowers the load. The strain gauge senses the load on the crane. The signal from the strain gauge is compared with setpoints; a high-level setpoint, a low-level setpoint and a slack-line setpoint. If the strain gauge signal exceeds the high-level setpoint, the line drive is disabled. This event may occur during raising of a fuel assembly which encounters resistance. The high-level setpoint may be overridden under proper precautions. The line drive is also disabled if the strain gauge signal is less than the low-level setpoint. This event occurs when a fuel assembly being deposited contacts the bottom of its slot or an obstruction in, or at the entry to the slot. To preclude lateral movement and possible damage to a fuel assembly suspended from the crane line, the traverse drive of the crane is disabled once the strain-gauge exceets the lov-level setpoint. The traverse drive can only be enabled after the strain-gauge signal is less than the slack-line set-point. This occurs when the lines has been set in slack-line setting. When the line is tensioned after slack-li ne setting, the traverse drive remains enabled only if the line has been disconnected from the fuel assembly

  19. Neutron detector assembly

    International Nuclear Information System (INIS)

    Hanai, Koi; Shirayama, Shinpei.

    1978-01-01

    Purpose: To prevent gamma-ray from leaking externally passing through the inside of a neutron detector assembly. Constitution: In a neutron detector assembly having a protection pipe formed with an enlarged diameter portion which serves also as a spacer, partition plates with predetermined width are disposed at the upper and the lower portions in this expanded portion. A lot of metal particles are filled into spaces formed by the partition plates. In such a structure, the metal particles well-absorb the gamma-rays from above and convert them into heat to provide shielding for the gamma-rays. (Horiuchi, T.)

  20. Assembling RNA Nanoparticles.

    Science.gov (United States)

    Xiao, Shou-Jun

    2017-01-01

    RNA nanoparticles are designed and self-assembled according to noncanonical interactions of naturally conserved RNA motifs and/or canonical Watson-Crick base-pairing interactions, which have potential applications in gene therapy and nanomedicine. These artificially engineered nanoparticles are mainly synthesized from in vitro transcribed RNAs, purified by denaturing and native polyacrylamide gel electrophoresis (PAGE), and characterized with native PAGE, AFM, and TEM technologies. The protocols of in vitro transcription, denaturing and native PAGE, and RNA nanoparticle self-assembly are described in detail.

  1. Assembling an aesthetic.

    Science.gov (United States)

    Candela, Emily

    2012-12-01

    Recent research informing and related to the study of three-dimensional scientific models is assembled here in a way that explores an aesthetic, specifically, of touch. I concentrate on the materiality of models, drawing on insights from the history and philosophy of science, design and metaphysics. This article chronicles the ways in which touch, or material interactions, operate in the world of 3D models, and its role in what models mean and do. I end with a call for greater attention to scientific process, described as assembly of and within science, which is revealed by this focus on touch. Copyright © 2012 Elsevier Ltd. All rights reserved.

  2. Nuclear fuel assembly

    International Nuclear Information System (INIS)

    1975-01-01

    The nuclear fuel assembly described includes a cluster of fuel elements supported at a distance from each other so that their axes are parallel in order to establish secondary channels between them reserved for the coolant. Several ducts for an auxiliary cooling fluid are arranged in the cluster. The wall of each duct is pierced with coolant ejection holes which are placed circumferentially to a pre-determined pattern established according to the position of the duct in the cluster and by the axial distance of the ejection hole along the duct. This assembly is intended for reactors cooled by light or heavy water [fr

  3. Fire resistant PV shingle assembly

    Science.gov (United States)

    Lenox, Carl J.

    2012-10-02

    A fire resistant PV shingle assembly includes a PV assembly, including PV body, a fire shield and a connection member connecting the fire shield below the PV body, and a support and inter-engagement assembly. The support and inter-engagement assembly is mounted to the PV assembly and comprises a vertical support element, supporting the PV assembly above a support surface, an upper interlock element, positioned towards the upper PV edge, and a lower interlock element, positioned towards the lower PV edge. The upper interlock element of one PV shingle assembly is inter-engageable with the lower interlock element of an adjacent PV shingle assembly. In some embodiments the PV shingle assembly may comprise a ventilation path below the PV body. The PV body may be slidably mounted to the connection member to facilitate removal of the PV body.

  4. Two Functionally Distinct Sources of Actin Monomers Supply the Leading Edge of Lamellipodia

    Science.gov (United States)

    Vitriol, Eric A.; McMillen, Laura M.; Kapustina, Maryna; Gomez, Shawn M.; Vavylonis, Dimitrios; Zheng, James Q.

    2015-01-01

    Summary Lamellipodia, the sheet-like protrusions of motile cells, consist of networks of actin filaments (F-actin) regulated by the ordered assembly from and disassembly into actin monomers (G-actin). Traditionally, G-actin is thought to exist as a homogeneous pool. Here, we show that there are two functionally and molecularly distinct sources of G-actin that supply lamellipodial actin networks. G-actin originating from the cytosolic pool requires the monomer binding protein thymosin β4 (Tβ4) for optimal leading edge localization, is targeted to formins, and is responsible for creating an elevated G/F-actin ratio that promotes membrane protrusion. The second source of G-actin comes from recycled lamellipodia F-actin. Recycling occurs independently of Tβ4 and appears to regulate lamellipodia homeostasis. Tβ4-bound G-actin specifically localizes to the leading edge because it doesn’t interact with Arp2/3-mediated polymerization sites found throughout the lamellipodia. These findings demonstrate that actin networks can be constructed from multiple sources of monomers with discrete spatiotemporal functions. PMID:25865895

  5. Turbomachine blade assembly

    Science.gov (United States)

    Garcia Crespo, Andres Jose

    2016-11-01

    Embodiments of the present disclosure include a system comprising a turbomachine blade assembly having a blade portion, a shank portion, and a mounting portion, wherein the blade portion, the shank portion, and the mounting portion comprise a first plurality of plies extending from a tip of the airfoil to a base of the dovetail.

  6. Fuel sub-assembly

    International Nuclear Information System (INIS)

    Jolly, R.

    1982-01-01

    A fuel sub-assembly for a liquid metal cooled nuclear reactor is described in which the bundle of fuel pins are braced apart by a series of spaced grids. The grids at the lower end are capable of yielding, thus allowing pins swollen by irradiation to be withdrawn with a reduced risk of damage. (U.K.)

  7. Nanoparticle assemblies and superstructures

    National Research Council Canada - National Science Library

    Kotov, Nicholas A

    2006-01-01

    ... building blocks of larger and more complex systems. Therefore, the present challenge of nanoscale science is to shift from making certain building blocks to organizing them in one-, two-, and three-dimensional structures. Such assemblies and superstructures are the next logical step in the development of nanoscience and nanotechnology. In this re...

  8. Spool assembly support analysis

    International Nuclear Information System (INIS)

    Norman, B.F.

    1994-01-01

    This document provides the wind/seismic analysis and evaluation for the pump pit spool assemblies. Hand calculations were used for the analysis. UBC, AISC, and load factors were used in this evaluation. The results show that the actual loads are under the allowable loads and all requirements are met

  9. Nanotechnology: A molecular assembler

    Science.gov (United States)

    Kelly, T. Ross; Snapper, Marc L.

    2017-09-01

    The idea of nanometre-scale machines that can assemble molecules has long been thought of as the stuff of science fiction. Such a machine has now been built -- and might herald a new model for organic synthesis. See Letter p.374

  10. Macroscopic magnetic Self assembly

    NARCIS (Netherlands)

    Löthman, Per Arvid

    2018-01-01

    Exploring the macroscopic scale's similarities to the microscale is part and parcel of this thesis as reflected in the research question: what can we learn about the microscopic scale by studying the macroscale? Investigations of the environment in which the self-assembly takes place, and the

  11. Assembling Sustainable Territories

    DEFF Research Database (Denmark)

    Vandergeest, Peter; Ponte, Stefano; Bush, Simon

    2015-01-01

    that territorialisation is accomplished not just through (re)defining bounded space, but more broadly through the assembling of four elements: space, subjects, objects, and expertise. Four case studies of sustainability certification in seafood are analyzed to show that ‘green gabbing’ is not necessarily the central...

  12. Assembling sustainable territories

    NARCIS (Netherlands)

    Vandergeest, Peter; Ponte, Stefano; Bush, Simon

    2015-01-01

    The authors show how certification assembles ‘sustainable’ territories through a complex layering of regulatory authority in which both government and nongovernment entities claim rule-making authority, sometimes working together, sometimes in parallel, sometimes competitively. It is argued that

  13. Turneri preemia 2015: Assemble

    Index Scriptorium Estoniae

    2015-01-01

    Turneri 2015. aasta preemia pälvis radikaalne noorte arhitektide kollektiiv Assemble. Rühmitus on 18-liikmeline ja baseerub Ida-Londonis ning selle tegevust võib üldistatult nimetada hüljatud ruumide taaselustamiseks kogukondlike aktsioonide kaudu

  14. Industrial Assembly Cases

    DEFF Research Database (Denmark)

    Ellekilde, Lars-Peter; Buch, Jacob Pørksen; Iversen, Thorbjørn Mosekjær

    This technical report presents 13 different industrial assembly tasks, which are composed of 70 different operations. The report is written to provide an overview and do as such not contain product specific information such as object weights, dimensions etc. The operations are classified into a set...

  15. Biosynthesis: Reprogramming assembly lines

    Science.gov (United States)

    Menon, Binuraj R. K.; Jenner, Matthew

    2018-03-01

    Rational engineering of biosynthetic assembly lines for production of new compounds is an attractive prospect, yet it presents many challenges. Learning from biology, some of the rules for expanding the chemical diversity of non-ribosomal peptides have been uncovered in two recent studies.

  16. Ordinary General Assembly

    CERN Multimedia

    Staff Association

    2011-01-01

    Tuesday 12 April at 14.00 Council Chamber, Bldg 503 In conformity with the Statutes of the Staff Association, an ordinary General Assembly is organized once a year (article IV.2.1). Agenda   Adoption of the Agenda Approval of the Draft Minutes of the Ordinary General Assembly of 20 April 2010 Presentation and approval of the Activity Report 2010 Presentation and approval of the Financial Report 2010 Presentation and approval of the Auditors Report 2010 Programme for 2011 Presentation et and approval of the draft budget and subscription rate 2012 Election of the Election Committee Election of the Board of Auditors Miscellaneous We remind members of article IV.3.4 in the Statutes of the Association which reads: “After having dealt with all the items on the agenda, the members may, with the consent of the Assembly, have other matters discussed, but decisions may be taken only on the items listed on the agenda. Nevertheless, the Assembly ma...

  17. Ordinary General Assembly

    CERN Multimedia

    Staff Association

    2011-01-01

    Tuesday 12 April at 14.00 Council Chamber, Bldg 503 In conformity with the Statutes of the Staff Association, an ordinary General Assembly is organized once a year (article IV.2.1). Agenda   Adoption of the Agenda Approval of the Draft Minutes of the Ordinary General Assembly of 20 April 2010 Presentation and approval of the Activity Report 2010 Presentation and approval of the Financial Report 2010 Presentation and approval of the Auditors Report 2010 Programme for 2011 Presentation and approval of the draft budget and subscription rate 2012 Election of the Election Committee Election of the Board of Auditors Miscellaneous We remind members of article IV.3.4 in the Statutes of the Association which reads: “After having dealt with all the items on the agenda, the members may, with the consent of the Assembly, have other matters discussed, but decisions may be taken only on the items listed on the agenda. Nevertheless, the Assembly may r...

  18. Ordinary General Assembly

    CERN Multimedia

    Staff Association

    2010-01-01

    Tuesday 20 April at 10.00 Council Chamber, Bldg 503 In conformity with the Statutes of the Staff Association, an ordinary General Assembly is organized once a year (article IV.2.1). Agenda   Adoption of the Agenda Approval of the Draft Minutes of the Ordinary General Assembly of 12 May 2009 Presentation and approval of the Activity Report 2009 Presentation and approval of the Financial Report 2009 Presentation and approval of the Auditors Report 2009 Programme for 2010 Presentation et and approval of the draft budget and subscription rate 2010 Election of the Election Committee Election of the Board of Auditors Miscellaneous We remind members of article IV.3.4 in the Statutes of the Association which reads: “After having dealt with all the items on the agenda, the members may, with the consent of the Assembly, have other matters discussed, but decisions may be taken only on the items listed on the agenda. Nevertheless, the Assembly may require t...

  19. Lageos assembly operation plan

    Science.gov (United States)

    Brueger, J.

    1975-01-01

    Guidelines and constraints procedures for LAGEOS assembly, operation, and design performance are given. Special attention was given to thermal, optical, and dynamic analysis and testing. The operation procedures illustrate the interrelation and sequence of tasks in a flow diagram. The diagram also includes quality assurance functions for verification of operation tasks.

  20. Assembly of primary cilia

    DEFF Research Database (Denmark)

    Pedersen, Lotte B; Veland, Iben R; Schrøder, Jacob M

    2008-01-01

    knowledge about IFT is based on studies performed in Chlamydomonas and Caenorhabditis elegans. Therefore, our review of the IFT literature includes studies performed in these two model organisms. The role of several non-IFT proteins (e.g., centrosomal proteins) in the ciliary assembly process is also...... discussed. Developmental Dynamics, 2008. (c) 2008 Wiley-Liss, Inc....

  1. Feedback Interactions of Polymerized Actin with the Cell Membrane: Waves, Pulses, and Oscillations

    Science.gov (United States)

    Carlsson, Anders

    Polymerized filaments of the protein actin have crucial functions in cell migration, and in bending the cell membrane to drive endocytosis or the formation of protrusions. The nucleation and polymerization of actin filaments are controlled by upstream agents in the cell membrane, including nucleation-promoting factors (NPFs) that activate the Arp2/3 complex to form new branches on pre-existing filaments. But polymerized actin (F-actin) also feeds back on the assembly of NPFs. We explore the effects of the resulting feedback loop of F-actin and NPFs on two phenomena: actin pulses that drive endocytosis in yeast, and actin waves traveling along the membrane of several cell types. In our model of endocytosis in yeast, the actin network is grown explicitly in three dimensions, exerts a negative feedback interaction on localized patch of NPFs in the membrane, and bends the membrane by exerting a distribution of forces. This model explains observed actin and NPF pulse dynamics, and the effects of several interventions including i) NPF mutations, ii) inhibition of actin polymerization, and iii) deletion of a protein that allows F-actin to bend the cell membrane. The model predicts that mutation of the active region of an NPF will enhance the accumulation of that NPF, and we confirm this prediction by quantitative fluorescence microscopy. For actin waves, we treat a similar model, with NPFs distributed over a larger region of the cell membrane. This model naturally generates actin waves, and predicts a transition from wave behavior to spatially localized oscillations when NPFs are confined to a small region. We also predict a transition from waves to static polarization as the negative-feedback coupling between F-actin and the NPFs is reduced. Supported by NIGMS Grant R01 GM107667.

  2. School Assemblies: The Lost Art.

    Science.gov (United States)

    Beach, Daniel R.

    1979-01-01

    Guidelines and suggestions are offered for successful school assemblies. The school assembly should be a positive event; an occasion for developing unity, group loyalty, and desirable audience habits. (Author/MLF)

  3. Assembling large, complex environmental metagenomes

    Energy Technology Data Exchange (ETDEWEB)

    Howe, A. C. [Michigan State Univ., East Lansing, MI (United States). Microbiology and Molecular Genetics, Plant Soil and Microbial Sciences; Jansson, J. [USDOE Joint Genome Institute (JGI), Walnut Creek, CA (United States); Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States). Earth Sciences Division; Malfatti, S. A. [USDOE Joint Genome Institute (JGI), Walnut Creek, CA (United States); Tringe, S. G. [USDOE Joint Genome Institute (JGI), Walnut Creek, CA (United States); Tiedje, J. M. [Michigan State Univ., East Lansing, MI (United States). Microbiology and Molecular Genetics, Plant Soil and Microbial Sciences; Brown, C. T. [Michigan State Univ., East Lansing, MI (United States). Microbiology and Molecular Genetics, Computer Science and Engineering

    2012-12-28

    The large volumes of sequencing data required to sample complex environments deeply pose new challenges to sequence analysis approaches. De novo metagenomic assembly effectively reduces the total amount of data to be analyzed but requires significant computational resources. We apply two pre-assembly filtering approaches, digital normalization and partitioning, to make large metagenome assemblies more computationaly tractable. Using a human gut mock community dataset, we demonstrate that these methods result in assemblies nearly identical to assemblies from unprocessed data. We then assemble two large soil metagenomes from matched Iowa corn and native prairie soils. The predicted functional content and phylogenetic origin of the assembled contigs indicate significant taxonomic differences despite similar function. The assembly strategies presented are generic and can be extended to any metagenome; full source code is freely available under a BSD license.

  4. X-Ray Assembler Data

    Data.gov (United States)

    U.S. Department of Health & Human Services — Federal regulations require that an assembler who installs one or more certified components of a diagnostic x-ray system submit a report of assembly. This database...

  5. Welding facilities for NPP assembling

    International Nuclear Information System (INIS)

    Rojtenberg, S.S.

    1987-01-01

    Recommendations concerning the choice of equipment for welding in pre-assembling work shops, in the enlarging assembling shops and at the assembling site, are given. Advanced production automatic welders and semiautomatic machines, applied during the NPP equipment assembling as well as automatic machines specially produced for welding the main reactor components and pipelines are described. Automatic and semiautomatic machine and manual welding post supply sources are considered

  6. Reflector-moderated critical assemblies

    International Nuclear Information System (INIS)

    Paxton, H.C.; Jarvis, G.A.; Byers, C.C.

    1975-07-01

    Experiments with reflector-moderated critical assemblies were part of the Rover Program at the Los Alamos Scientific Laboratory (LASL). These assemblies were characterized by thick D 2 O or beryllium reflectors surrounding large cavities that contained highly enriched uranium at low average densities. Because interest in this type of system has been revived by LASL Plasma Cavity Assembly studies, more detailed descriptions of the early assemblies than had been available in the unclassified literature are provided. (U.S.)

  7. Nuclear fuel assembly

    International Nuclear Information System (INIS)

    Takeda, Tadashi; Sato, Kenji; Goto, Masakazu.

    1984-01-01

    Purpose: To facilitate identification of a fuel assembly upon fuel exchange in BWR type reactors. Constitution: Fluorescent material is coated or metal plating is applied to the impressed portion of a upper tie plate handle of a fuel assembly, and the fluorescent material or the metal plating surface is covered with a protective membrane made of transparent material. This enables to distinguish the impressed surface from a distant place and chemical reaction between the impressed surface and the reactor water can be prevented. Furthermore, since the protective membrane is formed such that it protrudes toward the upper side relative to the impressed surface, there is no risk of depositions of claddings thereover. (Moriyama, K.)

  8. Fuel nozzle assembly

    Science.gov (United States)

    Johnson, Thomas Edward [Greer, SC; Ziminsky, Willy Steve [Simpsonville, SC; Lacey, Benjamin Paul [Greer, SC; York, William David [Greer, SC; Stevenson, Christian Xavier [Inman, SC

    2011-08-30

    A fuel nozzle assembly is provided. The assembly includes an outer nozzle body having a first end and a second end and at least one inner nozzle tube having a first end and a second end. One of the nozzle body or nozzle tube includes a fuel plenum and a fuel passage extending therefrom, while the other of the nozzle body or nozzle tube includes a fuel injection hole slidably aligned with the fuel passage to form a fuel flow path therebetween at an interface between the body and the tube. The nozzle body and the nozzle tube are fixed against relative movement at the first ends of the nozzle body and nozzle tube, enabling the fuel flow path to close at the interface due to thermal growth after a flame enters the nozzle tube.

  9. Nuclear fuel assembly

    International Nuclear Information System (INIS)

    Ito, Arata; Wakamatsu, Mitsuo.

    1976-01-01

    Object: To permit the coolant in an FBR type reactor to enter from the entrance nozzle into a nuclear fuel assembly without causing cavitation. Structure: In a nuclear fuel assembly, which comprises a number of thin fuel pines bundled together at a uniform spacing and enclosed within an outer cylinder, with a handling head connected to an upper portion of the outer cylinder and an entrance nozzle connected to a lower portion of the cylinder, the inner surface of the entrance nozzle is provided with a buffer member and an orifice successively in the direction of flow of the coolant. The coolant entering from a low pressure coolant chamber into the entrance nozzle strikes the buffer member and is attenuated, and thereafter flows through an orifice into the outer cylinder. (Horiuchi, T.)

  10. Molten core retention assembly

    International Nuclear Information System (INIS)

    Lampe, R.F.

    1976-01-01

    Molten fuel produced in a core overheating accident is caught by a molten core retention assembly consisting of a horizontal baffle plate having a plurality of openings therein, heat exchange tubes having flow holes near the top thereof mounted in the openings, and a cylindrical imperforate baffle attached to the plate and surrounding the tubes. The baffle assembly is supported from the core support plate of the reactor by a plurality of hanger rods which are welded to radial beams passing under the baffle plate and intermittently welded thereto. Preferably the upper end of the cylindrical baffle terminates in an outwardly facing lip to which are welded a plurality of bearings having slots therein adapted to accept the hanger rods

  11. Nuclear fuel assemblies

    International Nuclear Information System (INIS)

    Butterfield, R.S.; Garner, D.L.M.

    1977-01-01

    Reference is made to nuclear fuel assemblies designed for cooling on the 'tube-in-shell' principle in which the fuel is contained by a shell and is cooled by coolant passed through tubes extending through the shell. It has been proposed to employ coated particle fuel as a porous bed on the tube side and the bleed coolant from the tubes into direct contact with the fuel particles. In this way heat is extracted both by direct contact with the fuel and by heat transfer through the coolant tube walls. The system described aims to provide an improved structure of tube and shell for a fuel assembly of this kind and is particularly suitable for use in a gas cooled fast reactor, being able to withstand the neutron flux and high temperature conditions in these reactors. Constructional details are given. (U.K.)

  12. Nuclear reactor fuel assembly

    International Nuclear Information System (INIS)

    1975-01-01

    A description is given of a nuclear reactor fuel assembly comprising a cluster of fuel elements supported by transversal grids so that their axes are parallel to and at a distance from each other, in order to establish interstices for the axial flow of a coolant. At least one of the interstices is occupied by an axial duct reserved for an auxiliary cooling fluid and is fitted with side holes through which the auxiliary cooling fluid is sprayed into the cluster. Deflectors extend as from a transversal grid in a position opposite the holes to deflect the cooling fluid jet towards those parts of the fuel elements that are not accessible to the auxiliary coolant. This assembly is intended for reactors cooled by light or heavy water [fr

  13. Gamma counter shutter assembly

    International Nuclear Information System (INIS)

    Aday, R.W. Jr.; Barber, D.G.

    1976-01-01

    A shutter assembly for a radioactivity measuring apparatus is described having a sample counting chamber, the assembly having a bulky solid lead cylinder with a sample access port extending therethrough for alignment with the sample chamber. The cylinder is rotated by a Geneva wheel arrangement having a drive wheel with a plurality of equi-angularly disposed pins perpendicular to the surface thereof engaging radially extending open-ended slots in a driven wheel secured to the lead cylinder for concurrent rotation therewith. The drive wheel is rotated at a constant speed with the driven wheel accelerating as a pin traverses the slot from the open end toward the driven wheel center and then decelerating as the pin traverses the reverse direction to provide precise positioning with adjacent pins engaging the open ends of adjacent slots in the stop position of the cylinder. 8 Claims, 3 Drawing Figures

  14. Mechanical seal assembly

    Science.gov (United States)

    Kotlyar, Oleg M.

    2001-01-01

    An improved mechanical seal assembly is provided for sealing rotating shafts with respect to their shaft housings, wherein the rotating shafts are subject to substantial axial vibrations. The mechanical seal assembly generally includes a rotating sealing ring fixed to the shaft, a non-rotating sealing ring adjacent to and in close contact with the rotating sealing ring for forming an annular seal about the shaft, and a mechanical diode element that applies a biasing force to the non-rotating sealing ring by means of hemispherical joint. The alignment of the mechanical diode with respect to the sealing rings is maintained by a series of linear bearings positioned axially along a desired length of the mechanical diode. Alternative embodiments include mechanical or hydraulic amplification components for amplifying axial displacement of the non-rotating sealing ring and transferring it to the mechanical diode.

  15. Mechanical Seal Assembly

    Energy Technology Data Exchange (ETDEWEB)

    Kotlyar, Oleg M.

    1999-06-18

    An improved mechanical seal assembly is provided for sealing rotating shafts with respect to their shaft housings, wherein the rotating shafts are subject to substantial axial vibrations. The mechanical seal assembly generally includes a rotating sealing ring fixed to the shaft, a non-rotating sealing ring adjacent to and in close contact with the rotating sealing ring for forming an annular seal about the shaft, and a mechanical diode element that applies a biasing force to the non-rotating sealing ring by means of hemispherical joint. The alignment of the mechanical diode with respect to the sealing rings is maintained by a series of linear bearings positioned axially along a desired length of the mechanical diode. Alternative embodiments include mechanical or hydraulic amplification components for amplifying axial displacement of the non-rotating sealing ring and transferring it to the mechanical diode.

  16. Nuclear fuel assemblies

    International Nuclear Information System (INIS)

    Natori, Hisahide; Kurihara, Kunitoshi.

    1982-01-01

    Purpose: To increase the fuel safety by decreasing the gap conductance between fuels and cladding tubes, as well as improve the reactor core controllability by rendering the void coefficient negative. Constitution: Fuel assemblies in a pressure tube comprise a tie-rod, fuel rods in a central region, and fuel rods with burnable poison in the outer circumference region. Here, B 4 C is used as the burnable poison by 1.17 % by weight ratio. The degrees of enrichment for the fissile plutonium as PuO 2 -UO 2 fuel used in the assemblies are 2.7 %, 2.7 % and 1.5 % respectively in the innermost layer, the intermediate layer and the outermost layer. This increases the burn-up degree to improve the plant utilizability, whereby the void coefficient is rendered negative to improve the reactor core controllability. (Horiuchi, T.)

  17. Nuclear fuel assembly

    International Nuclear Information System (INIS)

    Ueda, Tomihiro.

    1970-01-01

    The present invention relates to fuel assemblies employing wire wrap spacers for retaining uniform spatial distribution between fuel elements. Clad fuel elements are helically wound in the oxial direction with a wave-formed wire strand. The strand is therefore provided with spring action which permits the fuel elements to expand freely in the axial and radial directions so as to retain proper spacing and reduce stresses due to thermal deformation. (Ownes, K.J.)

  18. Assembling Toyota in Portugal

    OpenAIRE

    Machado, Tiago; Moniz, António

    2003-01-01

    A lot has been written over the last decade with regard to Toyota and the productive model associated to it (toyota-ism). And more specifically concerning the "(…) best-seller that changed the... sociological world" (Castillo, 1998: 31). But the case of Salvador Caetano’s Ovar Industrial Division (OID), that assembles Toyota light commercial vehicles in Portugal, allows us to put forward a sub-hypothesis that fits into the analysis schema proposed in the First GERPISA International Program – ...

  19. Fuel assembly manufacturing device

    International Nuclear Information System (INIS)

    Picard, P.; Villaeys, R.

    1995-01-01

    The device comprises a central support on which the frame is mounted, a magazine which supports the fuel rods in passages aligned with those in the frame and a traction assembly on the opposite side of the magazine and including an array of pull rods designed to be advanced through the passages in the frame, to grip respective fuel rods in magazine and to pull those rods into the passages on the return stroke. 13 figs

  20. Composite airfoil assembly

    Science.gov (United States)

    Garcia-Crespo, Andres Jose

    2015-03-03

    A composite blade assembly for mounting on a turbine wheel includes a ceramic airfoil and an airfoil platform. The ceramic airfoil is formed with an airfoil portion, a blade shank portion and a blade dovetail tang. The metal platform includes a platform shank and a radially inner platform dovetail. The ceramic airfoil is captured within the metal platform, such that in use, the ceramic airfoil is held within the turbine wheel independent of the metal platform.

  1. Uncertainties Affecting BOSFN for the Mark 15 Assembly

    International Nuclear Information System (INIS)

    Hamm, L.L.

    2001-01-01

    Technical and transient protection limits are specified on the nominal burnout safety factor, BOSFN, to avoid significant release of fission products caused by local film boiling burnout. The risk of fission product release, BOR, due to film boiling burnout is statistically determined where allowances are made to account for differences between the nominal assembly and the actual assembly. This report describes the calculational model behind BOR and how the specific numerical values were estimated. The data listed in this report enable damage calculations with COBAD to be performed for the Mark 15 assembly

  2. Structural Aspects of Bacterial Outer Membrane Protein Assembly.

    Science.gov (United States)

    Calmettes, Charles; Judd, Andrew; Moraes, Trevor F

    2015-01-01

    The outer membrane of Gram-negative bacteria is predominantly populated by β-Barrel proteins and lipid anchored proteins that serve a variety of biological functions. The proper folding and assembly of these proteins is essential for bacterial viability and often plays a critical role in virulence and pathogenesis. The β-barrel assembly machinery (Bam) complex is responsible for the proper assembly of β-barrels into the outer membrane of Gram-negative bacteria, whereas the localization of lipoproteins (Lol) system is required for proper targeting of lipoproteins to the outer membrane.

  3. Fourth Doctoral Student Assembly

    CERN Multimedia

    Ingrid Haug

    2016-01-01

    On 10 May, over 130 PhD students and their supervisors, from both CERN and partner universities, gathered for the 4th Doctoral Student Assembly in the Council Chamber.   The assembly was followed by a poster session, at which eighteen doctoral students presented the outcome of their scientific work. The CERN Doctoral Student Programme currently hosts just over 200 students in applied physics, engineering, computing and science communication/education. The programme has been in place since 1985. It enables students to do their research at CERN for a maximum of three years and to work on a PhD thesis, which they defend at their University. The programme is steered by the TSC committee, which holds two selection committees per year, in June and December. The Doctoral Student Assembly was opened by the Director-General, Fabiola Gianotti, who stressed the importance of the programme in the scientific environment at CERN, emphasising that there is no more rewarding activity than lear...

  4. Metrology for ITER Assembly

    International Nuclear Information System (INIS)

    Bogusch, E.

    2006-01-01

    The overall dimensions of the ITER Tokamak and the particular assembly sequence preclude the use of conventional optical metrology, mechanical jigs and traditional dimensional control equipment, as used for the assembly of smaller, previous generation, fusion devices. This paper describes the state of the art of the capabilities of available metrology systems, with reference to the previous experience in Fusion engineering and in other industries. Two complementary procedures of transferring datum from the primary datum network on the bioshield to the secondary datum s inside the VV with the desired accuracy of about 0.1 mm is described, one method using the access directly through the ports and the other using transfer techniques, developed during the co-operation with ITER/EFDA. Another important task described is the development of a method for the rapid and easy measurement of the gaps between sectors, required for the production of the customised splice plates between them. The scope of the paper includes the evaluation of the composition and cost of the systems and team of technical staff required to meet the requirements of the assembly procedure. The results from a practical, full-scale demonstration of the methodologies used, using the proposed equipment, is described. This work has demonstrated the feasibility of achieving the necessary accuracies for the successful building of ITER. (author)

  5. Ordinary General Assembly

    CERN Multimedia

    Association du personnel

    2010-01-01

    Tuesday 20 April at 10.00 Council Chamber, Bldg 503 In conformity with the Statutes of the Staff Association, an ordinary General Assembly is organized once a year (article IV.2.1). Agenda Adoption of the Agenda Approval of the Draft Minutes of the Ordinary General Assembly of 12 May 2009 Presentation and approval of the Activity Report 2009 Presentation and approval of the Financial Report 2009 Presentation and approval of the Auditors Report 2009 Programme for 2010 Presentation et and approval of the draft budget and subscription rate 2010 Modifications to the statutes of the association Election of the Election Committee Election of the Board of Auditors Miscellaneous We remind members of article IV.3.4 in the Statutes of the Association which reads: “After having dealt with all the items on the agenda, the members may, with the consent of the Assembly, have other matters discussed, but decisions may be taken only on the items listed on the agenda...

  6. SCT Barrel Assembly Complete

    CERN Multimedia

    L. Batchelor

    As reported in the April 2005 issue of the ATLAS eNews, the first of the four Semiconductor Tracker (SCT) barrels, complete with modules and services, arrived safely at CERN in January of 2005. In the months since January, the other three completed barrels arrived as well, and integration of the four barrels into the entire barrel assembly commenced at CERN, in the SR1 building on the ATLAS experimental site, in July. Assembly was completed on schedule in September, with the addition of the innermost layer to the 4-barrel assembly. Work is now underway to seal the barrel thermal enclosure. This is necessary in order to enclose the silicon tracker in a nitrogen atmosphere and provide it with faraday-cage protection, and is a delicate and complicated task: 352 silicon module powertapes, 352 readout-fibre bundles, and over 400 Detector Control System sensors must be carefully sealed into the thermal enclosure bulkhead. The team is currently verifying the integrity of the low mass cooling system, which must be d...

  7. Localization of thymosin ß10 in breast cancer cells

    DEFF Research Database (Denmark)

    Mælan, A.ase Elisabeth; Rasmussen, Trine Kring; Larsson, Lars-Inge

    2007-01-01

    as in cell motility and spreading. We have studied the distribution of endogenously expressed thymosin ß10 in cultured human breast cancer cell lines. Both unperturbed monolayer cultures and wound-healing models were examined using double-staining for thymosin ß10 and polymerized (F-) actin. Our findings...... show that thymosin ß10 is expressed in all three-cancer cell lines (SK-BR-3, MCF-7 and MDA-MB-231) studied. No or little staining was detected in confluent cells, whereas strong staining occurred in semiconfluent cells and in cells populating monolayer wounds. Importantly, the distribution of staining...... for thymosin ß10 was inverse of staining for F-actin. These data support a physiological role for thymosin ß10 in sequestration of G-actin as well as in cancer cell motility....

  8. Computational and experimental investigation of local stress fiber orientation in uniaxially and biaxially constrained microtissues

    NARCIS (Netherlands)

    Obbink - Huizer, C.; Foolen, J.; Oomens, C.W.J.; Borochin, M.A.; Chen, C.S.; Bouten, C.V.C.; Baaijens, F.P.T.

    2014-01-01

    The orientation of cells and associated F-actin stress fibers is essential for proper tissue functioning. We have previously developed a computational model that qualitatively describes stress fiber orientation in response to a range of mechanical stimuli. In this paper, the aim is to quantitatively

  9. Dielectrophoretic assembly of carbon nanotube devices

    DEFF Research Database (Denmark)

    Dimaki, Maria

    The purpose of this project has been to assemble single-walled carbon nanotubes on electrodes at the tip of a biocompatible cantilever and use these for chemical species sensing in air and liquid, for example in order to measure the local activity from ion channels in the cell membrane....... The electrical resistance of carbon nanotubes has been shown to be extremely sensitive to gas molecules. Dielectrophoresis is a method capable of quickly attracting nanotubes on microelectrodes by using an electric field, thus enabling nanotube integration in microsystems. Dielectrophoresis offers also....... A model for the dielectrophoretic assembly of carbon nanotubes on microelectrodes was developed and several simulations were conducted using values from the available literature for the various key parameters. The model can give qualitative results regarding the parameters dominating the dielectrophoretic...

  10. Liner mounting assembly

    Science.gov (United States)

    Halila, Ely E. (Inventor)

    1994-01-01

    A mounting assembly includes an annular supporting flange disposed coaxially about a centerline axis which has a plurality of circumferentially spaced apart supporting holes therethrough. An annular liner is disposed coaxially with the supporting flange and includes a plurality of circumferentially spaced apart mounting holes aligned with respective ones of the supporting holes. Each of a plurality of mounting pins includes a proximal end fixedly joined to the supporting flange through a respective one of the supporting holes, and a distal end disposed through a respective one of the liner mounting holes for supporting the liner to the supporting flange while unrestrained differential thermal movement of the liner relative to the supporting flange.

  11. Modelling Polar Self Assembly

    Science.gov (United States)

    Olvera de La Cruz, Monica; Sayar, Mehmet; Solis, Francisco J.; Stupp, Samuel I.

    2001-03-01

    Recent experimental studies in our group have shown that self assembled thin films of noncentrosymmetric supramolecular objects composed of triblock rodcoil molecules exhibit finite polar order. These aggregates have both long range dipolar and short range Ising-like interactions. We study the ground state of a simple model with these competing interactions. We find that the competition between Ising-like and dipolar forces yield a periodic domain structure, which can be controlled by adjusting the force constants and film thickness. When the surface forces are included in the potential, the system exhibits a finite macroscopic polar order.

  12. Nuclear reactor core assembly

    International Nuclear Information System (INIS)

    Baxi, C.B.

    1978-01-01

    The object of the present invention is to provide a fast reactor core assembly design for use with a fluid coolant such as liquid sodium or carbon monoxide incorporating a method of increasing the percentage of coolant flow though the blanket elements relative to the total coolant flow through the blanket and fuel elements during shutdown conditions without using moving parts. It is claimed that deterioration due to reactor radiation or temperature conditions is avoided and ready modification or replacement is possible. (U.K.)

  13. Progress of EMBarrel assembly

    CERN Multimedia

    Chalifour, M

    2002-01-01

    The assembly of the sixteen "M" modules into a vertical axis cylinder has been achieved last Friday, completing the first wheel of the Electromagnetic Barrel Calorimeter (see picture). With this, an important milestone in the construction of the ATLAS detector has been reached. Future steps are the rotation of the cylinder axis into horizontal position, in order to integrate the presamplers and heat exchangers by the end of October. The transportation of the wheel and its insertion into the cryostat is the next major milestone, and is planned for the beginning of 2003. The construction of the modules (the so-called "P" modules) of the second wheel is ongoing at Saclay, Annecy and CERN, and will be completed in the coming months. The assembly of the second wheel should start at CERN in February, and its insertion in the cryostat is scheduled for June 2003. This achievement is the result of a successful collaboration of all institutes involved in the construction of the EM Barrel, namely Annecy, Saclay and CE...

  14. Fuel assembly supporting structure

    International Nuclear Information System (INIS)

    Aisch, F.W.; Fuchs, H.P.; Knoedler, D.; Steinke, A.; Steven, J.

    1976-01-01

    For use in forming the core of a pressurized-water reactor, a fuel assembly supporting structure for holding a bundle of interspaced fuel rods, is formed by interspaced end pieces having holes in which the end portions of control rod guide tubes are inserted, fuel rod spacer grids being positioned by these guide tubes between the end pieces. The end pieces are fastened to the end portions of the guide tubes, to integrate the supporting structure, and in the case of at least one of the end pieces, this is done by means which releases that end piece from the guide tubes when the end pieces receive an abnormal thrust force directed towards each other and which would otherwise place the guide tubes under a compressive stress that would cause them to buckle. The spacer grids normally hold the fuel rods interspaced by distances determined by nuclear physics, and buckling of the control rod guide tubes can distort the fuel rod spacer grids with consequent dearrangement of the fuel rod interspacing. A sudden loss of pressure in a pressurized-water reactor pressure vessel can result in the pressurized coolant in the vessel discharging from the vessel at such high velocity as to result in the abnormal thrust force on the end pieces of each fuel assembly, which could cause buckling of the control rod guide tubes when the end pieces are fixed to them in the normal rigid and unyielding manner

  15. ANNUAL GENERAL ASSEMBLY

    CERN Multimedia

    2001-01-01

    All members and beneficiaries of the Pension Fund are invited to attend the Annual General Asssembly to be held in the CERN Auditorium on Wednesday 3 October 2001 at 14.30 hrs The Agenda comprises:   Opening Remarks (P. Levaux) Some aspects of risk in a pension fund (C. Cuénoud) Annual Report 2000: Presentation and results (C. Cuénoud) Copies of the Report are available from divisional secretariats. Results of the actuarial reviews (G. Maurin) Questions from members and beneficiaries Persons wishing to ask questions are encouraged to submit them, where possible, in writing in advance, addressed to Mr C. Cuénoud, Administrator of the Fund. Conclusions (P. Levaux) As usual, participants are invited to drinks after the assembly. NB The minutes of the 2000 General Assembly are available from the Administration of the Fund (tel. + 41 22 767 91 94; e-mail Graziella.Praire@cern.ch) The English version will be published next week.

  16. Bottom head assembly

    International Nuclear Information System (INIS)

    Fife, A.B.

    1998-01-01

    A bottom head dome assembly is described which includes, in one embodiment, a bottom head dome and a liner configured to be positioned proximate the bottom head dome. The bottom head dome has a plurality of openings extending there through. The liner also has a plurality of openings extending there through, and each liner opening aligns with a respective bottom head dome opening. A seal is formed, such as by welding, between the liner and the bottom head dome to resist entry of water between the liner and the bottom head dome at the edge of the liner. In the one embodiment, a plurality of stub tubes are secured to the liner. Each stub tube has a bore extending there through, and each stub tube bore is coaxially aligned with a respective liner opening. A seat portion is formed by each liner opening for receiving a portion of the respective stub tube. The assembly also includes a plurality of support shims positioned between the bottom head dome and the liner for supporting the liner. In one embodiment, each support shim includes a support stub having a bore there through, and each support stub bore aligns with a respective bottom head dome opening. 2 figs

  17. ULTRASONIC ASSEMBLY [REVIEW

    Directory of Open Access Journals (Sweden)

    PORAV Viorica

    2015-05-01

    Full Text Available The paper exposes the possibility of machine producesers to optimize the costs of clothes assembling. Ultrasonic systems being frequently utilized have many advantages on semi products of synthetic textile and technical textile. First of all, sewing – cutting process can be accomplished under high speeds and rate of losses can be minimized. Cutting seal applications are frequently used for underwear and sportswear. Slicing and unit cutting machines, as well as portable sealing machines are available for labeling sector. Products such as bag, pocket and cover can be sewed in a seamless manner for promotion purposes. All objects in terms of accessories are obtained in same standard. Our quilting machines are preferred in worldwide due to its threadless, high quality sealing. An alternative to the classic sewing assembly, with thread and needles is ultrasonic seaming. In ultrasonic welding, there are no connective bolts, nails, soldering materials, or adhesives necessary to bind the materials together. Ultrasonic is defined as acoustic frequencies above the range audible to the human ear. Ultrasonic frequencies are administered to the fabric from the sonotrode of bonding machine. The high frequency and powerful energy produced, when is release in one special environment, the ultrasound heating this environment. The ability to ultrasonic weld textiles and films depend on their thermoplastic contents and the desired end results. The paper defines the weld ability of more common textiles and films. The welding refers to all types of bonding and sealing, as in point bonding of fabric, or continuous sealing of film.

  18. PWR fuel assembly

    International Nuclear Information System (INIS)

    Yamada, Yuji.

    1995-01-01

    A lower end plug is secured to a lower end of a thimble tube. A bolt-like thimble screw is screw-coupled and fastened to a female screw disposed to the end plug by way of a bushing screw-coupled to a lower nozzle. Then, the thimble screw and the lower nozzle are welded to secure the thimble tube and the lower nozzle. The lower portion of the bushing extends near the lower surface of the lower nozzle. The extended portion is provided with a recess to which a bolt head of the thimble screw is tightly inserted and a seating-face portion against which a seating-face of the bolt head abuts. Then, the extended portion of the bushing and the lower nozzle are spot-welded on the side of the lower surface of the nozzle, to prevent rotation of the bushing. This can easily prevent the rotation of the bushing after adjustment, to simplify the assembling of the fuel assembly. (I.N.)

  19. Fuel assembly and reactor core

    International Nuclear Information System (INIS)

    Masumi, Ryoji; Aoyama, Motoo; Koyama, Jun-ichi; Ishibashi, Yoko; Mochida, Takaaki; Soneda, Hideo.

    1994-01-01

    In a fuel assembly having moderator rods, an axial average value of a ratio between the total of the lateral cross sectional area of a portion to be filled with moderators and the total of the lateral cross sectional area of fuel pellets is determined as greater than 0.4, a lateral cross sectional area of a portion to be filled with moderators per one moderator rod is determined as from 14 to 50cm 2 and the ratio between the total of the lateral cross sectional area of moderators and a total of the lateral cross sectional area of fuel pellets in a horizontal cross section is determined as from 2.7 to 3.4. Since the axial average value for lateral cross sectional area of a portion to be filled with moderators/lateral cross sectional area of fuel pellets is determined as ≥ 0.4, the lateral cross sectional area of moderators of moderator rods is increased, the lateral cross sectional area of a gap water region is decreased to reduce the value of local power peaking coefficient, so that thermal margin is ensured. At least one of the moderating rods is formed as a double-walled water rod tube to enhance an effect of spectral shift by flow rate control, reduce an uranium enrichment degree, and conduct operation without inserting control rods. (N.H.)

  20. Spatio-temporal Dynamics and Mechanisms of Stress Granule Assembly.

    Directory of Open Access Journals (Sweden)

    Daisuke Ohshima

    2015-06-01

    Full Text Available Stress granules (SGs are non-membranous cytoplasmic aggregates of mRNAs and related proteins, assembled in response to environmental stresses such as heat shock, hypoxia, endoplasmic reticulum (ER stress, chemicals (e.g. arsenite, and viral infections. SGs are hypothesized as a loci of mRNA triage and/or maintenance of proper translation capacity ratio to the pool of mRNAs. In brain ischemia, hippocampal CA3 neurons, which are resilient to ischemia, assemble SGs. In contrast, CA1 neurons, which are vulnerable to ischemia, do not assemble SGs. These results suggest a critical role SG plays in regards to cell fate decisions. Thus SG assembly along with its dynamics should determine the cell fate. However, the process that exactly determines the SG assembly dynamics is largely unknown. In this paper, analyses of experimental data and computer simulations were used to approach this problem. SGs were assembled as a result of applying arsenite to HeLa cells. The number of SGs increased after a short latent period, reached a maximum, then decreased during the application of arsenite. At the same time, the size of SGs grew larger and became localized at the perinuclear region. A minimal mathematical model was constructed, and stochastic simulations were run to test the modeling. Since SGs are discrete entities as there are only several tens of them in a cell, commonly used deterministic simulations could not be employed. The stochastic simulations replicated observed dynamics of SG assembly. In addition, these stochastic simulations predicted a gamma distribution relative to the size of SGs. This same distribution was also found in our experimental data suggesting the existence of multiple fusion steps in the SG assembly. Furthermore, we found that the initial steps in the SG assembly process and microtubules were critical to the dynamics. Thus our experiments and stochastic simulations presented a possible mechanism regulating SG assembly.

  1. Selecting Operations for Assembler Encoding

    Directory of Open Access Journals (Sweden)

    Tomasz Praczyk

    2010-04-01

    Full Text Available Assembler Encoding is a neuro-evolutionary method in which a neural network is represented in the form of a simple program called Assembler Encoding Program. The task of the program is to create the so-called Network Definition Matrix which maintains all the information necessary to construct the network. To generate Assembler Encoding Programs and the subsequent neural networks evolutionary techniques are used.
    The performance of Assembler Encoding strongly depends on operations used in Assembler Encoding Programs. To select the most effective operations, experiments in the optimization and the predator-prey problem were carried out. In the experiments, Assembler Encoding Programs equipped with different types of operations were tested. The results of the tests are presented at the end of the paper.

  2. Gas separation membrane module assembly

    Science.gov (United States)

    Wynn, Nicholas P [Palo Alto, CA; Fulton, Donald A [Fairfield, CA

    2009-03-31

    A gas-separation membrane module assembly and a gas-separation process using the assembly. The assembly includes a set of tubes, each containing gas-separation membranes, arranged within a housing. The housing contains a tube sheet that divides the space within the housing into two gas-tight spaces. A permeate collection system within the housing gathers permeate gas from the tubes for discharge from the housing.

  3. Integral nuclear fuel element assembly

    International Nuclear Information System (INIS)

    Schluderberg, D. C.

    1985-01-01

    An integral nuclear fuel element assembly utilizes longitudinally finned fuel pins. The continuous or interrupted fins of the fuel pins are brazed to fins of juxtaposed fuel pins or directly to the juxtaposed fuel pins or both. The integrally brazed fuel assembly is designed to satisfy the thermal and hydraulic requirements of a fuel assembly lattice having moderator to fuel atom ratios required to achieve high conversion and breeding ratios

  4. Fuel assembly and reactor core

    International Nuclear Information System (INIS)

    Aoyama, Motoo; Koyama, Jun-ichi; Uchikawa, Sadao; Bessho, Yasunori; Nakajima, Akiyoshi; Maruyama, Hiromi; Ozawa, Michihiro; Nakamura, Mitsuya.

    1990-01-01

    The present invention concerns fuel assemblies charged in a BWR type reactor and the reactor core. The fuel assembly comprises fuel rods containing burnable poisons and fuel rods not containing burnable poisons. Both of the highest and the lowest gadolinia concentrations of the fuel rods containing gadolinia as burnable poisons are present in the lower region of the fuel assembly. This can increase the spectral shift effect without increasing the maximum linear power density. (I.N.)

  5. Rocket Assembly and Checkout Facility

    Data.gov (United States)

    Federal Laboratory Consortium — FUNCTION: Integrates, tests, and calibrates scientific instruments flown on sounding rocket payloads. The scientific instruments are assembled on an optical bench;...

  6. Assembly of the PLT device

    International Nuclear Information System (INIS)

    Marino, R.

    1975-11-01

    The assembly of the PLT device began in June 1974 with a preassembly of the mechanical structure at a remote site. The preassembly sequence incorporated final fabrication procedures with an initial staging operation. This successful staging/fabrication procedure proved to be an invaluable asset when the final assembly was started in August 1974. The assembly continued with the initial reassembly of the previously tested structural components at the final machine site. Construction was interrupted at several points to allow for toroidal field coil, vacuum vessel, and poloidal coil installation. Two phases of toroidal field coil power tests were included in the assembly sequence prior to, and just after the vacuum vessel insertion

  7. Next-generation transcriptome assembly

    Energy Technology Data Exchange (ETDEWEB)

    Martin, Jeffrey A.; Wang, Zhong

    2011-09-01

    Transcriptomics studies often rely on partial reference transcriptomes that fail to capture the full catalog of transcripts and their variations. Recent advances in sequencing technologies and assembly algorithms have facilitated the reconstruction of the entire transcriptome by deep RNA sequencing (RNA-seq), even without a reference genome. However, transcriptome assembly from billions of RNA-seq reads, which are often very short, poses a significant informatics challenge. This Review summarizes the recent developments in transcriptome assembly approaches - reference-based, de novo and combined strategies-along with some perspectives on transcriptome assembly in the near future.

  8. Seismic behaviour of fuel assembly

    Energy Technology Data Exchange (ETDEWEB)

    Song, Heuy Gap; Jhung, Myung Jo [Korea Atomic Energy Research Institute, Taejon (Korea, Republic of)

    1993-11-01

    A general approach for the dynamic time-history analysis of the reactor core is presented in this paper as a part of the fuel assembly qualification program. Several detailed core models are set up to reflect the placement of the fuel assemblies within the core shroud. Peak horizontal responses are obtained for each model for the motions induced from earthquake. The dynamic responses such as fuel assembly shear force, bending moment and displacement, and spacer grid impact loads are carefully investigated. Also, the sensitivity responses are obtained for the earthquake motions and the fuel assembly non-linear response characteristics are discussed. (Author) 9 refs., 24 figs., 1 tab.

  9. Airfoil nozzle and shroud assembly

    Science.gov (United States)

    Shaffer, J.E.; Norton, P.F.

    1997-06-03

    An airfoil and nozzle assembly are disclosed including an outer shroud having a plurality of vane members attached to an inner surface and having a cantilevered end. The assembly further includes a inner shroud being formed by a plurality of segments. Each of the segments having a first end and a second end and having a recess positioned in each of the ends. The cantilevered end of the vane member being positioned in the recess. The airfoil and nozzle assembly being made from a material having a lower rate of thermal expansion than that of the components to which the airfoil and nozzle assembly is attached. 5 figs.

  10. The unique organization of filamentous actin in the medullary canal of the medulla oblongata.

    Science.gov (United States)

    Tan, Bai-Hong; Guo, Chun-Yan; Xiong, Tian-Qing; Chen, Ling-Meng; Li, Yan-Chao

    2017-04-01

    In the central canal, F-actin is predominantly localized in the apical region, forming a ring-like structure around the circumference of the lumen. However, an exception is found in the medulla oblongata, where the apical F-actin becomes interrupted in the ventral aspect of the canal. To clarify the precise localization of F-actin, the fluorescence signals for F-actin were converted to the peroxidase/DAB reaction products in this study by a phalloidin-based ultrastructural technique, which demonstrated that F-actin is located mainly in the microvilli and terminal webs in the ependymocytes. It is because the ventrally oriented ependymocytes do not possess well-developed microvilli or terminal web that led to a discontinuous labeling of F-actin in the medullary canal. Since spinal motions can change the shape and size of the central canal, we next examined the cytoskeletons in the medullary canal in both rats and monkeys, because these two kinds of animals show different kinematics at the atlanto-occipital articulation. Our results first demonstrated that the apical F-actin in the medullary canal is differently organized in the animals with different head-neck kinemics, which suggests that the mechanic stretching of spinal motions is capable of inducing F-actin reorganization and the subsequent cell-shape changes in the central canal. Copyright © 2017 Elsevier Ltd. All rights reserved.

  11. Precise Truss Assembly Using Commodity Parts and Low Precision Welding

    Science.gov (United States)

    Komendera, Erik; Reishus, Dustin; Dorsey, John T.; Doggett, W. R.; Correll, Nikolaus

    2014-01-01

    Hardware and software design and system integration for an intelligent precision jigging robot (IPJR), which allows high precision assembly using commodity parts and low-precision bonding, is described. Preliminary 2D experiments that are motivated by the problem of assembling space telescope optical benches and very large manipulators on orbit using inexpensive, stock hardware and low-precision welding are also described. An IPJR is a robot that acts as the precise "jigging", holding parts of a local structure assembly site in place, while an external low precision assembly agent cuts and welds members. The prototype presented in this paper allows an assembly agent (for this prototype, a human using only low precision tools), to assemble a 2D truss made of wooden dowels to a precision on the order of millimeters over a span on the order of meters. The analysis of the assembly error and the results of building a square structure and a ring structure are discussed. Options for future work, to extend the IPJR paradigm to building in 3D structures at micron precision are also summarized.

  12. Improved de novo genomic assembly for the domestic donkey

    Science.gov (United States)

    Newton, Richard; Paillot, Romain; Bryant, Neil; Vaudin, Mark

    2018-01-01

    Donkeys and horses share a common ancestor dating back to about 4 million years ago. Although a high-quality genome assembly at the chromosomal level is available for the horse, current assemblies available for the donkey are limited to moderately sized scaffolds. The absence of a better-quality assembly for the donkey has hampered studies involving the characterization of patterns of genetic variation at the genome-wide scale. These range from the application of genomic tools to selective breeding and conservation to the more fundamental characterization of the genomic loci underlying speciation and domestication. We present a new high-quality donkey genome assembly obtained using the Chicago HiRise assembly technology, providing scaffolds of subchromosomal size. We make use of this new assembly to obtain more accurate measures of heterozygosity for equine species other than the horse, both genome-wide and locally, and to detect runs of homozygosity potentially pertaining to positive selection in domestic donkeys. Finally, this new assembly allowed us to identify fine-scale chromosomal rearrangements between the horse and the donkey that likely played an active role in their divergence and, ultimately, speciation. PMID:29740610

  13. Improved de novo genomic assembly for the domestic donkey.

    Science.gov (United States)

    Renaud, Gabriel; Petersen, Bent; Seguin-Orlando, Andaine; Bertelsen, Mads Frost; Waller, Andrew; Newton, Richard; Paillot, Romain; Bryant, Neil; Vaudin, Mark; Librado, Pablo; Orlando, Ludovic

    2018-04-01

    Donkeys and horses share a common ancestor dating back to about 4 million years ago. Although a high-quality genome assembly at the chromosomal level is available for the horse, current assemblies available for the donkey are limited to moderately sized scaffolds. The absence of a better-quality assembly for the donkey has hampered studies involving the characterization of patterns of genetic variation at the genome-wide scale. These range from the application of genomic tools to selective breeding and conservation to the more fundamental characterization of the genomic loci underlying speciation and domestication. We present a new high-quality donkey genome assembly obtained using the Chicago HiRise assembly technology, providing scaffolds of subchromosomal size. We make use of this new assembly to obtain more accurate measures of heterozygosity for equine species other than the horse, both genome-wide and locally, and to detect runs of homozygosity potentially pertaining to positive selection in domestic donkeys. Finally, this new assembly allowed us to identify fine-scale chromosomal rearrangements between the horse and the donkey that likely played an active role in their divergence and, ultimately, speciation.

  14. Superlattices assembled through shape-induced directional binding

    Science.gov (United States)

    Lu, Fang; Yager, Kevin G.; Zhang, Yugang; Xin, Huolin; Gang, Oleg

    2015-04-01

    Organization of spherical particles into lattices is typically driven by packing considerations. Although the addition of directional binding can significantly broaden structural diversity, nanoscale implementation remains challenging. Here we investigate the assembly of clusters and lattices in which anisotropic polyhedral blocks coordinate isotropic spherical nanoparticles via shape-induced directional interactions facilitated by DNA recognition. We show that these polyhedral blocks--cubes and octahedrons--when mixed with spheres, promote the assembly of clusters with architecture determined by polyhedron symmetry. Moreover, three-dimensional binary superlattices are formed when DNA shells accommodate the shape disparity between nanoparticle interfaces. The crystallographic symmetry of assembled lattices is determined by the spatial symmetry of the block's facets, while structural order depends on DNA-tuned interactions and particle size ratio. The presented lattice assembly strategy, exploiting shape for defining the global structure and DNA-mediation locally, opens novel possibilities for by-design fabrication of binary lattices.

  15. Automated optical assembly

    Science.gov (United States)

    Bala, John L.

    1995-08-01

    Automation and polymer science represent fundamental new technologies which can be directed toward realizing the goal of establishing a domestic, world-class, commercial optics business. Use of innovative optical designs using precision polymer optics will enable the US to play a vital role in the next generation of commercial optical products. The increased cost savings inherent in the utilization of optical-grade polymers outweighs almost every advantage of using glass for high volume situations. Optical designers must gain experience with combined refractive/diffractive designs and broaden their knowledge base regarding polymer technology beyond a cursory intellectual exercise. Implementation of a fully automated assembly system, combined with utilization of polymer optics, constitutes the type of integrated manufacturing process which will enable the US to successfully compete with the low-cost labor employed in the Far East, as well as to produce an equivalent product.

  16. Fuel sub-assembly

    International Nuclear Information System (INIS)

    Jolly, R.

    1988-01-01

    A nuclear fuel sub-assembly includes a hexagonal bundle of parallel, spaced apart fuel pins coupled at one end to an end-holding grid comprising a number of transverse spaced apart rails to each of which is connected a series of pin-receiving cells which render the pins axially captive with the rails. The series of cells are defined by a pair of metal strips each of which has a series of pocket formations such that when the pocket formations are in registry they define cylindrical shaped cells provided with internal projections which engage annular recesses in the end caps of the fuel pins to effect axial constraint of the pins. (author)

  17. Ultrasonic calibration assembly

    International Nuclear Information System (INIS)

    1981-01-01

    Ultrasonic transducers for in-service inspection of nuclear reactor vessels have several problems associated with them which this invention seeks to overcome. The first is that of calibration or referencing a zero start point for the vertical axis of transducer movement to locate a weld defect. The second is that of verifying the positioning (vertically or at a predetermined angle). Thirdly there is the problem of ascertaining the speed per unit distance in the operating medium of the transducer beam prior to the actual inspection. The apparatus described is a calibration assembly which includes a fixed, generally spherical body having a surface for reflecting an ultrasonic beam from one of the transducers which can be moved until the reflection from the spherical body is the highest amplitude return signal indicating radial alignment from the body. (U.K.)

  18. Rotatable seal assembly

    International Nuclear Information System (INIS)

    Garibaldi, J.L.; Logan, C.M.

    1982-01-01

    An assembly is provided for rotatably supporting a rotor on a stator so that vacuum chambers in the rotor and stator remain in communication while the chambers are sealed from ambient air, which enables the use of a ball bearing or the like to support most of the weight of the rotor. The apparatus includes a seal device mounted on the rotor to rotate therewith, but shiftable in position on the rotor while being sealed to the rotor as by an oring. The seal device has a flat face that is biased towards a flat face on the stator, and pressurized air is pumped between the faces to prevent contact between them while spacing them a small distance apart to avoid the inflow of large amounts of air between the faces and into the vacuum chambers

  19. Reactor fuel assembly fastening

    International Nuclear Information System (INIS)

    Formanek, F.J.; Schukei, G.E.

    1980-01-01

    A nuclear fuel assembly is described, adapted to be locked into first mating surfaces on a core support stand, comprising a lower end fitting having posts for resting on the stand; elongated hook members pivotally connected at one end to the lower end fitting and having a second mating surface at the other end to engage the first mating surfaces; actuating means located between the posts on the lower end fitting and being vertically movable relative to the end fitting; and rigid links pivotally attached at one end to the hook members intermediate the connection of the hook members to the end fitting and the second mating surface and pivotally attached at the other end to the actuating means, the link having a length between the pivoted connections such that the second mating surface on the hook members locks into engagement with the first mating surfaces on the stand as the links approach the horizontal. (author)

  20. Nuclear fuel assembly

    International Nuclear Information System (INIS)

    Borrman, B.; Nylund, O.

    1984-01-01

    A fuel assembly with a fuel channel which surrounds a plurality of fuel rods and which is divided, by means of a stiffening device of cruciform cross-section and four wings, into four sub-channels each of which comprises a bundle of fuel rods. Each fuel channel side has a plurality of stamped, inwardly-directed projections, arranged vertically one after the other, aid projections being welded to one and the same stiffening wing. Each one of the wall portions located between the projections defines, together with two adjacently positioned projections and a portion of the stiffening wing, a communiation opening between two bundles located on on one side each of the stiffening wing. (Author)

  1. Nuclear fuel assembly

    International Nuclear Information System (INIS)

    Wakamatsu, Mitsuo.

    1974-01-01

    Object: To improve a circulating flow passage of coolant so as to be able to accurately detect the temperature of coolant, rare gases contained, and the like. Structure: A fuel assembly comprising a flow regulating lattice provided with a plurality of communication holes in an axial direction, said lattice being positioned at the upper end of an outer tube in which nuclear fuel elements are received, and a neutron shielding body having a plurality of spiral coolant flow passages disposed between the lattice and the nuclear fuel elements, whereby a coolant comprised of liquid sodium or the like, which moves up passing through the coolant flow passages and the flow regulating passage, is regulated and passed through a detector mounted at the upper part of the flow regulating lattice to detect coolant temperature, flow rate, and rare gases or the like as the origin of nuclear fission contained in the coolant due to breakage of fuel elements. (Kamimura, M.)

  2. Nuclear reactor assembly

    International Nuclear Information System (INIS)

    Dorner, H.; Scholz, M.; Jungmann, A.

    1975-01-01

    A nuclear reactor assembly includes a reactor pressure tank having a substantially cylindrical side wall surrounded by the wall of a cylindrical cavity formed by a biological shield. A rotative cylindrical wall is interposed between the walls and has means for rotating it from outside of the shield, and a probe is carried by the rotative wall for monitoring the pressure tank's wall. The probe is vertically movable relative to the rotative cylindrical wall, so that by the probe's vertical movement and rotation of the rotative cylinder, the reactor's wall can be very extensively monitored. If the reactor pressure tank's wall fails, it is contained by the rotative wall which is backed-up by the shield cavity wall. (Official Gazette)

  3. Subcritical nuclear assembly

    International Nuclear Information System (INIS)

    Vega C, H. R.

    2014-08-01

    A Subcritical Nuclear Assembly is a device where the nuclear-fission chain reaction is initiated and maintained using an external neutron source. It is a valuable educational and research tool where in a safe way many reactor parameters can be measured. Here, we have used the Wigner-Seitz method in the six-factor formula to calculate the effective multiplication factor of a subcritical nuclear reactor Nuclear Chicago model 9000. This reactor has approximately 2500 kg of natural uranium heterogeneously distributed in slugs. The reactor uses a 239 PuBe neutron source that is located in the center of an hexagonal array. Using Monte Carlo methods, with the MCNP5 code, a three-dimensional model of the subcritical reactor was designed to estimate the effective multiplication factor, the neutron spectra, the total and thermal neutron fluences along the radial and axial axis. With the neutron spectra in two locations outside the reactor the ambient dose equivalent were estimated. (Author)

  4. Reconfigurable assembly work station

    Energy Technology Data Exchange (ETDEWEB)

    Lin, Yhu-Tin; Abell, Jeffrey A.; Spicer, John Patrick

    2017-11-14

    A reconfigurable autonomous workstation includes a multi-faced superstructure including a horizontally-arranged frame section supported on a plurality of posts. The posts form a plurality of vertical faces arranged between adjacent pairs of the posts, the faces including first and second faces and a power distribution and position reference face. A controllable robotic arm suspends from the rectangular frame section, and a work table fixedly couples to the power distribution and position reference face. A plurality of conveyor tables are fixedly coupled to the work table including a first conveyor table through the first face and a second conveyor table through the second face. A vision system monitors the work table and each of the conveyor tables. A programmable controller monitors signal inputs from the vision system to identify and determine orientation of the component on the first conveyor table and control the robotic arm to execute an assembly task.

  5. Multivalent protein assembly using monovalent self-assembling building blocks

    NARCIS (Netherlands)

    Petkau - Milroy, K.; Sonntag, M.H.; Colditz, A.; Brunsveld, L.

    2013-01-01

    Discotic molecules, which self-assemble in water into columnar supramolecular polymers, emerged as an alternative platform for the organization of proteins. Here, a monovalent discotic decorated with one single biotin was synthesized to study the self-assembling multivalency of this system in regard

  6. Method and apparatus for assembling a permanent magnet pole assembly

    Science.gov (United States)

    Carl, Jr., Ralph James; Bagepalli, Bharat Sampathkumaran [Niskayuna, NY; Jansen, Patrick Lee [Scotia, NY; Dawson, Richard Nils [Voorheesville, NY; Qu, Ronghai [Clifton Park, NY; Avanesov, Mikhail Avramovich [Moscow, RU

    2009-08-11

    A pole assembly for a rotor, the pole assembly includes a permanent magnet pole including at least one permanent magnet block, a plurality of laminations including a pole cap mechanically coupled to the pole, and a plurality of laminations including a base plate mechanically coupled to the pole.

  7. Self-assembly of self-assembled molecular triangles

    Indian Academy of Sciences (India)

    While the solution state structure of 1 can be best described as a trinuclear complex, in the solidstate well-fashioned intermolecular - and CH- interactions are observed. Thus, in the solid-state further self-assembly of already self-assembled molecular triangle is witnessed. The triangular panels are arranged in a linear ...

  8. Cooperative effects of fibronectin matrix assembly and initial cell-substrate adhesion strength in cellular self-assembly.

    Science.gov (United States)

    Brennan, James R; Hocking, Denise C

    2016-03-01

    The cell-dependent polymerization of intercellular fibronectin fibrils can stimulate cells to self-assemble into multicellular structures. The local physical cues that support fibronectin-mediated cellular self-assembly are largely unknown. Here, fibronectin matrix analogs were used as synthetic adhesive substrates to model cell-matrix fibronectin fibrils having different integrin-binding specificity, affinity, and/or density. We utilized this model to quantitatively assess the relationship between adhesive forces derived from cell-substrate interactions and the ability of fibronectin fibril assembly to induce cellular self-assembly. Results indicate that the strength of initial, rather than mature, cell-substrate attachments correlates with the ability of substrates to support fibronectin-mediated cellular self-assembly. The cellular response to soluble fibronectin was bimodal and independent of the integrin-binding specificity of the substrate; increasing soluble fibronectin levels above a critical threshold increased aggregate cohesion on permissive substrates. Once aggregates formed, continuous fibronectin polymerization was necessary to maintain cohesion. During self-assembly, soluble fibronectin decreased cell-substrate adhesion strength and induced aggregate cohesion via a Rho-dependent mechanism, suggesting that the balance of contractile forces derived from fibronectin fibrils within cell-cell versus cell-substrate adhesions controls self-assembly and aggregate cohesion. Thus, initial cell-substrate attachment strength may provide a quantitative basis with which to build predictive models of fibronectin-mediated microtissue fabrication on a variety of substrates. Cellular self-assembly is a process by which cells and extracellular matrix (ECM) proteins spontaneously organize into three-dimensional (3D) tissues in the absence of external forces. Cellular self-assembly can be initiated in vitro, and represents a potential tool for tissue engineers to

  9. Local food:

    DEFF Research Database (Denmark)

    Sundbo, Donna Isabella Caroline

    2013-01-01

    are identified and then categorised according to whether they pertain to the food product itself or the production methods and facilities and whether they describe physical or social properties of local food. From this a model with four categories is developed. It is found that properties of the product are more......Recently there has been more focus on food in general and local food in particular. But what is local food? And what are the perceptions of this concept according to theory and to providers and consumers of local food? This article first summarises and compares three different theoretical...... perspectives on local food, namely experience economy, local food systems and what is termed pro-industrialism. These have differing and sometimes opposite conceptualisations and aims for the concept of local food. Using the perspective of experience economy as theoretical background, the concept of local food...

  10. Evaluation of GRCh38 and de novo haploid genome assemblies demonstrates the enduring quality of the reference assembly.

    Science.gov (United States)

    Schneider, Valerie A; Graves-Lindsay, Tina; Howe, Kerstin; Bouk, Nathan; Chen, Hsiu-Chuan; Kitts, Paul A; Murphy, Terence D; Pruitt, Kim D; Thibaud-Nissen, Françoise; Albracht, Derek; Fulton, Robert S; Kremitzki, Milinn; Magrini, Vincent; Markovic, Chris; McGrath, Sean; Steinberg, Karyn Meltz; Auger, Kate; Chow, William; Collins, Joanna; Harden, Glenn; Hubbard, Timothy; Pelan, Sarah; Simpson, Jared T; Threadgold, Glen; Torrance, James; Wood, Jonathan M; Clarke, Laura; Koren, Sergey; Boitano, Matthew; Peluso, Paul; Li, Heng; Chin, Chen-Shan; Phillippy, Adam M; Durbin, Richard; Wilson, Richard K; Flicek, Paul; Eichler, Evan E; Church, Deanna M

    2017-05-01

    The human reference genome assembly plays a central role in nearly all aspects of today's basic and clinical research. GRCh38 is the first coordinate-changing assembly update since 2009; it reflects the resolution of roughly 1000 issues and encompasses modifications ranging from thousands of single base changes to megabase-scale path reorganizations, gap closures, and localization of previously orphaned sequences. We developed a new approach to sequence generation for targeted base updates and used data from new genome mapping technologies and single haplotype resources to identify and resolve larger assembly issues. For the first time, the reference assembly contains sequence-based representations for the centromeres. We also expanded the number of alternate loci to create a reference that provides a more robust representation of human population variation. We demonstrate that the updates render the reference an improved annotation substrate, alter read alignments in unchanged regions, and impact variant interpretation at clinically relevant loci. We additionally evaluated a collection of new de novo long-read haploid assemblies and conclude that although the new assemblies compare favorably to the reference with respect to continuity, error rate, and gene completeness, the reference still provides the best representation for complex genomic regions and coding sequences. We assert that the collected updates in GRCh38 make the newer assembly a more robust substrate for comprehensive analyses that will promote our understanding of human biology and advance our efforts to improve health. © 2017 Schneider et al.; Published by Cold Spring Harbor Laboratory Press.

  11. Local Content

    CSIR Research Space (South Africa)

    Gibberd, Jeremy

    2016-10-01

    Full Text Available Local content refers to materials and products made in a country as opposed those that are imported. There is an increasing interest in the concept of local content as a means of supporting local economies and providing jobs (Belderbos & Sleuwaegen...

  12. Octanol-assisted liposome assembly on chip

    Science.gov (United States)

    Deshpande, Siddharth; Caspi, Yaron; Meijering, Anna E. C.; Dekker, Cees

    2016-01-01

    Liposomes are versatile supramolecular assemblies widely used in basic and applied sciences. Here we present a novel microfluidics-based method, octanol-assisted liposome assembly (OLA), to form monodisperse, cell-sized (5-20 μm), unilamellar liposomes with excellent encapsulation efficiency. Akin to bubble blowing, an inner aqueous phase and a surrounding lipid-carrying 1-octanol phase is pinched off by outer fluid streams. Such hydrodynamic flow focusing results in double-emulsion droplets that spontaneously develop a side-connected 1-octanol pocket. Owing to interfacial energy minimization, the pocket splits off to yield fully assembled solvent-free liposomes within minutes. This solves the long-standing fundamental problem of prolonged presence of residual oil in the liposome bilayer. We demonstrate the unilamellarity of liposomes with functional α-haemolysin protein pores in the membrane and validate the biocompatibility by inner leaflet localization of bacterial divisome proteins (FtsZ and ZipA). OLA offers a versatile platform for future analytical tools, delivery systems, nanoreactors and synthetic cells.

  13. Moisture Research - Optimizing Wall Assemblies

    Energy Technology Data Exchange (ETDEWEB)

    Arena, L.; Mantha, P.

    2013-05-01

    The Consortium for Advanced Residential Buildings (CARB) evaluated several different configurations of wall assemblies to determine the accuracy of moisture modeling and make recommendations to ensure durable, efficient assemblies. WUFI and THERM were used to model the hygrothermal and heat transfer characteristics of these walls.

  14. Fuel cell sub-assembly

    Science.gov (United States)

    Chi, Chang V.

    1983-01-01

    A fuel cell sub-assembly comprising a plurality of fuel cells, a first section of a cooling means disposed at an end of the assembly and means for connecting the fuel cells and first section together to form a unitary structure.

  15. Newnes electronics assembly pocket book

    CERN Document Server

    Brindley, Keith

    2013-01-01

    Produced in association with the Engineering Training Authority with contributions from dozens of people in the electronics industry. The material covers common skills in electrical and electronic engineering and concentrates mainly on wiring and assembly. 'Newnes Electronics Assembly Pocket Book' is for electronics technicians, students and apprentices.

  16. A Theoretical and Experimental Study of DNA Self-assembly

    Science.gov (United States)

    Chandran, Harish

    The control of matter and phenomena at the nanoscale is fast becoming one of the most important challenges of the 21st century with wide-ranging applications from energy and health care to computing and material science. Conventional top-down approaches to nanotechnology, having served us well for long, are reaching their inherent limitations. Meanwhile, bottom-up methods such as self-assembly are emerging as viable alternatives for nanoscale fabrication and manipulation. A particularly successful bottom up technique is DNA self-assembly where a set of carefully designed DNA strands form a nanoscale object as a consequence of specific, local interactions among the different components, without external direction. The final product of the self-assembly process might be a static nanostructure or a dynamic nanodevice that performs a specific function. Over the past two decades, DNA self-assembly has produced stunning nanoscale objects such as 2D and 3D lattices, polyhedra and addressable arbitrary shaped substrates, and a myriad of nanoscale devices such as molecular tweezers, computational circuits, biosensors and molecular assembly lines. In this dissertation we study multiple problems in the theory, simulations and experiments of DNA self-assembly. We extend the Turing-universal mathematical framework of self-assembly known as the Tile Assembly Model by incorporating randomization during the assembly process. This allows us to reduce the tile complexity of linear assemblies. We develop multiple techniques to build linear assemblies of expected length N using far fewer tile types than previously possible. We abstract the fundamental properties of DNA and develop a biochemical system, which we call meta-DNA, based entirely on strands of DNA as the only component molecule. We further develop various enzyme-free protocols to manipulate meta-DNA systems and provide strand level details along with abstract notations for these mechanisms. We simulate DNA circuits by

  17. Advanced gray rod control assembly

    Science.gov (United States)

    Drudy, Keith J; Carlson, William R; Conner, Michael E; Goldenfield, Mark; Hone, Michael J; Long, Jr., Carroll J; Parkinson, Jerod; Pomirleanu, Radu O

    2013-09-17

    An advanced gray rod control assembly (GRCA) for a nuclear reactor. The GRCA provides controlled insertion of gray rod assemblies into the reactor, thereby controlling the rate of power produced by the reactor and providing reactivity control at full power. Each gray rod assembly includes an elongated tubular member, a primary neutron-absorber disposed within the tubular member said neutron-absorber comprising an absorber material, preferably tungsten, having a 2200 m/s neutron absorption microscopic capture cross-section of from 10 to 30 barns. An internal support tube can be positioned between the primary absorber and the tubular member as a secondary absorber to enhance neutron absorption, absorber depletion, assembly weight, and assembly heat transfer characteristics.

  18. Method of transporting fuel assemblies

    International Nuclear Information System (INIS)

    Okada, Katsutoshi.

    1979-01-01

    Purpose: To enable safety transportation of fuel assemblies for FBR type reactors by surrounding each of fuel elements in a wrapper tube by a rubbery, hollow cylindrical container and by sealing medium such as air to the inside of the container. Method: A fuel element is contained in a hollow cylindrical rubber-like tube. The fuel element has an upper end plug, a lower end plug and a wire spirally wound around the outer periphery. Upon transportation of the fuel assemblies, each of the fuel elements is covered with the container and arranged in the wrapper tube and then the fuel assemblies are assembled. Then, medium such as air is sealed for each of the fuel elements by way of an opening and then the opening is tightly closed. Before loading the transported fuel assemblies in the reactor, the medium is discharged through the opening and the container is completely extracted and removed from the inside of the wrapper tube. (Seki, T.)

  19. Pattern Driven Stress Localization

    Science.gov (United States)

    Croll, Andrew; Crosby, Alfred

    2010-03-01

    The self-assembly of patterns from isotropic initial states is a major driver of modern soft-matter research. This avenue of study is directed by the desire to understand the complex physics of the varied structures found in Nature, and by technological interest in functional materials that may be derived through biomimicry. In this work we show how a simple striped phase can respond with significant complexity to an appropriately chosen perturbation. In particular, we show how a buckled elastic plate transitions into a state of stress localization using a simple, self-assembled variation in surface topography. The collection of topographic boundaries act in concert to change the state from isotropic sinusoidal wrinkles, to sharp folds or creases separated by relatively flat regions. By varying the size of the imposed topographic pattern or the wavelength of the wrinkles, we construct a state diagram of the system. The localized state has implications for both biological systems, and for the control of non-linear pattern formation.

  20. ASSEMBLY TRANSFER SYSTEM DESCRIPTION DOCUMENT

    International Nuclear Information System (INIS)

    Gorpani, B.

    2000-01-01

    The Assembly Transfer System (ATS) receives, cools, and opens rail and truck transportation casks from the Carrier/Cask Handling System (CCHS). The system unloads transportation casks consisting of bare Spent Nuclear Fuel (SNF) assemblies, single element canisters, and Dual Purpose Canisters (DPCs). For casks containing DPCs, the system opens the DPCs and unloads the SNF. The system stages the assemblies, transfer assemblies to and from fuel-blending inventory pools, loads them into Disposal Containers (DCs), temporarily seals and inerts the DC, decontaminates the DC and transfers it to the Disposal Container Handling System. The system also prepares empty casks and DPCs for off-site shipment. Two identical Assembly Transfer System lines are provided in the Waste Handling Building (WHB). Each line operates independently to handle the waste transfer throughput and to support maintenance operations. Each system line primarily consists of wet and dry handling areas. The wet handling area includes a cask transport system, cask and DPC preparation system, and a wet assembly handling system. The basket transport system forms the transition between the wet and dry handling areas. The dry handling area includes the dry assembly handling system, assembly drying system, DC preparation system, and DC transport system. Both the wet and dry handling areas are controlled by the control and tracking system. The system operating sequence begins with moving transportation casks to the cask preparation area. The cask preparation operations consist of cask cavity gas sampling, cask venting, cask cool-down, outer lid removal, and inner shield plug lifting fixture attachment. Casks containing bare SNF (no DPC) are filled with water and placed in the cask unloading pool. The inner shield plugs are removed underwater. For casks containing a DPC, the cask lid(s) is removed, and the DPC is penetrated, sampled, vented, and cooled. A DPC lifting fixture is attached and the cask is placed

  1. Nuclear fuel assemblies and fuel pins usable in such assemblies

    International Nuclear Information System (INIS)

    Jolly, R.

    1982-01-01

    A novel end cap for a nuclear fuel assembly is described in detail. It consists of a trisection arrangement which is received within a cell of a cellular grid. The cell contains abutment means with which the trisection comes into abutment. The grid also contains an abutment means for preventing the trisections from being inserted into the cell in an incorrect orientation. The present design allows fuel pins to be securely held in a hold-down grid of a sub-assembly. The design also allows easier dis-assembly of the swollen and embrittled fuel pins prior to reprocessing. (U.K.)

  2. ITER assembly and maintenance

    International Nuclear Information System (INIS)

    Honda, T.; Davis, F.; Lousteau, D.

    1991-01-01

    This document is intended to describe the work conducted by the ITER Assembly and Maintenance (A and M) Design Unit and the supporting home teams during the ITER Conceptual Design Activities, carried out from 1988 through 1990. Its content consists of two main sections, i.e., Chapter III, which describes the identified tasks to be performed by the A and M system and a general description of the required equipment; and Chapter IV, which provides a more detailed description of the equipment proposed to perform the assigned tasks. A two-stage R and D program is now planned, i.e., (1) a prototype equipment functional tests using full scale mock-ups and (2) a full scale integration demonstration test facility with real components (vacuum vessel with ports, blanket modules, divertor modules, armor tiles, etc.). Crucial in-vessel and ex-vessel operations and the associated remote handling equipment, including handling of divertor plates and blanket modules will be demonstrated in the first phase, whereby the database needed to proceed with the engineering phase will be acquired. The second phase will demonstrate the ability of the overall system to execute the required maintenance procedures and evaluate the performance of the prototype equipment

  3. Nuclear fuel assembly

    International Nuclear Information System (INIS)

    Hirano, Yasushi; Hirukawa, Koji; Sakurada, Koichi.

    1994-01-01

    A bundle of fuel rods is divided into four fuel rod group regions of small fuel rod bundles by a cross-shaped partitioning structure consisting of paired plate-like structures which connect two opposing surfaces of a channel box. A water removing material with less neutron absorption (for example, Zr or a Zr alloy) or a solid moderator is inserted and secured to a portion of a non-boiling water region interposed between the paired plate-like structure. It has a structure that light water flows to the region in the plate-like structure. The volume, density or composition of the water removing material is controlled depending on the composition of the fuels, to change the moderating characteristics of neutrons in the non-boiling water region. This can easily moderate the difference of nuclear characteristics between each of fuel assemblies using fuel materials of different fuel compositions. Further, the reactivity control effect of the burnable poisons can be enhanced without worsening fuel economy or linear power density. (I.N.)

  4. Subcritical nuclear assembly

    Energy Technology Data Exchange (ETDEWEB)

    Vega C, H. R., E-mail: fermineutron@yahoo.com [Universidad Autonoma de Zacatecas, Unidad Academica de Estudios Nucleares, Cipres No. 10, Fracc. La Penuela, 98068 Zacatecas (Mexico)

    2014-08-15

    A Subcritical Nuclear Assembly is a device where the nuclear-fission chain reaction is initiated and maintained using an external neutron source. It is a valuable educational and research tool where in a safe way many reactor parameters can be measured. Here, we have used the Wigner-Seitz method in the six-factor formula to calculate the effective multiplication factor of a subcritical nuclear reactor Nuclear Chicago model 9000. This reactor has approximately 2500 kg of natural uranium heterogeneously distributed in slugs. The reactor uses a {sup 239}PuBe neutron source that is located in the center of an hexagonal array. Using Monte Carlo methods, with the MCNP5 code, a three-dimensional model of the subcritical reactor was designed to estimate the effective multiplication factor, the neutron spectra, the total and thermal neutron fluences along the radial and axial axis. With the neutron spectra in two locations outside the reactor the ambient dose equivalent were estimated. (Author)

  5. Seed size and provenance mediate the joint effects of disturbance and seed predation on community assembly

    Science.gov (United States)

    John L. Maron; Dean E. Pearson; Teal Potter; Yvette K. Ortega

    2012-01-01

    Local plant community assembly is influenced by a series of filters that affect the recruitment and establishment of species. These filters include regional factors that limit seeds of any given species from reaching a local site as well as local interactions such as post-dispersal seed predation and disturbance, which dictate what species actually establish. How these...

  6. Myosin heavy chain-like localizes at cell contact sites during Drosophila myoblast fusion and interacts in vitro with Rolling pebbles 7

    Energy Technology Data Exchange (ETDEWEB)

    Bonn, Bettina R.; Rudolf, Anja; Hornbruch-Freitag, Christina; Daum, Gabor; Kuckwa, Jessica; Kastl, Lena; Buttgereit, Detlev [Developmental Biology, Department of Biology, Philipps-Universität Marburg, Karl-von-Frisch-Strasse 8, 35037 Marburg (Germany); Renkawitz-Pohl, Renate, E-mail: renkawit@biologie.uni-marburg.de [Developmental Biology, Department of Biology, Philipps-Universität Marburg, Karl-von-Frisch-Strasse 8, 35037 Marburg (Germany)

    2013-02-15

    Besides representing the sarcomeric thick filaments, myosins are involved in many cellular transport and motility processes. Myosin heavy chains are grouped into 18 classes. Here we show that in Drosophila, the unconventional group XVIII myosin heavy chain-like (Mhcl) is transcribed in the mesoderm of embryos, most prominently in founder cells (FCs). An ectopically expressed GFP-tagged Mhcl localizes in the growing muscle at cell–cell contacts towards the attached fusion competent myoblast (FCM). We further show that Mhcl interacts in vitro with the essential fusion protein Rolling pebbles 7 (Rols7), which is part of a protein complex established at cell contact sites (Fusion-restricted Myogenic-Adhesive Structure or FuRMAS). Here, branched F-actin is likely needed to widen the fusion pore and to integrate the myoblast into the growing muscle. We show that the localization of Mhcl is dependent on the presence of Rols7, and we postulate that Mhcl acts at the FuRMAS as an actin motor protein. We further show that Mhcl deficient embryos develop a wild-type musculature. We thus propose that Mhcl functions redundantly to other myosin heavy chains in myoblasts. Lastly, we found that the protein is detectable adjacent to the sarcomeric Z-discs, suggesting an additional function in mature muscles. - Highlights: ► The class XVIII myosin encoding gene Mhcl is transcribed in the mesoderm. ► Mhcl localization at contact sites of fusing myoblasts depends on Rols7. ► Mhcl interacts in vitro with Rols7 which is essential for myogenesis. ► Functional redundancy with other myosins is likely as mutants show no muscle defects. ► Mhcl localizes adjacent to Z-discs of sarcomeres and might support muscle integrity.

  7. Alterative Expression and Localization of Profilin 1/VASPpS157 and Cofilin 1/VASPpS239 Regulates Metastatic Growth and is Modified by DHA Supplementation

    Science.gov (United States)

    Ali, Mehboob; Heyob, Kathryn; Jacob, Naduparambil K.; Rogers, Lynette K.

    2016-01-01

    Profilin 1, cofilin 1, and vasodialator stimulated phosphoprotein (VASP) are actin binding proteins (ABP) which regulate actin remodelling and facilitate cancer cell metastases. MiR~17–92 is highly expressed in metastatic tumors and profilin1 and cofilin1 are predicted targets. Docosahexaenoic acid (DHA) inhibits cancer cell proliferation and adhesion. These studies tested the hypothesis that the metastatic phenotype is driven by changes in ABPs including alternative phosphorylation and/or changes in subcellular localization. Additionally, we tested the efficacy of DHA supplementation to attenuate or inhibit these changes. Human lung cancer tissue sections were analyzed for F-actin content and expression and cellular localization of profilin1, cofilin1 and VASP (S157 or S239 phosphorylation). The metastatic phenotype was investigated in A549 and MLE12 cells lines using 8 Br-cAMP as a metastasis inducer and DHA as a therapeutic agent. Migration was assessed by wound assay and expression measured by western blot and confocal analysis. MiR~17–92 expression was measured by qRT-PCR. Results indicated increased expression and altered cellular distribution of profilin1/VASPpS157 but no changes in cofilin1/VASPpS239 in the human malignant tissues compared to normal tissues. In A549 and MLE12 cells, the expression patterns of profilin1/VASPpS157 or cofilin1/VASPpS239 suggested an interaction in regulation of actin dynamics. Furthermore, DHA inhibited cancer cell migration and viability, ABP expression and cellular localization, and modulated expression of miR~17–92 in A549 cells with minimal effects in MLE12 cells. Further investigations are warranted to understand ABP interactions, changes in cellular localization, regulation by miR~17–92, and DHA as a novel therapeutic. PMID:27496138

  8. Myosin heavy chain-like localizes at cell contact sites during Drosophila myoblast fusion and interacts in vitro with Rolling pebbles 7

    International Nuclear Information System (INIS)

    Bonn, Bettina R.; Rudolf, Anja; Hornbruch-Freitag, Christina; Daum, Gabor; Kuckwa, Jessica; Kastl, Lena; Buttgereit, Detlev; Renkawitz-Pohl, Renate

    2013-01-01

    Besides representing the sarcomeric thick filaments, myosins are involved in many cellular transport and motility processes. Myosin heavy chains are grouped into 18 classes. Here we show that in Drosophila, the unconventional group XVIII myosin heavy chain-like (Mhcl) is transcribed in the mesoderm of embryos, most prominently in founder cells (FCs). An ectopically expressed GFP-tagged Mhcl localizes in the growing muscle at cell–cell contacts towards the attached fusion competent myoblast (FCM). We further show that Mhcl interacts in vitro with the essential fusion protein Rolling pebbles 7 (Rols7), which is part of a protein complex established at cell contact sites (Fusion-restricted Myogenic-Adhesive Structure or FuRMAS). Here, branched F-actin is likely needed to widen the fusion pore and to integrate the myoblast into the growing muscle. We show that the localization of Mhcl is dependent on the presence of Rols7, and we postulate that Mhcl acts at the FuRMAS as an actin motor protein. We further show that Mhcl deficient embryos develop a wild-type musculature. We thus propose that Mhcl functions redundantly to other myosin heavy chains in myoblasts. Lastly, we found that the protein is detectable adjacent to the sarcomeric Z-discs, suggesting an additional function in mature muscles. - Highlights: ► The class XVIII myosin encoding gene Mhcl is transcribed in the mesoderm. ► Mhcl localization at contact sites of fusing myoblasts depends on Rols7. ► Mhcl interacts in vitro with Rols7 which is essential for myogenesis. ► Functional redundancy with other myosins is likely as mutants show no muscle defects. ► Mhcl localizes adjacent to Z-discs of sarcomeres and might support muscle integrity

  9. Drive piston assembly for a valve actuator assembly

    Science.gov (United States)

    Sun, Zongxuan

    2010-02-23

    A drive piston assembly is provided that is operable to selectively open a poppet valve. The drive piston assembly includes a cartridge defining a generally stepped bore. A drive piston is movable within the generally stepped bore and a boost sleeve is coaxially disposed with respect to the drive piston. A main fluid chamber is at least partially defined by the generally stepped bore, drive piston, and boost sleeve. First and second feedback chambers are at least partially defined by the drive piston and each are disposed at opposite ends of the drive piston. At least one of the drive piston and the boost sleeve is sufficiently configured to move within the generally stepped bore in response to fluid pressure within the main fluid chamber to selectively open the poppet valve. A valve actuator assembly and engine are also provided incorporating the disclosed drive piston assembly.

  10. Bearing assemblies, apparatuses, and motor assemblies using the same

    Science.gov (United States)

    Sexton, Timothy N.; Cooley, Craig H.; Knuteson, Cody W.

    2015-12-29

    Various embodiments of the invention relate to bearing assemblies, apparatuses and motor assemblies that include geometric features configured to impart a selected amount of heat transfer and/or hydrodynamic film formation. In an embodiment, a bearing assembly may include a plurality of superhard bearing pads distributed circumferentially about an axis. At least some of the plurality of superhard bearing pads may include a plurality of sub-superhard bearing elements defining a bearing surface. At least some of the plurality of sub-superhard bearing elements may be spaced from one another by one or more voids to impart a selected amount of heat transfer and hydrodynamic film formation thereon during operation. The bearing assembly may also include a support ring that carries the plurality of superhard bearing pads. In addition, at least a portion of the sub-superhard bearing elements may extend beyond the support ring.

  11. Altering F-Actin Structure of C17.2 Cells using Single-Walled Carbon Nanotubes

    Science.gov (United States)

    Magers, Jay; Gillette, Nathan L. D.; Rotkin, Slava V.; Jedlicka, Sabrina; Pirbhai, Massooma; Lehigh Univesity Collaboration; Susquehanna University Collaboration

    Advancements in nanotechnology have become fundamental to the delivery of drugs to treat various diseases. One such advancement is that of carbon nanotubes and their possible implications on drug delivery. Single-walled carbon nanotubes (SWCNTs) have great potential in the biomedical field as a means to deliver materials such as drugs and genes into the human body due to their size and chemistry. However, the effects of the nanotubes on cells they interact with are still unknown. Previous studies have shown that a low dosage of SWCNTs can affect differentiation of C17.2 neural stem cells. In this experiment, we investigate how the tubes affect the structure of the cells. Specifically, we determined the impact on the cell by examining the actin filament length, protrusions along the edge of the cells, and actin distribution. Presenter/Author 1.

  12. Illustrating how mechanical assemblies work

    KAUST Repository

    Mitra, Niloy J.; Yang, Yongliang; Yan, Dongming; Li, Wilmot; Agrawala, Maneesh

    2010-01-01

    How things work visualizations use a variety of visual techniques to depict the operation of complex mechanical assemblies. We present an automated approach for generating such visualizations. Starting with a 3D CAD model of an assembly, we first infer the motions of individual parts and the interactions between parts based on their geometry and a few user specified constraints. We then use this information to generate visualizations that incorporate motion arrows, frame sequences and animation to convey the causal chain of motions and mechanical interactions between parts. We present results for a wide variety of assemblies. © 2010 ACM.

  13. Illustrating how mechanical assemblies work

    KAUST Repository

    Mitra, Niloy J.; Yang, Yongliang; Yan, Dongming; Li, Wilmot; Agrawala, Maneesh

    2013-01-01

    How-things-work visualizations use a variety of visual techniques to depict the operation of complex mechanical assemblies. We present an automated approach for generating such visualizations. Starting with a 3D CAD model of an assembly, we first infer the motions of the individual parts and the interactions across the parts based on their geometry and a few user-specified constraints. We then use this information to generate visualizations that incorporate motion arrows, frame sequences, and animation to convey the causal chain of motions and mechanical interactions across parts. We demonstrate our system on a wide variety of assemblies. © 2013 ACM 0001-0782/13/01.

  14. Lateral loadings on snubber assemblies

    International Nuclear Information System (INIS)

    Raphael, L.S.

    1981-01-01

    This paper examines the installation of snubber assemblies in power plants with respect to transverse or lateral loads as well as axial loads. Evaluation of the effects of low level, lateral loads was performed by analytical means. At higher loadings, the snubber assembly could no longer be treated as a column; therefore, the effects of lateral loadings was determined by test. The test consisted of applying both lateral and axial loads simultaneously. Results of both the analysis and the test showed that the application of lateral loads had a considerable effect on the snubber assemblies

  15. Fuel assembly in a reactor

    International Nuclear Information System (INIS)

    Saito, Shozo; Kawahara, Akira.

    1975-01-01

    Object: To provide a fuel assembly in a reactor which can effectively prevent damage of the clad tube caused by mutual interference between pellets and the clad tube. Structure: A clad tube for a fuel element, which is located in the outer peripheral portion, among the fuel elements constituting fuel assemblies arranged in assembled and lattice fashion within a channel box, is increased in thickness by reducing the inside diameter thereof to be smaller than that of fuel elements internally located, thereby preventing damage of the clad tube resulting from rapid rise in output produced when control rods are removed. (Kamimura, M.)

  16. Directed Assembly of Gold Nanoparticles

    DEFF Research Database (Denmark)

    Westerlund, Axel Rune Fredrik; Bjørnholm, Thomas

    2009-01-01

    As a complement to common "top-down" lithography techniques, "bottom-up" assembly techniques are emerging as promising tools to build nanoscale structures in a predictable way. Gold nanoparticles that are stable and relatively easy to synthesize are important building blocks in many such structures...... due to their useful optical and electronic properties. Programmed assembly of gold nanoparticles in one, two, and three dimensions is therefore of large interest. This review focuses on the progress from the last three years in the field of directed gold nanoparticle and nanorod assembly using...

  17. Illustrating how mechanical assemblies work

    KAUST Repository

    Mitra, Niloy J.

    2010-07-26

    How things work visualizations use a variety of visual techniques to depict the operation of complex mechanical assemblies. We present an automated approach for generating such visualizations. Starting with a 3D CAD model of an assembly, we first infer the motions of individual parts and the interactions between parts based on their geometry and a few user specified constraints. We then use this information to generate visualizations that incorporate motion arrows, frame sequences and animation to convey the causal chain of motions and mechanical interactions between parts. We present results for a wide variety of assemblies. © 2010 ACM.

  18. Modular nuclear fuel assembly rack

    International Nuclear Information System (INIS)

    Davis, C.J.

    1982-01-01

    A modular nuclear fuel assembly rack constructed of an array of identical cells, each cell constructed of a plurality of identical flanged plates. The unique assembly of the plates into a rigid rack provides a cellular compartment for nuclear fuel assemblies and a cavity between the cells for accepting neutron absorbing materials thus allowing a closely spaced array. The modular rack size can be easily adapted to conform with available storage space. U-shaped flanges at the edges of the plates are nested together at the intersection of four cells in the array. A bar is placed at the intersection to lock the cells together

  19. Assembly line performance and modeling

    Science.gov (United States)

    Rane, Arun B.; Sunnapwar, Vivek K.

    2017-09-01

    Automobile sector forms the backbone of manufacturing sector. Vehicle assembly line is important section in automobile plant where repetitive tasks are performed one after another at different workstations. In this thesis, a methodology is proposed to reduce cycle time and time loss due to important factors like equipment failure, shortage of inventory, absenteeism, set-up, material handling, rejection and fatigue to improve output within given cost constraints. Various relationships between these factors, corresponding cost and output are established by scientific approach. This methodology is validated in three different vehicle assembly plants. Proposed methodology may help practitioners to optimize the assembly line using lean techniques.

  20. Control rod guide tube assemblies

    International Nuclear Information System (INIS)

    Jabsen, F.S.

    1979-01-01

    A nuclear fuel assembly including sleeves telescoped over end portions of control rod guide tubes which bear against internal shoulders of the sleeves. Upper ends of the sleeves protrude beyond a control rod guide tube spider and are locked in place by means of a resilient cellular lattice or lock that is seated in mating grooves in the outer surfaces of the sleeves. A grapple is provided for disengaging the entire lock structure spider and associated washers, springs and a grill from the end of the fuel assembly in order to enable these components to be removed and subsequently replaced on the fuel assembly after inspection and repair. (UK)

  1. Gravity Probe B Assembled

    Science.gov (United States)

    2000-01-01

    In this photo, the Gravity Probe B (GP-B) space vehicle is being assembled at the Sunnyvale, California location of the Lockheed Martin Corporation. The GP-B is the relativity experiment developed at Stanford University to test two extraordinary predictions of Albert Einstein's general theory of relativity. The experiment will measure, very precisely, the expected tiny changes in the direction of the spin axes of four gyroscopes contained in an Earth-orbiting satellite at a 400-mile altitude. So free are the gyroscopes from disturbance that they will provide an almost perfect space-time reference system. They will measure how space and time are very slightly warped by the presence of the Earth, and, more profoundly, how the Earth's rotation very slightly drags space-time around with it. These effects, though small for the Earth, have far-reaching implications for the nature of matter and the structure of the Universe. GP-B is among the most thoroughly researched programs ever undertaken by NASA. This is the story of a scientific quest in which physicists and engineers have collaborated closely over many years. Inspired by their quest, they have invented a whole range of technologies that are already enlivening other branches of science and engineering. Launched April 20, 2004 , the GP-B program was managed for NASA by the Marshall Space Flight Center. Development of the GP-B is the responsibility of Stanford University along with major subcontractor Lockheed Martin Corporation. (Image credit to Russ Underwood, Lockheed Martin Corporation).

  2. Theseus Assembly Sequence #2

    Science.gov (United States)

    1996-01-01

    Crew members are seen here assembling the tail of the Theseus prototype research aircraft at NASA's Dryden Flight Research Center, Edwards, California, in May of 1996. The Theseus aircraft, built and operated by Aurora Flight Sciences Corporation, Manassas, Virginia, was a unique aircraft flown at NASA's Dryden Flight Research Center, Edwards, California, under a cooperative agreement between NASA and Aurora. Dryden hosted the Theseus program, providing hangar space and range safety for flight testing. Aurora Flight Sciences was responsible for the actual flight testing, vehicle flight safety, and operation of the aircraft. The Theseus remotely piloted aircraft flew its maiden flight on May 24, 1996, at Dryden. During its sixth flight on November 12, 1996, Theseus experienced an in-flight structural failure that resulted in the loss of the aircraft. As of the beginning of the year 2000, Aurora had not rebuilt the aircraft. Theseus was built for NASA under an innovative, $4.9 million fixed-price contract by Aurora Flight Sciences Corporation and its partners, West Virginia University, Morgantown, West Virginia, and Fairmont State College, Fairmont, West Virginia. The twin-engine, unpiloted vehicle had a 140-foot wingspan, and was constructed largely of composite materials. Powered by two 80-horsepower, turbocharged piston engines that drove twin 9-foot-diameter propellers, Theseus was designed to fly autonomously at high altitudes, with takeoff and landing under the active control of a ground-based pilot in a ground control station 'cockpit.' With the potential ability to carry 700 pounds of science instruments to altitudes above 60,000 feet for durations of greater than 24 hours, Theseus was intended to support research in areas such as stratospheric ozone depletion and the atmospheric effects of future high-speed civil transport aircraft engines. Instruments carried aboard Theseus also would be able to validate satellite-based global environmental change

  3. Theseus Assembly Sequence #3

    Science.gov (United States)

    1996-01-01

    The Theseus prototype research aircraft being assembled at NASA's Dryden Flight Research Center, Edwards, California, in May of 1996. The Theseus aircraft, built and operated by Aurora Flight Sciences Corporation, Manassas, Virginia, was a unique aircraft flown at NASA's Dryden Flight Research Center, Edwards, California, under a cooperative agreement between NASA and Aurora. Dryden hosted the Theseus program, providing hangar space and range safety for flight testing. Aurora Flight Sciences was responsible for the actual flight testing, vehicle flight safety, and operation of the aircraft. The Theseus remotely piloted aircraft flew its maiden flight on May 24, 1996, at Dryden. During its sixth flight on November 12, 1996, Theseus experienced an in-flight structural failure that resulted in the loss of the aircraft. As of the beginning of the year 2000, Aurora had not rebuilt the aircraft. Theseus was built for NASA under an innovative, $4.9 million fixed-price contract by Aurora Flight Sciences Corporation and its partners, West Virginia University, Morgantown, West Virginia, and Fairmont State College, Fairmont, West Virginia. The twin-engine, unpiloted vehicle had a 140-foot wingspan, and was constructed largely of composite materials. Powered by two 80-horsepower, turbocharged piston engines that drove twin 9-foot-diameter propellers, Theseus was designed to fly autonomously at high altitudes, with takeoff and landing under the active control of a ground-based pilot in a ground control station 'cockpit.' With the potential ability to carry 700 pounds of science instruments to altitudes above 60,000 feet for durations of greater than 24 hours, Theseus was intended to support research in areas such as stratospheric ozone depletion and the atmospheric effects of future high-speed civil transport aircraft engines. Instruments carried aboard Theseus also would be able to validate satellite-based global environmental change measurements. Dryden's Project Manager was

  4. Theseus Assembly Sequence #1

    Science.gov (United States)

    1996-01-01

    The Theseus prototype research aircraft being assembled at NASA's Dryden Flight Research Center, Edwards, California, in May of 1996. The Theseus aircraft, built and operated by Aurora Flight Sciences Corporation, Manassas, Virginia, was a unique aircraft flown at NASA's Dryden Flight Research Center, Edwards, California, under a cooperative agreement between NASA and Aurora. Dryden hosted the Theseus program, providing hangar space and range safety for flight testing. Aurora Flight Sciences was responsible for the actual flight testing, vehicle flight safety, and operation of the aircraft. The Theseus remotely piloted aircraft flew its maiden flight on May 24, 1996, at Dryden. During its sixth flight on November 12, 1996, Theseus experienced an in-flight structural failure that resulted in the loss of the aircraft. As of the beginning of the year 2000, Aurora had not rebuilt the aircraft. Theseus was built for NASA under an innovative, $4.9 million fixed-price contract by Aurora Flight Sciences Corporation and its partners, West Virginia University, Morgantown, West Virginia, and Fairmont State College, Fairmont, West Virginia. The twin-engine, unpiloted vehicle had a 140-foot wingspan, and was constructed largely of composite materials. Powered by two 80-horsepower, turbocharged piston engines that drove twin 9-foot-diameter propellers, Theseus was designed to fly autonomously at high altitudes, with takeoff and landing under the active control of a ground-based pilot in a ground control station 'cockpit.' With the potential ability to carry 700 pounds of science instruments to altitudes above 60,000 feet for durations of greater than 24 hours, Theseus was intended to support research in areas such as stratospheric ozone depletion and the atmospheric effects of future high-speed civil transport aircraft engines. Instruments carried aboard Theseus also would be able to validate satellite-based global environmental change measurements. Dryden's Project Manager was

  5. Robotically Assembled Aerospace Structures: Digital Material Assembly using a Gantry-Type Assembler

    Science.gov (United States)

    Trinh, Greenfield; Copplestone, Grace; O'Connor, Molly; Hu, Steven; Nowak, Sebastian; Cheung, Kenneth; Jenett, Benjamin; Cellucci, Daniel

    2017-01-01

    This paper evaluates the development of automated assembly techniques for discrete lattice structures using a multi-axis gantry type CNC machine. These lattices are made of discrete components called "digital materials." We present the development of a specialized end effector that works in conjunction with the CNC machine to assemble these lattices. With this configuration we are able to place voxels at a rate of 1.5 per minute. The scalability of digital material structures due to the incremental modular assembly is one of its key traits and an important metric of interest. We investigate the build times of a 5x5 beam structure on the scale of 1 meter (325 parts), 10 meters (3,250 parts), and 30 meters (9,750 parts). Utilizing the current configuration with a single end effector, performing serial assembly with a globally fixed feed station at the edge of the build volume, the build time increases according to a scaling law of n4, where n is the build scale. Build times can be reduced significantly by integrating feed systems into the gantry itself, resulting in a scaling law of n3. A completely serial assembly process will encounter time limitations as build scale increases. Automated assembly for digital materials can assemble high performance structures from discrete parts, and techniques such as built in feed systems, parallelization, and optimization of the fastening process will yield much higher throughput.

  6. Architecture and assembly of the Bacillus subtilis spore coat.

    Science.gov (United States)

    Plomp, Marco; Carroll, Alicia Monroe; Setlow, Peter; Malkin, Alexander J

    2014-01-01

    Bacillus spores are encased in a multilayer, proteinaceous self-assembled coat structure that assists in protecting the bacterial genome from stresses and consists of at least 70 proteins. The elucidation of Bacillus spore coat assembly, architecture, and function is critical to determining mechanisms of spore pathogenesis, environmental resistance, immune response, and physicochemical properties. Recently, genetic, biochemical and microscopy methods have provided new insight into spore coat architecture, assembly, structure and function. However, detailed spore coat architecture and assembly, comprehensive understanding of the proteomic composition of coat layers, and specific roles of coat proteins in coat assembly and their precise localization within the coat remain in question. In this study, atomic force microscopy was used to probe the coat structure of Bacillus subtilis wild type and cotA, cotB, safA, cotH, cotO, cotE, gerE, and cotE gerE spores. This approach provided high-resolution visualization of the various spore coat structures, new insight into the function of specific coat proteins, and enabled the development of a detailed model of spore coat architecture. This model is consistent with a recently reported four-layer coat assembly and further adds several coat layers not reported previously. The coat is organized starting from the outside into an outermost amorphous (crust) layer, a rodlet layer, a honeycomb layer, a fibrous layer, a layer of "nanodot" particles, a multilayer assembly, and finally the undercoat/basement layer. We propose that the assembly of the previously unreported fibrous layer, which we link to the darkly stained outer coat seen by electron microscopy, and the nanodot layer are cotH- and cotE- dependent and cotE-specific respectively. We further propose that the inner coat multilayer structure is crystalline with its apparent two-dimensional (2D) nuclei being the first example of a non-mineral 2D nucleation crystallization

  7. Architecture and Assembly of the Bacillus subtilis Spore Coat

    Science.gov (United States)

    Plomp, Marco; Carroll, Alicia Monroe; Setlow, Peter; Malkin, Alexander J.

    2014-01-01

    Bacillus spores are encased in a multilayer, proteinaceous self-assembled coat structure that assists in protecting the bacterial genome from stresses and consists of at least 70 proteins. The elucidation of Bacillus spore coat assembly, architecture, and function is critical to determining mechanisms of spore pathogenesis, environmental resistance, immune response, and physicochemical properties. Recently, genetic, biochemical and microscopy methods have provided new insight into spore coat architecture, assembly, structure and function. However, detailed spore coat architecture and assembly, comprehensive understanding of the proteomic composition of coat layers, and specific roles of coat proteins in coat assembly and their precise localization within the coat remain in question. In this study, atomic force microscopy was used to probe the coat structure of Bacillus subtilis wild type and cotA, cotB, safA, cotH, cotO, cotE, gerE, and cotE gerE spores. This approach provided high-resolution visualization of the various spore coat structures, new insight into the function of specific coat proteins, and enabled the development of a detailed model of spore coat architecture. This model is consistent with a recently reported four-layer coat assembly and further adds several coat layers not reported previously. The coat is organized starting from the outside into an outermost amorphous (crust) layer, a rodlet layer, a honeycomb layer, a fibrous layer, a layer of “nanodot” particles, a multilayer assembly, and finally the undercoat/basement layer. We propose that the assembly of the previously unreported fibrous layer, which we link to the darkly stained outer coat seen by electron microscopy, and the nanodot layer are cotH- and cotE- dependent and cotE-specific respectively. We further propose that the inner coat multilayer structure is crystalline with its apparent two-dimensional (2D) nuclei being the first example of a non-mineral 2D nucleation crystallization

  8. Direct hierarchical assembly of nanoparticles

    Science.gov (United States)

    Xu, Ting; Zhao, Yue; Thorkelsson, Kari

    2014-07-22

    The present invention provides hierarchical assemblies of a block copolymer, a bifunctional linking compound and a nanoparticle. The block copolymers form one micro-domain and the nanoparticles another micro-domain.

  9. Shaft seal assembly and method

    Science.gov (United States)

    Keba, John E. (Inventor)

    2007-01-01

    A pressure-actuated shaft seal assembly and associated method for controlling the flow of fluid adjacent a rotatable shaft are provided. The seal assembly includes one or more seal members that can be adjusted between open and closed positions, for example, according to the rotational speed of the shaft. For example, the seal member can be configured to be adjusted according to a radial pressure differential in a fluid that varies with the rotational speed of the shaft. In addition, in the closed position, each seal member can contact a rotatable member connected to the shaft to form a seal with the rotatable member and prevent fluid from flowing through the assembly. Thus, the seal can be closed at low speeds of operation and opened at high speeds of operation, thereby reducing the heat and wear in the seal assembly while maintaining a sufficient seal during all speeds of operation.

  10. NEDDylation promotes stress granule assembly.

    Science.gov (United States)

    Jayabalan, Aravinth Kumar; Sanchez, Anthony; Park, Ra Young; Yoon, Sang Pil; Kang, Gum-Yong; Baek, Je-Hyun; Anderson, Paul; Kee, Younghoon; Ohn, Takbum

    2016-07-06

    Stress granules (SGs) harbour translationally stalled messenger ribonucleoproteins and play important roles in regulating gene expression and cell fate. Here we show that neddylation promotes SG assembly in response to arsenite-induced oxidative stress. Inhibition or depletion of key components of the neddylation machinery concomitantly inhibits stress-induced polysome disassembly and SG assembly. Affinity purification and subsequent mass-spectrometric analysis of Nedd8-conjugated proteins from translationally stalled ribosomal fractions identified ribosomal proteins, translation factors and RNA-binding proteins (RBPs), including SRSF3, a previously known SG regulator. We show that SRSF3 is selectively neddylated at Lys85 in response to arsenite. A non-neddylatable SRSF3 (K85R) mutant do not prevent arsenite-induced polysome disassembly, but fails to support the SG assembly, suggesting that the neddylation pathway plays an important role in SG assembly.

  11. Analysis of PWR assembly bow

    International Nuclear Information System (INIS)

    Fetterman, Robert J.; Franceschini, Fausto

    2008-01-01

    Excessive out of core assembly bow has been observed during refueling outages of certain PWRs. Assembly bow can take on a rather complex S-shape, and in other cases C-shape bow is prevalent. Concerns have been raised regarding the impact of the observed assembly bow on the in-core power distribution and the safety analyses supporting the plant operations. In response to these concerns, Westinghouse has developed a comprehensive analysis process for determining the effects of assembly bow on core power distributions and plant operating margins. This methodology has been applied to a particular reactor as part of an overall safety reanalysis completed in support of plant modifications. This paper provides a brief description of the methods used and a summary of the pertinent results. (authors)

  12. Analysis of PWR assembly bow

    Energy Technology Data Exchange (ETDEWEB)

    Fetterman, Robert J.; Franceschini, Fausto [Westinghouse Electric Company LLC, Pittsburgh, PA (United States)

    2008-07-01

    Excessive out of core assembly bow has been observed during refueling outages of certain PWRs. Assembly bow can take on a rather complex S-shape, and in other cases C-shape bow is prevalent. Concerns have been raised regarding the impact of the observed assembly bow on the in-core power distribution and the safety analyses supporting the plant operations. In response to these concerns, Westinghouse has developed a comprehensive analysis process for determining the effects of assembly bow on core power distributions and plant operating margins. This methodology has been applied to a particular reactor as part of an overall safety reanalysis completed in support of plant modifications. This paper provides a brief description of the methods used and a summary of the pertinent results. (authors)

  13. Power peak in vicinity of WWER-440 control assembly

    International Nuclear Information System (INIS)

    Mikus, J.

    2002-01-01

    This paper presents information concerning the WWER-440 local power peaking problem induced by a control assembly and corresponding investigation possibilities on the light-water zero-power reactor LR-O at the Nuclear Research Institute Rez plc. Brief description of the disposable CA model, experimental arrangement and conditions on the LR-O reactor, preparation of the relevant measurements in the WWER-440 type cores with CA model, as well as some preliminary results of the fission density distribution obtained in a core without boron and with fuel assemblies having profiled enrichment are mentioned too (Author)

  14. DNA controlled assembly of liposomes

    DEFF Research Database (Denmark)

    Vogel, Stefan; Jakobsen, Ulla; Simonsen, Adam Cohen

    2009-01-01

    DNA-encoding of solid nanoparticles requires surfacechemistry, which is often tedious and not generally applicable. In the present study non-covalently attached DNA are used to assemble soft nanoparticles (liposomes) in solution. This process displays remarkably sharp thermal transitions from...... assembled to disassembled state for which reason this method allows easy and fast detection of polynucleotides (e.g. DNA or RNA), including single nucleotide polymorphisms as well as insertions and deletions....

  15. General Assembly debate on IAEA

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1960-01-15

    On 3 November 1959, the General Assembly of the United Nations considered the annual report of the International Atomic Energy Agency, the first report to cover a full operational year of the Agency - 1 July 1959 to 30 June 1959, more recent developments having been summarized in a preface. At the end of the debate the Assembly adopted a resolution, submitted jointly by Czechoslovakia, the Union of South Africa and the United Arab Republic, taking note of the report

  16. Another successful Doctoral Student Assembly

    CERN Multimedia

    Katarina Anthony

    2014-01-01

    On Wednesday 2 April, CERN hosted its third Doctoral Student Assembly in the Council Chamber.   CERN PhD students show off their posters in CERN's Main Building. Speaking to a packed house, Director-General Rolf Heuer gave the assembly's opening speech and introduced the poster session that followed. Seventeen CERN PhD students presented posters on their work, and were greeted by their CERN and University supervisors. It was a very successful event!

  17. BRET fuel assembly dismantling machine

    International Nuclear Information System (INIS)

    Titzler, P.A.; Bennett, K.L.; Kelley, R.S. Jr.; Stringer, J.L.

    1984-08-01

    An automated remote nuclear fuel assembly milling and dismantling machine has been designed, developed, and demonstrated at the Hanford Engineering Development Laboratory (HEDL) in Richland, Washington. The machine can be used to dismantle irradiated breeder fuel assemblies from the Fast Flux Test Facility prior to fuel reprocessing. It can be installed in an existing remotely operated shielded hot cell facility, the Fuels and Materials Examination Facility (FMEF), at the Hanford Site in Richland, Washington

  18. Los Alamos Critical Assemblies Facility

    International Nuclear Information System (INIS)

    Malenfant, R.E.

    1981-06-01

    The Critical Assemblies Facility of the Los Alamos National Laboratory has been in existence for thirty-five years. In that period, many thousands of measurements have been made on assemblies of 235 U, 233 U, and 239 Pu in various configurations, including the nitrate, sulfate, fluoride, carbide, and oxide chemical compositions and the solid, liquid, and gaseous states. The present complex of eleven operating machines is described, and typical applications are presented

  19. Assembly delay line pulse generators

    CERN Multimedia

    CERN PhotoLab

    1971-01-01

    Assembly of six of the ten delay line pulse generators that will power the ten kicker magnet modules. One modulator part contains two pulse generators. Capacitors, inductances, and voltage dividers are in the oil tank on the left. Triggered high-pressure spark gap switches are on the platforms on the right. High voltage pulse cables to the kicker magnet emerge under the spark gaps. In the centre background are the assembled master gaps.

  20. CADM1 controls actin cytoskeleton assembly and regulates extracellular matrix adhesion in human mast cells.

    Directory of Open Access Journals (Sweden)

    Elena P Moiseeva

    Full Text Available CADM1 is a major receptor for the adhesion of mast cells (MCs to fibroblasts, human airway smooth muscle cells (HASMCs and neurons. It also regulates E-cadherin and alpha6beta4 integrin in other cell types. Here we investigated a role for CADM1 in MC adhesion to both cells and extracellular matrix (ECM. Downregulation of CADM1 in the human MC line HMC-1 resulted not only in reduced adhesion to HASMCs, but also reduced adhesion to their ECM. Time-course studies in the presence of EDTA to inhibit integrins demonstrated that CADM1 provided fast initial adhesion to HASMCs and assisted with slower adhesion to ECM. CADM1 downregulation, but not antibody-dependent CADM1 inhibition, reduced MC adhesion to ECM, suggesting indirect regulation of ECM adhesion. To investigate potential mechanisms, phosphotyrosine signalling and polymerisation of actin filaments, essential for integrin-mediated adhesion, were examined. Modulation of CADM1 expression positively correlated with surface KIT levels and polymerisation of cortical F-actin in HMC-1 cells. It also influenced phosphotyrosine signalling and KIT tyrosine autophosphorylation. CADM1 accounted for 46% of surface KIT levels and 31% of F-actin in HMC-1 cells. CADM1 downregulation resulted in elongation of cortical actin filaments in both HMC-1 cells and human lung MCs and increased cell rigidity of HMC-1 cells. Collectively these data suggest that CADM1 is a key adhesion receptor, which regulates MC net adhesion, both directly through CADM1-dependent adhesion, and indirectly through the regulation of other adhesion receptors. The latter is likely to occur via docking of KIT and polymerisation of cortical F-actin. Here we propose a stepwise model of adhesion with CADM1 as a driving force for net MC adhesion.

  1. Localized superconductors

    International Nuclear Information System (INIS)

    Ma, M.; Lee, P.A.

    1985-01-01

    We study the effects of Anderson localization on superconductivity by using a Bardeen-Cooper-Schrieffer (BCS)-type trial wave function which pairs electrons in exact time-reversed eigenstates of the single-particle Hamiltonian. Within this approximation, and neglecting localization effects on the effective Coulomb repulsion and the electron-phonon coupling, we find that superconductivity persists below the mobility edge. In fact, Anderson's theorem is valid in the localized phase as long as rhoΔ 0 L/sup d/ > 1 (rho is the density of states averaged over +- Δ 0 of the Fermi energy, Δ 0 the BCS gap parameter, and L the localization length). Hence the gap order parameter Δ(r) remains uniform in space at the BCS value Δ 0 . The superfluid density and response to electromagnetic perturbations, however, show marked differences from the ''dirty superconductor'' regime. For rhoΔ 0 L/sup d/ < 1, Δ(r) fluctuates spatially and eventually drops to zero. In the limit when states are site localized, the system crosses over into the ''Anderson negative-U glass.'' Considerations beyond the trial wave-function approximation will speed up the destruction of superconductivity. The superconductor formed from localized states has the property that its quasiparticle excitations are also localized. Such excitations can be probed by observing the normal current in a tunneling junction

  2. Self-Assembled Polystyrene Beads for Templated Covalent Functionalization of Graphitic Substrates Using Diazonium Chemistry.

    Science.gov (United States)

    Van Gorp, Hans; Walke, Peter; Bragança, Ana M; Greenwood, John; Ivasenko, Oleksandr; Hirsch, Brandon E; De Feyter, Steven

    2018-04-11

    A network of self-assembled polystyrene beads was employed as a lithographic mask during covalent functionalization reactions on graphitic surfaces to create nanocorrals for confined molecular self-assembly studies. The beads were initially assembled into hexagonal arrays at the air-liquid interface and then transferred to the substrate surface. Subsequent electrochemical grafting reactions involving aryl diazonium molecules created covalently bound molecular units that were localized in the void space between the nanospheres. Removal of the bead template exposed hexagonally arranged circular nanocorrals separated by regions of chemisorbed molecules. Small molecule self-assembly was then investigated inside the resultant nanocorrals using scanning tunneling microscopy to highlight localized confinement effects. Overall, this work illustrates the utility of self-assembly principles to transcend length scale gaps in the development of hierarchically patterned molecular materials.

  3. The mathematics of virus shell assembly. Progress report 1995--1996

    Energy Technology Data Exchange (ETDEWEB)

    Berger, B.

    1996-08-01

    This research focuses on applying computational and mathematical techniques to problems in biology, and more specifically to problems in protein folding. Significant progress has been made in the following areas relating to virus shell assembly: the local rules theory has been further developed; development has begun on a second-generation simulator which provides a more physically realistic model of assembly, collaborative efforts have continued with an experimental biologist to verify and inspire the local rules theory; an investigation has been initiated into the mechanics of virus shell assembly; laboratory experiments have been conducted on bacteriophage T4 which verify that the previously believed structure for the core may be incorrect.

  4. A conceptual design of assembly strategy and dedicated tools for assembly of 40o sector

    International Nuclear Information System (INIS)

    Park, H.K.; Nam, K.O.; Kim, D.J.; Ahn, H.J.; Lee, J.H.; Im, K.; Shaw, R.

    2010-01-01

    The International Thermanuclear Experimental Reactor (ITER) tokamak device is composed of 9 vacuum vessel (VV)/toroidal field coils (TFCs)/vacuum vessel thermal shields (VVTS) 40 o sectors. Each VV/TFCs/VVTS 40 o sector is made up of one 40 o VV, two 20 o TFCs and associated VVTS segments. The 40 o sectors are sub-assembled at assembly hall respectively and then nine 40 o sectors sub-assembled at assembly hall are finally assembled at tokamak in-pit hall. The assembly strategy and tools for the 40 o sector sub-assembly and final assembly should be developed to satisfy the basic assembly requirements of the ITER tokamak device. Accordingly, the purpose-built assembly tools should be designed and manufactured considering assembly plan, available space, cost, safety, easy operation, efficient maintenance, and so on. The 40 o sector assembly tools are classified into 2 groups. One group is the sub-assembly tools including upending tool, lifting tool, sub-assembly tool, VV supports and bracing tools used at assembly hall and the other group is the in-pit assembly tools including lifting tool, central column, radial beams and their supports. This paper describes the current status of the assembly strategy and major tools for the VV/TFCs/VVTS 40 o sector assembly at in-pit hall and assembly hall. The conceptual design of the major assembly tools and assembly process at assembly hall and tokamak in-pit hall are presented also.

  5. De novo assembly and phasing of a Korean human genome.

    Science.gov (United States)

    Seo, Jeong-Sun; Rhie, Arang; Kim, Junsoo; Lee, Sangjin; Sohn, Min-Hwan; Kim, Chang-Uk; Hastie, Alex; Cao, Han; Yun, Ji-Young; Kim, Jihye; Kuk, Junho; Park, Gun Hwa; Kim, Juhyeok; Ryu, Hanna; Kim, Jongbum; Roh, Mira; Baek, Jeonghun; Hunkapiller, Michael W; Korlach, Jonas; Shin, Jong-Yeon; Kim, Changhoon

    2016-10-13

    Advances in genome assembly and phasing provide an opportunity to investigate the diploid architecture of the human genome and reveal the full range of structural variation across population groups. Here we report the de novo assembly and haplotype phasing of the Korean individual AK1 (ref. 1) using single-molecule real-time sequencing, next-generation mapping, microfluidics-based linked reads, and bacterial artificial chromosome (BAC) sequencing approaches. Single-molecule sequencing coupled with next-generation mapping generated a highly contiguous assembly, with a contig N50 size of 17.9 Mb and a scaffold N50 size of 44.8 Mb, resolving 8 chromosomal arms into single scaffolds. The de novo assembly, along with local assemblies and spanning long reads, closes 105 and extends into 72 out of 190 euchromatic gaps in the reference genome, adding 1.03 Mb of previously intractable sequence. High concordance between the assembly and paired-end sequences from 62,758 BAC clones provides strong support for the robustness of the assembly. We identify 18,210 structural variants by direct comparison of the assembly with the human reference, identifying thousands of breakpoints that, to our knowledge, have not been reported before. Many of the insertions are reflected in the transcriptome and are shared across the Asian population. We performed haplotype phasing of the assembly with short reads, long reads and linked reads from whole-genome sequencing and with short reads from 31,719 BAC clones, thereby achieving phased blocks with an N50 size of 11.6 Mb. Haplotigs assembled from single-molecule real-time reads assigned to haplotypes on phased blocks covered 89% of genes. The haplotigs accurately characterized the hypervariable major histocompatability complex region as well as demonstrating allele configuration in clinically relevant genes such as CYP2D6. This work presents the most contiguous diploid human genome assembly so far, with extensive investigation of

  6. Sequencing and de novo assembly of 150 genomes from Denmark as a population reference

    DEFF Research Database (Denmark)

    Maretty, Lasse; Jensen, Jacob Malte; Petersen, Bent

    2017-01-01

    Hundreds of thousands of human genomes are now being sequenced to characterize genetic variation and use this information to augment association mapping studies of complex disorders and other phenotypic traits. Genetic variation is identified mainly by mapping short reads to the reference genome......-coverage sequencing with mate-pair libraries extending up to 20 kilobases. We report de novo assemblies of 150 individuals (50 trios) from the GenomeDenmark project. The quality of these assemblies is similar to those obtained using the more expensive long-read technology. We use the assemblies to identify a rich set...... or by performing local assembly. However, these approaches are biased against discovery of structural variants and variation in the more complex parts of the genome. Hence, large-scale de novo assembly is needed. Here we show that it is possible to construct excellent de novo assemblies from high...

  7. Sequencing and de novo assembly of 150 genomes from Denmark as a population reference

    DEFF Research Database (Denmark)

    Maretty, Lasse; Jensen, Jacob Malte; Petersen, Bent

    2017-01-01

    Hundreds of thousands of human genomes are now being sequenced to characterize genetic variation and use this information to augment association mapping studies of complex disorders and other phenotypic traits. Genetic variation is identified mainly by mapping short reads to the reference genome...... or by performing local assembly. However, these approaches are biased against discovery of structural variants and variation in the more complex parts of the genome. Hence, large-scale de novo assembly is needed. Here we show that it is possible to construct excellent de novo assemblies from high......-coverage sequencing with mate-pair libraries extending up to 20 kilobases. We report de novo assemblies of 150 individuals (50 trios) from the GenomeDenmark project. The quality of these assemblies is similar to those obtained using the more expensive long-read technology. We use the assemblies to identify a rich set...

  8. Proton-Fueled, Reversible DNA Hybridization Chain Assembly for pH Sensing and Imaging.

    Science.gov (United States)

    Liu, Lan; Liu, Jin-Wen; Huang, Zhi-Mei; Wu, Han; Li, Na; Tang, Li-Juan; Jiang, Jian-Hui

    2017-07-05

    Design of DNA self-assembly with reversible responsiveness to external stimuli is of great interest for diverse applications. We for the first time develop a pH-responsive, fully reversible hybridization chain reaction (HCR) assembly that allows sensitive sensing and imaging of pH in living cells. Our design relies on the triplex forming sequences that form DNA triplex with toehold regions under acidic conditions and then induce a cascade of strand displacement and DNA assembly. The HCR assembly has shown dynamic responses in physiological pH ranges with excellent reversibility and demonstrated the potential for in vitro detection and live-cell imaging of pH. Moreover, this method affords HCR assemblies with highly localized fluorescence responses, offering advantages of improving sensitivity and better selectivity. The proton-fueled, reversible HCR assembly may provide a useful approach for pH-related cell biology study and disease diagnostics.

  9. Localized Scleroderma

    Science.gov (United States)

    ... How Is Localized Scleroderma Diagnosed? Doctors who are familiar with scleroderma, or who are experts at examining ... systemic treatment with a medication or other treatment interventions (for example, ultraviolet light), are reserved for more ...

  10. Self-Assembly of Infinite Structures

    Directory of Open Access Journals (Sweden)

    Scott M. Summers

    2009-06-01

    Full Text Available We review some recent results related to the self-assembly of infinite structures in the Tile Assembly Model. These results include impossibility results, as well as novel tile assembly systems in which shapes and patterns that represent various notions of computation self-assemble. Several open questions are also presented and motivated.

  11. Subcritical assemblies, use and their feasibility assessment

    International Nuclear Information System (INIS)

    Haroon, M.R.

    1982-03-01

    In developing countries, subcritical assemblies can be a useful tool for training and research in the field of nuclear technology with minimum cost. The historical development of subcritical assemblies and the reactor physics experiments which can be carried out using this facility are outlined. The different types of subcritical assemblies have been described and material requirements for each assembly have been pointed out. (author)

  12. Molecular self-assembly advances and applications

    CERN Document Server

    Dequan, Alex Li

    2012-01-01

    In the past several decades, molecular self-assembly has emerged as one of the main themes in chemistry, biology, and materials science. This book compiles and details cutting-edge research in molecular assemblies ranging from self-organized peptide nanostructures and DNA-chromophore foldamers to supramolecular systems and metal-directed assemblies, even to nanocrystal superparticles and self-assembled microdevices

  13. TOOL ASSEMBLY WITH BI-DIRECTIONAL BEARING

    Science.gov (United States)

    Longhurst, G.E.

    1961-07-11

    A two-direction motion bearing which is incorporated in a refueling nuclear fuel element trsnsfer tool assembly is described. A plurality of bi- directional bearing assembliesare fixed equi-distantly about the circumference of the transfer tool assembly to provide the tool assembly with a bearing surface- for both axial and rotational motion. Each bi-directional bearing assembly contains a plurality of circumferentially bulged rollers mounted in a unique arrangement which will provide a bearing surface for rotational movement of the tool assembly within a bore. The bi-direc tional bearing assembly itself is capable of rational motion and thus provides for longitudinal movement of the tool assembly.

  14. Benchmark assemblies of the Los Alamos Critical Assemblies Facility

    International Nuclear Information System (INIS)

    Dowdy, E.J.

    1985-01-01

    Several critical assemblies of precisely known materials composition and easily calculated and reproducible geometries have been constructed at the Los Alamos National Laboratory. Some of these machines, notably Jezebel, Flattop, Big Ten, and Godiva, have been used as benchmark assemblies for the comparison of the results of experimental measurements and computation of certain nuclear reaction parameters. These experiments are used to validate both the input nuclear data and the computational methods. The machines and the applications of these machines for integral nuclear data checks are described

  15. Benchmark assemblies of the Los Alamos critical assemblies facility

    International Nuclear Information System (INIS)

    Dowdy, E.J.

    1986-01-01

    Several critical assemblies of precisely known materials composition and easily calculated and reproducible geometries have been constructed at the Los Alamos National Laboratory. Some of these machines, notably Jezebel, Flattop, Big Ten, and Godiva, have been used as benchmark assemblies for the comparison of the results of experimental measurements and computation of certain nuclear reaction parameters. These experiments are used to validate both the input nuclear data and the computational methods. The machines and the applications of these machines for integral nuclear data checks are described. (author)

  16. Benchmark assemblies of the Los Alamos critical assemblies facility

    International Nuclear Information System (INIS)

    Dowdy, E.J.

    1985-01-01

    Several critical assemblies of precisely known materials composition and easily calculated and reproducible geometries have been constructed at the Los Alamos National Laboratory. Some of these machines, notably Jezebel, Flattop, Big Ten, and Godiva, have been used as benchmark assemblies for the comparison of the results of experimental measurements and computation of certain nuclear reaction parameters. These experiments are used to validate both the input nuclear data and the computational methods. The machines and the applications of these machines for integral nuclear data checks are described

  17. Cleaning device for fuel assemblies

    International Nuclear Information System (INIS)

    Kita, Kaoru.

    1986-01-01

    Purpose: To completely remove obstacles deposited to the lower sides of supporting lattices for fuel assemblies by utilizing water within a pit before reloading of the fuel assemblies. Constitution: A cylindrical can, to which a fuel assembly is inserted through the upper end opening thereof, is vertically disposed within water of a pit and the bottom of the can is communicated with a pump by way of a suction pipe and a filter device disposed out of the pit. While on the other hand, a fuel assembly is suspended downwardly by a crane and inserted to the inside of the can through the upper end of the opening thereof and supported therein followed by starting the pump. As a result, water in the pit is circulated through the inside of the can, suction pipe, filtering device, pump, discharge pipe and to the inside of the pit thereby enabling to completely eliminate obstacles deposited to the lower surface, etc. of supporting lattices for the fuel assembly supported within the can. (Takahashi, M.)

  18. Container for spent fuel assembly

    International Nuclear Information System (INIS)

    Sawai, Takeshi.

    1996-01-01

    The container of the present invention comprises a container main body having a body portion which can contain spent fuel assemblies and a lid, and heat pipes having an evaporation portion disposed along the outer surface of the spent fuel assemblies to be contained and a condensation portion exposed to the outside of the container main body. Further, the heat pipe is formed spirally at the evaporation portions so as to surround the outer circumference of the spent fuel assemblies, branched into a plurality of portions at the condensation portion, each of the branched portion of the condensation portion being exposed to the outside of the container main body, and is tightly in contact with the periphery of the slit portions disposed to the container main body. Then, since released after heat is transferred to the outside of the container main body from the evaporation portion of the heat pipe along the outer surface of the spent fuel assemblies by way of the condensation portion of the heat pipes exposed to the outside of the container main body, the efficiency of the heat transfer is extremely improved to enhance the effect of removing heat of spent fuel assemblies. Further, cooling effect is enhanced by the spiral form of the evaporation portion and the branched condensation portion. (N.H.)

  19. Assembly considerations for large reflectors

    Science.gov (United States)

    Bush, H.

    1988-01-01

    The technologies developed at LaRC in the area of erectable instructures are discussed. The information is of direct value to the Large Deployable Reflector (LDR) because an option for the LDR backup structure is to assemble it in space. The efforts in this area, which include development of joints, underwater assembly simulation tests, flight assembly/disassembly tests, and fabrication of 5-meter trusses, led to the use of the LaRC concept as the baseline configuration for the Space Station Structure. The Space Station joint is linear in the load and displacement range of interest to Space Station; the ability to manually assemble and disassemble a 45-foot truss structure was demonstrated by astronauts in space as part of the ACCESS Shuttle Flight Experiment. The structure was built in 26 minutes 46 seconds, and involved a total of 500 manipulations of untethered hardware. Also, the correlation of the space experience with the neutral buoyancy simulation was very good. Sections of the proposed 5-meter bay Space Station truss have been built on the ground. Activities at LaRC have included the development of mobile remote manipulator systems (which can traverse the Space Station 5-meter structure), preliminary LDR sun shield concepts, LDR construction scenarios, and activities in robotic assembly of truss-type structures.

  20. Network spandrels reflect ecological assembly.

    Science.gov (United States)

    Maynard, Daniel S; Serván, Carlos A; Allesina, Stefano

    2018-03-01

    Ecological networks that exhibit stable dynamics should theoretically persist longer than those that fluctuate wildly. Thus, network structures which are over-represented in natural systems are often hypothesised to be either a cause or consequence of ecological stability. Rarely considered, however, is that these network structures can also be by-products of the processes that determine how new species attempt to join the community. Using a simulation approach in tandem with key results from random matrix theory, we illustrate how historical assembly mechanisms alter the structure of ecological networks. We demonstrate that different community assembly scenarios can lead to the emergence of structures that are often interpreted as evidence of 'selection for stability'. However, by controlling for the underlying selection pressures, we show that these assembly artefacts-or spandrels-are completely unrelated to stability or selection, and are instead by-products of how new species are introduced into the system. We propose that these network-assembly spandrels are critically overlooked aspects of network theory and stability analysis, and we illustrate how a failure to adequately account for historical assembly can lead to incorrect inference about the causes and consequences of ecological stability. © 2018 John Wiley & Sons Ltd/CNRS.

  1. Inverse design of multicomponent assemblies

    Science.gov (United States)

    Piñeros, William D.; Lindquist, Beth A.; Jadrich, Ryan B.; Truskett, Thomas M.

    2018-03-01

    Inverse design can be a useful strategy for discovering interactions that drive particles to spontaneously self-assemble into a desired structure. Here, we extend an inverse design methodology—relative entropy optimization—to determine isotropic interactions that promote assembly of targeted multicomponent phases, and we apply this extension to design interactions for a variety of binary crystals ranging from compact triangular and square architectures to highly open structures with dodecagonal and octadecagonal motifs. We compare the resulting optimized (self- and cross) interactions for the binary assemblies to those obtained from optimization of analogous single-component systems. This comparison reveals that self-interactions act as a "primer" to position particles at approximately correct coordination shell distances, while cross interactions act as the "binder" that refines and locks the system into the desired configuration. For simpler binary targets, it is possible to successfully design self-assembling systems while restricting one of these interaction types to be a hard-core-like potential. However, optimization of both self- and cross interaction types appears necessary to design for assembly of more complex or open structures.

  2. Lipid nanoparticle interactions and assemblies

    Science.gov (United States)

    Preiss, Matthew Ryan

    Novel liposome-nanoparticle assemblies (LNAs) provide a biologically inspired route for designing multifunctional bionanotheranostics. LNAs combine the benefits of lipids and liposomes to encapsulate, transport, and protect hydrophilic and hydrophobic therapeutics with functional nanoparticles. Functional nanoparticles endow LNAs with additional capabilities, including the ability to target diseases, triggered drug release, controlled therapeutic output, and diagnostic capabilities to produce a drug delivery system that can effectively and efficiently deliver therapeutics while reducing side effects. Not only could LNAs make existing drugs better, they could also provide an avenue to allow once promising non-approved drugs (rejected due to harmful side effects, inadequate pharmacokinetics, and poor efficacy) to be safely used through targeted and controlled delivery directly to the diseased site. LNAs have the potential to be stimuli responsive, delivering drugs on command by external (ultrasound, RF heating, etc.) or internal (pH, blood sugar, heart rate, etc.) stimuli. Individually, lipids and nanoparticles have been clinically approved for therapy, such as Doxil (a liposomal doxorubicin for cancer treatment), and diagnosis, such as Feridex (an iron oxide nanoparticle an MRI contrast enhancement agent for liver tumors). In order to engineer these multifunctional LNAs for theranostic applications, the interactions between nanoparticles and lipids must be better understood. This research sought to explore the formation, design, structures, characteristics, and functions of LNAs. To achieve this goal, different types of LNAs were formed, specifically magnetoliposomes, bilayer decorated LNAs (DLNAs), and lipid-coated magnetic nanoparticles (LMNPs). A fluorescent probe was embedded in the lipid bilayer of magnetoliposomes allowing the local temperature and membrane fluidity to be observed. When subjected to an electromagnetic field that heated the encapsulated iron

  3. Design of the ITER Tokamak Assembly Tools

    International Nuclear Information System (INIS)

    Park, Hyunki; Her, Namil; Kim, Byungchul; Im, Kihak; Jung, Kijung; Lee, Jaehyuk; Im, Kisuk

    2006-01-01

    ITER (International Thermonuclear Experimental Reactor) Procurement allocation among the seven Parties, EU, JA, CN, IN , KO, RF and US had been decided in Dec. 2005. ITER Tokamak assembly tools is one of the nine components allocated to Korea for the construction of the ITER. Assembly tools except measurement and common tools are supplied to assemble the ITER Tokamak and classified into 9 groups according to components to be assembled. Among the 9 groups of assembly tools, large-sized Sector Sub-assembly Tools and Sector Assembly Tools are used at the first stage of ITER Tokamak construction and need to be designed faster than seven other assembly tools. ITER IT (International Team) proposed Korea to accomplish ITA (ITER Transitional Arrangements) Task on detailed design, manufacturing feasibility and contract specification of specific, large sized tools such as Upending Tool, Lifting Tool, Sector Sub-assembly Tool and Sector Assembly Tool in Oct. 2004. Based on the concept design by ITER IT, Korea carried out ITA Task on detailed design of large-sized and specific Sector Sub-assembly and Sector Assembly Tools until Mar. 2006. The Sector Sub-assembly Tools mainly consist of the Upending, Lifting, Vacuum Vessel Support and Bracing, and Sector Sub-assembly Tool, among which the design of three tools are herein. The Sector Assembly Tools mainly consist of the Toroidal Field (TF) Gravity Support Assembly, Sector In-pit Assembly, TF Coil Assembly, Vacuum Vessel (VV) Welding and Vacuum Vessel Thermal Shield (TS) Assembly Tool, among which the design of Sector In-pit Assembly Tool is described herein

  4. Locals Collection

    Directory of Open Access Journals (Sweden)

    Stephen Hastings-King

    2010-03-01

    Full Text Available A locals collection is a set of parameters that are used to delimit data-mining operations. This piece uses a collection of locals from around Essex Massachusetts to shape and delimit an interrogation of post-reality in contemporary America. It explores the notion of crisis, the possibility of a crisis of empire that may or may not emerge in a media-space that does not allow crisis of empire to be mentioned and relations this maybe-crisis to the various levels of economic dysfunction that have become evident since late 2008. But mostly this piece explores ways in which particular stories about particular people do and do not link/link to these larger-scale narratives. This is the first of a potential series of locals collections that will mine the American post-real.

  5. Three-Dimensional Self-Assembled Photonic Crystal Waveguide

    Science.gov (United States)

    Baek, Kang-Hyun

    Photonic crystals (PCs), two- or three-dimensionally periodic, artificial, and dielectric structures, have a specific forbidden band for electromagnetic waves, referred to as photonic bandgap (PBG). The PBG is analogous to the electronic bandgap in natural crystal structures with periodic atomic arrangement. A well-defined and embedded planar, line, or point defect within the PCs causes a break in its structural periodicity, and introduces a state in the PBG for light localization. It offers various applications in integrated optics and photonics including optical filters, sharp bending light guides and very low threshold lasers. Using nanofabrication processes, PCs of the 2-D slab-type and 3-D layer-by-layer structures have been investigated widely. Alternatively, simple and low-cost self-assembled PCs with full 3-D PBG, inverse opals, have been suggested. A template with face centered cubic closed packed structure, opal, may initially be built by self-assembly of colloidal spheres, and is selectively removed after infiltrating high refractive index materials into the interstitials of spheres. In this dissertation, the optical waveguides utilizing the 3-D self-assembled PCs are discussed. The waveguides were fabricated by microfabrication technology. For high-quality colloidal silica spheres and PCs, reliable synthesis, self-assembly, and characterization techniques were developed. Its theoretical and experimental demonstrations are provided and correlated. They suggest that the self-assembled PCs with PBG are feasible for the applications in integrated optics and photonics.

  6. SV40 Assembly In Vivo and In Vitro

    Directory of Open Access Journals (Sweden)

    Ariella Oppenheim

    2008-01-01

    Full Text Available The Simian virus 40 (SV40 capsid is a T = 7d icosahedral lattice ∼45 nm in diameter surrounding the ∼5 kb circular minichromosome. The outer shell is composed of 360 monomers of the major capsid protein VP1, tightly bound in 72 pentamers. VP1 is a jellyroll β-barrel, with extending N- and C-terminal arms. The N-terminal arms bind DNA and face the interior of the capsid. The flexible C-arms tie together the 72 pentamers in three distinct kinds of interactions, thus facilitating the formation of a T = 7 icosahedron from identical pentameric building blocks. Assembly in vivo was shown to occur by addition of capsomers around the DNA. We apply a combination of biochemical and genetic approaches to study SV40 assembly. Our in vivo and in vitro studies suggest the following model: one or two capsomers bind at a high affinity to ses, the viral DNA encapsidation signal, forming the nucleation centre for assembly. Next, multiple capsomers attach concomitantly, at lower affinity, around the minichromosome. This increases their local concentration facilitating rapid, cooperative assembly reaction. Formation of the icosahedron proceeds either by gradual addition of single pentamers to the growing shell or by concerted assembly of pentamer clusters.

  7. Cadmium verification measurements of HFIR shroud assembly 22

    International Nuclear Information System (INIS)

    Chapman, J.A.; Schultz, F.J.

    1994-04-01

    This report discusses radiation-based nondestructive examination methods which have been used to successfully verify the presence of cadmium in High Flux Isotope Reactor (HFIR) spent-fuel shroud assembly number 22 (SA22). These measurements show, in part, that SA22 is certified to meet the criticality safety specifications for a proposed reconfiguration of the HFIR spent-fuel storage array. Measurement of the unique 558.6-keV gamma-ray from neutron radiative capture on cadmium provided conclusive evidence for the presence of cadmium in the outer shroud of the assembly. Cadmium verification in the center post and outer shroud was performed by measuring the degree of neutron transmission in SA22 relative to two calibration shroud assemblies. Each measurement was performed at a single location on the center post and outer shroud. These measurements do not provide information on the spatial distribution or uniformity of cadmium within an assembly. Separate measurements using analog and digital radiography were performed to (a) globally map the continuity of cadmium internal mass, and (b) locally determine the thickness of cadmium. Radiography results will be reported elsewhere. The measurements reported here should not be used to infer the thickness of cadmium in either the center post or outer shroud of an assembly

  8. Control rod guide tube assembly

    International Nuclear Information System (INIS)

    Jabsen, F.S.

    1982-01-01

    An improved fuel assembly is described as consisting of a sleeve that engages one end of a control rod guide tube essentially fixing the guide tube to one of the fuel assembly end structures. The end of the sleeve protrudes above the surface of the end fitting. The outer surface of the sleeve has a peripheral groove that engages the resilient sides of a cellular grid or lattice shaped lock. This lock fixes the sleeve in position between the various elements that comprise the end fitting, thereby eliminating a profusion of costly and potentially troublesome nuts, threaded studs and the like that are frequently employed in the fuel assemblies that are presently in use

  9. Fixture for aligning motor assembly

    Science.gov (United States)

    Shervington, Roger M.; Vaghani, Vallabh V.; Vanek, Laurence D.; Christensen, Scott A.

    2009-12-08

    An alignment fixture includes a rotor fixture, a stator fixture and a sensor system which measures a rotational displacement therebetween. The fixture precisely measures rotation of a generator stator assembly away from a NULL position referenced by a unique reference spline on the rotor shaft. By providing an adjustable location of the stator assembly within the housing, the magnetic axes within each generator shall be aligned to a predetermined and controlled tolerance between the generator interface mounting pin and the reference spline on the rotor shaft. Once magnetically aligned, each generator is essentially a line replaceable unit which may be readily mounted to any input of a multi-generator gearbox assembly with the assurance that the magnetic alignment will be within a predetermined tolerance.

  10. Device for identifying fuel assembly

    International Nuclear Information System (INIS)

    Imai, Tetsuo; Miyazawa, Tatsuo.

    1982-01-01

    Purpose: To accurately identify a symbol printed on a hanging tool at the upper part of a fuel assembly. Constitution: Optical fibers are bundled to prepare a detector which is disposed at a predetermined position on a hanging tool. This position is set by a guide. Thus, the light emitted from an illumination lamp arrives at the bottom of a groove printed on the upper surface of the tool, and is divided into a weak light reflected upwardly and a strong light reflected on the surface lower than the groove. When these lights are received by the optical fibers, the fibers corresponding to the grooved position become dark, and the fibers corresponding to the ungrooved position become bright. Since the fuel assembly is identified by the dark and bright of the optical fibers as symbols, different machining can be performed every fuel assembly on the upper surface of the tool. (Yoshihara, H.)

  11. Self-assembling peptide semiconductors

    Science.gov (United States)

    Tao, Kai; Makam, Pandeeswar; Aizen, Ruth; Gazit, Ehud

    2017-01-01

    Semiconductors are central to the modern electronics and optics industries. Conventional semiconductive materials bear inherent limitations, especially in emerging fields such as interfacing with biological systems and bottom-up fabrication. A promising candidate for bioinspired and durable nanoscale semiconductors is the family of self-assembled nanostructures comprising short peptides. The highly ordered and directional intermolecular π-π interactions and hydrogen-bonding network allow the formation of quantum confined structures within the peptide self-assemblies, thus decreasing the band gaps of the superstructures into semiconductor regions. As a result of the diverse architectures and ease of modification of peptide self-assemblies, their semiconductivity can be readily tuned, doped, and functionalized. Therefore, this family of electroactive supramolecular materials may bridge the gap between the inorganic semiconductor world and biological systems. PMID:29146781

  12. Workload analyse of assembling process

    Science.gov (United States)

    Ghenghea, L. D.

    2015-11-01

    The workload is the most important indicator for managers responsible of industrial technological processes no matter if these are automated, mechanized or simply manual in each case, machines or workers will be in the focus of workload measurements. The paper deals with workload analyses made to a most part manual assembling technology for roller bearings assembling process, executed in a big company, with integrated bearings manufacturing processes. In this analyses the delay sample technique have been used to identify and divide all bearing assemblers activities, to get information about time parts from 480 minutes day work time that workers allow to each activity. The developed study shows some ways to increase the process productivity without supplementary investments and also indicated the process automation could be the solution to gain maximum productivity.

  13. Insulation assembly for electric machine

    Science.gov (United States)

    Rhoads, Frederick W.; Titmuss, David F.; Parish, Harold; Campbell, John D.

    2013-10-15

    An insulation assembly is provided that includes a generally annularly-shaped main body and at least two spaced-apart fingers extending radially inwards from the main body. The spaced-apart fingers define a gap between the fingers. A slot liner may be inserted within the gap. The main body may include a plurality of circumferentially distributed segments. Each one of the plurality of segments may be operatively connected to another of the plurality of segments to form the continuous main body. The slot liner may be formed as a single extruded piece defining a plurality of cavities. A plurality of conductors (extendable from the stator assembly) may be axially inserted within a respective one of the plurality of cavities. The insulation assembly electrically isolates the conductors in the electric motor from the stator stack and from other conductors.

  14. Fuel assemblies for nuclear reactors

    International Nuclear Information System (INIS)

    Jabsen, F.S.

    1979-01-01

    In a nuclear fuel assembly, hollow guide posts protrude into a fuel assembly and fitting grill from a biased spring pad with a plunger that moves with the spring pad plugging one end of each of the guide posts. A plate on the end fitting grill that has a hole for fluid discharge partially plugs the other end of the guide post. Pressurized water coolant that fills the guide post volume acts as a shock absorber and should the reactor core receive a major seismic or other shock, the fuel assembly is compelled to move towards a pad depending from a transversely disposed support grid. The pad bears against the spring pad and the plunger progressively blocks the orifices provided by slots in the guide posts thus gradually absorbing the applied shock. After the orifice has been completely blocked, controlled fluid discharge continues through a hole coil spring cooperating in the attenuation of the shock. (author)

  15. z~2: An Epoch of Disk Assembly

    Science.gov (United States)

    Simons, Raymond C.; Kassin, Susan A.; Weiner, Benjamin; Heckman, Timothy M.; Trump, Jonathan; SIGMA, DEEP2

    2018-01-01

    At z = 0, the majority of massive star-forming galaxies contain thin, rotationally supported gas disks. It was once accepted that galaxies form thin disks early: collisional gas with high velocity dispersion should dissipate energy, conserve angular momentum, and develop strong rotational support in only a few galaxy crossing times (~few hundred Myr). However, this picture is complicated at high redshift, where the processes governing galaxy assembly tend to be violent and inhospitable to disk formation. We present results from our SIGMA survey of star-forming galaxy kinematics at z = 2. These results challenge the simple picture described above: galaxies at z = 2 are unlike local well-ordered disks. Their kinematics tend to be much more disordered, as quantified by their low ratios of rotational velocity to gas velocity dispersion (Vrot/σg): less than 35% of galaxies have Vrot/σg > 3. For comparison, nearly 100% of local star-forming galaxies meet this same threshold. We combine our high redshift sample with a similar low redshift sample from the DEEP2 survey. This combined sample covers a continuous redshift baseline over 0.1 < z < 2.5, spanning 10 Gyrs of cosmic time. Over this period, galaxies exhibit remarkably smooth kinematic evolution on average. All galaxies tend towards rotational support with time, and it is reached earlier in higher mass systems. This is due to both a significant decline in gas velocity dispersion and a mild rise in ordered rotational motions. These results indicate that z = 2 is a period of disk assembly, during which the strong rotational support present in today’s massive disk galaxies is only just beginning to emerge.

  16. DNA-guided nanoparticle assemblies

    Science.gov (United States)

    Gang, Oleg; Nykypanchuk, Dmytro; Maye, Mathew; van der Lelie, Daniel

    2013-07-16

    In some embodiments, DNA-capped nanoparticles are used to define a degree of crystalline order in assemblies thereof. In some embodiments, thermodynamically reversible and stable body-centered cubic (bcc) structures, with particles occupying <.about.10% of the unit cell, are formed. Designs and pathways amenable to the crystallization of particle assemblies are identified. In some embodiments, a plasmonic crystal is provided. In some aspects, a method for controlling the properties of particle assemblages is provided. In some embodiments a catalyst is formed from nanoparticles linked by nucleic acid sequences and forming an open crystal structure with catalytically active agents attached to the crystal on its surface or in interstices.

  17. Muscle assembly: a titanic achievement?

    Science.gov (United States)

    Gregorio, C C; Granzier, H; Sorimachi, H; Labeit, S

    1999-02-01

    The formation of perfectly aligned myofibrils in striated muscle represents a dramatic example of supramolecular assembly in eukaryotic cells. Recently, considerable progress has been made in deciphering the roles that titin, the third most abundant protein in muscle, has in this process. An increasing number of sarcomeric proteins (ligands) are being identified that bind to specific titin domains. Titin may serve as a molecular blueprint for sarcomere assembly and turnover by specifying the precise position of its ligands within each half-sarcomere in addition to functioning as a molecular spring that maintains the structural integrity of the contracting myofibrils.

  18. Radical probing of spliceosome assembly.

    Science.gov (United States)

    Grewal, Charnpal S; Kent, Oliver A; MacMillan, Andrew M

    2017-08-01

    Here we describe the synthesis and use of a directed hydroxyl radical probe, tethered to a pre-mRNA substrate, to map the structure of this substrate during the spliceosome assembly process. These studies indicate an early organization and proximation of conserved pre-mRNA sequences during spliceosome assembly. This methodology may be adapted to the synthesis of a wide variety of modified RNAs for use as probes of RNA structure and RNA-protein interaction. Copyright © 2017 Elsevier Inc. All rights reserved.

  19. A generalized macro-assembler

    International Nuclear Information System (INIS)

    Kaul, Mohan Lai

    1970-01-01

    The objective of this research is to study existing macro assemblers, and to create a generalized macro assembler, MAG-I, which is a system independent of a source language, and provides the following possibilities: development of any existing language, translation from a language to another, and creation of a new language. The user can choose his own notations to define macros. The system is implemented on an IBM 360/91 computer. Programs are written in symbolic language and the input/output software is written in Fortran [fr

  20. Local equilibrium

    Energy Technology Data Exchange (ETDEWEB)

    Anon.

    1984-12-15

    From 3-6 September the First International Workshop on Local Equilibrium in Strong Interaction Physics took place in Bad-Honnef at the Physics Centre of the German Physical Society. A number of talks covered the experimental and theoretical investigation of the 'hotspots' effect, both in high energy particle physics and in intermediate energy nuclear physics.

  1. DNA Self-Assembly: From Chirality to Evolution

    Directory of Open Access Journals (Sweden)

    Youri Timsit

    2013-04-01

    Full Text Available Transient or long-term DNA self-assembly participates in essential genetic functions. The present review focuses on tight DNA-DNA interactions that have recently been found to play important roles in both controlling DNA higher-order structures and their topology. Due to their chirality, double helices are tightly packed into stable right-handed crossovers. Simple packing rules that are imposed by DNA geometry and sequence dictate the overall architecture of higher order DNA structures. Close DNA-DNA interactions also provide the missing link between local interactions and DNA topology, thus explaining how type II DNA topoisomerases may sense locally the global topology. Finally this paper proposes that through its influence on DNA self-assembled structures, DNA chirality played a critical role during the early steps of evolution.

  2. EB1 is required for primary cilia assembly in fibroblasts

    DEFF Research Database (Denmark)

    Schrøder, Jacob M; Schneider, Linda; Christensen, Søren T

    2007-01-01

    EB1 is a small microtubule (MT)-binding protein that associates preferentially with MT plus ends and plays a role in regulating MT dynamics. EB1 also targets other MT-associated proteins to the plus end and thereby regulates interactions of MTs with the cell cortex, mitotic kinetochores, and diff...... that localization of EB1 at the centriole/basal body is required for primary cilia assembly in fibroblasts....

  3. Improving intrinsic corrosion reliability of printed circuit board assembly

    DEFF Research Database (Denmark)

    Ambat, Rajan; Conseil, Helene

    2016-01-01

    conditions, therefore the protection of electronic devices is becoming a critical factor in system design. Humidity and local condensation inside electronic enclosures can significantly alter the performance of electronic devices. The presence of moisture in a PCB alters its quality, functionality, thermal...... performance, and thermo-mechanical properties, while condensation on the surface of printed circuit board assemblies (PCBAs) can lead to electrical failures, like electrochemical migration. The result is reduced life span for electronic products and heavy economic loss due to failures....

  4. Biocompatible and Biomimetic Self-Assembly of Functional Nanostructures

    Science.gov (United States)

    2010-02-28

    evaporation induced self-assembly of aqueous silica precursors with a biologically compatible surfactant, glycerol monooleate ( GMO ) via dip-coating...film is first deposited, it has a relatively low contact angle with water and remains in a semi-solid state. Upon exposure to UV/ozone, the GMO begins...Figure 8. A) Water contact angle of a GMO -templated silica film as a function of UV light and ozone exposure time, B) Localization of fluorescently

  5. Pattern fuel assembly loading system

    International Nuclear Information System (INIS)

    Ahmed, H.J.; Gerkey, K.S.; Miller, T.W.; Wylie, M.E.

    1986-01-01

    This patent describes an interactive system for facilitating preloading of fuel rods into magazines, which comprises: an operator work station adapted for positioning between a supply of fuel rods of predetermined types, and the magazine defining grid locations for a predetermined fuel assembly; display means associated with the work station; scanner means associated with the work station and adapted for reading predetermined information accompanying the fuel rods; a rectangular frame adapted for attachment to one end of the fuel assembly loading magazine; prompter/detector means associated with the frame for detecting insertion of a fuel rod into the magazine; and processing means responsive to the scanner means and the sensing means for prompting the operator via the display means to pre-load the fuel rods into desired grid locations in the magazine. An apparatus is described for facilitating pre-loading of fuel rods in predetermined grid locations of a fuel assembly loading magazine, comprising: a rectangular frame adapted for attachment to one end of the fuel assembly loading magazine; and means associated with the frame for detecting insertion of fuel rods into the magazine

  6. Monolithic fiber optic sensor assembly

    Science.gov (United States)

    Sanders, Scott

    2015-02-10

    A remote sensor element for spectrographic measurements employs a monolithic assembly of one or two fiber optics to two optical elements separated by a supporting structure to allow the flow of gases or particulates therebetween. In a preferred embodiment, the sensor element components are fused ceramic to resist high temperatures and failure from large temperature changes.

  7. ATLAS Assembly Hall Open Day

    CERN Multimedia

    Patrice Loiez

    2004-01-01

    To mark the 50th Anniversary of the founding of CERN, a day of tours, displays and presentations was held in October 2004. The assembly halls for the experiments that were waiting to be installed on the LHC, such as ATLAS shown here, were transformed into display areas and cafés.

  8. Flow resistance in rod assemblies

    International Nuclear Information System (INIS)

    Korsun, A.S.; Sokolova, M.S.

    2000-01-01

    The general form of relation between the resistance force and the velocity vector, resistance tensor structure and possible types of anisotropy in the flow thorough such structures as rod or tube assemblies are under discussion. Some questions of experimental determination of volumetric resistance force tensor are also under consideration. (author)

  9. Simulated nuclear reactor fuel assembly

    International Nuclear Information System (INIS)

    Berta, V.T.

    1993-01-01

    An apparatus for electrically simulating a nuclear reactor fuel assembly. It includes a heater assembly having a top end and a bottom end and a plurality of concentric heater tubes having electrical circuitry connected to a power source, and radially spaced from each other. An outer target tube and an inner target tube is concentric with the heater tubes and with each other, and the outer target tube surrounds and is radially spaced from the heater tubes. The inner target tube is surrounded by and radially spaced from the heater tubes and outer target tube. The top of the assembly is generally open to allow for the electrical power connection to the heater tubes, and the bottom of the assembly includes means for completing the electrical circuitry in the heater tubes to provide electrical resistance heating to simulate the power profile in a nuclear reactor. The embedded conductor elements in each heater tube is split into two halves for a substantial portion of its length and provided with electrical isolation such that each half of the conductor is joined at one end and is not joined at the other end

  10. In vitro assembly of catalase.

    Science.gov (United States)

    Baureder, Michael; Barane, Elisabeth; Hederstedt, Lars

    2014-10-10

    Most aerobic organisms contain catalase, which functions to decompose hydrogen peroxide. Typical catalases are structurally complex homo-tetrameric enzymes with one heme prosthetic group buried in each subunit. It is not known how catalase in the cell is assembled from its constituents. The bacterium Enterococcus faecalis cannot synthesize heme but can acquire it from the environment to form a cytoplasmic catalase. We have in E. faecalis monitored production of the enzyme polypeptide (KatA) depending on the availability of heme and used our findings to devise a procedure for the purification of preparative amounts of in vivo-synthesized apocatalase. We show that fully active catalase can be obtained in vitro by incubating isolated apoprotein with hemin. We have characterized features of the assembly process and describe a temperature-trapped hemylated intermediate of the enzyme maturation process. Hemylation of apocatalase does not require auxiliary cell components, but rapid assembly of active enzyme seemingly is assisted in the cell. Our findings provide insight about catalase assembly and offer new experimental possibilities for detailed studies of this process. © 2014 by The American Society for Biochemistry and Molecular Biology, Inc.

  11. In Vitro Assembly of Catalase*

    Science.gov (United States)

    Baureder, Michael; Barane, Elisabeth; Hederstedt, Lars

    2014-01-01

    Most aerobic organisms contain catalase, which functions to decompose hydrogen peroxide. Typical catalases are structurally complex homo-tetrameric enzymes with one heme prosthetic group buried in each subunit. It is not known how catalase in the cell is assembled from its constituents. The bacterium Enterococcus faecalis cannot synthesize heme but can acquire it from the environment to form a cytoplasmic catalase. We have in E. faecalis monitored production of the enzyme polypeptide (KatA) depending on the availability of heme and used our findings to devise a procedure for the purification of preparative amounts of in vivo-synthesized apocatalase. We show that fully active catalase can be obtained in vitro by incubating isolated apoprotein with hemin. We have characterized features of the assembly process and describe a temperature-trapped hemylated intermediate of the enzyme maturation process. Hemylation of apocatalase does not require auxiliary cell components, but rapid assembly of active enzyme seemingly is assisted in the cell. Our findings provide insight about catalase assembly and offer new experimental possibilities for detailed studies of this process. PMID:25148685

  12. Fuel assemblies for nuclear reactor

    International Nuclear Information System (INIS)

    Nishi, Akihito.

    1987-01-01

    Purpose: To control power-up rate at the initial burning stage of new fuel assemblies due to fuel exchange in a pressure tube type power reactor. Constitution: Burnable poisons are disposed to a most portion of fuel pellets in a fuel assembly to such a low concentration as the burn-up rate changes with time at the initial stage of the burning. The most portion means substantially more than one-half part of the pellets and gadolinia is used as burn-up poisons to be dispersed and the concentration is set to less than about 0.2 %. Upon elapse of about 15 days after the charging, the burnable poisons are eliminated and the infinite multiplication factors are about at 1.2 to attain a predetermined power state. Since the power-up rate of the nuclear reactor fuel assembly is about 0.1 % power/hour and the power-up rate of the fuel assembly around the exchanged channel is lower than that, it can be lowered sufficiently than the limit for the power-up rate practiced upon reactor start-up thereby enabling to replace fuels during power operation. (Horiuchi, T.)

  13. FMIT Test assemblies. Progress report

    International Nuclear Information System (INIS)

    Nygren, R.E.; Opperman, E.K.

    1978-08-01

    This progress report is a reference document for a number of inter-related tasks supporting the Fusion Materials Irradiation Test (FMIT) Facility being developed by the Hanford Engineering Development Laboratory. The report describes the basic configuration of test assemblies and supporting rationale based on the neutron flux distribution. Perturbed and unperturbed flux profiles are discussed as well as heating rates and cooling requirements

  14. Dynamics of assembly production flow

    Science.gov (United States)

    Ezaki, Takahiro; Yanagisawa, Daichi; Nishinari, Katsuhiro

    2015-06-01

    Despite recent developments in management theory, maintaining a manufacturing schedule remains difficult because of production delays and fluctuations in demand and supply of materials. The response of manufacturing systems to such disruptions to dynamic behavior has been rarely studied. To capture these responses, we investigate a process that models the assembly of parts into end products. The complete assembly process is represented by a directed tree, where the smallest parts are injected at leaves and the end products are removed at the root. A discrete assembly process, represented by a node on the network, integrates parts, which are then sent to the next downstream node as a single part. The model exhibits some intriguing phenomena, including overstock cascade, phase transition in terms of demand and supply fluctuations, nonmonotonic distribution of stockout in the network, and the formation of a stockout path and stockout chains. Surprisingly, these rich phenomena result from only the nature of distributed assembly processes. From a physical perspective, these phenomena provide insight into delay dynamics and inventory distributions in large-scale manufacturing systems.

  15. A Role for Myosin Va in Human Cytomegalovirus Nuclear Egress.

    Science.gov (United States)

    Wilkie, Adrian R; Sharma, Mayuri; Pesola, Jean M; Ericsson, Maria; Fernandez, Rosio; Coen, Donald M

    2018-03-15

    Herpesviruses replicate and package their genomes into capsids in replication compartments within the nuclear interior. Capsids then move to the inner nuclear membrane for envelopment and release into the cytoplasm in a process called nuclear egress. We previously found that nuclear F-actin is induced upon infection with the betaherpesvirus human cytomegalovirus (HCMV) and is important for nuclear egress and capsid localization away from replication compartment-like inclusions toward the nuclear rim. Despite these and related findings, it has not been shown that any specific motor protein is involved in herpesvirus nuclear egress. In this study, we have investigated whether the host motor protein, myosin Va, could be fulfilling this role. Using immunofluorescence microscopy and coimmunoprecipitation, we observed associations between a nuclear population of myosin Va and the viral major capsid protein, with both concentrating at the periphery of replication compartments. Immunoelectron microscopy showed that nearly 40% of assembled nuclear capsids associate with myosin Va. We also found that myosin Va and major capsid protein colocalize with nuclear F-actin. Importantly, antagonism of myosin Va with RNA interference or a dominant negative mutant revealed that myosin Va is important for the efficient production of infectious virus, capsid accumulation in the cytoplasm, and capsid localization away from replication compartment-like inclusions toward the nuclear rim. Our results lead us to suggest a working model whereby human cytomegalovirus capsids associate with myosin Va for movement from replication compartments to the nuclear periphery during nuclear egress. IMPORTANCE Little is known regarding how newly assembled and packaged herpesvirus capsids move from the nuclear interior to the periphery during nuclear egress. While it has been proposed that an actomyosin-based mechanism facilitates intranuclear movement of alphaherpesvirus capsids, a functional role for

  16. Surface-Assisted Self-Assembly Strategies Leading to Supramolecular Hydrogels.

    Science.gov (United States)

    Vigier-Carrière, Cécile; Boulmedais, Fouzia; Schaaf, Pierre; Jierry, Loïc

    2018-02-05

    Localized molecular self-assembly processes leading to the growth of nanostructures exclusively from the surface of a material is one of the great challenges in surface chemistry. In the last decade, several works have been reported on the ability of modified or unmodified surfaces to manage the self-assembly of low-molecular-weight hydrogelators (LMWH) resulting in localized supramolecular hydrogel coatings mainly based on nanofiber architectures. This Minireview highlights all strategies that have emerged recently to initiate and localize LMWH supramolecular hydrogel formation, their related fundamental issues and applications. © 2018 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

  17. Monitoring device for local power peaking coefficients

    International Nuclear Information System (INIS)

    Mihashi, Ishi

    1987-01-01

    Purpose: To determine and monitor the local power peaking coefficients by a method not depending on the combination of fuel types. Constitution: Representative values for the local power distribution can be obtained by determining corresponding burn-up degrees based on the burn-up degree of each of fuel assembly segments obtained in a power distribution monitor and by the interpolation and extrapolation of void coefficients. The typical values are multiplied with compensation coefficients for the control rod effect and coefficients for compensating the effect of adjacent fuel assemblies in a calculation device to obtain typical values for the present local power distribution compensated with all of the effects. Further, the calculation device compares them with typical values of the present local power distribution to obtain an aimed local power peaking coefficient as the maximum value thereof. According to the present invention, since the local power peaking coefficients can be determined not depending on the combination of the kind of fuels, if the combination of fuel assemblies is increased upon fuel change, the amount of operation therefor is not increased. (Kamimura, M.)

  18. Multi-Robot Assembly Strategies and Metrics

    Science.gov (United States)

    MARVEL, JEREMY A.; BOSTELMAN, ROGER; FALCO, JOE

    2018-01-01

    We present a survey of multi-robot assembly applications and methods and describe trends and general insights into the multi-robot assembly problem for industrial applications. We focus on fixtureless assembly strategies featuring two or more robotic systems. Such robotic systems include industrial robot arms, dexterous robotic hands, and autonomous mobile platforms, such as automated guided vehicles. In this survey, we identify the types of assemblies that are enabled by utilizing multiple robots, the algorithms that synchronize the motions of the robots to complete the assembly operations, and the metrics used to assess the quality and performance of the assemblies. PMID:29497234

  19. Multi-Robot Assembly Strategies and Metrics.

    Science.gov (United States)

    Marvel, Jeremy A; Bostelman, Roger; Falco, Joe

    2018-02-01

    We present a survey of multi-robot assembly applications and methods and describe trends and general insights into the multi-robot assembly problem for industrial applications. We focus on fixtureless assembly strategies featuring two or more robotic systems. Such robotic systems include industrial robot arms, dexterous robotic hands, and autonomous mobile platforms, such as automated guided vehicles. In this survey, we identify the types of assemblies that are enabled by utilizing multiple robots, the algorithms that synchronize the motions of the robots to complete the assembly operations, and the metrics used to assess the quality and performance of the assemblies.

  20. Coronavirus envelope (E) protein remains at the site of assembly

    International Nuclear Information System (INIS)

    Venkatagopalan, Pavithra; Daskalova, Sasha M.; Lopez, Lisa A.; Dolezal, Kelly A.; Hogue, Brenda G.

    2015-01-01

    Coronaviruses (CoVs) assemble at endoplasmic reticulum Golgi intermediate compartment (ERGIC) membranes and egress from cells in cargo vesicles. Only a few molecules of the envelope (E) protein are assembled into virions. The role of E in morphogenesis is not fully understood. The cellular localization and dynamics of mouse hepatitis CoV A59 (MHV) E protein were investigated to further understanding of its role during infection. E protein localized in the ERGIC and Golgi with the amino and carboxy termini in the lumen and cytoplasm, respectively. E protein does not traffic to the cell surface. MHV was genetically engineered with a tetracysteine tag at the carboxy end of E. Fluorescence recovery after photobleaching (FRAP) showed that E is mobile in ERGIC/Golgi membranes. Correlative light electron microscopy (CLEM) confirmed the presence of E in Golgi cisternae. The results provide strong support that E proteins carry out their function(s) at the site of budding/assembly. - Highlights: • Mouse hepatitis coronavirus (MHV-CoV) E protein localizes in the ERGIC and Golgi. • MHV-CoV E does not transport to the cell surface. • MHV-CoV can be genetically engineered with a tetracysteine tag appended to E. • First FRAP and correlative light electron microscopy of a CoV E protein. • Live-cell imaging shows that E is mobile in ERGIC/Golgi membranes

  1. Coronavirus envelope (E) protein remains at the site of assembly

    Energy Technology Data Exchange (ETDEWEB)

    Venkatagopalan, Pavithra [The Biodesign Institute, Center for Infectious Diseases and Vaccinology, Arizona State University, Tempe, AZ 85287-5401 (United States); School of Life Sciences, Arizona State University, Tempe, AZ 85287-5401 (United States); Microbiology Graduate Program, Arizona State University, Tempe, AZ 85287-5401 (United States); Daskalova, Sasha M. [The Biodesign Institute, Center for Infectious Diseases and Vaccinology, Arizona State University, Tempe, AZ 85287-5401 (United States); Department of Biochemistry and Chemistry, Arizona State University, Tempe, AZ 85287-5401 (United States); Lopez, Lisa A. [The Biodesign Institute, Center for Infectious Diseases and Vaccinology, Arizona State University, Tempe, AZ 85287-5401 (United States); School of Life Sciences, Arizona State University, Tempe, AZ 85287-5401 (United States); Molecular and Cellular Biology Graduate Program, Arizona State University, Tempe, AZ 85287-5401 (United States); Dolezal, Kelly A. [The Biodesign Institute, Center for Infectious Diseases and Vaccinology, Arizona State University, Tempe, AZ 85287-5401 (United States); School of Life Sciences, Arizona State University, Tempe, AZ 85287-5401 (United States); Microbiology Graduate Program, Arizona State University, Tempe, AZ 85287-5401 (United States); Hogue, Brenda G., E-mail: Brenda.Hogue@asu.edu [The Biodesign Institute, Center for Infectious Diseases and Vaccinology, Arizona State University, Tempe, AZ 85287-5401 (United States); School of Life Sciences, Arizona State University, Tempe, AZ 85287-5401 (United States)

    2015-04-15

    Coronaviruses (CoVs) assemble at endoplasmic reticulum Golgi intermediate compartment (ERGIC) membranes and egress from cells in cargo vesicles. Only a few molecules of the envelope (E) protein are assembled into virions. The role of E in morphogenesis is not fully understood. The cellular localization and dynamics of mouse hepatitis CoV A59 (MHV) E protein were investigated to further understanding of its role during infection. E protein localized in the ERGIC and Golgi with the amino and carboxy termini in the lumen and cytoplasm, respectively. E protein does not traffic to the cell surface. MHV was genetically engineered with a tetracysteine tag at the carboxy end of E. Fluorescence recovery after photobleaching (FRAP) showed that E is mobile in ERGIC/Golgi membranes. Correlative light electron microscopy (CLEM) confirmed the presence of E in Golgi cisternae. The results provide strong support that E proteins carry out their function(s) at the site of budding/assembly. - Highlights: • Mouse hepatitis coronavirus (MHV-CoV) E protein localizes in the ERGIC and Golgi. • MHV-CoV E does not transport to the cell surface. • MHV-CoV can be genetically engineered with a tetracysteine tag appended to E. • First FRAP and correlative light electron microscopy of a CoV E protein. • Live-cell imaging shows that E is mobile in ERGIC/Golgi membranes.

  2. Net Locality

    DEFF Research Database (Denmark)

    de Souza e Silva, Adriana Araujo; Gordon, Eric

    Provides an introduction to the new theory of Net Locality and the profound effect on individuals and societies when everything is located or locatable. Describes net locality as an emerging form of location awareness central to all aspects of digital media, from mobile phones, to Google Maps......, to location-based social networks and games, such as Foursquare and facebook. Warns of the threats these technologies, such as data surveillance, present to our sense of privacy, while also outlining the opportunities for pro-social developments. Provides a theory of the web in the context of the history...... of emerging technologies, from GeoCities to GPS, Wi-Fi, Wiki Me, and Google Android....

  3. Local supertwistors

    International Nuclear Information System (INIS)

    Merkulov, S.A.

    1987-01-01

    Geometry of local supertwistors is investigated. It is proved that the Yang-Mills equations for the introduced ansatz for supertwistor connection are equivalent to free bach equations, describing the dynamics of N=1 conformal supergravity. Analogous interpretation of the dynamics of N=1 conformal supergravity coupled to a vector superfield is proposed. It is proved that any complex conformally right or left flat superspace automatically satisfies the Bach equations

  4. Influência de processos locais e regionais nas assembléias de peixes em reservatórios do Estado do Paraná, Brasil - DOI: 10.4025/actascibiolsci.v25i1.2087 Influence of local and regional processes on fish Assemblager in reservoirs of Paraná State, Brazil - DOI: 10.4025/actascibiolsci.v25i1.2087

    Directory of Open Access Journals (Sweden)

    Angelo Antonio Agostinho

    2003-04-01

    Full Text Available O objetivo deste estudo foi identificar os principais processos (locais e/ou regionais que influenciam a composição e a estrutura das assembléias de peixes em reservatórios do Estado do Paraná. Foram amostrados seis reservatórios (Capivari, Guaricana, Alagados, Fiú, Mourão e Rio dos Patos. As coletas foram trimestrais (de julho/95 a fevereiro/97 e de março/98 a fevereiro/99, com uso de redes de espera simples e tresmalhos, de diferentes malhagens, expostas por 24 horas. Todos os exemplares foram identificados, medidos, pesados e a abundância das espécies foi expressa pela captura por unidade de esforço (CPUE, dada em número (no ind./ 1000m2 de rede* 24h. Variáveis abióticas (processos locais também foram medidas no momento de coleta. A análise de correspondência com remoção do efeito do arco (DCA e a análise de componentes principais (PCA foram utilizadas para sumarizar os dados de abundância e abióticos, respectivamente. Os escores dos eixos dessas análises foram utilizados para avaliar a relação entre os fatores abióticos (locais e regionais e a estrutura das assembléias de peixes. Os processos regionais parecem ser os principais responsáveis pela composição e, conseqüentemente, pela estrutura das assembléias de peixes nos reservatóriosThe aim of this study was to identify the main processes (local and/or regional that influence in the composition and structure of fish assemblages in reservoirs located in the state of Paraná. Six reservoirs were sampled (Capivari, Guaricana, Alagados, Fiú, Mourão and Rio dos Patos. The samples were quarterly taken from July/95 to February/97 and March/98 to February/99 using gillnets and trammel nets of different mesh sizes set for 24 hours. The abundance was indexed by the catch per effort in number (No. ind./ 1000m2 net* 24 hs. All fishes collected were identified, measured and weighted. Some abiotic variables (local process were measured during the samples. The detrended

  5. Molecular Assemblies of Finite Shapes: Design and Self-Assembly ...

    Indian Academy of Sciences (India)

    Assembly via Coordination · Slide 2 · Slide 3 · Slide 4 · Slide 5 · Slide 6 · Slide 7 · Slide 8 · Slide 9 · Slide 10 · Slide 11 · Slide 12 · Slide 13 · Slide 14 · Slide 15 · Slide 16 · Slide 17 · Slide 18 · Slide 19 · Slide 20 · Slide 21 · Molecular Box · Slide 23.

  6. Autonomous Assembly of Structures in Space

    Data.gov (United States)

    National Aeronautics and Space Administration — In-orbit assembly of structures is a task that must be performed by space-walking humans, and yet it is costly, time-consuming, and potentially dangerous. Assembly...

  7. Properties of Molecular organized assemblies at interfaces

    Indian Academy of Sciences (India)

    Dr.AURNA

    Organized molecular assemblies. An organized molecular assembly is a group of atoms or ..... Simulations of the growth of clusters on a .... dynamics and function. ➢Actively ... Study of amphiphilic derivatives of YIGSR, mutated at hyper active ...

  8. Biomedical Applications of Self-Assembling Peptides

    NARCIS (Netherlands)

    Radmalekshahi, Mazda; Lempsink, Ludwijn; Amidi, Maryam; Hennink, Wim E.; Mastrobattista, Enrico

    2016-01-01

    Self-assembling peptides have gained increasing attention as versatile molecules to generate diverse supramolecular structures with tunable functionality. Because of the possibility to integrate a wide range of functional domains into self-assembling peptides including cell attachment sequences,

  9. Storage method for spent fuel assembly

    International Nuclear Information System (INIS)

    Tajiri, Hiroshi.

    1992-01-01

    In the present invention, spent fuel assemblies are arranged at a dense pitch in a storage rack by suppressing the reactivity of the assemblies, to increase storage capacity for the spent fuel assemblies. That is, neutron absorbers are filled in the cladding tube of an absorbing rod, and the diameter thereof is substantially equal with that of a fuel rod. A great amount of the absorbing rods are arranged at the outer circumference of the fuel assembly. Then, they are fixed integrally to the fuel assembly and stored in a storage rack. In this case, the storage rack may be constituted only with angle materials which are inexpensive and installed simply. With such a constitution, in the fuel assembly having absorbing rods wound therearound, neutrons are absorbed by absorbing rods and the reactivity is lowered. Accordingly, the assembly arrangement pitch in the storage rack can be made dense. As a result, the storage capacity for the assemblies is increased. (I.S.)

  10. Local supertwistors

    International Nuclear Information System (INIS)

    Merkulov, S.A.

    1987-01-01

    The geometry of local supertwistors is investigated. An ansatz on the form of the supertwistor superconnection is introduced. Because of this restriction on the form of such a superconnection the Yang-Mills equations for the superconnection turn out to be equivalent to the free Bach equations describing the dynamics of simple conformal supergravity. It is shown that the equations of motion of conformal supergravity interacting with a vector superfield admit an analogous interpretation. It is proved that an arbitrary conformally right-flat or left-flat superspace is automatically a solution of the Bach equations

  11. Magnetic scanning of LWR fuel assemblies

    International Nuclear Information System (INIS)

    Fiarman, S.; Moodenbaugh, A.

    1980-01-01

    Nondestructive assay (NDA) techniques are available both for fresh and spent fuel, but generally are too time consuming and do not uniquely identify an assembly. A new method is reported to obtain a signature from a magnetic scan of each assembly. This scan is an NDA technique that detects magnetic inclusions. It is potentially fast (5 min/assembly), and may provide a unique signature from the magnetic properties of each fuel assembly

  12. Virtual Reality and Haptics for Product Assembly

    Directory of Open Access Journals (Sweden)

    Maria Teresa Restivo

    2012-01-01

    Full Text Available Haptics can significantly enhance the user's sense of immersion and interactivity. An industrial application of virtual reality and haptics for product assembly is described in this paper, which provides a new and low-cost approach for product assembly design, assembly task planning and assembly operation training. A demonstration of the system with haptics device interaction was available at the session of exp.at'11.

  13. Regenerator cross arm seal assembly

    Science.gov (United States)

    Jackman, Anthony V.

    1988-01-01

    A seal assembly for disposition between a cross arm on a gas turbine engine block and a regenerator disc, the seal assembly including a platform coextensive with the cross arm, a seal and wear layer sealingly and slidingly engaging the regenerator disc, a porous and compliant support layer between the platform and the seal and wear layer porous enough to permit flow of cooling air therethrough and compliant to accommodate relative thermal growth and distortion, a dike between the seal and wear layer and the platform for preventing cross flow through the support layer between engine exhaust and pressurized air passages, and air diversion passages for directing unregenerated pressurized air through the support layer to cool the seal and wear layer and then back into the flow of regenerated pressurized air.

  14. Fuel assembly and reactor core

    International Nuclear Information System (INIS)

    Moriwaki, Masanao; Aoyama, Motoo; Masumi, Ryoji; Ishibashi, Yoko.

    1995-01-01

    A fuel assembly comprises a plurality of fuel rods filled with nuclear fuels, a plurality of burnable poison-incorporated fuel rods and a spectral shift-type water rod. As the burnable poison for the burnable poison-incorporated fuel rod, a plurality of burnable poison elements each having a different neutron absorption cross section are used. A burnable poison element such as boron having a relatively small neutron absorbing cross section is disposed more in the upper half region than the lower half region of the burnable poison-incorporated fuel rods. In addition, a burnable poison element such as gadolinium having a relatively large neutron absorbing cross section is disposed more in the lower half-region than the upper half region thereof. This can flatten the power distribution in the vertical direction of the fuel assembly and the power distribution in the horizontal direction at the final stage of the operation cycle. (I.N.)

  15. System for assembling nuclear fuel elements

    International Nuclear Information System (INIS)

    1980-01-01

    An automatic system is described for assembling nuclear fuel elements, in particular those employing mixed oxide fuels. The system includes a sealing mechanism which allows movement during the assembling of the fuel element along the assembly stations without excessive release of contaminants. (U.K.)

  16. Plutonium demonstration assemblies in the CNA core

    International Nuclear Information System (INIS)

    Romain, J.L.

    1975-01-01

    The SENA (Societe d'Exploitation Nucleaire des Ardennes) has decided to load two plutonium assemblies at the beginning of the 6th cycle of the CNA (Centrale Nucleaire des Ardennes). These assemblies will be loaded in September 1975 and will undergo three irradiation cycles. A general description of these two assemblies and nuclear design calculations that have been performed are presented [fr

  17. Shock absorbing structure for nuclear fuel assemblies

    International Nuclear Information System (INIS)

    Jabsen, F.S.

    1981-01-01

    A hydraulic apparatus is described that absorbs shocks that may be applied to fuel assemblies. Spring pads mounted on the upper end fittings of the fuel assemblies have plungers that move within hollow guide posts attached to the upper grids of the fuel assemblies. (L.L.)

  18. 3D Programmable Micro Self Assembly

    National Research Council Canada - National Science Library

    Bohringer, Karl F; Parviz, Babak A; Klavins, Eric

    2005-01-01

    .... We have developed a "self assembly tool box" consisting of a range of methods for micro-scale self-assembly in 2D and 3D We have shown physical demonstrations of simple 3D self-assemblies which lead...

  19. Assemble-to-order systems: a review

    NARCIS (Netherlands)

    Atan, Z.; Ahmadi, T.; Stegehuis, C.; de Kok, A.G.; Adan, I.J.B.F.

    2017-01-01

    In this paper, we review the recent literature on assemble-to-order systems. Each assemble-to-order system consists of multiple components and end-products. The components are assembled into the end-products after information on customer demand is received but the decision on what components to

  20. Shock buffer for nuclear control assembly

    International Nuclear Information System (INIS)

    Bevilacqua, F.

    1977-01-01

    A shock buffer is provided for the gradual deceleration of a rapidly descending control element assembly in a nuclear reactor. The interactive buffer components are associated respectively with the movable control element assembly and part of the upper guide structure independent of and spaced from the fuel assemblies of the reactor

  1. Metal-ceramic joint assembly

    Science.gov (United States)

    Li, Jian

    2002-01-01

    A metal-ceramic joint assembly in which a brazing alloy is situated between metallic and ceramic members. The metallic member is either an aluminum-containing stainless steel, a high chromium-content ferritic stainless steel or an iron nickel alloy with a corrosion protection coating. The brazing alloy, in turn, is either an Au-based or Ni-based alloy with a brazing temperature in the range of 9500 to 1200.degree. C.

  2. Nuclear fuel sub-assemblies

    International Nuclear Information System (INIS)

    Dodd, J.A.; Butterfield, C.E.; Waite, E.

    1979-01-01

    A fast reactor fuel sub-assembly has honeycomb grids for laterally supporting the fuel pins. The grids are of two series and are arranged alternately along the bundle. The grids of a first series provide a discrete cell for each pin but the grids of the second series have a peripheral group of cells only. The grids of the second series provide intermediate support of the edge pins to restrain bow. (author)

  3. Biologically Assembled Quantum Electronic Arrays

    Science.gov (United States)

    2013-06-07

    Koh , Faxian Xiu, Xingchen Ye, Dong-Kyun Ko, Kang L. Wang, Cherie R. Kagan, Christopher B. Murray. Multiscale Periodic Assembly of Striped Nanocrystal...study is the LlM method (See M. T. Raman et al, Applied . Physics L etters 94, 042507, 2009). This method is a type of first-order reversal...Demonstrated graphene field- effect transistor: (top) optical Image of transferred graphene, (middle) Raman spectrum, (bottom) current voltage

  4. Tungsten--carbide critical assembly

    International Nuclear Information System (INIS)

    Hansen, G.E.; Paxton, H.C.

    1975-06-01

    The tungsten--carbide critical assembly mainly consists of three close-fitting spherical shells: a highly enriched uranium shell on the inside, a tungsten--carbide shell surrounding it, and a steel shell on the outside. Ideal critical specifications indicate a rather low computed value of k/sub eff/. Observed and calculated fission-rate distributions for 235 U, 238 U, and 237 Np are compared, and calculated leakage neutrons per fission in various energy groups are given. (U.S.)

  5. Algorithms for Automated DNA Assembly

    Science.gov (United States)

    2010-01-01

    known results. The total number of possible assembly graphs for a single goal part is (2n 1)!/(n 1)!n! [also known as the Catalan number (20...correct theoretical construction scheme is de- veloped manually, it is likely to be suboptimal by any number of cost metrics. Modular, robust and...collection of information if it does not display a currently valid OMB control number . 1. REPORT DATE 23 MAR 2010 2. REPORT TYPE 3. DATES COVERED

  6. Neutron metrology in the fuel assemblies of a material test reactor

    International Nuclear Information System (INIS)

    Voorbraak, W.P.; Paardekoper, A.; Polle, A.N.; Freudenreich, W.E.

    1993-08-01

    Results are presented of detailed thermal and fast neutron measurements performed in all fuel and control assemblies of the HFR in Petten. The results give information about deviations of a general shape of vertical thermal and fast fluence rate distributions due to material transitions in the reactor core and different control assembly settings. Further it is demonstrated that the ratio of fast and thermal fluence rate at the various monitor positions in the assemblies give useful information for the (relative) local burn-up of the fuel. (orig.)

  7. EFTF cobalt test assembly results

    International Nuclear Information System (INIS)

    Rawlins, J.A.; Wootan, D.W.; Carter, L.L.; Brager, H.R.; Schenter, R.E.

    1988-01-01

    A cobalt test assembly containing yttrium hydride pins for neutron moderation was irradiated in the Fast Flux Test Facility during Cycle 9A for 137.7 equivalent full power days at a power level fo 291 MW. The 36 test pins consisted of a batch of 32 pins containing cobalt metal to produce Co-60, and a set of 4 pins with europium oxide to produce Gd-153, a radioisotope used in detection of the bone disease Osteoporosis. Post-irradiation examination of the cobalt pins determined the Co-60 produced with an accuracy of about 5 %. The measured Co-60 spatially distributed concentrations were within 20 % of the calculated concentrations. The assembly average Co-60 measured activity was 4 % less than the calculated value. The europium oxide pins were gamma scanned for the europium isotopes Eu-152 and Eu-154 to an absolute accuracy of about 10 %. The measured europium radioisotpe anc Gd-153 concentrations were within 20 % of calculated values. In conclusion, the hydride assembly performed well and is an excellent vehicle for many Fast Flux Test Facility isotope production applications. The results also demonstrate that the calculational methods developed by the Westinghouse Hanford Company are very accurate. (author)

  8. Rotor assembly and assay method

    Science.gov (United States)

    Burtis, C.A.; Johnson, W.F.; Walker, W.A.

    1993-09-07

    A rotor assembly for carrying out an assay includes a rotor body which is rotatable about an axis of rotation, and has a central chamber and first, second, third, fourth, fifth, and sixth chambers which are in communication with and radiate from the central chamber. The rotor assembly further includes a shuttle which is movable through the central chamber and insertable into any of the chambers, the shuttle including a reaction cup carrying an immobilized antigen or an antibody for transport among the chambers. A method for carrying out an assay using the rotor assembly includes moving the reaction cup among the six chambers by passing the cup through the central chamber between centrifugation steps in order to perform the steps of: separating plasma from blood cells, binding plasma antibody or antigen, washing, drying, binding enzyme conjugate, reacting with enzyme substrate and optically comparing the resulting reaction product with unreacted enzyme substrate solution. The movement of the reaction cup can be provided by attaching a magnet to the reaction cup and supplying a moving magnetic field to the rotor. 34 figures.

  9. Thermomechanical behaviour of bolted assemblies

    International Nuclear Information System (INIS)

    Scliffet, L.

    1995-01-01

    This paper presents first results obtained in an R and D study on the thermomechanical behaviour of bolted assemblies. Thermal shocks during operating transients both severely distort such assemblies and cause variations in stud pre-loads. So during a hot shock, the thermal gradient in the flange induced over-tightening due to the differential thermal expansion involved. Over-tightening can reach 70% of the nominal value, usually after 10 to 15 mn, after which the stress relaxes as soon as the heating affects the stud. A series of hot shocks causes assembly fatigue, notably resulting in thread plasticization, making it impossible to tighten the studs. In the case of cold transients, the reverse phenomenon is observed. The hot flange contracts sharply upon contact with the cold fluid, causing stress relief in the expanded studs. The resulting loss of tensile stress, which reaches up to 50%, can then cause severe leakage, especially if the nominal tightening capacity is already impaired. The study presented is based on tests and modelling. (author). 16 figs

  10. Fuel assembly and reactor core

    International Nuclear Information System (INIS)

    Yuchi, Yoko; Aoyama, Motoo; Haikawa, Katsumasa; Yamanaka, Akihiro; Koyama, Jun-ichi.

    1996-01-01

    In a fuel assembly of a BWR type reactor, a region substantially containing burnable poison is divided into an upper region and a lower region having different average concentrations of burnable poison along a transverse cross section perpendicular to the axial direction. The ratio of burnable poison contents of both regions is determined to not more than 80%, and the average concentration of the burnable poison in the lower region is determined to not less than 9% by weight. An infinite multiplication factor at an initial stage of the burning of the fuel assembly is controlled effectively by the burnable poisons. Namely, the ratio of the axial power can be controlled by the distribution of the enrichment degree of uranium fuels and the distribution of the burnable poison concentration in the axial direction. Since the average enrichment degree of the reactor core has to be increased in order to provide an initially loaded reactor core at high burnup degree. Distortion of the power distribution in the axial direction of the reactor core to which fuel assemblies at high enrichment degree are loaded is flattened to improve thermal margin, to extend continuous operation period and increase a burnup degree upon take-out thereby improving fuel economy without worsening the reactor core characteristics of the initially loaded reactor core. (N.H.)

  11. Fuel assembly and reactor core

    International Nuclear Information System (INIS)

    Ishibashi, Yoko; Aoyama, Motoo; Oyama, Jun-ichi; Masumi, Ryoji; Soneda, Hideo.

    1994-01-01

    A fuel assembly comprises a plurality of fuel rods filled with nuclear fuels, a plurality of burnable poison rods incorporated with burnable poisons, and water rods which can vary the height in the tube depending on the coolant flow rate flown into the assembly. The amount of entire burnable poisons of the burnable poison-containing rods in adjacent with the water rods is smaller than the amount of entire burnable poisons in the burnable poison containing rods not in adjacent with the water rods. Then the average concentration of burnable poisons in the axial upper half region is made smaller than the average concentration of the burnable poisons at the axial lower half region. Further, a burnable poison concentration at the upper half region of at least one of burnable poison-containing rods in adjacent with the water rods is made lower than the burnable poison concentration in the lower half region. Since this can fasten the combustion of the burnable poisons, a fuel assembly having good fuel economy can be attained. (I.N.)

  12. Optimizing Transcriptome Assemblies for Eleusine indica Leaf and Seedling by Combining Multiple Assemblies from Three De Novo Assemblers

    Directory of Open Access Journals (Sweden)

    Shu Chen

    2015-03-01

    Full Text Available Due to rapid advances in sequencing technology, increasing amounts of genomic and transcriptomic data are available for plant species, presenting enormous challenges for biocomputing analysis. A crucial first step for a successful transcriptomics-based study is the building of a high-quality assembly. Here, we utilized three different de novo assemblers (Trinity, Velvet, and CLC and the EvidentialGene pipeline tr2aacds to assemble two optimized transcript sets for the notorious weed species, . Two RNA sequencing (RNA-seq datasets from leaf and aboveground seedlings were processed using three assemblers, which resulted in 20 assemblies for each dataset. The contig numbers and N50 values of each assembly were compared to study the effect of read number, k-mer size, and in silico normalization on assembly output. The 20 assemblies were then processed through the tr2aacds pipeline to remove redundant transcripts and to select the transcript set with the best coding potential. Each assembly contributed a considerable proportion to the final transcript combination with the exception of the CLC-k14. Thus each assembler and parameter set did assemble better contigs for certain transcripts. The redundancy, total contig number, N50, fully assembled contig number, and transcripts related to target-site herbicide resistance were evaluated for the EvidentialGene and Trinity assemblies. Comparing the EvidentialGene set with the Trinity assembly revealed improved quality and reduced redundancy in both leaf and seedling EvidentialGene sets. The optimized transcriptome references will be useful for studying herbicide resistance in and the evolutionary process in the three allotetraploid offspring.

  13. Research and design calculation of multipurpose critical assembly using moderated light water and low enriched fuel from 1.6 to 5.0% U-235

    International Nuclear Information System (INIS)

    Nguyen Kien Cuong; Vo Doan Hai Dang; Luong Ba Vien; Le Vinh Vinh; Huynh Ton Nghiem; Nguyen Minh Tuan; Nguyen Manh Hung; Pham Quang Huy; Tran Quoc Duong; Tran Tri Vien

    2015-01-01

    Basing on the idea in ??using fuel of nuclear power plants such as PWR (AP-1000) and VVER-1000 with light water as moderation, design calculation of critical assembly was performed to confirm the possibility of using these fuels. Designed critical assembly has simple structure consisting of low enriched fuel from 1.6% to 5% U-235; water has functions as cooling, biological protection and control. Critical assembly is operated at nominal power 100 W with fuel pitch about 2.0 cm. Applications of the critical assembly are quite abundant in basic research, education and training with low investment cost compare with research reactor and easy in operation. So critical assembly can be used for university or training centre for nuclear engineering training. Main objectives of the project are: design calculation in neutronics, thermal hydraulics and safety analysis for critical configuration benchmarks using low enriched fuel; design in mechanical and auxiliary systems for critical assembly; determine technical specifications and estimate construction, installation cost of critical assembly. The process of design, fabrication, installation and construction of critical assembly will be considered with different implementation phases and localization capabilities in installation of critical assembly is highly feasibility. Cost estimation of construction and installation of critical assembly was implemented and showed that investment cost for critical assembly is much lower than research reactor and most of components, systems of critical assembly can be localized with current technique quality of the country. (author)

  14. Centrioles: some self-assembly required.

    Science.gov (United States)

    Song, Mi Hye; Miliaras, Nicholas B; Peel, Nina; O'Connell, Kevin F

    2008-12-01

    Centrioles play an important role in organizing microtubules and are precisely duplicated once per cell cycle. New (daughter) centrioles typically arise in association with existing (mother) centrioles (canonical assembly), suggesting that mother centrioles direct the formation of daughter centrioles. However, under certain circumstances, centrioles can also selfassemble free of an existing centriole (de novo assembly). Recent work indicates that the canonical and de novo pathways utilize a common mechanism and that a mother centriole spatially constrains the self-assembly process to occur within its immediate vicinity. Other recently identified mechanisms further regulate canonical assembly so that during each cell cycle, one and only one daughter centriole is assembled per mother centriole.

  15. Robust, directed assembly of fluorescent nanodiamonds.

    Science.gov (United States)

    Kianinia, Mehran; Shimoni, Olga; Bendavid, Avi; Schell, Andreas W; Randolph, Steven J; Toth, Milos; Aharonovich, Igor; Lobo, Charlene J

    2016-10-27

    Arrays of fluorescent nanoparticles are highly sought after for applications in sensing, nanophotonics and quantum communications. Here we present a simple and robust method of assembling fluorescent nanodiamonds into macroscopic arrays. Remarkably, the yield of this directed assembly process is greater than 90% and the assembled patterns withstand ultra-sonication for more than three hours. The assembly process is based on covalent bonding of carboxyl to amine functional carbon seeds and is applicable to any material, and to non-planar surfaces. Our results pave the way to directed assembly of sensors and nanophotonics devices.

  16. Peripheral pin alignment system for fuel assemblies

    International Nuclear Information System (INIS)

    Anthony, A.J.

    1981-01-01

    An alignment system is provided for nuclear fuel assemblies in a nuclear core. The core support structure of the nuclear reactor includes upwardly pointing alignment pins arranged in a square grid and engage peripheral depressions formed in the lateral periphery of the lower ends of each of the fuel assemblies of the core. In a preferred embodiment, the depressions are located at the corners of the fuel assemblies so that each depression includes one-quarter of a cylindrical void. Accordingly, each fuel assembly is positioned and aligned by one-quarter of four separate alignment pins which engage the fuel assemblies at their lower exterior corners. (author)

  17. Towards a Viable Local Government Structure in Nigeria:

    African Journals Online (AJOL)

    M.P._Ezekiel & D.O_Oriakhogba

    rates.22 Politically also, the role of the local government is to ensure effective .... potential cost savings that might result from large governmental unit.32 Under ... institutional status.33 These are very common in the USA and France. .... the thresholds of consent (in House of Assembly in respect to the area and local.

  18. Genome Sequence Databases (Overview): Sequencing and Assembly

    Energy Technology Data Exchange (ETDEWEB)

    Lapidus, Alla L.

    2009-01-01

    From the date its role in heredity was discovered, DNA has been generating interest among scientists from different fields of knowledge: physicists have studied the three dimensional structure of the DNA molecule, biologists tried to decode the secrets of life hidden within these long molecules, and technologists invent and improve methods of DNA analysis. The analysis of the nucleotide sequence of DNA occupies a special place among the methods developed. Thanks to the variety of sequencing technologies available, the process of decoding the sequence of genomic DNA (or whole genome sequencing) has become robust and inexpensive. Meanwhile the assembly of whole genome sequences remains a challenging task. In addition to the need to assemble millions of DNA fragments of different length (from 35 bp (Solexa) to 800 bp (Sanger)), great interest in analysis of microbial communities (metagenomes) of different complexities raises new problems and pushes some new requirements for sequence assembly tools to the forefront. The genome assembly process can be divided into two steps: draft assembly and assembly improvement (finishing). Despite the fact that automatically performed assembly (or draft assembly) is capable of covering up to 98% of the genome, in most cases, it still contains incorrectly assembled reads. The error rate of the consensus sequence produced at this stage is about 1/2000 bp. A finished genome represents the genome assembly of much higher accuracy (with no gaps or incorrectly assembled areas) and quality ({approx}1 error/10,000 bp), validated through a number of computer and laboratory experiments.

  19. Large-scale parallel genome assembler over cloud computing environment.

    Science.gov (United States)

    Das, Arghya Kusum; Koppa, Praveen Kumar; Goswami, Sayan; Platania, Richard; Park, Seung-Jong

    2017-06-01

    The size of high throughput DNA sequencing data has already reached the terabyte scale. To manage this huge volume of data, many downstream sequencing applications started using locality-based computing over different cloud infrastructures to take advantage of elastic (pay as you go) resources at a lower cost. However, the locality-based programming model (e.g. MapReduce) is relatively new. Consequently, developing scalable data-intensive bioinformatics applications using this model and understanding the hardware environment that these applications require for good performance, both require further research. In this paper, we present a de Bruijn graph oriented Parallel Giraph-based Genome Assembler (GiGA), as well as the hardware platform required for its optimal performance. GiGA uses the power of Hadoop (MapReduce) and Giraph (large-scale graph analysis) to achieve high scalability over hundreds of compute nodes by collocating the computation and data. GiGA achieves significantly higher scalability with competitive assembly quality compared to contemporary parallel assemblers (e.g. ABySS and Contrail) over traditional HPC cluster. Moreover, we show that the performance of GiGA is significantly improved by using an SSD-based private cloud infrastructure over traditional HPC cluster. We observe that the performance of GiGA on 256 cores of this SSD-based cloud infrastructure closely matches that of 512 cores of traditional HPC cluster.

  20. Simulations of curved assemblies in soft matter and biological systems

    Science.gov (United States)

    Qiao, Cong

    regularly packed regions with local hexagonal order and vacancies. A similar lattice structure has been observed in experiments in which mutually attractive colloidal particles pack on the surface of a spherical droplet (G. Meng, J. Paulose, D. R. Nelson, and V. N. Manoharan, ''Elastic instability of a crystal growing on a curved surface'', Science 343, 634-637 (2014).), suggesting that the two systems experience a similar form of geometric frustration. We therefore study the adsorption and packing of spherical particles on a spherical template, as a function of the strength and range of interparticle attractions, as well as the radius of the spherical template. We observe that the adsorbed particles form two different classes of packing arrangements, one with icosahedrally ordered topological defects, and the other with highly disordered defects and vacancies. The latter regime is consistent with experiments on colloidal packing on spherical droplets and the immature HIV lattice. Our results suggest that the transition between these regimes is controlled by the range of the interparticle attractions. In the last chapter, we study a model for the assembly and budding of a capsid on a membrane, such as occurs during the exit of the immature HIV virus from a cell. We use a coarse-grained subunit model to represent the capsid proteins, and a fluid membrane model to represent the cell membrane. We find that the size and structure of the assembled capsid depends sensitively on the timescale of budding.

  1. Assembly study for JT-60SA tokamak

    Energy Technology Data Exchange (ETDEWEB)

    Shibanuma, K., E-mail: shibanuma.kiyoshi@jaea.go.jp [Japan Atomic Energy Agency, Naka, Ibaraki-ken 311-0193 (Japan); Arai, T.; Hasegawa, K.; Hoshi, R.; Kamiya, K.; Kawashima, H.; Kubo, H.; Masaki, K.; Saeki, H.; Sakurai, S.; Sakata, S.; Sakasai, A.; Sawai, H.; Shibama, Y.K.; Tsuchiya, K.; Tsukao, N.; Yagyu, J.; Yoshida, K.; Kamada, Y. [Japan Atomic Energy Agency, Naka, Ibaraki-ken 311-0193 (Japan); Mizumaki, S. [Toshiba Corporation, Minato-ku, Tokyo 105-8001 (Japan); and others

    2013-10-15

    The assembly scenarios and assembly tools of the major tokamak components for JT-60SA are studied in the following. (1) The assembly frame (with a dedicated 30-tonne crane), which is located around the JT-60SA tokamak, is adopted for effective assembly works in the torus hall and the temporary support of the components during assembly. (2) Metrology for precise positioning of the components is also studied by defining the metrology points on the components. (3) The sector segmentation for weld joints and positioning of the vacuum vessel (VV), the assembly scenario and tools for VV thermal shield (TS), the connection of the outer intercoil structure (OIS) and the installation of the final toroidal field coil (TFC) are studied, as typical examples of the assembly scenarios and tools for JT-60SA.

  2. Capacitor assembly and related method of forming

    Science.gov (United States)

    Zhang, Lili; Tan, Daniel Qi; Sullivan, Jeffrey S.

    2017-12-19

    A capacitor assembly is disclosed. The capacitor assembly includes a housing. The capacitor assembly further includes a plurality of capacitors disposed within the housing. Furthermore, the capacitor assembly includes a thermally conductive article disposed about at least a portion of a capacitor body of the capacitors, and in thermal contact with the capacitor body. Moreover, the capacitor assembly also includes a heat sink disposed within the housing and in thermal contact with at least a portion of the housing and the thermally conductive article such that the heat sink is configured to remove heat from the capacitor in a radial direction of the capacitor assembly. Further, a method of forming the capacitor assembly is also presented.

  3. Deterministic nanoparticle assemblies: from substrate to solution

    International Nuclear Information System (INIS)

    Barcelo, Steven J; Gibson, Gary A; Yamakawa, Mineo; Li, Zhiyong; Kim, Ansoon; Norris, Kate J

    2014-01-01

    The deterministic assembly of metallic nanoparticles is an exciting field with many potential benefits. Many promising techniques have been developed, but challenges remain, particularly for the assembly of larger nanoparticles which often have more interesting plasmonic properties. Here we present a scalable process combining the strengths of top down and bottom up fabrication to generate deterministic 2D assemblies of metallic nanoparticles and demonstrate their stable transfer to solution. Scanning electron and high-resolution transmission electron microscopy studies of these assemblies suggested the formation of nanobridges between touching nanoparticles that hold them together so as to maintain the integrity of the assembly throughout the transfer process. The application of these nanoparticle assemblies as solution-based surface-enhanced Raman scattering (SERS) materials is demonstrated by trapping analyte molecules in the nanoparticle gaps during assembly, yielding uniformly high enhancement factors at all stages of the fabrication process. (paper)

  4. Storage arrangement for nuclear reactor fuel assemblies

    International Nuclear Information System (INIS)

    Wade, E.E.

    1977-01-01

    Said invention is intended for providing an arrangement of spent fuel assembly storage inside which the space is efficiently used without accumulating a critical mass. The storage is provided for long fuel assemblies having along their longitudinal axis an active part containing the fuel and an inactive part empty of fuel. Said storage arrangement comprises a framework constituting some long-shaped cells designed so as each of them can receive a fuel assembly. Means of axial positioning of said assembly in a cell make it possible to support the fuel assemblies inside the framework according to a spacing ratio, along the cell axis, such as the active part of an assembly is adjacent to the inactive part of the adjacent assemblies [fr

  5. Impact analysis of spent fuel jacket assemblies

    International Nuclear Information System (INIS)

    Aramayo, G.A.

    1994-01-01

    As part of the analyses performed in support of the reracking of the High Flux Isotope Reactor pool, it became necessary to prove the structural integrity of the spent fuel jacket assemblies subjected to gravity drop that result from postulated accidents associated with the handling of these assemblies while submerged in the pool. The spent fuel jacket assemblies are an integral part of the reracking project, and serve to house fuel assemblies. The structure integrity of the jacket assemblies from loads that result from impact from a height of 10 feet onto specified targets has been performed analytically using the computer program LS-DYNA3D. Nine attitudes of the assembly at the time of impact have been considered. Results of the analyses show that there is no failure of the assemblies as a result of the impact scenarios considered

  6. Probabilistic reasoning for assembly-based 3D modeling

    KAUST Repository

    Chaudhuri, Siddhartha; Kalogerakis, Evangelos; Guibas, Leonidas; Koltun, Vladlen

    2011-01-01

    Assembly-based modeling is a promising approach to broadening the accessibility of 3D modeling. In assembly-based modeling, new models are assembled from shape components extracted from a database. A key challenge in assembly-based modeling

  7. Local Sustainability

    International Nuclear Information System (INIS)

    Carrizosa Umana, Julio

    1998-01-01

    The current polemic about the possibilities of sustainable development has led to a renovated interest for the topic of the sustainability of the communities and the local sustainability. In front of the global sustainability whose conditions have been exposed by systemic ecologists and for macro economists, the sustainability of specific places arises in the planet whose conditions are object of study of the ecology of landscapes, of the ecological economy, of the cultural anthropology, of the environmental sociology and naturally, of the integral environmentalism. In this discussion the Colombian case charges unusual interest to be one of the few countries of Latin America, where a very dense net of municipalities exists, each one with its urban helmet and with a position and some functions defined by the political constitution of the nation. This net of municipalities and of urban helmets it also constitutes net of alternative to the current macro-cephalic situation. As well as Bogota grew, in a hundred years, of less than a hundred thousand inhabitants to six million inhabitants, each one of these municipalities contains a potential of growth that depends on the characteristics of its ecological, social, economic and politic sustainability

  8. Harmony Search for Balancing Two-sided Assembly Lines

    Directory of Open Access Journals (Sweden)

    Hindriyanto Dwi Purnomo

    2012-01-01

    Full Text Available Two-sided assembly lines balancing problems are important problem for large-sized products such as cars and buses, in which, tasks operations can be performed in the two sides of the line. In this paper, Harmony Search algorithm is proposed to solve two-sided assembly lines balancing problems type-I (TALBP-I. The proposed method adopts the COMSOAL heuristic and specific features of TALBP in the Harmony operators – the harmony memory consideration, random selection and pitch adjustment – in order to maintain the local and global search. The proposed method is evaluated based on 6 benchmark problems that are commonly used in TALBP. The experiment results show that the proposed method work well and produces better solution than the heuristic method and genetic algorithm.

  9. Introduction to assembly of finite element methods on graphics processors

    International Nuclear Information System (INIS)

    Cecka, Cristopher; Lew, Adrian; Darve, Eric

    2010-01-01

    Recently, graphics processing units (GPUs) have had great success in accelerating numerical computations. We present their application to computations on unstructured meshes such as those in finite element methods. Multiple approaches in assembling and solving sparse linear systems with NVIDIA GPUs and the Compute Unified Device Architecture (CUDA) are presented and discussed. Multiple strategies for efficient use of global, shared, and local memory, methods to achieve memory coalescing, and optimal choice of parameters are introduced. We find that with appropriate preprocessing and arrangement of support data, the GPU coprocessor achieves speedups of 30x or more in comparison to a well optimized serial implementation on the CPU. We also find that the optimal assembly strategy depends on the order of polynomials used in the finite-element discretization.

  10. Fabrication of PWR fuel assembly and CANDU fuel bundle

    International Nuclear Information System (INIS)

    Lee, G.S.; Suh, K.S.; Chang, H.I.; Chung, S.H.

    1980-01-01

    For the project of localization of nuclear fuel fabrication, the R and D to establish the fabrication technology of CANDU fuel bundle as well as PWR fuel assembly was carried out. The suitable boss height and the prober Beryllium coating thickness to get good brazing condition of appendage were studied in the fabrication process of CANDU fuel rod. Basic Studies on CANLUB coating method also were performed. Problems in each fabrication process step and process flow between steps were reviewed and modified. The welding conditions for top and bottom nozzles, guide tube, seal and thimble screw pin were established in the fabrication processes of PWR fuel assembly. Additionally, some researches for a part of PWR grid brazing problems are also carried out

  11. Assembly of finite element methods on graphics processors

    KAUST Repository

    Cecka, Cris

    2010-08-23

    Recently, graphics processing units (GPUs) have had great success in accelerating many numerical computations. We present their application to computations on unstructured meshes such as those in finite element methods. Multiple approaches in assembling and solving sparse linear systems with NVIDIA GPUs and the Compute Unified Device Architecture (CUDA) are created and analyzed. Multiple strategies for efficient use of global, shared, and local memory, methods to achieve memory coalescing, and optimal choice of parameters are introduced. We find that with appropriate preprocessing and arrangement of support data, the GPU coprocessor using single-precision arithmetic achieves speedups of 30 or more in comparison to a well optimized double-precision single core implementation. We also find that the optimal assembly strategy depends on the order of polynomials used in the finite element discretization. © 2010 John Wiley & Sons, Ltd.

  12. Self-assembling enzymes and the origins of the cytoskeleton

    Science.gov (United States)

    Barry, Rachael; Gitai, Zemer

    2011-01-01

    The bacterial cytoskeleton is composed of a complex and diverse group of proteins that self-assemble into linear filaments. These filaments support and organize cellular architecture and provide a dynamic network controlling transport and localization within the cell. Here, we review recent discoveries related to a newly appreciated class of self-assembling proteins that expand our view of the bacterial cytoskeleton and provide potential explanations for its evolutionary origins. Specifically, several types of metabolic enzymes can form structures similar to established cytoskeletal filaments and, in some cases, these structures have been repurposed for structural uses independent of their normal role. The behaviors of these enzymes suggest that some modern cytoskeletal proteins may have evolved from dual-role proteins with catalytic and structural functions. PMID:22014508

  13. Plural beam electron gun assembly

    International Nuclear Information System (INIS)

    Stratton, M.G.

    1977-01-01

    The invention relates to a cathode ray tube plural-beam-in-line bi-potential electron gun assembly, having applied beam currents of differing levels, manifests structurally modified gun structures to effect focused beam landings at the screen that are evidenced as substantially equi-sized spots thereby providing improved resolution and brightness of the screen imagery. The structural changes embody modifications of the related focusing and accelerator electrodes of the respective guns to provide a partial telescoping arrangement for effecting the discrete placement, forming and shielding of the final focusing lenses. The three lenses so formed are in different planes in partial overlapping axial relationship

  14. Red Assembly: the work remains

    Directory of Open Access Journals (Sweden)

    Leslie Witz

    Full Text Available This issue of Kronos is dedicated to Terry Flynn, assistant curator at the Ann Bryant Art Gallery, who was instrumental in the successful installing of 'Red Assembly' there in 2015. Friend, colleague, artist and inspiration. Hamba Kahle. The work that emerged from the encounter with Red, an art installation by Simon Gush and his collaborators, in the workshop 'Red Assembly', held in East London in August 2015, is assembled here in Kronos, the journal of southern African histories based at the University of the Western Cape, and previously in parallax, the cultural studies journal based at the University of Leeds published in May 2016. What is presented there and here is not simply more work, work that follows, or even additional works. Rather, it is the work that arises as a response to a question that structured our entire project: does Red, now also installed in these two journals, have the potential to call the discourse of history into question? This article responds to this question through several pairings: theft - gift; copy - rights; time - history; kronos - chronos. Here we identify a reversal in this installation of the gift into the commodity, and another with regard to conventional historical narratives which privilege the search for sources and origins. A difference between (the historian's search for origination and (the artist's originality becomes visible in a conversation between and over the historic and the artistic that does not simply try to rescue History by means of the work of art. It is in this sense that we invite the displacements, detours, and paths made possible through Simon Gush's Red, the 'Red Assembly' workshop and the work/gift of installation and parallaxing. To gesture beyond 'histories' is the provocation to which art is neither cause nor effect. Thinking with the work of art, that is, grasping thought in the working of art, has extended the sense of history's limit and the way the limit of history is

  15. Reconstitutable control rod spider assembly

    International Nuclear Information System (INIS)

    Shallenberger, J.M.; Ferian, S.J.

    1990-01-01

    A reconstitutable control rod/spider assembly includes a hollow connecting finger of the spider having a pair of opposing flat segments formed on the interior thereof and engaging a pair of opposing flat sectors formed on the exterior of a stem extending form the upper end of control rod. The stem also has an externally-threaded portion engaging a nut and a pilot aligning portion for the nut. The nut has a radially flexible and expandable thread-defining element captured in its bore. The segments and sectors allow the rod to be removed and reattached after turning through 180 0 to allow more even wear on the rod. (author)

  16. Competitive assembly of South Pacific invasive ant communities

    Directory of Open Access Journals (Sweden)

    Sarty Megan

    2009-01-01

    Full Text Available Abstract Background The relative importance of chance and determinism in structuring ecological communities has been debated for nearly a century. Evidence for determinism or assembly rules is often evaluated with null models that randomize the occurrence of species in particular locales. However, analyses of the presence or absence of species ignores the potential influence of species abundances, which have long been considered of major importance on community structure. Here, we test for community assembly rules in ant communities on small islands of the Tokelau archipelago using both presence-absence and abundance data. We conducted three sets of analyses on two spatial scales using three years of sampling data from 39 plots on 11 islands. Results First, traditional null model tests showed support for negative species co-occurrence patterns among plots within islands, but not among islands. A plausible explanation for this result is that analyses at larger spatial scales merge heterogeneous habitats that have considerable effects on species occurrences. Second, analyses of ant abundances showed that samples with high ant abundances had fewer species than expected by chance, both within and among islands. One ant species, the invasive yellow crazy ant Anoplolepis gracilipes, appeared to have a particularly strong effect on community structure correlated with its abundance. Third, abundances of most ant species were inversely correlated with the abundances of all other ants at both spatial scales. This result is consistent with competition theory, which predicts species distributions are affected by diffuse competition with suites of co-occurring species. Conclusion Our results support a pluralistic explanation for ant species abundances and assembly. Both stochastic and deterministic processes interact to determine ant community assembly, though abundance patterns clearly drive the deterministic patterns in this community. These deterministic

  17. Fuel injection assembly for use in turbine engines and method of assembling same

    Science.gov (United States)

    Berry, Jonathan Dwight; Johnson, Thomas Edward; York, William David; Uhm, Jong Ho

    2015-12-15

    A fuel injection assembly for use in a turbine engine is provided. The fuel injection assembly includes an end cover, an endcap assembly, a fluid supply chamber, and a plurality of tube assemblies positioned at the endcap assembly. Each of the tube assemblies includes housing having a fuel plenum and a cooling fluid plenum. The cooling fluid plenum is positioned downstream from the fuel plenum and separated from the fuel plenum by an intermediate wall. The plurality of tube assemblies also include a plurality of tubes that extends through the housing. Each of the plurality of tubes is coupled in flow communication with the fluid supply chamber and a combustion chamber positioned downstream from the tube assembly. The plurality of tube assemblies further includes an aft plate at a downstream end of the cooling fluid plenum. The plate includes at least one aperture.

  18. Quantum Locality?

    Science.gov (United States)

    Stapp, Henry P.

    2012-05-01

    , in response to Griffiths' challenge, why a putative proof of locality that he has described is flawed.

  19. PAVE: Program for assembling and viewing ESTs

    Directory of Open Access Journals (Sweden)

    Bomhoff Matthew

    2009-08-01

    Full Text Available Abstract Background New sequencing technologies are rapidly emerging. Many laboratories are simultaneously working with the traditional Sanger ESTs and experimenting with ESTs generated by the 454 Life Science sequencers. Though Sanger ESTs have been used to generate contigs for many years, no program takes full advantage of the 5' and 3' mate-pair information, hence, many tentative transcripts are assembled into two separate contigs. The new 454 technology has the benefit of high-throughput expression profiling, but introduces time and space problems for assembling large contigs. Results The PAVE (Program for Assembling and Viewing ESTs assembler takes advantage of the 5' and 3' mate-pair information by requiring that the mate-pairs be assembled into the same contig and joined by n's if the two sub-contigs do not overlap. It handles the depth of 454 data sets by "burying" similar ESTs during assembly, which retains the expression level information while circumventing time and space problems. PAVE uses MegaBLAST for the clustering step and CAP3 for assembly, however it assembles incrementally to enforce the mate-pair constraint, bury ESTs, and reduce incorrect joins and splits. The PAVE data management system uses a MySQL database to store multiple libraries of ESTs along with their metadata; the management system allows multiple assemblies with variations on libraries and parameters. Analysis routines provide standard annotation for the contigs including a measure of differentially expressed genes across the libraries. A Java viewer program is provided for display and analysis of the results. Our results clearly show the benefit of using the PAVE assembler to explicitly use mate-pair information and bury ESTs for large contigs. Conclusion The PAVE assembler provides a software package for assembling Sanger and/or 454 ESTs. The assembly software, data management software, Java viewer and user's guide are freely available.

  20. PAVE: program for assembling and viewing ESTs.

    Science.gov (United States)

    Soderlund, Carol; Johnson, Eric; Bomhoff, Matthew; Descour, Anne

    2009-08-26

    New sequencing technologies are rapidly emerging. Many laboratories are simultaneously working with the traditional Sanger ESTs and experimenting with ESTs generated by the 454 Life Science sequencers. Though Sanger ESTs have been used to generate contigs for many years, no program takes full advantage of the 5' and 3' mate-pair information, hence, many tentative transcripts are assembled into two separate contigs. The new 454 technology has the benefit of high-throughput expression profiling, but introduces time and space problems for assembling large contigs. The PAVE (Program for Assembling and Viewing ESTs) assembler takes advantage of the 5' and 3' mate-pair information by requiring that the mate-pairs be assembled into the same contig and joined by n's if the two sub-contigs do not overlap. It handles the depth of 454 data sets by "burying" similar ESTs during assembly, which retains the expression level information while circumventing time and space problems. PAVE uses MegaBLAST for the clustering step and CAP3 for assembly, however it assembles incrementally to enforce the mate-pair constraint, bury ESTs, and reduce incorrect joins and splits. The PAVE data management system uses a MySQL database to store multiple libraries of ESTs along with their metadata; the management system allows multiple assemblies with variations on libraries and parameters. Analysis routines provide standard annotation for the contigs including a measure of differentially expressed genes across the libraries. A Java viewer program is provided for display and analysis of the results. Our results clearly show the benefit of using the PAVE assembler to explicitly use mate-pair information and bury ESTs for large contigs. The PAVE assembler provides a software package for assembling Sanger and/or 454 ESTs. The assembly software, data management software, Java viewer and user's guide are freely available.

  1. Spectrometric assembly for portable installations

    International Nuclear Information System (INIS)

    Kluger, A.; Popescu, C.

    1997-01-01

    The components of the portable spectrometric assembly are: - the detecting probe with Na I(Tl) crystal and air-tight case of industrial type; - a microcomputer; - a unit of analogical processing of the signal from the detecting probe; - a single-channel analyzer with adjustable threshold; - commands and display module; - a source of high voltage; - an electrical supply battery. The device uses the method of gamma photons detection in energetic windows. Through theoretical and experimental studies carried out during the prototype development phase, the superiority of this method has been proved as compared with the installations which make use of the classical principle of photon integral detection. The achieved prototype has a basic program enabling the setting of all working parameters (measuring time, discriminating thresholds, discriminators operating conditions, etc.). Through the included interface RS232 it is possible to transmit the data to a more powerful computer in order to continually process the results. The spectrometric assembly, realized on the basis of micro-computers, can be used in a wide range of applications: measurement of thickness and erosion of walls and tubes, measurement of level in closed containers, of soil density, etc. The adjustment for specific application is performed only through a program modification. (authors)

  2. The VEGA Assembly Spectrum Code

    International Nuclear Information System (INIS)

    Milosevic, M.

    1997-01-01

    The VEGA is assembly spectrum code, developed as a design tool for producing a few-group averaged cross section data for a wide range of reactor types including both thermal and fast reactors. It belongs to a class of codes, which may be characterized by the separate stages for micro group, spectrum and macro group assembly calculations. The theoretical foundation for the development of the VEGA code was integral transport theory in the first-flight collision probability formulation. Two versions of VEGA are now in use, VEGA-1 established on standard equivalence theory and VEGA-2 based on new subgroup method applicable for any geometry for which a flux solution is possible. This paper describes a features which are unique to the VEGA codes with concentration on the basic principles and algorithms used in the proposed subgroup method. Presented validation of this method, comprise the results for a homogenous uranium-plutonium mixture and a PWR cell containing a recycled uranium-plutonium oxide. Example application for a realistic fuel dissolver benchmark problem , which was extensive analyzed in the international calculations, is also included. (author)

  3. Water rod and fuel assembly

    International Nuclear Information System (INIS)

    Tsutsumi, Shinro; Tada, Nobuo; Nakajima, Junjiro; Aizawa, Yasuhiro.

    1995-01-01

    A water rod disposed in a fuel assembly comprises a larger diameter tube constituting an upwarding flow channel for coolants flown from the lower portion of a reactor core, and a smaller diameter tube connected fixedly to the larger diameter tube at the periphery of the upper end thereof and constituting a downwarding flow channel for coolants upwardly flown in the larger diameter tube. The larger diameter tube is formed by subjecting a base tube made of a zirconium alloy to PILGER mil fabrication and annealing in α region repeatingly for several times, then subjecting it to α + β treatment for once. The smaller diameter tube is formed by subjecting a base tube made of a zirconium alloy to PILGER mil fabrication and annealing in α region repeatingly for several times, then subjecting it to β treatment for once. With such procedures, the amount of irradiation growth of the tube in the axial direction is made greater in the larger diameter tube than that in the smaller diameter tube. Accordingly, since the smaller diameter tube is never bent by pressing, mechanical integrity of the fuel assembly is never lost. (I.N.)

  4. Fuel assemblies for nuclear reactors

    International Nuclear Information System (INIS)

    Leclercg, J.

    1985-01-01

    Improvements to guide tubes for the fuel assemblies of light water nuclear reactors, said assemblies being immersed in operation in the cooling water of the core of such a reactor, the guide tubes being of the type made from zircaloy and fixed at their two ends respectively to an upper end part and a lower end part made from stainless steel or Irconel and which incorporate devices for braking the fall of the control rods which they house during the rapid shutdown of the reactor, wherein the said braking devices are constituted by means for restricting the diameter of the guide tubes comprising for each guide tube a zircaloy inner sleeve spot welded to the said guide tube and whose internal diameter permits the passage, with a calibrated clearance, of the corresponding control rod, the sleeve being distributed over the lower portion of each guide tube and associated with orifices made in the actual guide tubes to produce the progressive hydraulic absorption of the end of the fall of the control rods

  5. Nanoparticle Assemblies at Fluid Interfaces

    Energy Technology Data Exchange (ETDEWEB)

    Russell, Thomas P. [Univ. of Massachusetts, Amherst, MA (United States). Dept. of Polymer Science and Engineering

    2015-03-10

    A systematic study of the structure and dynamics of nanoparticles (NP) and NP-surfactants was performed. The ligands attached to both the NPs and NP-surfactants dictate the manner in which the nanoscopic materials assemble at fluid interfaces. Studies have shown that a single layer of the nanoscpic materials form at the interface to reduce the interactions between the two immiscible fluids. The shape of the NP is, also, important, where for spherical particles, a disordered, liquid-like monolayer forms, and, for nanorods, ordered domains at the interface is found and, if the monolayers are compressed, the orientation of the nanorods with respect to the interface can change. By associating end-functionalized polymers to the NPs assembled at the interface, NP-surfactants are formed that increase the energetic gain in segregating each NP at the interface which allows the NP-surfactants to jam at the interface when compressed. This has opened the possibility of structuring the two liquids by freezing in shape changes of the liquids.

  6. Local Foods, Local Places Summary Reports

    Science.gov (United States)

    These reports summarize community projects done with Local Foods, Local Places assistance, including farmers markets, cooperatives, community gardens, and other food-related enterprises that can boost local economies and drive revitalization.

  7. Mitochondrial Protein Synthesis, Import, and Assembly

    Science.gov (United States)

    Fox, Thomas D.

    2012-01-01

    The mitochondrion is arguably the most complex organelle in the budding yeast cell cytoplasm. It is essential for viability as well as respiratory growth. Its innermost aqueous compartment, the matrix, is bounded by the highly structured inner membrane, which in turn is bounded by the intermembrane space and the outer membrane. Approximately 1000 proteins are present in these organelles, of which eight major constituents are coded and synthesized in the matrix. The import of mitochondrial proteins synthesized in the cytoplasm, and their direction to the correct soluble compartments, correct membranes, and correct membrane surfaces/topologies, involves multiple pathways and macromolecular machines. The targeting of some, but not all, cytoplasmically synthesized mitochondrial proteins begins with translation of messenger RNAs localized to the organelle. Most proteins then pass through the translocase of the outer membrane to the intermembrane space, where divergent pathways sort them to the outer membrane, inner membrane, and matrix or trap them in the intermembrane space. Roughly 25% of mitochondrial proteins participate in maintenance or expression of the organellar genome at the inner surface of the inner membrane, providing 7 membrane proteins whose synthesis nucleates the assembly of three respiratory complexes. PMID:23212899

  8. Fuel assembly for BWR type reactor

    International Nuclear Information System (INIS)

    Ueda, Makoto

    1990-01-01

    Various considerations are applied to fuel rods for improving the fuel burnup degree. If a gap between the fuel rods is changed, this varies the easiness for the flow of coolants depending on places, to reduce the thermal margin. Then, it is noted for the distribution of stresses generated due to the difference of water pressure caused by the difference of water streams between the inside and the outside of a channel box, and composite value, of stresses upon occurrence of earthquakes, neutron irradiation and a channel creep phenomenon caused by the stresses of due to the water pressure difference described above, the thickness of the channel box is increased in the upstream and decreased toward the downstream. Further, fuel spacers at the position where the thickness of the channel box is changed are spaced apart from the channel box so as not to brought into contact with the channel box. This can contribute to the reduction of coolants pressure loss, improvement of critical power and improvement of reactivity, as well as remarkably moderate local stresses applied from the fuel spacers to the channel box due to horizontal vibrations upon occurrence of earthquakes to improve the integrity of fuel assembly. (N.H.)

  9. Self consistent field theory of virus assembly

    Science.gov (United States)

    Li, Siyu; Orland, Henri; Zandi, Roya

    2018-04-01

    The ground state dominance approximation (GSDA) has been extensively used to study the assembly of viral shells. In this work we employ the self-consistent field theory (SCFT) to investigate the adsorption of RNA onto positively charged spherical viral shells and examine the conditions when GSDA does not apply and SCFT has to be used to obtain a reliable solution. We find that there are two regimes in which GSDA does work. First, when the genomic RNA length is long enough compared to the capsid radius, and second, when the interaction between the genome and capsid is so strong that the genome is basically localized next to the wall. We find that for the case in which RNA is more or less distributed uniformly in the shell, regardless of the length of RNA, GSDA is not a good approximation. We observe that as the polymer-shell interaction becomes stronger, the energy gap between the ground state and first excited state increases and thus GSDA becomes a better approximation. We also present our results corresponding to the genome persistence length obtained through the tangent-tangent correlation length and show that it is zero in case of GSDA but is equal to the inverse of the energy gap when using SCFT.

  10. Non-Gaussian halo assembly bias

    International Nuclear Information System (INIS)

    Reid, Beth A.; Verde, Licia; Dolag, Klaus; Matarrese, Sabino; Moscardini, Lauro

    2010-01-01

    The strong dependence of the large-scale dark matter halo bias on the (local) non-Gaussianity parameter, f NL , offers a promising avenue towards constraining primordial non-Gaussianity with large-scale structure surveys. In this paper, we present the first detection of the dependence of the non-Gaussian halo bias on halo formation history using N-body simulations. We also present an analytic derivation of the expected signal based on the extended Press-Schechter formalism. In excellent agreement with our analytic prediction, we find that the halo formation history-dependent contribution to the non-Gaussian halo bias (which we call non-Gaussian halo assembly bias) can be factorized in a form approximately independent of redshift and halo mass. The correction to the non-Gaussian halo bias due to the halo formation history can be as large as 100%, with a suppression of the signal for recently formed halos and enhancement for old halos. This could in principle be a problem for realistic galaxy surveys if observational selection effects were to pick galaxies occupying only recently formed halos. Current semi-analytic galaxy formation models, for example, imply an enhancement in the expected signal of ∼ 23% and ∼ 48% for galaxies at z = 1 selected by stellar mass and star formation rate, respectively

  11. Quantum Locality?

    Energy Technology Data Exchange (ETDEWEB)

    Stapp, Henry

    2011-11-10

    vagaries that he cites do not upset the proof in question. It is show here in detail why the precise statement of this theorem justifies the specified application of CQT. It is also shown, in response to his challenge, why a putative proof of locality that he has proposed is not valid.

  12. The MARVEL assembly for neutron multiplication

    Energy Technology Data Exchange (ETDEWEB)

    David L. Chichester; Mathew T. Kinlaw

    2013-10-01

    A new multiplying test assembly is under development at Idaho National Laboratory to support research, validation, evaluation, and learning. The item is comprised of three stacked, highly-enriched uranium (HEU) cylinders, each 11.4 cm in diameter and having a combined height of up to 11.7 cm. The combined mass of all three cylinders is 20.3 kg of HEU. Calculations for the bare configuration of the assembly indicate a multiplication level of >3.5 (keff=0.72). Reflected configurations of the assembly, using either polyethylene or tungsten, are possible and have the capability of raising the assembly's multiplication level to greater than 10. This paper describes simulations performed to assess the assembly's multiplication level under different conditions and describes the resources available at INL to support the use of these materials. We also describe some preliminary calculations and test activities using the assembly to study neutron multiplication.

  13. Chemical reactions directed Peptide self-assembly.

    Science.gov (United States)

    Rasale, Dnyaneshwar B; Das, Apurba K

    2015-05-13

    Fabrication of self-assembled nanostructures is one of the important aspects in nanoscience and nanotechnology. The study of self-assembled soft materials remains an area of interest due to their potential applications in biomedicine. The versatile properties of soft materials can be tuned using a bottom up approach of small molecules. Peptide based self-assembly has significant impact in biology because of its unique features such as biocompatibility, straight peptide chain and the presence of different side chain functionality. These unique features explore peptides in various self-assembly process. In this review, we briefly introduce chemical reaction-mediated peptide self-assembly. Herein, we have emphasised enzymes, native chemical ligation and photochemical reactions in the exploration of peptide self-assembly.

  14. Dynamic Multi-Component Hemiaminal Assembly

    Science.gov (United States)

    You, Lei; Long, S. Reid; Lynch, Vincent M.

    2012-01-01

    A simple approach to generating in situ metal templated tris-(2-picolyl)amine-like multi-component assemblies with potential applications in molecular recognition and sensing is reported. The assembly is based on the reversible covalent association between di-(2-picolyl)amine and aldehydes. Zinc ion is the best for inducing assembly among the metal salts investigated, while 2-picolinaldehyde is the best among the heterocyclic aldehydes studied. Although an equilibrium constant of 6.6 * 103 M-1 was measured for the assembly formed by 2-picolinaldehdye, di-(2-picolyl)amine, and zinc triflate, the equilibrium constants for other systems are in the 102 M-1 range. X-ray structural analysis revealed that zinc adopts a trigonal bipyramidal geometry within the assembled ligand. The diversity and equilibrium of the assemblies are readily altered by simply changing concentrations, varying components, or adding counter anions. PMID:21919095

  15. Three invariant Hi-C interaction patterns: Applications to genome assembly.

    Science.gov (United States)

    Oddes, Sivan; Zelig, Aviv; Kaplan, Noam

    2018-06-01

    Assembly of reference-quality genomes from next-generation sequencing data is a key challenge in genomics. Recently, we and others have shown that Hi-C data can be used to address several outstanding challenges in the field of genome assembly. This principle has since been developed in academia and industry, and has been used in the assembly of several major genomes. In this paper, we explore the central principles underlying Hi-C-based assembly approaches, by quantitatively defining and characterizing three invariant Hi-C interaction patterns on which these approaches can build: Intrachromosomal interaction enrichment, distance-dependent interaction decay and local interaction smoothness. Specifically, we evaluate to what degree each invariant pattern holds on a single locus level in different species, cell types and Hi-C map resolutions. We find that these patterns are generally consistent across species and cell types but are affected by sequencing depth, and that matrix balancing improves consistency of loci with all three invariant patterns. Finally, we overview current Hi-C-based assembly approaches in light of these invariant patterns and demonstrate how local interaction smoothness can be used to easily detect scaffolding errors in extremely sparse Hi-C maps. We suggest that simultaneously considering all three invariant patterns may lead to better Hi-C-based genome assembly methods. Copyright © 2018 Elsevier Inc. All rights reserved.

  16. Centrioles: Some Self-Assembly Required

    OpenAIRE

    Song, Mi Hye; Miliaras, Nicholas B.; Peel, Nina; O'Connell, Kevin F.

    2008-01-01

    Centrioles play an important role in organizing microtubules and are precisely duplicated once per cell cycle. New (daughter) centrioles typically arise in association with existing (mother) centrioles (canonical assembly), suggesting that mother centrioles direct the formation of daughter centrioles. However, under certain circumstances, centrioles can also self-assemble free of an existing centriole (de novo assembly). Recent work indicates that the canonical and de novo pathways utilize a ...

  17. Fuel assembly for a nuclear reactor

    International Nuclear Information System (INIS)

    Gjertsen, R.K.; Tower, S.N.; Huckestein, E.A.

    1982-01-01

    A fuel assembly for a nuclear reactor comprises a 5x5 array of guide tubes in a generally 20x20 array of fuel elements, the guide tubes being arranged to accommodate either control rods or water displacer rods. The fuel assembly has top and bottom Inconel (Registered Trade Mark) grids and intermediate Zircaloy grids in engagement with the guide tubes and supporting the fuel elements and guide tubes while allowing flow of reactor coolant through the assembly. (author)

  18. Optics assembly for high power laser tools

    Science.gov (United States)

    Fraze, Jason D.; Faircloth, Brian O.; Zediker, Mark S.

    2016-06-07

    There is provided a high power laser rotational optical assembly for use with, or in high power laser tools for performing high power laser operations. In particular, the optical assembly finds applications in performing high power laser operations on, and in, remote and difficult to access locations. The optical assembly has rotational seals and bearing configurations to avoid contamination of the laser beam path and optics.

  19. GAIA: AREVAs New PWR fuel assembly design

    Energy Technology Data Exchange (ETDEWEB)

    Vollmert, N.; Gentet, G.; Louf, P.H.; Mindt, M.; O' Brian, J.; Peucker, J.

    2015-07-01

    GAIA is the label of a new PWR Fuel Assembly design developed by AREVA with the objective to provide its customers an advanced fuel assembly design regarding both robustness and performance. Since 2012 GAIA lead fuel assemblies are under irradiation in a Swedish reactor and since 2015 in a U.S. reactor. Visual inspections and examinations carried out so far during the outages confirmed the intended reliability, robustness and the performance enhancement of the design. (Author)

  20. Assembling draft genomes using contiBAIT

    OpenAIRE

    O'Neill, Kieran; Hills, Mark; Gottlieb, Mike; Borkowski, Matthew; Karsan, Aly; Lansdorp, Peter M.

    2017-01-01

    A Summary: Massively parallel sequencing is now widely used, but data interpretation is only as good as the reference assembly to which it is aligned. While the number of reference assemblies has rapidly expanded, most of these remain at intermediate stages of completion, either as scaffold builds, or as chromosome builds (consisting of correctly ordered, but not necessarily correctly oriented scaffolds separated by gaps). Completion of de novo assemblies remains difficult, as regions that ar...