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Sample records for cell envelope subtilisin-like

  1. Subtilisin-like proteases in nematodes.

    Science.gov (United States)

    Poole, Catherine B; Jin, Jingmin; McReynolds, Larry A

    2007-09-01

    Cleavage by subtilisin-like proteases (subtilases) is an essential step in post-translational processing of proteins found in organisms ranging from yeast to mammals. Our knowledge of the diversity of this protease family in nematodes is aided by the rapid increase in sequence information, especially from the Brugia malayi genome project. Genetic studies of the subtilases in Caenorhabitis elegans give valuable insight into the biological function of these proteases in other nematode species. In this review, we focus on the subtilases in filarial nematodes as well as other parasitic and free-living nematodes in comparison to what is known in C. elegans. Topics to be addressed include expansion and diversity of the subtilase gene family during evolution, enhanced complexity created by alternative RNA splicing, molecular and biochemical characterization of the different subtilases and the challenges of designing subtilase-specific inhibitors for parasitic nematodes. PMID:17570539

  2. Substantial decrease in cell wall α-1,3-glucan caused by disruption of the kexB gene encoding a subtilisin-like processing protease in Aspergillus oryzae.

    Science.gov (United States)

    Mizutani, Osamu; Shiina, Matsuko; Yoshimi, Akira; Sano, Motoaki; Watanabe, Takeshi; Yamagata, Youhei; Nakajima, Tasuku; Gomi, Katsuya; Abe, Keietsu

    2016-09-01

    Disruption of the kexB encoding a subtilisin-like processing protease in Aspergillus oryzae (ΔkexB) leads to substantial morphological defects when the cells are grown on Czapek-Dox agar plates. We previously found that the disruption of kexB causes a constitutive activation of the cell wall integrity pathway. To understand how the disruption of the kexB affects cell wall organization and components, we analyzed the cell wall of ΔkexB grown on the plates. The results revealed that both total N-acetylglucosamine content, which constitutes chitin, and chitin synthase activities were increased. Whereas total glucose content, which constitutes β-1,3-glucan and α-1,3-glucan, was decreased; this decrease was attributed to a remarkable decrease in α-1,3-glucan. Additionally, the β-1,3-glucan in the alkali-insoluble fraction of the ΔkexB showed a high degree of polymerization. These results suggested that the loss of α-1,3-glucan in the ΔkexB was compensated by increases in the chitin content and the average degree of β-1,3-glucan polymerization. PMID:26980104

  3. Isolation and characterization of a Solanum tuberosum subtilisin-like protein with caspase-3 activity (StSBTc-3).

    Science.gov (United States)

    Fernández, María Belén; Daleo, Gustavo Raúl; Guevara, María Gabriela

    2015-01-01

    Plant proteases with caspase-like enzymatic activity have been widely studied during the last decade. Previously, we have reported the presence and induction of caspase-3 like activity in the apoplast of potato leaves during Solanum tuberosum- Phytophthora infestans interaction. In this work we have purified and identified a potato extracellular protease with caspase-3 like enzymatic activity from potato leaves infected with P. infestans. Results obtained from the size exclusion chromatography show that the isolated protease is a monomeric enzyme with an estimated molecular weight of 70 kDa approximately. Purified protease was analyzed by MALDI-TOF MS, showing a 100% of sequence identity with the deduced amino acid sequence of a putative subtilisin-like protease from S. tuberosum (Solgenomics protein ID: PGSC0003DMP400018521). For this reason the isolated protease was named as StSBTc-3. This report constitutes the first evidence of isolation and identification of a plant subtilisin-like protease with caspase-3 like enzymatic activity. In order to elucidate the possible function of StSBTc-3 during plant pathogen interaction, we demonstrate that like animal caspase-3, StSBTc-3 is able to produce in vitro cytoplasm shrinkage in plant cells and to induce plant cell death. This result suggest that, StSBTc-3 could exert a caspase executer function during potato- P. infestans interaction, resulting in the restriction of the pathogen spread during plant-pathogen interaction. PMID:25486023

  4. HOMOLOGY MODELING AND PROTEIN ENGINEERING STRATEGY OF SUBTILASES, THE FAMILY OF SUBTILISIN-LIKE SERINE PROTEINASES

    NARCIS (Netherlands)

    SIEZEN, RJ; DEVOS, WM; LEUNISSEN, JAM

    1991-01-01

    Subtilases are members of the family of subtilisin-like serine proteases. Presently, > 50 subtilases are known, > 40 of which with their complete amino acid sequences. We have compared these sequences and the available three-dimensional structures (subtilisin BPN', subtilisin Carlsberg, thermitase a

  5. Homology modelling and protein engineering strategy of subtilases, the family of subtilisin-like serine proteinases

    NARCIS (Netherlands)

    Siezen, Roland J.; Vos, Willem M. de; Leunissen, Jack A.M.; Dijkstra, Bauke W.

    1991-01-01

    Subtilases are members of the family of subtilisin-like serine proteases. Presently, >50 subtilases are known, >40 of which with their complete amino acid sequences. We have compared these sequences and the available three-dimensional structures (subtilisin BPN', subtilisin Carlsberg, thermitase and

  6. Characterization of a cloned subtilisin-like serine proteinase from a psychrotrophic Vibrio species.

    Science.gov (United States)

    Arnórsdottir, Jóhanna; Smáradóttir, Rúna B; Magnússon, Olafur Th; Thorbjarnardóttir, Sigrídur H; Eggertsson, Gudmundur; Kristjánsson, Magnús M

    2002-11-01

    The gene encoding a subtilisin-like serine proteinase in the psychrotrophic Vibrio sp. PA44 has been successfully cloned, sequenced and expressed in Escherichia coli. The gene is 1593 basepairs and encodes a precursor protein of 530 amino acid residues with a calculated molecular mass of 55.7 kDa. The enzyme is isolated, however, as an active 40.6-kDa proteinase, without a 139 amino acid residue N-terminal prosequence. Under mild conditions the enzyme undergoes a further autocatalytic cleavage to give a 29.7-kDa proteinase that retains full enzymatic activity. The deduced amino acid sequence of the enzyme has high homology to proteinases of the proteinase K family of subtilisin-like proteinases. With respect to the enzyme characteristics compared in this study the properties of the wild-type and recombinant proteinases are the same. Sequence analysis revealed that especially with respect to the thermophilic homologues, aqualysin I from Thermus aquaticus and a proteinase from Thermus strain Rt41A, the cold-adapted Vibrio-proteinase has a higher content of polar/uncharged amino acids, as well as aspartate residues. The thermophilic enzymes had a higher content of arginines, and relatively higher number of hydrophobic amino acids and a higher aliphatic index. These factors may contribute to the adaptation of these proteinases to different temperature conditions.

  7. Crystallization of the virulent and benign subtilisin-like proteases from the ovine footrot pathogen Dichelobacter nodosus

    International Nuclear Information System (INIS)

    The subtilisin-like proteases AprV2 and BprV from virulent strains and AprB2 and BprB from benign strains of D. nodosus have been crystallized and X-ray diffraction data have been collected to 2.0, 2.0, 1.7 and 1.8 Å resolution, respectively. Dichelobacter nodosus is the principal causative agent of ovine footrot, a disease of significant economic importance to the sheep industry. D. nodosus secretes a number of subtilisin-like serine proteases which mediate tissue damage and presumably contribute to the pathogenesis of footrot. Strains causing virulent footrot secrete the proteases AprV2, AprV5 and BprV and strains causing benign footrot secrete the closely related proteases AprB2, AprB5 and BprB. Here, the cloning, purification and crystallization of AprV2, AprB2, BprV and BprB are reported. Crystals of AprV2 and AprB2 diffracted to 2.0 and 1.7 Å resolution, respectively. The crystals of both proteases belonged to space group P1, with unit-cell parameters a = 43.1, b = 46.0, c = 47.2 Å, α = 97.8, β = 115.2, γ = 115.2° for AprV2 and a = 42.7, b = 45.8, c = 45.7 Å, α = 98.4, β = 114.0, γ = 114.6° for AprB2. Crystals of BprV and BprB diffracted to 2.0 and 1.8 Å resolution, respectively. The crystals of both proteases belonged to space group P21, with unit-cell parameters a = 38.5, b = 89.6, c = 47.7 Å, β = 113.6° for BprV and a = 38.5, b = 90.5, c = 44.1 Å, β = 109.9° for BprB. The crystals of all four proteases contained one molecule in the asymmetric unit, with a solvent content ranging from 36 to 40%

  8. Subtilisin-like protease-1 secreted through type IV secretion system contributes to high virulence of Streptococcus suis 2.

    Science.gov (United States)

    Yin, Supeng; Li, Ming; Rao, Xiancai; Yao, Xinyue; Zhong, Qiu; Wang, Min; Wang, Jing; Peng, Yizhi; Tang, Jiaqi; Hu, Fuquan; Zhao, Yan

    2016-01-01

    Streptococcus suis serotype 2 is an emerging zoonotic pathogen that triggered two outbreaks of streptococcal toxic shock syndrome (STSS) in China. Our previous research demonstrated that a type IV secretion system (T4SS) harbored in the 89K pathogenicity island contributes to the pathogenicity of S. suis 2. In the present study, a shotgun proteomics approach was employed to identify the effectors secreted by T4SS in S. suis 2, and surface-associated subtilisin-like protease-1 (SspA-1) was identified as a potential virulence effector. Western blot analysis and pull-down assay revealed that SspA-1 secretion depends on T4SS. Knockout mutations affecting sspA-1 attenuated S. suis 2 and impaired the pathogen's ability to trigger inflammatory response in mice. And purified SspA-1 induced the secretion of IL-6, TNF-α, and IL-12p70 in THP-1 cells directly. SspA-1 is the first T4SS virulence effector reported in Gram-positive bacteria. Overall, these findings allow us to gain further insights into the pathogenesis of T4SS and STSS. PMID:27270879

  9. A homolog of Subtilisin-like Proprotein Convertase 7 is essential to anterior neural development in Xenopus.

    Directory of Open Access Journals (Sweden)

    Sema Senturker

    Full Text Available BACKGROUND: Subtilisin-like Proprotein Convertase 7 (SPC7 is a member of the subtilisin/kexin family of pro-protein convertases. It cleaves many pro-proteins to release their active proteins, including members of the bone morphogenetic protein (BMP family of signaling molecules. Other SPCs are known to be required during embryonic development but corresponding data regarding SPC7 have not been reported previously. METHODOLOGY/PRINCIPAL FINDINGS: We demonstrated that Xenopus SPC7 (SPC7 was expressed predominantly in the developing brain and eye, throughout the neural plate initially, then more specifically in the lens and retina primordia as development progressed. Since no prior functional information has been reported for SPC7, we used gain- and loss-of-function experiments to investigate the possibility that it may also convey patterning or tissue specification information similarly to Furin, SPC4, and SPC6. Overexpression of SPC7 was without effect. In contrast, injection of SPC7 antisense morpholino oligonucleotides (MO into a single blastomere at the 2- or 4-cell stage produced marked disruption of head structures; anophthalmia was salient. Bilateral injections suppressed head and eye formation completely. In parallel with suppression of eye and brain development by SPC7 knockdown, expression of early anterior neural markers (Sox2, Otx2, Rx2, and Pax6 and late eye-specific markers (β-Crystallin and Opsin, and of BMP target genes such as Tbx2 and Tbx3, was reduced or eliminated. Taken together, these findings suggest a critical role for SPC7-perhaps, at least in part, due to activation of one or more BMPs-in early patterning of the anterior neural plate and its derivatives. CONCLUSION/SIGNIFICANCE: SPC7 is required for normal development of the eye and brain, possibly through processing BMPs, though other potential substrates cannot be excluded.

  10. Original features of cell-envelope proteinases of Lactobacillus helveticus. A review.

    Science.gov (United States)

    Sadat-Mekmene, Leila; Genay, Magali; Atlan, Danièle; Lortal, Sylvie; Gagnaire, Valérie

    2011-03-15

    Lactobacillus helveticus is a lactic acid bacterium very used in fermented milks and cheese. The rapid growth of L. helveticus in milk is supported by an efficient cell envelope proteinase (CEP) activity, due to subtilisin-like serine proteases. These enzymes play also crucial roles in texture and flavor formation in dairy products as well as in generating in situ bioactive peptides. In L. helveticus, several genes encoding putative CEPs were detected and characterized by a large intraspecific diversity; little is known about regulation of expression of CEP-encoding genes. Anchored at the bacterial surface, CEPs are large-sized enzymes (> 150 kDa) hydrolyzing β- and α(s1)-casein as well. Substrate cleavages occur after almost all types of amino acids residues, but mass spectrometry analysis revealed L. helveticus strains with specific profiles of substrate hydrolysis, which could explain identification of strains associated with interesting technological properties. In this review, the most recent data regarding CEP-encoding genes, CEP activities toward caseins and L. helveticus strain diversity are discussed. PMID:21354644

  11. The subtilisin-like protease SBT3 contributes to insect resistance in tomato.

    Science.gov (United States)

    Meyer, Michael; Huttenlocher, Franziska; Cedzich, Anna; Procopio, Susanne; Stroeder, Jasper; Pau-Roblot, Corinne; Lequart-Pillon, Michelle; Pelloux, Jérôme; Stintzi, Annick; Schaller, Andreas

    2016-07-01

    Subtilisin-like proteases (SBTs) constitute a large family of extracellular plant proteases, the function of which is still largely unknown. In tomato plants, the expression of SBT3 was found to be induced in response to wounding and insect attack in injured leaves but not in healthy systemic tissues. The time course of SBT3 induction resembled that of proteinase inhibitor II and other late wound response genes suggesting a role for SBT3 in herbivore defense. Consistent with such a role, larvae of the specialist herbivore Manduca sexta performed better on transgenic plants silenced for SBT3 expression (SBT3-SI). Supporting a contribution of SBT3 to systemic wound signaling, systemic induction of late wound response genes was attenuated in SBT3-SI plants. The partial loss of insect resistance may thus be explained by a reduction in systemic defense gene expression. Alternatively, SBT3 may play a post-ingestive role in plant defense. Similar to other anti-nutritive proteins, SBT3 was found to be stable and active in the insect's digestive system, where it may act on unidentified proteins of insect or plant origin. Finally, a reduction in the level of pectin methylesterification that was observed in transgenic plants with altered levels of SBT3 expression suggested an involvement of SBT3 in the regulation of pectin methylesterases (PMEs). While such a role has been described in other systems, PME activity and the degree of pectin methylesterification did not correlate with the level of insect resistance in SBT3-SI and SBT3 overexpressing plants and are thus unrelated to the observed resistance phenotype. PMID:27259555

  12. Shaping the Archaeal Cell Envelope

    NARCIS (Netherlands)

    Ellen, Albert F.; Zolghadr, Behnam; Driessen, Arnold M. J.; Albers, Sonja-Verena

    2010-01-01

    Although archaea have a similar cellular organization as other prokaryotes, the lipid composition of their membranes and their cell surface is unique. Here we discuss recent developments in our understanding of the archaeal protein secretion mechanisms, the assembly of macromolecular cell surface st

  13. Fibrin(ogen)olytic and antiplatelet activities of a subtilisin-like protease from Solanum tuberosum (StSBTc-3).

    Science.gov (United States)

    Pepe, Alfonso; Frey, María Eugenia; Muñoz, Fernando; Fernández, María Belén; Pedraza, Anabela; Galbán, Gustavo; García, Diana Noemí; Daleo, Gustavo Raúl; Guevara, María Gabriela

    2016-06-01

    Plant serine proteases have been widely used in food science and technology as well as in medicine. In this sense, several plant serine proteases have been proposed as potential anti-coagulants and anti-platelet agents. Previously, we have reported the purification and identification of a plant serine protease from Solanum tuberosum leaves. This potato enzyme, named as StSBTc-3, has a molecular weight of 72 kDa and it was characterized as a subtilisin like protease. In this work we determine and characterize the biochemical and medicinal properties of StSBTc-3. Results obtained show that, like the reported to other plant serine proteases, StSBTc-3 is able to degrade all chains of human fibrinogen and to produces fibrin clot lysis in a dose dependent manner. The enzyme efficiently hydrolyzes β subunit followed by partially hydrolyzed α and γ subunits of human fibrinogen. Assays performed to determine StSBTc-3 substrate specificity using oxidized insulin β-chain as substrate, show seven cleavage sites: Asn3-Gln4; Cys7-Gly8; Glu13-Ala14; Leu15-Tyr16; Tyr16-Leu17; Arg22-Gly23 and Phe25-Tyr26, all of them were previously reported for other serine proteases with fibrinogenolytic activity. The maximum StSBTc-3 fibrinogenolytic activity was determined at pH 8.0 and at 37 C. Additionally, we demonstrate that StSBTc-3 is able to inhibit platelet aggregation and is unable to exert cytotoxic activity on human erythrocytes in vitro at all concentrations assayed. These results suggest that StSBTc-3 could be evaluated as a new agent to be used in the treatment of thromboembolic disorders such as strokes, pulmonary embolism and deep vein thrombosis. PMID:27039890

  14. Properties of a subtilisin-like proteinase from a psychrotrophic Vibrio species comparison with proteinase K and aqualysin I.

    Science.gov (United States)

    Kristjánsson, M M; Magnússon, O T; Gudmundsson, H M; Alfredsson, G A; Matsuzawa, H

    1999-03-01

    An extracellular serine proteinase purified from cultures of a psychrotrophic Vibrio species (strain PA-44) belongs to the proteinase K family of the superfamily of subtilisin-like proteinases. The enzyme is secreted as a 47-kDa protein, but under mild heat treatment (30 min at 40 degrees C) undergoes autoproteolytic cleavage on the carboxyl-side of the molecule to give a proteinase with a molecular mass of about 36 kDa that apparently shares most of the enzymatic characteristics and the stability of the 47-kDa protein. In this study, selected enzymatic properties of the Vibrio proteinase were compared with those of the related proteinases, proteinase K and aqualysin I, as representative mesophilic and thermophilic enzymes, respectively. The catalytic efficiency (kcat/Km) for the amidase activity of the cold-adapted enzyme against succinyl-AAPF-p-nitroanilide was significantly higher than that of its mesophilic and thermophilic counterparts, especially when compared with aqualysin I. The stability of the Vibrio proteinase, both towards heat and denaturants, was found to be significantly lower than of either proteinase K or aqualysin I. One or more disulfide bonds in the psychrotrophic proteinase are important for the integrity of the active enzyme structure, as disulfide cleavage, either by reduction with dithiothreitol or by sulfitolysis, led to a loss in its activity. Under the same conditions, aqualysin I was also partially inactivated by dithiothreitol, but the activity of proteinase K was unaffected. The disulfides of either proteinase K or aqualysin I were not reactive towards sulfitolysis, except under denaturing conditions, while all disulfides of the Vibrio proteinase reacted in absence of a denaturant. The reactivity of the disulfides of the proteins as a function of denaturant concentration followed the order: Vibrio proteinase > proteinase K > aqualysin I. The same order of reactivity was also observed for the inactivation of the enzymes by H2O2

  15. Virulence testing and extracellular subtilisin-like (Pr1) and trypsin-like (Pr2) activity during propagule production of Paecilomyces fumosoroseus isolates from whiteflies (Homoptera: Aleyrodidae).

    Science.gov (United States)

    Castellanos-Moguel, Judith; González-Barajas, Margarita; Mier, Teresa; Reyes-Montes, María Del Rocío; Aranda, Eduardo; Toriello, Conchita

    2007-03-01

    To properly characterize several isolates of Paecilomyces fumosoroseus, a fungal entomopathogen of whiteflies (Homoptera: Aleyrodidae) and other insect pests for biocontrol purposes, virulence towards Trialeurodes vaporariorum, and subtilisin-like (Pr1) and trypsin-like (Pr2) protease activity during propagule production were investigated in monospore cultures (MCs). The virulence of three MCs towards second instar whiteflies was measured and expressed as lethal median concentration (LC50). Number and widthlength ratio of propagules (blastospores, hyphal bodies, short hyphae, submerged conidia) and extracellular proteolytic activity was determined simultaneously in liquid medium. Total protease activity was assayed with azocasein, Pr1 and Pr2 activity was determined with the substrates N-Succinyl-Ala-Ala-Pro-Phe-p-nitroanilide and N-Benzoyl-Phe-Val-Arg-pnitroanilide, respectively. Natural variability in virulence, propagule production and cuticle-degrading proteases among isolates was observed. Bioassays showed a LC50 of 1.1 x 1,000, 2.5 x 10,000 and 7.6 x 10,000 conidia/ml for MCs EH-506/3, EH-503/3 and EH-520/3, respectively, EH-506/3 being the most virulent isolate. Isolate EH-503/3 produced the highest yield of propagules (7.7 x 10000000 propagules/ml), followed by EH-520/3 with 6.4 x 10000000 and EH-506/3 with 1.0 x 10000000 propagules/ml. Subtilisin-like (Pr1) and trypsin-like (Pr2) activity was present in the three MCs. Subtilisin-like (Pr1) activity was highest (745.7 UPr1/ml at 120 h) in the most virulent isolate, EH-506/3, pointing at Pr1 as a phenotypic marker of virulence for P. fumosoroseus. EH-506/3 appears to be a good candidate for whitefly biocontrol due to its high virulence, Pr1 concentration and rapid transition to blastospores in submerged liquid medium.

  16. Virulence Properties of the Legionella Pneumophila Cell Envelope

    OpenAIRE

    Shevchuk, Olga; Jäger, Jens; Steinert, Michael

    2011-01-01

    The bacterial envelope plays a crucial role in the pathogenesis of infectious diseases. In this review, we summarize the current knowledge of the structure and molecular composition of the Legionella pneumophila cell envelope. We describe lipopolysaccharides biosynthesis and the biological activities of membrane and periplasmic proteins and discuss their decisive functions during the pathogen–host interaction. In addition to adherence, invasion, and intracellular survival of L. pneumophila, s...

  17. Virulence properties of the Legionella pneumophila cell envelope

    OpenAIRE

    Olga eShevchuk; Jens eJäger; Michael eSteinert

    2011-01-01

    The bacterial envelope plays a crucial role in the pathogenesis of infectious diseases. In this review, we summarize the current knowledge of the structure and molecular composition of the Legionella pneumophila cell envelope. We describe LPS biosynthesis and the biological activities of membrane and periplasmic proteins and discuss their decisive functions during the pathogen-host interaction. In addition to adherence, invasion and intracellular survival of L. pneumophila, special emphasis i...

  18. Polymers in cell encapsulation from an enveloped cell perspective.

    Science.gov (United States)

    de Vos, Paul; Lazarjani, Hamideh Aghajani; Poncelet, Denis; Faas, Marijke M

    2014-04-01

    In the past two decades, many polymers have been proposed for producing immunoprotective capsules. Examples include the natural polymers alginate, agarose, chitosan, cellulose, collagen, and xanthan and synthetic polymers poly(ethylene glycol), polyvinyl alcohol, polyurethane, poly(ether-sulfone), polypropylene, sodium polystyrene sulfate, and polyacrylate poly(acrylonitrile-sodium methallylsulfonate). The biocompatibility of these polymers is discussed in terms of tissue responses in both the host and matrix to accommodate the functional survival of the cells. Cells should grow and function in the polymer network as adequately as in their natural environment. This is critical when therapeutic cells from scarce cadaveric donors are considered, such as pancreatic islets. Additionally, the cell mass in capsules is discussed from the perspective of emerging new insights into the release of so-called danger-associated molecular pattern molecules by clumps of necrotic therapeutic cells. We conclude that despite two decades of intensive research, drawing conclusions about which polymer is most adequate for clinical application is still difficult. This is because of the lack of documentation on critical information, such as the composition of the polymer, the presence or absence of confounding factors that induce immune responses, toxicity to enveloped cells, and the permeability of the polymer network. Only alginate has been studied extensively and currently qualifies for application. This review also discusses critical issues that are not directly related to polymers and are not discussed in the other reviews in this issue, such as the functional performance of encapsulated cells in vivo. Physiological endocrine responses may indeed not be expected because of the many barriers that the metabolites encounter when traveling from the blood stream to the enveloped cells and back to circulation. However, despite these diffusion barriers, many studies have shown optimal

  19. Targeting bactoprenol-coupled cell envelope precursors.

    Science.gov (United States)

    Ulm, Hannah; Schneider, Tanja

    2016-09-01

    Targeting the bactoprenol-coupled cell wall precursor lipid II is a validated antibacterial strategy. In this review, selected prototype lipid II-binding antibiotics of different chemical classes are discussed. Although these compounds attack the same molecular target, they trigger nuanced and diverse cellular effects. Consequently, the mechanisms of antibacterial resistance and the likelihood of resistance development may vary substantially. PMID:27495122

  20. The subtilisin-like protease AprV2 is required for virulence and uses a novel disulphide-tethered exosite to bind substrates.

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    Ruth M Kennan

    Full Text Available Many bacterial pathogens produce extracellular proteases that degrade the extracellular matrix of the host and therefore are involved in disease pathogenesis. Dichelobacter nodosus is the causative agent of ovine footrot, a highly contagious disease that is characterized by the separation of the hoof from the underlying tissue. D. nodosus secretes three subtilisin-like proteases whose analysis forms the basis of diagnostic tests that differentiate between virulent and benign strains and have been postulated to play a role in virulence. We have constructed protease mutants of D. nodosus; their analysis in a sheep virulence model revealed that one of these enzymes, AprV2, was required for virulence. These studies challenge the previous hypothesis that the elastase activity of AprV2 is important for disease progression, since aprV2 mutants were virulent when complemented with aprB2, which encodes a variant that has impaired elastase activity. We have determined the crystal structures of both AprV2 and AprB2 and characterized the biological activity of these enzymes. These data reveal that an unusual extended disulphide-tethered loop functions as an exosite, mediating effective enzyme-substrate interactions. The disulphide bond and Tyr92, which was located at the exposed end of the loop, were functionally important. Bioinformatic analyses suggested that other pathogenic bacteria may have proteases that utilize a similar mechanism. In conclusion, we have used an integrated multidisciplinary combination of bacterial genetics, whole animal virulence trials in the original host, biochemical studies, and comprehensive analysis of crystal structures to provide the first definitive evidence that the extracellular secreted proteases produced by D. nodosus are required for virulence and to elucidate the molecular mechanism by which these proteases bind to their natural substrates. We postulate that this exosite mechanism may be used by proteases produced by

  1. Virulence properties of the Legionella pneumophila cell envelope

    Directory of Open Access Journals (Sweden)

    Olga eShevchuk

    2011-04-01

    Full Text Available The bacterial envelope plays a crucial role in the pathogenesis of infectious diseases. In this review, we summarize the current knowledge of the structure and molecular composition of the Legionella pneumophila cell envelope. We describe LPS biosynthesis and the biological activities of membrane and periplasmic proteins and discuss their decisive functions during the pathogen-host interaction. In addition to adherence, invasion and intracellular survival of L. pneumophila, special emphasis is laid on iron acquisition, detoxification, key elicitors of the immune response and the diverse functions of outer membrane vesicles. The critical analysis of the literature reveals that the dynamics and phenotypic plasticity of the Legionella cell surface during the different metabolic stages requires more attention in the future.

  2. Nuclear envelope rupture and repair during cancer cell migration

    Science.gov (United States)

    Denais, Celine M.; Gilbert, Rachel M.; Isermann, Philipp; McGregor, Alexandra L.; te Lindert, Mariska; Weigelin, Bettina; Davidson, Patricia M.; Friedl, Peter; Wolf, Katarina; Lammerding, Jan

    2016-01-01

    During cancer metastasis, tumor cells penetrate tissues through tight interstitial spaces, requiring extensive deformation of the cell and its nucleus. Here, we investigated tumor cell migration in confining microenvironments in vitro and in vivo. Nuclear deformation caused localized loss of nuclear envelope (NE) integrity, which led to the uncontrolled exchange of nucleo-cytoplasmic content, herniation of chromatin across the NE, and DNA damage. The incidence of NE rupture increased with cell confinement and with depletion of nuclear lamins, NE proteins that structurally support the nucleus. Cells restored NE integrity using components of the endosomal sorting complexes required for transport-III (ESCRT-III) machinery. Our findings indicate that cell migration incurs substantial physical stress on the NE and its content, requiring efficient NE and DNA damage repair for survival. PMID:27013428

  3. ESCRT III repairs nuclear envelope ruptures during cell migration to limit DNA damage and cell death.

    Science.gov (United States)

    Raab, M; Gentili, M; de Belly, H; Thiam, H R; Vargas, P; Jimenez, A J; Lautenschlaeger, F; Voituriez, Raphaël; Lennon-Duménil, A M; Manel, N; Piel, M

    2016-04-15

    In eukaryotic cells, the nuclear envelope separates the genomic DNA from the cytoplasmic space and regulates protein trafficking between the two compartments. This barrier is only transiently dissolved during mitosis. Here, we found that it also opened at high frequency in migrating mammalian cells during interphase, which allowed nuclear proteins to leak out and cytoplasmic proteins to leak in. This transient opening was caused by nuclear deformation and was rapidly repaired in an ESCRT (endosomal sorting complexes required for transport)-dependent manner. DNA double-strand breaks coincided with nuclear envelope opening events. As a consequence, survival of cells migrating through confining environments depended on efficient nuclear envelope and DNA repair machineries. Nuclear envelope opening in migrating leukocytes could have potentially important consequences for normal and pathological immune responses. PMID:27013426

  4. Protamine-induced permeabilization of cell envelopes of gram-positive and gram-negative bacteria

    DEFF Research Database (Denmark)

    Johansen, Charlotte; Verheul, A.; Gram, Lone;

    1997-01-01

    carboxyfluorescein and ATP after 2 to 5 min. Maximum antibacterial activity was reached at alkaline pH and in the absence of divalent cations. The efficient permeabilization of cell envelopes of both gram-positive and gram-negative bacteria suggests that protamine causes a general disruption of the cell envelope...

  5. Genetic interaction maps in Escherichia coli reveal functional crosstalk among cell envelope biogenesis pathways.

    Directory of Open Access Journals (Sweden)

    Mohan Babu

    2011-11-01

    Full Text Available As the interface between a microbe and its environment, the bacterial cell envelope has broad biological and clinical significance. While numerous biosynthesis genes and pathways have been identified and studied in isolation, how these intersect functionally to ensure envelope integrity during adaptive responses to environmental challenge remains unclear. To this end, we performed high-density synthetic genetic screens to generate quantitative functional association maps encompassing virtually the entire cell envelope biosynthetic machinery of Escherichia coli under both auxotrophic (rich medium and prototrophic (minimal medium culture conditions. The differential patterns of genetic interactions detected among > 235,000 digenic mutant combinations tested reveal unexpected condition-specific functional crosstalk and genetic backup mechanisms that ensure stress-resistant envelope assembly and maintenance. These networks also provide insights into the global systems connectivity and dynamic functional reorganization of a universal bacterial structure that is both broadly conserved among eubacteria (including pathogens and an important target.

  6. Brucella abortus Choloylglycine Hydrolase Affects Cell Envelope Composition and Host Cell Internalization

    Science.gov (United States)

    Marchesini, María Inés; Connolly, Joseph; Delpino, María Victoria; Baldi, Pablo C.; Mujer, Cesar V.; DelVecchio, Vito G.; Comerci, Diego J.

    2011-01-01

    Choloylglycine hydrolase (CGH, E.C. 3.5.1.24) is a conjugated bile salt hydrolase that catalyses the hydrolysis of the amide bond in conjugated bile acids. Bile salt hydrolases are expressed by gastrointestinal bacteria, and they presumably decrease the toxicity of host's conjugated bile salts. Brucella species are the causative agents of brucellosis, a disease affecting livestock and humans. CGH confers Brucella the ability to deconjugate and resist the antimicrobial action of bile salts, contributing to the establishment of a successful infection through the oral route in mice. Additionally, cgh-deletion mutant was also attenuated in intraperitoneally inoculated mice, which suggests that CGH may play a role during systemic infection other than hydrolyzing conjugated bile acids. To understand the role CGH plays in B. abortus virulence, we infected phagocytic and epithelial cells with a cgh-deletion mutant (Δcgh) and found that it is defective in the internalization process. This defect along with the increased resistance of Δcgh to the antimicrobial action of polymyxin B, prompted an analysis of the cell envelope of this mutant. Two-dimensional electrophoretic profiles of Δcgh cell envelope-associated proteins showed an altered expression of Omp2b and different members of the Omp25/31 family. These results were confirmed by Western blot analysis with monoclonal antibodies. Altogether, the results indicate that Brucella CGH not only participates in deconjugation of bile salts but also affects overall membrane composition and host cell internalization. PMID:22174816

  7. Analysis of 4070A envelope levels in retroviral preparations and effect on target cell transduction efficiency.

    Science.gov (United States)

    Slingsby, J H; Baban, D; Sutton, J; Esapa, M; Price, T; Kingsman, S M; Kingsman, A J; Slade, A

    2000-07-01

    A number of stable producer cell lines for high-titer Mo-MuLV vectors have been constructed. Development has previously centered on increasing end-point titers by producing maximal levels of Mo-MuLV Gag/Pol, envelope glycoproteins, and retroviral RNA genomes. We describe the production yields and transduction efficiency characteristics of two Mo-MuLV packaging cell lines, FLYA13 and TEFLYA. Although they both produce 4070A-pseudotyped retroviral vectors reproducibly at >1 x 10(6) LFU ml(-1), the transduction efficiency of unconcentrated and concentrated virus from FLYA13 lines is poor compared with vector preparations from TEFLYA lines. A powerful inhibitor of retroviral transduction is secreted by FLYA13 packaging cells. We show that the inhibitory factor does not affect transduction of target cells by RD114-pseudotyped vectors. This suggests that the inhibitory factor functions at the level of envelope-receptor interactions. Phosphate starvation of target cells shows a two-fold increase in Pit2 receptor mRNA and causes some improvement in FLYA13 virus transduction efficiency. Western blots show that FLYA13 viral samples contain an eight-fold higher ratio of 4070A envelope to p30gag than that of virus produced by TEFLYA producer cell lines. This study correlates overexpression of 4070A envelope glycoprotein in retroviral preparations with a reduction of transduction efficiency at high multiplicities of infection. We suggest that TEFLYA packaging cells express preferable levels of 4070A compared with FLYA13, which not only enables high-titer stocks to be generated, but also facilitates a high efficiency of transduction of target cells. PMID:10910141

  8. GAGE cancer-germline antigens are recruited to the nuclear envelope by germ cell-less (GCL)

    DEFF Research Database (Denmark)

    Gjerstorff, Morten F; Rösner, Heike I; Pedersen, Christina B;

    2012-01-01

    metazoan transcriptional regulator, Germ cell-less (GCL), as an interaction partner of GAGE12I. GCL directly binds LEM-domain proteins (LAP2β, emerin, MAN1) at the nuclear envelope, and we found that GAGE proteins were recruited to the nuclear envelope inner membrane by GCL. Based on yeast two...

  9. Expression of hepatitis C virus envelope protein 2 induces apoptosis in cultured mammalian cells

    Institute of Scientific and Technical Information of China (English)

    Li-Xin Zhu; Jing Liu; You-Hua Xie; Yu-Ying Kong; Ye Ye; Chun-Lin Wang; Guang-Di Li; Yuan Wang

    2004-01-01

    AIM: To explore the role of hepatitis C virus (HCV) envelope protein 2 (E2) in the induction of apoptosis.METHODS: A carboxyterminal truncated E2 (E2-661) was transiently expressed in several cultured mammalian cell lines or stably expressed in Chinese hamster ovary (CHO)cell line. Cell proliferation was assessed by 3H thymidine uptake. Apoptosis was examined by Hoechst 33258staining, flow cytometry and DNA fragmentation analysis.RESULTS: Reduced proliferation was readily observed in the E2-661 expressing cells. These cells manifested the typical features of apoptosis, including cell shrinkage,chromatin condensation and hypodiploid genomic DNA content. Similar apoptotic cell death was observed in an E2-661 stably expressing cell line.CONCLUSION: HCV E2 can induce apoptosis in cultured mammalian cells.

  10. In vitro and in vivo screening for novel essential cell-envelope proteins in Pseudomonas aeruginosa

    OpenAIRE

    Regina Fernández-Piñar; Alessandra Lo Sciuto; Alice Rossi; Serena Ranucci; Alessandra Bragonzi; Francesco Imperi

    2015-01-01

    The Gram-negative bacterium Pseudomonas aeruginosa represents a prototype of multi-drug resistant opportunistic pathogens for which novel therapeutic options are urgently required. In order to identify new candidates as potential drug targets, we combined large-scale transposon mutagenesis data analysis and bioinformatics predictions to retrieve a set of putative essential genes which are conserved in P. aeruginosa and predicted to encode cell envelope or secreted proteins. By generating unma...

  11. Transport of lipopolysaccharide across the cell envelope: the long road of discovery.

    Science.gov (United States)

    Ruiz, Natividad; Kahne, Daniel; Silhavy, Thomas J

    2009-09-01

    Intracellular lipid transport is poorly understood. Genetic studies to identify lipid-transport factors are complicated by the essentiality of many lipids, whereas biochemical and cell biology approaches aiming to determine localization and mechanisms of lipid transport are often challenged by the lack of adequate technology. Here, we review the epic history of how different approaches, technological advances and ingenuity contributed to the recent discovery of a multi-protein pathway that transports lipopolysaccharide across the envelope of Gram-negative bacteria.

  12. Subfractionation and analysis of the cell envelope (lipo)polysaccharides of Mycobacterium tuberculosis

    OpenAIRE

    Grzegorzewicz, Anna E.; Jackson, Mary

    2013-01-01

    The cell envelope of Mycobacterium tuberculosis, the causative agent of tuberculosis in humans, is the source of carbohydrates of exceptional structure which play essential roles in the physiology of the bacterium and in its interactions with the host during infection. Much of what is known about their biosynthesis was derived from the phenotypic analysis of knock-out or conditional knock-out mutants of Mycobacteria generated by random or specific insertional mutagenesis. Here, we describe th...

  13. Structure of a Pestivirus Envelope Glycoprotein E2 Clarifies Its Role in Cell Entry

    Directory of Open Access Journals (Sweden)

    Kamel El Omari

    2013-01-01

    Full Text Available Enveloped viruses have developed various adroit mechanisms to invade their host cells. This process requires one or more viral envelope glycoprotein to achieve cell attachment and membrane fusion. Members of the Flaviviridae such as flaviviruses possess only one envelope glycoprotein, E, whereas pestiviruses and hepacivirus encode two glycoproteins, E1 and E2. Although E2 is involved in cell attachment, it has been unclear which protein is responsible for membrane fusion. We report the crystal structures of the homodimeric glycoprotein E2 from the pestivirus bovine viral diarrhea virus 1 (BVDV1 at both neutral and low pH. Unexpectedly, BVDV1 E2 does not have a class II fusion protein fold, and at low pH the N-terminal domain is disordered, similarly to the intermediate postfusion state of E2 from sindbis virus, an alphavirus. Our results suggest that the pestivirus and possibly the hepacivirus fusion machinery are unlike any previously observed.

  14. Destructive effects of butyrate on the cell envelope of Helicobacter pylori.

    Science.gov (United States)

    Yonezawa, Hideo; Osaki, Takako; Hanawa, Tomoko; Kurata, Satoshi; Zaman, Cynthia; Woo, Timothy Derk Hoong; Takahashi, Motomichi; Matsubara, Sachie; Kawakami, Hayato; Ochiai, Kuniyasu; Kamiya, Shigeru

    2012-04-01

    Helicobacter pylori can be found in the oral cavity and is mostly detected by the use of PCR techniques. Growth of H. pylori is influenced by various factors in the mouth, such as the oral microflora, saliva and other antimicrobial substances, all of which make colonization of the oral cavity by H. pylori difficult. In the present study, we analysed the effect of the cell supernatant of a representative periodontal bacterium Porphyromonas gingivalis on H. pylori and found that the cell supernatant destroyed the H. pylori cell envelope. As P. gingivalis produces butyric acid, we focused our research on the effects of butyrate and found that it significantly inhibited the growth of H. pylori. H. pylori cytoplasmic proteins and DNA were detected in the extracellular environment after treatment with butyrate, suggesting that the integrity of the cell envelope was compromised and indicating that butyrate has a bactericidal effect on H. pylori. In addition, levels of extracellular H. pylori DNA increased following treatment with the cell supernatant of butyric acid-producing bacteria, indicating that the cell supernatant also has a bactericidal effect and that this may be due to its butyric acid content. In conclusion, butyric acid-producing bacteria may play a role in affecting H. pylori colonization of the oral cavity. PMID:22194341

  15. Analysis of Pseudomonas aeruginosa cell envelope proteome by capture of surface-exposed proteins on activated magnetic nanoparticles.

    Directory of Open Access Journals (Sweden)

    Davide Vecchietti

    Full Text Available We report on specific magneto-capturing followed by Multidimensional Protein Identification Technology (MudPIT for the analysis of surface-exposed proteins of intact cells of the bacterial opportunistic pathogen Pseudomonas aeruginosa. The magneto-separation of cell envelope fragments from the soluble cytoplasmic fraction allowed the MudPIT identification of the captured and neighboring proteins. Remarkably, we identified 63 proteins captured directly by nanoparticles and 67 proteins embedded in the cell envelope fragments. For a high number of proteins, our analysis strongly indicates either surface exposure or localization in an envelope district. The localization of most identified proteins was only predicted or totally unknown. This novel approach greatly improves the sensitivity and specificity of the previous methods, such as surface shaving with proteases that was also tested on P. aeruginosa. The magneto-capture procedure is simple, safe, and rapid, and appears to be well-suited for envelope studies in highly pathogenic bacteria.

  16. Ion bombardment induced formation of micro-craters in plant cell envelopes

    International Nuclear Information System (INIS)

    Ion beam bombardment of biological material has been recently applied for gene transfer in both plant and bacterial cells. A consistent physical mechanism for this significant result has not yet been developed. A fundamental question about the mechanism is the possible formation of pathways due to ion bombardment that are responsible for the gene transfer. We have carried out investigations of the effects of low-energy bombardment by both gaseous and metallic ion species of onion skin cells on their surface microstructure. Our experimental results reveal evidence demonstrating that the formation of micro-crater-like structures on the plant cell envelope surface is a general phenomenon consequent to ion bombardment, no matter what ion species, under certain ion beam conditions. The micro-craters are about 0.1-1 μm in size (diameter) and a few tens of nanometers in depth. The micro-crater formation process seems to be unrelated to the chemical composition of and rapid water evaporation from the cell envelope, but is associated with the special microstructure of the cell wall

  17. Phosphorylation of an envelope-associated Hsp70 homolog in amyloplasts isolated from cultured cells of sycamore (Acer pseudoplatanus L.).

    Science.gov (United States)

    Checa, S K; Viale, A M

    1998-09-01

    The presence of Hsp70 and Hsp60 molecular chaperones in amyloplasts isolated from cultured sycamore cells was analyzed by immunoblotting. Hsp70 homologs were located in both amyloplast envelope and stromal fractions, but no Hsp60 homologs were detected in any of the different suborganellar fractions. Incubation of whole amyloplasts or their envelope fraction with Mg2+ gamma-32P-ATP resulted in a rapid phosphorylation of the envelope-associated Hsp70 homolog, which constitutes a major target of phosphorylation in these plastids.

  18. Inflammatory response of endothelial cells to hepatitis C virus recombinant envelope glycoprotein 2 protein exposure

    Directory of Open Access Journals (Sweden)

    Ana Carolina Urbaczek

    2014-09-01

    Full Text Available The hepatitis C virus (HCV encodes approximately 10 different structural and non-structural proteins, including the envelope glycoprotein 2 (E2. HCV proteins, especially the envelope proteins, bind to cell receptors and can damage tissues. Endothelial inflammation is the most important determinant of fibrosis progression and, consequently, cirrhosis. The aim of this study was to evaluate and compare the inflammatory response of endothelial cells to two recombinant forms of the HCV E2 protein produced in different expression systems (Escherichia coli and Pichia pastoris. We observed the induction of cell death and the production of nitric oxide, hydrogen peroxide, interleukin-8 and vascular endothelial growth factor A in human umbilical vein endothelial cells (HUVECs stimulated by the two recombinant E2 proteins. The E2-induced apoptosis of HUVECs was confirmed using the molecular marker PARP. The apoptosis rescue observed when the antioxidant N-acetylcysteine was used suggests that reactive oxygen species are involved in E2-induced apoptosis. We propose that these proteins are involved in the chronic inflammation caused by HCV.

  19. Duck tembusu virus and its envelope protein induce programmed cell death.

    Science.gov (United States)

    Shaozhou, Wulin; Li, Chenxi; Zhang, Qingshan; Meng, Runzhe; Gao, Youlan; Liu, Hongyu; Bai, Xiaofei; Chen, Yuhuan; Liu, Ming; Liu, Siguo; Zhang, Yun

    2015-08-01

    The cytopathic effect produced in cells infected with duck tembusu virus (DTMUV) suggests that this emerging virus may induce apoptosis in primary cultures of duck embryo fibroblasts (DEF). Here, we present evidence that DTMUV infection of cultured cells activates apoptosis and that the ability of DTMUV to induce apoptosis is not restricted to cell type because DTMUV-induced apoptosis in duck and mammalian host cells. We further investigated which viral components induce apoptosis in DTMUV-infected host cells. The major envelope glycoprotein (E) was investigated for its apoptotic activities in expressed cells. Transient expression of the E protein alone triggered apoptosis in DEF, Vero, and BHK cells. Expression of the E protein resulted in activation of caspase-3-like proteases in cultured cells. These results indicate that infection of cells with DTMUV or expression of DTMUV E protein alone induces apoptosis, providing the basis for future to define the molecules that play key roles in the fate of DTMUV-infected cells. PMID:26056013

  20. Cell envelope components influencing filament length in the heterocyst-forming cyanobacterium Anabaena sp. strain PCC 7120.

    Science.gov (United States)

    Burnat, Mireia; Schleiff, Enrico; Flores, Enrique

    2014-12-01

    Heterocyst-forming cyanobacteria grow as chains of cells (known as trichomes or filaments) that can be hundreds of cells long. The filament consists of individual cells surrounded by a cytoplasmic membrane and peptidoglycan layers. The cells, however, share a continuous outer membrane, and septal proteins, such as SepJ, are important for cell-cell contact and filament formation. Here, we addressed a possible role of cell envelope components in filamentation, the process of producing and maintaining filaments, in the model cyanobacterium Anabaena sp. strain PCC 7120. We studied filament length and the response of the filaments to mechanical fragmentation in a number of strains with mutations in genes encoding cell envelope components. Previously published peptidoglycan- and outer membrane-related gene mutants and strains with mutations in two genes (all5045 and alr0718) encoding class B penicillin-binding proteins isolated in this work were used. Our results show that filament length is affected in most cell envelope mutants, but the filaments of alr5045 and alr2270 gene mutants were particularly fragmented. All5045 is a dd-transpeptidase involved in peptidoglycan elongation during cell growth, and Alr2270 is an enzyme involved in the biosynthesis of lipid A, a key component of lipopolysaccharide. These results indicate that both components of the cell envelope, the murein sacculus and the outer membrane, influence filamentation. As deduced from the filament fragmentation phenotypes of their mutants, however, none of these elements is as important for filamentation as the septal protein SepJ.

  1. Isolation of chromatin DNA tightly bound to the nuclear envelope of HeLa cells.

    Science.gov (United States)

    Kuvichkin, Vasily Vladimirovich

    2012-11-01

    Recent discovery of the role of nuclear pores in transcription, predicted by our early DNA-membrane complex (DMC) model, makes membrane-bound DNA (MBD) isolation from the cell nucleus and analysis of the MBD actual. The method of MBD isolation proposed by us retains DMC integrity during isolation. We used HeLa cells for DMC extraction. Changing the ionic composition of the isolation medium and replacing DNase I, used commonly for chromatin destruction, with a set of restriction enzymes allowed us to isolate the MBD. Treatment of a nuclear membrane with proteinase K and ultrasound has been used to increase the yield of MBD. Electron microscopic analysis of the purified fraction of isolated DMC supports our previous model of nuclear envelope lipid-chromatin interaction in the nuclear pore assembly.

  2. Quantitative proteomics of the Neisseria gonorrhoeae cell envelope and membrane vesicles for the discovery of potential therapeutic targets.

    Science.gov (United States)

    Zielke, Ryszard A; Wierzbicki, Igor H; Weber, Jacob V; Gafken, Philip R; Sikora, Aleksandra E

    2014-05-01

    Neisseria gonorrhoeae (GC) is a human-specific pathogen, and the agent of a sexually transmitted disease, gonorrhea. There is a critical need for new approaches to study and treat GC infections because of the growing threat of multidrug-resistant isolates and the lack of a vaccine. Despite the implied role of the GC cell envelope and membrane vesicles in colonization and infection of human tissues and cell lines, comprehensive studies have not been undertaken to elucidate their constituents. Accordingly, in pursuit of novel molecular therapeutic targets, we have applied isobaric tagging for absolute quantification coupled with liquid chromatography and mass spectrometry for proteome quantitative analyses. Mining the proteome of cell envelopes and native membrane vesicles revealed 533 and 168 common proteins, respectively, in analyzed GC strains FA1090, F62, MS11, and 1291. A total of 22 differentially abundant proteins were discovered including previously unknown proteins. Among those proteins that displayed similar abundance in four GC strains, 34 were found in both cell envelopes and membrane vesicles fractions. Focusing on one of them, a homolog of an outer membrane protein LptD, we demonstrated that its depletion caused loss of GC viability. In addition, we selected for initial characterization six predicted outer membrane proteins with unknown function, which were identified as ubiquitous in the cell envelopes derived from examined GC isolates. These studies entitled a construction of deletion mutants and analyses of their resistance to different chemical probes. Loss of NGO1985, in particular, resulted in dramatically decreased GC viability upon treatment with detergents, polymyxin B, and chloramphenicol, suggesting that this protein functions in the maintenance of the cell envelope permeability barrier. Together, these findings underscore the concept that the cell envelope and membrane vesicles contain crucial, yet under-explored determinants of GC

  3. Classification of Lactococcus lactis cell envelope proteinase based on gene sequencing, peptides formed after hydrolysis of milk, and computer modeling

    DEFF Research Database (Denmark)

    Børsting, Mette Winther; Qvist, K.B.; Brockmann, E.;

    2015-01-01

    Lactococcus lactis strains depend on a proteolytic system for growth in milk to release essential AA from casein. The cleavage specificities of the cell envelope proteinase (CEP) can vary between strains and environments and whether the enzyme is released or bound to the cell wall. Thirty-eight Lc...

  4. Reprogramming of somatic cells induced by fusion of embryonic stem cells using hemagglutinating virus of Japan envelope (HVJ-E)

    Energy Technology Data Exchange (ETDEWEB)

    Yue, Xiao-shan [Nano Medical Engineering Laboratory, RIKEN Advanced Science Institute, 2-1 Hirosawa, Wako-shi, Saitama 351-0198 (Japan); Department of Biomolecular Engineering, Graduate School of Bioscience and Technology, Tokyo Institute of Technology, Nagatsuta-cho, Midori-ku, Yokohama-shi, Kanagawa 226-8501 (Japan); Fujishiro, Masako [Nano Medical Engineering Laboratory, RIKEN Advanced Science Institute, 2-1 Hirosawa, Wako-shi, Saitama 351-0198 (Japan); Toyoda, Masashi [Department of Reproductive Biology, National Institute for Child Health and Development, 2-10-1, Okura, Setagaya-ku, Tokyo 157-8535 (Japan); Akaike, Toshihiro [Department of Biomolecular Engineering, Graduate School of Bioscience and Technology, Tokyo Institute of Technology, Nagatsuta-cho, Midori-ku, Yokohama-shi, Kanagawa 226-8501 (Japan); Ito, Yoshihiro, E-mail: y-ito@riken.jp [Nano Medical Engineering Laboratory, RIKEN Advanced Science Institute, 2-1 Hirosawa, Wako-shi, Saitama 351-0198 (Japan); Department of Biomolecular Engineering, Graduate School of Bioscience and Technology, Tokyo Institute of Technology, Nagatsuta-cho, Midori-ku, Yokohama-shi, Kanagawa 226-8501 (Japan)

    2010-04-16

    In this research, hemagglutinating virus of Japan envelope (HVJ-E) was used to reprogram somatic cells by fusion with mouse embryonic stem (ES) cells. Neomycin-resistant mouse embryonic fibroblasts (MEFs) were used as somatic cells. Nanog-overexpressing puromycin-resistant EB3 cells were used as mouse ES cells. These two cells were fused by exposing to HVJ-E and the generated fusion cells were selected by puromycin and G418 to get the stable fusion cell line. The fusion cells form colonies in feeder-free culture system. Microsatellite analysis of the fusion cells showed that they possessed genes from both ES cells and fibroblasts. The fusion cells were tetraploid, had alkali phosphatase activity, and expressed stem cell marker genes such as Pou5f1, Nanog, and Sox2, but not the fibroblast cell marker genes such as Col1a1 and Col1a2. The pluripotency of fusion cells was confirmed by their expression of marker genes for all the three germ layers after differentiation induction, and by their ability to form teratoma which contained all the three primary layers. Our results show that HVJ-E can be used as a fusion reagent for reprogramming of somatic cells.

  5. Hepatitis E Virus Produced from Cell Culture Has a Lipid Envelope.

    Directory of Open Access Journals (Sweden)

    Ying Qi

    Full Text Available The absence of a productive cell culture system hampered detailed analysis of the structure and protein composition of the hepatitis E virion. In this study, hepatitis E virus from a robust HEV cell culture system and from the feces of infected monkeys at the peak of virus excretion was purified by ultra-centrifugation. The common feature of the two samples after ultracentrifugation was that the ORF2 protein mainly remained in the top fractions. The ORF2 protein from cell culture system was glycosylated, with an apparent molecular weight of 88 kDa, and was not infectious in PLC/PRF/5 cells. The ORF2 protein in this fraction can bind to and protect HEV RNA from digestion by RNase A. The RNA-ORF2 product has a similar sedimentation coefficient to the virus from feces. The viral RNA in the cell culture supernatant was mainly in the fraction of 1.15 g/cm3 but that from the feces was mainly in the fraction of 1.21 g/cm3. Both were infectious in PLC/PRF/5 cells. And the fraction in the middle of the gradient (1.06 g/cm3 from the cell culture supernatant,but not that from the feces, also has ORF2 protein and HEV RNA but was not infectious in PLC/PRF/5.The infectious RNA-rich fraction from the cell culture contained ORF3 protein and lipid but the corresponding fraction from feces had no lipid and little ORF3 protein. The lipid on the surface of the virus has no effect on its binding to cells but the ORF3 protein interferes with binding. The result suggests that most of the secreted ORF2 protein is not associated with HEV RNA and that hepatitis E virus produced in cell culture differs in structure from the virus found in feces in that it has a lipid envelope.

  6. Expanded breadth of the T-cell response to mosaic HIV-1 envelope DNA vaccination

    Energy Technology Data Exchange (ETDEWEB)

    Korber, Bette [Los Alamos National Laboratory; Fischer, William [Los Alamos National Laboratory; Wallstrom, Timothy [Los Alamos National Laboratory

    2009-01-01

    An effective AIDS vaccine must control highly diverse circulating strains of HIV-1. Among HIV -I gene products, the envelope (Env) protein contains variable as well as conserved regions. In this report, an informatic approach to the design of T-cell vaccines directed to HIV -I Env M group global sequences was tested. Synthetic Env antigens were designed to express mosaics that maximize the inclusion of common potential Tcell epitope (PTE) 9-mers and minimize the inclusion of rare epitopes likely to elicit strain-specific responses. DNA vaccines were evaluated using intracellular cytokine staining (ICS) in inbred mice with a standardized panel of highly conserved 15-mer PTE peptides. I, 2 and 3 mosaic sets were developed that increased theoretical epitope coverage. The breadth and magnitude ofT-cell immunity stimulated by these vaccines were compared to natural strain Env's; additional comparisons were performed on mutant Env's, including gpl60 or gpl45 with or without V regions and gp41 deletions. Among them, the 2 or 3 mosaic Env sets elicited the optimal CD4 and CD8 responses. These responses were most evident in CD8 T cells; the 3 mosaic set elicited responses to an average of 8 peptide pools compared to 2 pools for a set of3 natural Env's. Synthetic mosaic HIV -I antigens can therefore induce T-cell responses with expanded breadth and may facilitate the development of effective T -cell-based HIV -1 vaccines.

  7. Evidence that Vpu modulates HIV-1 Gag-envelope interaction towards envelope incorporation and infectivity in a cell type dependent manner.

    Directory of Open Access Journals (Sweden)

    Archana Gautam

    Full Text Available The HIV-1 Vpu is required for efficient virus particle release from the plasma membrane and intracellular CD4 degradation in infected cells. In the present study, we found that the loss of virus infectivity as a result of envelope (Env incorporation defect caused by a Gag matrix (MA mutation (L30E was significantly alleviated by introducing a start codon mutation in vpu. Inactivation of Vpu partially restored the Env incorporation defect imposed by L30E substitution in MA. This effect was found to be comparable in cell types such as 293T, HeLa, NP2 and GHOST as well as in peripheral blood mononuclear cells (PBMC and monocyte-derived macrophages (MDM. However, in HeLa cells BST-2 knockdown was found to further alleviate the effect of Vpu inactivation on infectivity of L30E mutant. Our data demonstrated that the impaired infectivity of virus particles due to Env incorporation defect caused by MA mutation was modulated by start codon mutation in Vpu.

  8. MEASURING THE OPERATING EFFICIENCY OF SOLAR CELL COMPANIES IN TAIWAN WITH DATA ENVELOPMENT ANALYSIS

    Directory of Open Access Journals (Sweden)

    Jui-Min Hsiao

    2012-01-01

    Full Text Available This study discusses the Data Envelopment Analysis (DEA approach to measure the operating efficiency of solar cell companies. With active and constructive advancement of the government, competition in the solar cell industry became even tenser. When drawing up the competitive strategies, one firm should identify the key indicators of its operating efficiency. This study incorporates three inputs (the number of employees, fixed asset, operating expenses and three outputs (fund and investment, shareholders equity, sales revenue, gross margin to measure the operating efficiency of 12 DMUs (solar cell companies to provide reference for these companies in determining competitive strategies. Data are gathered from the market observation post system in Taiwan. The result indicates that there are six efficient DMUs and six inefficient DMUs. For the relatively inefficient DMUs, a slack variable analysis is performed and the efficiency scores to understand the usage of inputs and performance improvement of inefficient DMUs. The findings could benefit company operators seeking performance improvement in which they could benchmark practices being adapted by the most efficient companies. Together with Malmquist productivity index analysis, companies are able to assess the productivity change of DMUs over time. Finally, managerial implications are provided.

  9. Ultrastructural Study of Salmonella typhimurium Treated with Membrane-Active Agents: Specific Reaction of Dansylchloride with Cell Envelope Components

    Science.gov (United States)

    Schindler, Peter R. G.; Teuber, Michael

    1978-01-01

    Amino groups of cell envelope proteins, lipids, and lipopolysaccharides cannot be labeled in intact cells of Salmonella typhimurium G 30 by using 5-dimethylaminonaphthalene-1-sulfonylchloride incorporated in lecithin-cholesterol vesicles. However, application of membrane-interacting agents like tris(hydroxymethyl)aminomethane (Tris)-hydrochloride, ethylenediaminetetraacetate (Na salt) (EDTA), divalent cations, and sublethal doses of the cationic antibacterial agents polymyxin B and chlorhexidine induced specific fluorescent labeling of envelope proteins and lipids but not of cytoplasmic compounds, with the exception of a soluble protein with a molecular weight of 46,000 in sodium dodecyl sulfate-polyacrylamide gel electrophoresis. Treatment with Tris-hydrochloride buffer produced labeling of the heat-modifiable protein B/B+ and of proteins with molecular weights of 26,000, 22,000, and below 17,000. A combination of Tris-hydrochloride and EDTA induced additional dansylation of the major protein A and of proteins of molecular weights 80,000, 60,000, and 44,000. Polymyxin B and chlorhexidine caused similar labeling patterns. In every case, except with divalent cation treatment, protein B/B+ was the most prominently labeled species. Phosphatidylethanolamine was dansylated up to 30%. Lipopolysaccharide was not reactive under any condition or treatment. In addition, the peptidoglycan-bound lipoprotein did not react with dansylchloride in either intact or Tris-hydrochloride-treated cells. The results are discussed with regard to a possible localization of labeled and unlabeled compounds of the cell envelope on the basis of a model placing cell envelope amino groups into ion-ion interactions with anionic components of other envelope compounds like phosphate and carboxyl groups. Images PMID:97268

  10. Analysis of Pseudomonas aeruginosa Cell Envelope Proteome by Capture of Surface-Exposed Proteins on Activated Magnetic Nanoparticles

    OpenAIRE

    Davide Vecchietti; Dario Di Silvestre; Matteo Miriani; Francesco Bonomi; Mauro Marengo; Alessandra Bragonzi; Lara Cova; Eleonora Franceschi; Pierluigi Mauri; Giovanni Bertoni

    2012-01-01

    We report on specific magneto-capturing followed by Multidimensional Protein Identification Technology (MudPIT) for the analysis of surface-exposed proteins of intact cells of the bacterial opportunistic pathogen Pseudomonas aeruginosa. The magneto-separation of cell envelope fragments from the soluble cytoplasmic fraction allowed the MudPIT identification of the captured and neighboring proteins. Remarkably, we identified 63 proteins captured directly by nanoparticles and 67 proteins embedde...

  11. The HP0256 gene product is involved in motility and cell envelope architecture of Helicobacter pylori

    LENUS (Irish Health Repository)

    Douillard, Francois P

    2010-04-08

    Abstract Background Helicobacter pylori is the causative agent for gastritis, and peptic and duodenal ulcers. The bacterium displays 5-6 polar sheathed flagella that are essential for colonisation and persistence in the gastric mucosa. The biochemistry and genetics of flagellar biogenesis in H. pylori has not been fully elucidated. Bioinformatics analysis suggested that the gene HP0256, annotated as hypothetical, was a FliJ homologue. In Salmonella, FliJ is a chaperone escort protein for FlgN and FliT, two proteins that themselves display chaperone activity for components of the hook, the rod and the filament. Results Ablation of the HP0256 gene in H. pylori significantly reduced motility. However, flagellin and hook protein synthesis was not affected in the HP0256 mutant. Transmission electron transmission microscopy revealed that the HP0256 mutant cells displayed a normal flagellum configuration, suggesting that HP0256 was not essential for assembly and polar localisation of the flagella in the cell. Interestingly, whole genome microarrays of an HP0256 mutant revealed transcriptional changes in a number of genes associated with the flagellar regulon and the cell envelope, such as outer membrane proteins and adhesins. Consistent with the array data, lack of the HP0256 gene significantly reduced adhesion and the inflammatory response in host cells. Conclusions We conclude that HP0256 is not a functional counterpart of FliJ in H. pylori. However, it is required for full motility and it is involved, possibly indirectly, in expression of outer membrane proteins and adhesins involved in pathogenesis and adhesion.

  12. Genome-wide dynamics of a bacterial response to antibiotics that target the cell envelope

    Directory of Open Access Journals (Sweden)

    Tran Ngat

    2011-05-01

    Full Text Available Abstract Background A decline in the discovery of new antibacterial drugs, coupled with a persistent rise in the occurrence of drug-resistant bacteria, has highlighted antibiotics as a diminishing resource. The future development of new drugs with novel antibacterial activities requires a detailed understanding of adaptive responses to existing compounds. This study uses Streptomyces coelicolor A3(2 as a model system to determine the genome-wide transcriptional response following exposure to three antibiotics (vancomycin, moenomycin A and bacitracin that target distinct stages of cell wall biosynthesis. Results A generalised response to all three antibiotics was identified which involves activation of transcription of the cell envelope stress sigma factor σE, together with elements of the stringent response, and of the heat, osmotic and oxidative stress regulons. Attenuation of this system by deletion of genes encoding the osmotic stress sigma factor σB or the ppGpp synthetase RelA reduced resistance to both vancomycin and bacitracin. Many antibiotic-specific transcriptional changes were identified, representing cellular processes potentially important for tolerance to each antibiotic. Sensitivity studies using mutants constructed on the basis of the transcriptome profiling confirmed a role for several such genes in antibiotic resistance, validating the usefulness of the approach. Conclusions Antibiotic inhibition of bacterial cell wall biosynthesis induces both common and compound-specific transcriptional responses. Both can be exploited to increase antibiotic susceptibility. Regulatory networks known to govern responses to environmental and nutritional stresses are also at the core of the common antibiotic response, and likely help cells survive until any specific resistance mechanisms are fully functional.

  13. Cell envelope of Bordetella pertussis: immunological and biochemical analyses and characterization of a major outer membrane porin protein

    Energy Technology Data Exchange (ETDEWEB)

    Armstrong, S.K.

    1986-01-01

    Surface molecules of Bordetella pertussis which may be important in metabolism, pathogenesis, and immunity to whooping cough were examined using cell fractionation and /sup 125/I cell surface labeling. Antigenic envelope proteins were examined by immunofluorescence microscopy and Western blotting procedures using monoclonal antibodies and convalescent sera. A surface protein with a high M/sub r/, missing in a mutant lacking the filamentous hemagglutinin, was identified in virulent Bordetella pertussis but was absent in virulent B. pertussis strains. At least three envelope proteins were found only in virulent B. pertussis strains and were absent or diminished in avirulent and most phenotypically modulated strains. Transposon-induced mutants unable to produce hemolysin, dermonecrotic toxin, pertussis toxin, and filamentous hemagglutinin also lacked these three envelope proteins, confirming that virulence-associated envelope proteins were genetically regulated with other virulence-associated traits. Two dimensional gel electrophoresis revealed at least five heat modifiable proteins which migrated as higher or lower M/sub r/ moieties if solubilized at 25/sup 0/C instead of 100/sup 0/C.

  14. Nuclear envelope proteins modulate proliferation of vascular smooth muscle cells during cyclic stretch application.

    Science.gov (United States)

    Qi, Ying-Xin; Yao, Qing-Ping; Huang, Kai; Shi, Qian; Zhang, Ping; Wang, Guo-Liang; Han, Yue; Bao, Han; Wang, Lu; Li, Hai-Peng; Shen, Bao-Rong; Wang, Yingxiao; Chien, Shu; Jiang, Zong-Lai

    2016-05-10

    Cyclic stretch is an important inducer of vascular smooth muscle cell (VSMC) proliferation, which is crucial in vascular remodeling during hypertension. However, the molecular mechanism remains unclear. We studied the effects of emerin and lamin A/C, two important nuclear envelope proteins, on VSMC proliferation in hypertension and the underlying mechano-mechanisms. In common carotid artery of hypertensive rats in vivo and in cultured cells subjected to high (15%) cyclic stretch in vitro, VSMC proliferation was increased significantly, and the expression of emerin and lamin A/C was repressed compared with normotensive or normal (5%) cyclic stretch controls. Using targeted siRNA to mimic the repressed expression of emerin or lamin A/C induced by 15% stretch, we found that VSMC proliferation was enhanced under static and 5%-stretch conditions. Overexpression of emerin or lamin A/C reversed VSMC proliferation induced by 15% stretch. Hence, emerin and lamin A/C play critical roles in suppressing VSMC hyperproliferation induced by hyperstretch. ChIP-on-chip and MOTIF analyses showed that the DNAs binding with emerin contain three transcription factor motifs: CCNGGA, CCMGCC, and ABTTCCG; DNAs binding with lamin A/C contain the motifs CVGGAA, GCCGCYGC, and DAAGAAA. Protein/DNA array proved that altered emerin or lamin A/C expression modulated the activation of various transcription factors. Furthermore, accelerating local expression of emerin or lamin A/C reversed cell proliferation in the carotid artery of hypertensive rats in vivo. Our findings establish the pathogenetic role of emerin and lamin A/C repression in stretch-induced VSMC proliferation and suggest mechanobiological mechanism underlying this process that involves the sequence-specific binding of emerin and lamin A/C to specific transcription factor motifs.

  15. Characterization of a New Cell Envelope Proteinase PrtP from Lactobacillus rhamnosus CGMCC11055.

    Science.gov (United States)

    Guo, Tingting; Ouyang, Xudong; Xin, Yongping; Wang, Yue; Zhang, Susu; Kong, Jian

    2016-09-21

    Cell envelope proteinases (CEPs) play essential roles in lactic acid bacteria growth in milk and health-promoting properties of fermented dairy products. The genome of Lactobacillus rhamnosus CGMCC11055 possesses two putative CEP genes prtP and prtR2, and the PrtP displays the distinctive domain organization from PrtR2 reported. The PrtP was purified and biochemically characterized. The results showed that the optimal activity occurred at 44 °C, pH 6.5. p-Amidinophenylmethylsulfonyl fluoride obviously inhibited enzymatic activity, suggesting PrtP was a member of serine proteinases. Under the optimal conditions, β-casein was a favorite substrate over αS1- and κ-casein, and 35 oligopeptides were identified in the β-casein hydrolysate, including the phosphoserine peptide and bioactive isoleucine-proline-proline. By analysis of the amino acid sequences of those oligopeptides, proline was the preferred residue at the breakdown site. Therefore, we speculated that PrtP was a new type of CEPs from Lb. rhamnosus. PMID:27585760

  16. Proteomic analysis of Brucella abortus cell envelope and identification of immunogenic candidate proteins for vaccine development.

    Science.gov (United States)

    Connolly, Joseph P; Comerci, Diego; Alefantis, Timothy G; Walz, Alexander; Quan, Marian; Chafin, Ryan; Grewal, Paul; Mujer, Cesar V; Ugalde, Rodolfo A; DelVecchio, Vito G

    2006-07-01

    Brucella abortus is the etiologic agent of bovine brucellosis and causes a chronic disease in humans known as undulant fever. In livestock the disease is characterized by abortion and sterility. Live, attenuated vaccines such as S19 and RB51 have been used to control the spread of the disease in animals; however, they are considered unsafe for human use and they induce abortion in pregnant cattle. For the development of a safer and equally efficacious vaccine, immunoproteomics was utilized to identify novel candidate proteins from B. abortus cell envelope (CE). A total of 163 proteins were identified using 2-DE with MALDI-TOF MS and LC-MS/MS. Some of the major protein components include outer-membrane protein (OMP) 25, OMP31, Omp2b porin, and 60 kDa chaperonin GroEL. 2-DE Western blot analyses probed with antiserum from bovine and a human patient infected with Brucella identified several new immunogenic proteins such as fumarate reductase flavoprotein subunit, F0F1-type ATP synthase alpha subunit, and cysteine synthase A. The elucidation of the immunome of B. abortus CE identified a number of candidate proteins for developing vaccines against Brucella infection in bovine and humans. PMID:16739129

  17. Temporal expression of HIV-1 envelope proteins in baculovirus-infected insect cells: Implications for glycosylation and CD4 binding

    International Nuclear Information System (INIS)

    Three different human immunodeficiency virus type I (HIV-1) envelope derived recombinant proteins and the full length human CD4 polypeptide were expressed in Spodoptera frugiperda (Sf9) cells. DNA constructs encoding CD4, gp120, gp160, and gp160 delta were cloned into the baculovirus expression vector pVL941 or a derivative and used to generate recombinant viruses in a cotransfection with DNA from Autographa californica nuclear polyhedrosis virus (AcMNPV). Western blotting of cell extracts of the recombinant HIV-1 proteins showed that for each construct two major bands specifically reacted with anti-HIV-1 envelope antiserum. These bands corresponded to glycosylated and nonglycosylated versions of the HIV proteins as determined by 3H-mannose labeling and tunicamycin treatment of infected cells. A time course of HIV envelope expression revealed that at early times post-infection (24 hours) the proteins were fully glycosylated and soluble in nonionic detergents. However, at later times postinfection (48 hours), expression levels of recombinant protein reached a maximum but most of the increase was due to a rise in the level of the nonglycosylated species, which was largely insoluble in nonionic detergents. Thus, it appears that Sf9 cells cannot process large amounts of glycosylated recombinant proteins efficiently. As a measure of biological activity, the CD4 binding ability of both glycosylated and nonglycosylated recombinant HIV envelope proteins was tested in a coimmunoprecipitation assay. The results showed that CD4 and the glycosylated versions of recombinant gp120 or gp160 delta specifically associated with one another in this analysis. Nonglycosylated gp120 or gp160 delta proteins from tunicamycin-treated cultures did immunoprecipitate with anti-HIV-1 antiserum but did not interact with CD4

  18. Cellular Architecture of Treponema pallidum: Novel Flagellum, Periplasmic Cone, and Cell Envelope as Revealed by Cryo-Electron Tomography

    OpenAIRE

    Liu, Jun; Howell, Jerrilyn K.; Bradley, Sherille D.; Zheng, Yesha; Zhou, Z. Hong; Norris, Steven J

    2010-01-01

    High resolution cryo-electron tomography (cryo-ET) was utilized to visualize Treponema pallidum, the causative agent of syphilis, at the molecular level. Three-dimensional (3-D) reconstructions from 304 infectious organisms revealed unprecedented cellular structures of this unusual member in the spirochetal family. High resolution cryo-ET reconstructions provided the detailed structures of the cell envelope, which is significantly different from that of gram-negative bacteria. The 4 nm lipid ...

  19. Exogenous hepatitis B virus envelope proteins induce endoplasmic reticulum stress: involvement of cannabinoid axis in liver cancer cells

    Science.gov (United States)

    Montalbano, Roberta; Honrath, Birgit; Wissniowski, Thaddeus Till; Elxnat, Moritz; Roth, Silvia; Ocker, Matthias; Quint, Karl; Churin, Yuri; Roederfeld, Martin; Schroeder, Dirk; Glebe, Dieter; Roeb, Elke; Fazio, Pietro Di

    2016-01-01

    HBV represents the most common chronic viral infection and major cause of hepatocellular carcinoma (HCC), although its exact role in liver tumorigenesis is unclear. Massive storage of the small (SHBs), middle (MHBs) and large surface (LHBs) HBV envelope proteins leads to cell stress and sustained inflammatory responses. Cannabinoid (CB) system is involved in the pathogenesis of liver diseases, stimulating acute and chronic inflammation, liver damage and fibrogenesis; it triggers endoplasmic reticulum (ER) stress response. The aim of our work was to investigate the activation of ER stress pathway after ectopic HBV envelope proteins expression, in liver cancer cells, and the role exerted by CB receptors. PCR, immunofluorescence and western blotting showed that exogenous LHBs and MHBs induce a clear ER stress response in Huh-7 cells expressing CB1 receptor. Up-regulation of the chaperone BiP/GRP78 (Binding Immunoglobulin Protein/Glucose-Regulated Protein 78) and of the transcription factor CHOP/GADD153 (C/EBP Homologous Protein/Growth Arrest and DNA Damage inducible gene 153), phosphorylation of PERK (PKR-like ER Kinase) and eIF2α (Eukaryotic Initiation Factor 2α) and splicing of XBP1 (X-box binding protein 1) was observed. CB1−/− HepG2 cells did not show any ER stress activation. Inhibition of CB1 receptor counteracted BiP expression in transfected Huh-7 and in HBV+ PLC/PRF/5 cells; whereas no effect was observed in HBV− HLF cells. These results suggest that HBV envelope proteins are able to induce the ER stress pathway. CB1 expression is directly correlated with ER stress function. Further investigations are needed to clarify the involvement of cannabinoid in HCC progression after HBV infection. PMID:26967385

  20. Two-component system cross-regulation integrates Bacillus anthracis response to heme and cell envelope stress.

    Directory of Open Access Journals (Sweden)

    Laura A Mike

    2014-03-01

    Full Text Available Two-component signaling systems (TCSs are one of the mechanisms that bacteria employ to sense and adapt to changes in the environment. A prototypical TCS functions as a phosphorelay from a membrane-bound sensor histidine kinase (HK to a cytoplasmic response regulator (RR that controls target gene expression. Despite significant homology in the signaling domains of HKs and RRs, TCSs are thought to typically function as linear systems with little to no cross-talk between non-cognate HK-RR pairs. Here we have identified several cell envelope acting compounds that stimulate a previously uncharacterized Bacillus anthracis TCS. Furthermore, this TCS cross-signals with the heme sensing TCS HssRS; therefore, we have named it HssRS interfacing TCS (HitRS. HssRS reciprocates cross-talk to HitRS, suggesting a link between heme toxicity and cell envelope stress. The signaling between HssRS and HitRS occurs in the parental B. anthracis strain; therefore, we classify HssRS-HitRS interactions as cross-regulation. Cross-talk between HssRS and HitRS occurs at both HK-RR and post-RR signaling junctions. Finally, HitRS also regulates a previously unstudied ABC transporter implicating this transporter in the response to cell envelope stress. This chemical biology approach to probing TCS signaling provides a new model for understanding how bacterial signaling networks are integrated to enable adaptation to complex environments such as those encountered during colonization of the vertebrate host.

  1. A recombinant West Nile virus envelope protein vaccine candidate produced in Spodoptera frugiperda expresSF+ cells

    OpenAIRE

    Bonafé, Nathalie; Rininger, Joseph A.; Chubet, Richard G.; Foellmer, Harald G.; Fader, Stacey; Anderson, John F.; Bushmich, Sandra L.; Anthony, Karen; Ledizet, Michel; Fikrig, Erol; Koski, Raymond A.; Kaplan, Paul

    2008-01-01

    In this study, a recombinant truncated West Nile virus envelope protein antigen (rWNV-E) was produced in serum-free cultures of the expresSF+ insect cell line via baculovirus infection. This production system was selected based on its use in the production of candidate human and animal vaccine antigens. A defined fermentation and purification process for the rWNV-E antigen was established to control for purity and immunogenicity of each protein batch. The material formulated with aluminum hyd...

  2. Cellular architecture of Treponema pallidum: novel flagellum, periplasmic cone, and cell envelope as revealed by cryo electron tomography.

    Science.gov (United States)

    Liu, Jun; Howell, Jerrilyn K; Bradley, Sherille D; Zheng, Yesha; Zhou, Z Hong; Norris, Steven J

    2010-11-01

    High-resolution cryo electron tomography (cryo-ET) was utilized to visualize Treponema pallidum, the causative agent of syphilis, at the molecular level. Three-dimensional (3D) reconstructions from 304 infectious organisms revealed unprecedented cellular structures of this unusual member of the spirochetal family. High-resolution cryo-ET reconstructions provided detailed structures of the cell envelope, which is significantly different from that of Gram-negative bacteria. The 4-nm lipid bilayer of both outer membrane and cytoplasmic membrane resolved in 3D reconstructions, providing an important marker for interpreting membrane-associated structures. Abundant lipoproteins cover the outer leaflet of the cytoplasmic membrane, in contrast to the rare outer membrane proteins visible by scanning probe microscopy. High-resolution cryo-ET images also provided the first observation of T. pallidum chemoreceptor arrays, as well as structural details of the periplasmically located cone-shaped structure at both ends of the bacterium. Furthermore, 3D subvolume averages of periplasmic flagellar motors and flagellar filaments from living organisms revealed the novel flagellar architectures that may facilitate their rotation within the confining periplasmic space. Our findings provide the most detailed structural understanding of periplasmic flagella and the surrounding cell envelope, which enable this enigmatic bacterium to efficiently penetrate tissue and to escape host immune responses.

  3. Dynamic properties of extremophilic subtilisin-like serine-proteases

    DEFF Research Database (Denmark)

    Tiberti, Matteo; Papaleo, Elena

    2011-01-01

    The investigation of the structural determinants of enzymatic temperature adaptation is a crucial pre-requisite both in terms of fundamental research and industrial applications to develop new biocatalysts active at different temperature ranges. In several cases, the differences related to cold- ...

  4. Biomimetic Envelopes

    Directory of Open Access Journals (Sweden)

    Ilaria Mazzoleni

    2010-06-01

    Full Text Available How to translate the lessons learned from the analysis and observation of the animal world is the design learning experience presented in this article. Skin is a complex and incredibly sophisticated organ that performs various functions, including protection, sensation and heat and water regulation. In a similar way building envelopes serve multiple roles, as they are the interface between the building inhabitants and environmental elements. The resulting architectural building envelopes proto-architectural research and design projects here presented, inspired by the study of animal skins, perform and respond; they take into consideration various dynamic local environmental conditions, enhancing and supporting them rather than exploiting them, creating a more sustainable way of building and living.

  5. INTERNAL ENVELOPES

    CERN Multimedia

    Mail Office

    2001-01-01

    Internal mail envelopes often finish up in large piles in certain offices, thus creating a shortage for other users of the mail service, who would be grateful if everyone with an unused stock could deposit them in their mail box, after attaching them together with an elastic band or piece of string. The messengers will then collect them so that the Mail Office can put them back in circulation. Thank you for your understanding and collaboration.

  6. Differential sensitivity of bat cells to infection by enveloped RNA viruses: coronaviruses, paramyxoviruses, filoviruses, and influenza viruses.

    Directory of Open Access Journals (Sweden)

    Markus Hoffmann

    Full Text Available Bats (Chiroptera host major human pathogenic viruses including corona-, paramyxo, rhabdo- and filoviruses. We analyzed six different cell lines from either Yinpterochiroptera (including African flying foxes and a rhinolophid bat or Yangochiroptera (genera Carollia and Tadarida for susceptibility to infection by different enveloped RNA viruses. None of the cells were sensitive to infection by transmissible gastroenteritis virus (TGEV, a porcine coronavirus, or to infection mediated by the Spike (S protein of SARS-coronavirus (SARS-CoV incorporated into pseudotypes based on vesicular stomatitis virus (VSV. The resistance to infection was overcome if cells were transfected to express the respective cellular receptor, porcine aminopeptidase N for TGEV or angiotensin-converting enzyme 2 for SARS-CoV. VSV pseudotypes containing the S proteins of two bat SARS-related CoV (Bg08 and Rp3 were unable to infect any of the six tested bat cell lines. By contrast, viral pseudotypes containing the surface protein GP of Marburg virus from the family Filoviridae infected all six cell lines though at different efficiency. Notably, all cells were sensitive to infection by two paramyxoviruses (Sendai virus and bovine respiratory syncytial virus and three influenza viruses from different subtypes. These results indicate that bat cells are more resistant to infection by coronaviruses than to infection by paramyxoviruses, filoviruses and influenza viruses. Furthermore, these results show a receptor-dependent restriction of the infection of bat cells by CoV. The implications for the isolation of coronaviruses from bats are discussed.

  7. Formation of infectious hybrid virions with gibbon ape leukemia virus and human T-cell leukemia virus retroviral envelope glycoproteins and the gag and pol proteins of Moloney murine leukemia virus.

    OpenAIRE

    C. Wilson; Reitz, M S; Okayama, H; Eiden, M V

    1989-01-01

    The gibbon ape leukemia virus, SEATO strain, and human T-cell leukemia virus type I envelope glycoproteins can be functionally assembled with a Moloney murine leukemia virus core into infectious particles. The envelope-host cell receptor interaction is the major determinant of the host cell specificity for these hybrid virions.

  8. Effect of irradiation on kinetic behavior of Salmonella Typhimurium and Staphylococcus aureus in lettuce and damage of bacterial cell envelope

    Science.gov (United States)

    Shim, Won-Bo; Je, Gil-Soo; Kim, Kyeongyeol; Mtenga, Adelard B.; Lee, Won-Gyeong; Song, Jeong-Un; Chung, Duck-Hwa; Yoon, Yohan

    2012-05-01

    This study evaluated effect of gamma irradiation on survival of Salmonella Typhimurium and Staphylococcus aureus on lettuce and damage of cell envelope. S. Typhimurium and S. aureus were inoculated on red leaf lettuce, and they were irradiated at 0, 0.5, 1, 1.5, 2, 2.5, and 3 kGy, and the samples were then stored at 7 and 25 °C for 7 days. Survival of S. Typhimurium and S. aureus were enumerated on xylose lysine deoxycholate agar and Baird-Parker agar, respectively. D10 value (dose required to reduce 1 log CFU/leaf) was calculated, and kinetic parameters (maximum specific growth rate; μmax and lag phase duration; LPD) were calculated by the modified Gompertz model. In addition, cell envelope damage of the pathogens was observed by scanning electron microscope (SEM) and transmission electron microscope (TEM). D10 values were 0.35 and 0.33 kGy for S. Typhimurium and S. aureus, respectively. During storage at 7 °C, S. Typhimurium and S. aureus had significant (P<0.05) growth only on non-irradiated samples up to about 2.5 and 4 log CFU/leaf at 0.42 and 1.28 log CFU/leaf/day of μmax, respectively. At 25 °C, cell counts of S. Typhimurium and S. aureus on the samples irradiated at 0 and 0.5 kGy increased (P<0.05) up to 3-6 log CFU/leaf. The μmax of both pathogens were higher in 0 kGy (1.08-2.27 log CFU/leaf/day) and 0.5 kGy (0.58-0.92 log CFU/leaf/day), and LPDs ranged from 1.53 to 3.14 day. SEM and TEM observations showed that cells irradiated at 1.5 and 3 kGy showed disrupted cell membrane. These results indicate that gamma irradiation could be a useful decontamination technology to improve food safety of lettuce by destroying cells of S. Typhimurium and S. aureus.

  9. Determination of the Operating Envelope for a Direct Fired Fuel Cell Turbine Hybrid Using Hardware Based Simulation

    Energy Technology Data Exchange (ETDEWEB)

    David Tucker; Eric Liese; Randall Gemmen

    2009-02-10

    The operating range of a direct fired solid oxide fuel cell gas turbine (SOFC/GT) hybrid with bypass control of cathode airflow was determined using a hardware-based simulation facility designed and built by the U.S. Department of Energy, National Energy Technology Laboratory (NETL). Three methods of cathode airflow management using bypass valves in a hybrid power system were evaluated over the maximum range of operation. The cathode air flow was varied independently over the full range of operation of each bypass valve. Each operating point was taken at a steady state condition and was matched to the thermal, pressure and flow output of a corresponding fuel cell operation condition. Turbine electric load was also varied so that the maximum range of fuel cell operation could be studied, and a preliminary operating map could be made. Results are presented to show operating envelopes in terms of cathode air flow, fuel cell and turbine load, and compressor surge margin to be substantial.

  10. Depletion of the surface CD4 molecule by the envelope protein of human immunodeficiency virus expressed in a human CD4+ monocytoid cell line

    International Nuclear Information System (INIS)

    A CD4+ human monocytoid cell line, U937, was transfected with a constructed plasmid which has the envelope gene of human immunodeficiency virus under the transcriptional control of the human metallothionein IIA promoter and was cloned thereafter. These cloned cell lines (EH and EL cells) expressed the viral gp160 in the cytoplasm. The expression of surface CD4 antigen examined by Leu3a and OKT4 monoclonal antibodies, however, disappeared completely in EH cells, which produce a larger amount of gp160, while diminishing only partly in EL cells, which produce a smaller amount of gp160. These results indicate that the level of expression of surface CD4 antigen correlates inversely with the amount of intracellular gp160. Moreover, immunoprecipitation studies using lysate from EH cells showed that OKT4 monoclonal antibody precipitated a significant number of CD4 molecules even after surface CD4 disappeared. However, Leu3a monoclonal antibody, which recognizes the binding site for envelope protein, could not precipitate any CD4 molecules in the same cell lysate. Taken together, these results suggested that CD4 molecules are still synthesized normally after the augmented production of gp160 in the cells but form a complex with the envelope protein in the cytoplasm and become unable to be transported to the cell surface, resulting in the observed depletion of surface CD4 antigen. This mechanism may explain the decrease or absence of surface CD4 antigens in human lymphocytes infected with human immunodeficiency virus

  11. Envelope-specific B-cell populations in African green monkeys chronically infected with simian immunodeficiency virus.

    Science.gov (United States)

    Zhang, Ruijun; Martinez, David R; Nguyen, Quang N; Pollara, Justin; Arifin, Trina; Stolarchuk, Christina; Foulger, Andrew; Amos, Josh D; Parks, Robert; Himes, Jonathon E; Wang, Minyue; Edwards, Regina W; Trama, Ashley M; Vandergrift, Nathan; Colvin, Lisa; Dewar, Ken; Juretic, Nikoleta; Wasserscheid, Jessica; Ferrari, Guido; Liao, Hua-Xin; Permar, Sallie R

    2016-01-01

    African green monkeys (AGMs) are natural primate hosts of simian immunodeficiency virus (SIV). Interestingly, features of the envelope-specific antibody responses in SIV-infected AGMs are distinct from that of HIV-infected humans and SIV-infected rhesus monkeys, including gp120-focused responses and rapid development of autologous neutralization. Yet, the lack of genetic tools to evaluate B-cell lineages hinders potential use of this unique non-human primate model for HIV vaccine development. Here we define features of the AGM Ig loci and compare the proportion of Env-specific memory B-cell populations to that of HIV-infected humans and SIV-infected rhesus monkeys. AGMs appear to have a higher proportion of Env-specific memory B cells that are mainly gp120 directed. Furthermore, AGM gp120-specific monoclonal antibodies display robust antibody-dependent cellular cytotoxicity and CD4-dependent virion capture activity. Our results support the use of AGMs to model induction of functional gp120-specific antibodies by HIV vaccine strategies. PMID:27381634

  12. Infection of human and non-human cells by a highly fusogenic primary CD4-independent HIV-1 isolate with a truncated envelope cytoplasmic tail

    International Nuclear Information System (INIS)

    Truncation of the envelope cytoplasmic tail has enabled FIV, SIV, and some laboratory HIV-1 strains to acquire broader cellular tropism and enhanced fusogenicity. Here we have characterized a primary CD4-independent HIV-1 isolate (92UG046-T8) with a truncated cytoplasmic tail that was able to infect and induce syncytia in primary lymphocytes from human, chimpanzee, and monkey, as well as CD4-negative cell lines from human and monkey. Increased syncytia were also noticeable with 293 cells expressing the cloned envelope from the 92UG046-T8 isolate suggesting envelope-mediated cellular fusion. Except pooled serum from HIV-1-infected individuals, monoclonal anti-envelope antibodies or antibodies/antagonists against CD4, CXCR4, and CCR5 were not able to prevent infection by the 92UG046-T8 isolate. This is the first report showing a primary HIV-1 variant with truncated cytoplasmic tail which is highly fusogenic and can infect a broad range of cells from human and non-human origins. In vivo evolution of similar HIV-1 mutants may have important implications in AIDS pathogenesis

  13. Playing hide-and-seek with host macrophages through the use of mycobacterial cell envelope phthiocerol dimycocerosates and phenolic glycolipids

    Directory of Open Access Journals (Sweden)

    Ainhoa eARBUES

    2014-12-01

    Full Text Available Mycobacterial pathogens, including Mycobacterium tuberculosis, the etiological agent of tuberculosis (TB, have evolved a remarkable ability to evade the immune system in order to survive and to colonize the host. Among the most important evasion strategies is the capacity of these bacilli to parasitize host macrophages, since these are major effector cells against intracellular pathogens that can be used as long-term cellular reservoirs. Mycobacterial pathogens employ an array of virulence factors that manipulate macrophage function to survive and establish infection. Until recently, however, the role of mycobacterial cell envelope lipids as virulence factors in macrophage subversion has remained elusive. Here, we will address exclusively the proposed role for phthiocerol dimycocerosates (DIM in the modulation of the resident macrophage response and that of phenolic glycolipids (PGL in the regulation of the recruitment and phenotype of incoming macrophage precursors to the site of infection. We will provide a unique perspective of potential additional functions for these lipids, and highlight obstacles and opportunities to further understand their role in the pathogenesis of TB and other mycobacterial diseases.

  14. Influence of Disulfide-Stabilized Structure on the Specificity of Helper T-Cell and Antibody Responses to HIV Envelope Glycoprotein gp120▿ †

    OpenAIRE

    Mirano-Bascos, Denise; Steede, N. Kalaya; Robinson, James E.; Landry, Samuel J.

    2010-01-01

    CD4+ helper T cells specific for human immunodeficiency virus type 1 (HIV-1) are associated with control of viremia. Nevertheless, vaccines have had limited effectiveness thus far, in part because sequence variability and other structural features of the HIV envelope glycoprotein deflect the immune response. Previous studies indicated that CD4+ T-cell epitope dominance is controlled by antigen three-dimensional structure through its influence on antigen processing and presentation. In this wo...

  15. Expression of particulate-form of Japanese encephalitis virus envelope protein in a stably transfected Drosophila cell line

    Directory of Open Access Journals (Sweden)

    Zhang Li

    2007-02-01

    Full Text Available Abstract Background Japanese encephalitis virus (JEV, a member of the family Flaviviridae, is an important mosquito-borne human pathogen. Its envelope glycoprotein (E is the major determinant of the pathogenicity and host immune responses. In the present study, we explored the feasibility of producing recombinant JEV E protein in the virus-free Drosophila expression system. Results The coding sequence for the signal sequence of premembrane and E protein was cloned into the Drosophila expression vector pAc5.1/V5-His. A Drosophila cell line S2 was cotransfected with this construct as well as a plasmid providing hygromycin B resistance. A cell line expressing the JEV E protein was selected by immunofluoresence, confocal microscopy, and western blot analysis using three different monoclonal antibodies directed against JEV E protein. This cell line was stable in the yield of JEV E protein during two months in vitro maintenance in the presence of hygromycin B. The results showed that the recombinant E protein had an expected molecular weight of about 50 kilodalton, was immunoreactive with all three monoclonal antibodies, and found in both the cytoplasm and culture supernatant. Sucrose gradient ultracentrifugation analysis revealed that the secreted E protein product was in a particulate form. It migrated to the sucrose fraction with a density of 1.13 g/ml. Balb/c mice immunised with the sucrose fraction containing the E protein particles developed specific antibodies. These data show that functioning JEV E protein was expressed in the stable S2 cell line. Conclusion The Drosophila expression system is a more convenient, cheaper and safer approach to the production of vaccine candidates and diagnostic reagents for JEV.

  16. Positive selection of mutants with cell envelope defects of a Salmonella typhimurium strain hypersensitive to the products of genes hisF and hisH. [uv radiation

    Energy Technology Data Exchange (ETDEWEB)

    Anton, D.N.

    1979-03-01

    Strain SB564 and its derivative DA78 are hypersensitive to the inhibitory action of the proteins coded for by genes hisF and hisH on cell division. Transduction of hisO1242, a regulatory mutation that elicits a very high level of expression of the histidine operon, into these strains resulted in the production of long filamentous cells carrying large balloons and in growth failure. Forty-one hisO1242 derivatives that escaped inhibition were isolated. These strains showed a large variety of alterations, many of which were related to the cell envelope. The more-frequent alterations included: changes in cell shape, increased sensitivity to one or more of several drugs (deoxycholate, cycloserine, penicillin, novobiocin, acridine orange), increased autolytic activity in alkaline buffer, anomalous fermentation of maltose on eosin--methylene blue plates, and temperature-conditional cell division. The alterations are produced, in some of the strains, by pleiotropic mutations in gene envB. Strains affected in divC, divD, and rodA loci have also been identified. Genetic analaysis has shown that several strains carry more than one envelope mutation. It is assumed that envelope mutations are positively selected because they somehow alleviate the particularly severe inhibition of cell division caused, in strains SB564 and DA78, by the excessive synthesis of hisF and hisH gene products.

  17. Positive selection of mutants with cell envelope defects of a Salmonella typhimurium strain hypersensitive to the products of genes hisF and hisH

    International Nuclear Information System (INIS)

    Strain SB564 and its derivative DA78 are hypersensitive to the inhibitory action of the proteins coded for by genes hisF and hisH on cell division. Transduction of hisO1242, a regulatory mutation that elicits a very high level of expression of the histidine operon, into these strains resulted in the production of long filamentous cells carrying large balloons and in growth failure. Forty-one hisO1242 derivatives that escaped inhibition were isolated. These strains showed a large variety of alterations, many of which were related to the cell envelope. The more-frequent alterations included: changes in cell shape, increased sensitivity to one or more of several drugs (deoxycholate, cycloserine, penicillin, novobiocin, acridine orange), increased autolytic activity in alkaline buffer, anomalous fermentation of maltose on eosin--methylene blue plates, and temperature-conditional cell division. The alterations are produced, in some of the strains, by pleiotropic mutations in gene envB. Strains affected in divC, divD, and rodA loci have also been identified. Genetic analaysis has shown that several strains carry more than one envelope mutation. It is assumed that envelope mutations are positively selected because they somehow alleviate the particularly severe inhibition of cell division caused, in strains SB564 and DA78, by the excessive synthesis of hisF and hisH gene products

  18. Gram-positive bacterial cell envelopes: The impact on the activity of antimicrobial peptides.

    Science.gov (United States)

    Malanovic, Nermina; Lohner, Karl

    2016-05-01

    A number of cationic antimicrobial peptides, effectors of innate immunity, are supposed to act at the cytoplasmic membrane leading to permeabilization and eventually membrane disruption. Thereby, interaction of antimicrobial peptides with anionic membrane phospholipids is considered to be a key factor in killing of bacteria. Recently, evidence was provided that killing takes place only when bacterial cell membranes are completely saturated with peptides. This adds to an ongoing debate, which role cell wall components such as peptidoglycan, lipoteichoic acid and lipopolysaccharide may play in the killing event, i.e. if they rather entrap or facilitate antimicrobial peptides access to the cytoplasmic membrane. Therefore, in this review we focused on the impact of Gram-positive cell wall components for the mode of action and activity of antimicrobial peptides as well as in innate immunity. This led us to conclude that interaction of antimicrobial peptides with peptidoglycan may not contribute to a reduction of their antimicrobial activity, whereas interaction with anionic lipoteichoic acids may reduce the local concentration of antimicrobial peptides on the cytoplasmic membrane necessary for sufficient destabilization of the membranes and bacterial killing. Further affinity studies of antimicrobial peptides toward the different cell wall as well as membrane components will be needed to address this problem on a quantitative level. This article is part of a Special Issue entitled: Antimicrobial peptides edited by Karl Lohner and Kai Hilpert.

  19. Polycations increase the permeability of Mycobacterium vaccae cell envelopes to hydrophobic compounds.

    Science.gov (United States)

    Korycka-Machala, M; Ziółkowski, A; Rumijowska-Galewicz, A; Lisowska, K; Sedlaczek, L

    2001-10-01

    Polycations [protamine, polymyxin B nonapeptide (PMBN) and polyethyleneimine (PEI)] have been shown to increase the cell wall permeability of Mycobacterium vaccae to highly hydrophobic compounds, as manifested in enhanced intracellular bioconversion of beta-sitosterol to 4-androsten-3,17-dione (AD) and 1,4-androstadien-3,17-dione (ADD), and cell sensitization to erythromycin and rifampicin. The quantity of AD(D) formed per biomass unit was twice as high in the presence of PMBN and PEI, and three times higher with protamine. The sensitization factor, i.e. the MIC(50) ratio of the control bacteria to those exposed to polycations, ranged from 4 to 16, depending on the polycation/antibiotic combination. Non-covalently bound free lipids were extracted from the control and polycation-treated cells and fractionated with the use of chloroform, acetone and methanol. Chloroform- and acetone-eluted fractions (mainly neutral lipids and glycolipids, respectively) showed significant polycation-induced alterations in their quantitative and qualitative composition. The fatty acid profile of neutral lipids was reduced in comparison to control, whereas acetone-derived lipids were characterized by a much higher level of octadecenoic acid (C(18:1)) and a considerably lower content of docosanoic acid (C(22:0)), the marker compound of mycolate-containing glycolipids. Methanol-eluted fractions remained unaltered. Cell-wall-linked mycolates obtained from delipidated cells were apparently unaffected by the action of polycations, as judged from the TLC pattern of mycolic acid subclasses, the mean weight of mycolate preparations and the C(22:0) acid content in the mycolates, determined by GC/MS and pyrolysis GC. The results suggest the involvement of the components of non-covalently bound lipids in the outer layer in the M. vaccae permeability barrier.

  20. Two small (p)ppGpp synthases in Staphylococcus aureus mediate tolerance against cell envelope stress conditions.

    Science.gov (United States)

    Geiger, Tobias; Kästle, Benjamin; Gratani, Fabio Lino; Goerke, Christiane; Wolz, Christiane

    2014-02-01

    The stringent response is a conserved global regulatory mechanism that is related to the synthesis of (p)ppGpp nucleotides. Gram-positive bacteria, such as Staphylococcus aureus, possess three (p)ppGpp synthases: the bifunctional RSH (RelA/SpoT homolog) protein, which consists of a (p)ppGpp synthase and a (p)ppGpp hydrolase domain, and two truncated (p)ppGpp synthases, designated RelP and RelQ. Here, we characterized these two small (p)ppGpp synthases. Biochemical analyses of purified proteins and in vivo studies revealed a stronger synthetic activity for RelP than for RelQ. However, both enzymes prefer GDP over GTP as the pyrophosphate recipient to synthesize ppGpp. Each of the enzymes was shown to be responsible for the essentiality of the (p)ppGpp hydrolase domain of the RSH protein. The staphylococcal RSH-hydrolase is an efficient enzyme that prevents the toxic accumulation of (p)ppGpp. Expression of (p)ppGpp synthases in a hydrolase-negative background leads not only to growth arrest but also to cell death. Transcriptional analyses showed that relP and relQ are strongly induced upon vancomycin and ampicillin treatments. Accordingly, mutants lacking relP and relQ showed a significantly reduced survival rate upon treatments with cell wall-active antibiotics. Thus, RelP and RelQ are active (p)ppGpp synthases in S. aureus that are induced under cell envelope stress to mediate tolerance against these conditions.

  1. Construction of an Active Façade Envelope with Peltier Cells

    OpenAIRE

    Martín-Gómez, C. (César); Ibáñez-Puy, M. (María); Sacristán-Fernández, J.A. (José Antonio)

    2013-01-01

    The team researchers have been investigating on alternative ways for buildings to waste less energy. The result is the consecution of a new facade system with Peltier cells, that is to say, a new system of air conditioning that works both as a machine as a facade. That means the application in the field of construction of a technology that is already in use in other areas, fundamentally the military and aerospace. The new system has to be a prefabricated element that perfectly fix between the...

  2. Antigenic properties of the human immunodeficiency virus envelope glycoprotein gp120 on virions bound to target cells.

    Directory of Open Access Journals (Sweden)

    Meron Mengistu

    2015-03-01

    Full Text Available The HIV-1 envelope glycoprotein, gp120, undergoes multiple molecular interactions and structural rearrangements during the course of host cell attachment and viral entry, which are being increasingly defined at the atomic level using isolated proteins. In comparison, antigenic markers of these dynamic changes are essentially unknown for single HIV-1 particles bound to target cells. Such markers should indicate how neutralizing and/or non-neutralizing antibodies might interdict infection by either blocking infection or sensitizing host cells for elimination by Fc-mediated effector function. Here we address this deficit by imaging fluorescently labeled CCR5-tropic HIV-1 pseudoviruses using confocal and superresolution microscopy to track the exposure of neutralizing and non-neutralizing epitopes as they appear on single HIV-1 particles bound to target cells. Epitope exposure was followed under conditions permissive or non-permissive for viral entry to delimit changes associated with virion binding from those associated with post-attachment events. We find that a previously unexpected array of gp120 epitopes is exposed rapidly upon target cell binding. This array comprises both neutralizing and non-neutralizing epitopes, the latter being hidden on free virions yet capable of serving as potent targets for Fc-mediated effector function. Under non-permissive conditions for viral entry, both neutralizing and non-neutralizing epitope exposures were relatively static over time for the majority of bound virions. Under entry-permissive conditions, epitope exposure patterns changed over time on subsets of virions that exhibited concurrent variations in virion contents. These studies reveal that bound virions are distinguished by a broad array of both neutralizing and non-neutralizing gp120 epitopes that potentially sensitize a freshly engaged target cell for destruction by Fc-mediated effector function and/or for direct neutralization at a post-binding step

  3. Early infection HIV-1 envelope V1-V2 genotypes do not enhance binding or replication in cells expressing high levels of α4β7 integrin.

    Science.gov (United States)

    Etemad, Behzad; Gonzalez, Oscar A; McDonough, Sean; Pena-Cruz, Victor; Sagar, Manish

    2013-11-01

    It has been postulated that HIV-1 envelope properties, such as shorter and less-glycosylated V1-V2 loops commonly observed among non-subtype B early-transmitted viruses, promote utilization of the gut homing integrin α4β7. This property potentially confers an advantage to some HIV-1 variants early after acquisition. We found that replication-competent recombinant viruses incorporating HIV-1 subtype A compact and less-glycosylated early versus chronic phase V1-V2 loops demonstrated no significant difference in binding to α4β7 high CD8⁺ T cells or replication in α4β7 high CD4⁺ T cells. Integrin α4β7 usage does not select for shorter less-glycosylated envelopes during transmission. PMID:23797693

  4. Loss of cofilin 1 disturbs actin dynamics, adhesion between enveloping and deep cell layers and cell movements during gastrulation in zebrafish.

    Directory of Open Access Journals (Sweden)

    Chun-Wei Lin

    Full Text Available During gastrulation, cohesive migration drives associated cell layers to the completion of epiboly in zebrafish. The association of different layers relies on E-cadherin based cellular junctions, whose stability can be affected by actin turnover. Here, we examined the effect of malfunctioning actin turnover on the epibolic movement by knocking down an actin depolymerizing factor, cofilin 1, using antisense morpholino oligos (MO. Knockdown of cfl1 interfered with epibolic movement of deep cell layer (DEL but not in the enveloping layer (EVL and the defect could be specifically rescued by overexpression of cfl1. It appeared that the uncoordinated movements of DEL and EVL were regulated by the differential expression of cfl1 in the DEL, but not EVL as shown by in situ hybridization. The dissociation of DEL and EVL was further evident by the loss of adhesion between layers by using transmission electronic and confocal microscopy analyses. cfl1 morphants also exhibited abnormal convergent extension, cellular migration and actin filaments, but not involution of hypoblast. The cfl1 MO-induced cell migration defect was found to be cell-autonomous in cell transplantation assays. These results suggest that proper actin turnover mediated by Cfl1 is essential for adhesion between DEL and EVL and cell movements during gastrulation in zebrafish.

  5. The Envelope Cytoplasmic Tail of HIV-1 Subtype C Contributes to Poor Replication Capacity through Low Viral Infectivity and Cell-to-Cell Transmission

    Science.gov (United States)

    Lemaire, Morgane; Masquelier, Cécile; Beraud, Cyprien; Rybicki, Arkadiusz; Servais, Jean-Yves; Iserentant, Gilles; Schmit, Jean-Claude; Seguin-Devaux, Carole; Perez Bercoff, Danielle

    2016-01-01

    The cytoplasmic tail (gp41CT) of the HIV-1 envelope (Env) mediates Env incorporation into virions and regulates Env intracellular trafficking. Little is known about the functional impact of variability in this domain. To address this issue, we compared the replication of recombinant virus pairs carrying the full Env (Env viruses) or the Env ectodomain fused to the gp41CT of NL4.3 (EnvEC viruses) (12 subtype C and 10 subtype B pairs) in primary CD4+ T-cells and monocyte-derived-macrophages (MDMs). In CD4+ T-cells, replication was as follows: B-EnvEC = B-Env>C-EnvEC>C-Env, indicating that the gp41CT of subtype C contributes to the low replicative capacity of this subtype. In MDMs, in contrast, replication capacity was comparable for all viruses regardless of subtype and of gp41CT. In CD4+ T-cells, viral entry, viral release and viral gene expression were similar. However, infectivity of free virions and cell-to-cell transmission of C-Env viruses released by CD4+ T-cells was lower, suggestive of lower Env incorporation into virions. Subtype C matrix only minimally rescued viral replication and failed to restore infectivity of free viruses and cell-to-cell transmission. Taken together, these results show that polymorphisms in the gp41CT contribute to viral replication capacity and suggest that the number of Env spikes per virion may vary across subtypes. These findings should be taken into consideration in the design of vaccines. PMID:27598717

  6. Mutation of the dengue virus type 2 envelope protein heparan sulfate binding sites or the domain III lateral ridge blocks replication in Vero cells prior to membrane fusion

    International Nuclear Information System (INIS)

    Using an infectious cDNA clone we engineered seven mutations in the putative heparan sulfate- and receptor-binding motifs of the envelope protein of dengue virus serotype 2, strain 16681. Four mutant viruses, KK122/123EE, E202K, G304K, and KKK305/307/310EEE, were recovered following transfection of C6/36 cells. A fifth mutant, KK291/295EE, was recovered from C6/36 cells with a compensatory E295V mutation. All mutants grew in and mediated fusion of virus-infected C6/36 cells, but three of the mutants, KK122/123EE, E202K, G304K, did not grow in Vero cells without further modification. Two Vero cell lethal mutants, KK291/295EV and KKK307/307/310EEE, failed to replicate in DC-SIGN-transformed Raji cells and did not react with monoclonal antibodies known to block DENV attachment to Vero cells. Additionally, both mutants were unable to initiate negative-strand vRNA synthesis in Vero cells by 72 h post-infection, suggesting that the replication block occurred prior to virus-mediated membrane fusion. - Highlights: • Heparan sulfate- and receptor-binding motifs of DENV2 envelope protein were mutated. • Four mutant viruses were isolated—all could fuse C6/36 cells. • Two of these mutants were lethal in Vero cells without further modification. • Lethal mutations were KK291/295EV and KKK305/307/310EEE. • Cell attachment was implicated as the replication block for both mutants

  7. Mutation of the dengue virus type 2 envelope protein heparan sulfate binding sites or the domain III lateral ridge blocks replication in Vero cells prior to membrane fusion

    Energy Technology Data Exchange (ETDEWEB)

    Roehrig, John T., E-mail: jtr1@cdc.gov [Division of Vector-Borne Diseases, Centers for Disease Control and Prevention, Fort Collins, CO 80521 (United States); Butrapet, Siritorn; Liss, Nathan M. [Division of Vector-Borne Diseases, Centers for Disease Control and Prevention, Fort Collins, CO 80521 (United States); Bennett, Susan L. [Arthropod-borne and Infectious Diseases Laboratory, Department of Microbiology, Immunology, and Pathology, Colorado State University, Fort Collins, CO 80523 (United States); Luy, Betty E.; Childers, Thomas; Boroughs, Karen L.; Stovall, Janae L.; Calvert, Amanda E. [Division of Vector-Borne Diseases, Centers for Disease Control and Prevention, Fort Collins, CO 80521 (United States); Blair, Carol D. [Arthropod-borne and Infectious Diseases Laboratory, Department of Microbiology, Immunology, and Pathology, Colorado State University, Fort Collins, CO 80523 (United States); Huang, Claire Y.-H. [Division of Vector-Borne Diseases, Centers for Disease Control and Prevention, Fort Collins, CO 80521 (United States)

    2013-07-05

    Using an infectious cDNA clone we engineered seven mutations in the putative heparan sulfate- and receptor-binding motifs of the envelope protein of dengue virus serotype 2, strain 16681. Four mutant viruses, KK122/123EE, E202K, G304K, and KKK305/307/310EEE, were recovered following transfection of C6/36 cells. A fifth mutant, KK291/295EE, was recovered from C6/36 cells with a compensatory E295V mutation. All mutants grew in and mediated fusion of virus-infected C6/36 cells, but three of the mutants, KK122/123EE, E202K, G304K, did not grow in Vero cells without further modification. Two Vero cell lethal mutants, KK291/295EV and KKK307/307/310EEE, failed to replicate in DC-SIGN-transformed Raji cells and did not react with monoclonal antibodies known to block DENV attachment to Vero cells. Additionally, both mutants were unable to initiate negative-strand vRNA synthesis in Vero cells by 72 h post-infection, suggesting that the replication block occurred prior to virus-mediated membrane fusion. - Highlights: • Heparan sulfate- and receptor-binding motifs of DENV2 envelope protein were mutated. • Four mutant viruses were isolated—all could fuse C6/36 cells. • Two of these mutants were lethal in Vero cells without further modification. • Lethal mutations were KK291/295EV and KKK305/307/310EEE. • Cell attachment was implicated as the replication block for both mutants.

  8. Hepatitis B synthetic immunogen comprised of nucleocapsid T-cell sites and an envelope B-cell epitope.

    OpenAIRE

    Milich, D R; Hughes, J L; A. McLachlan; Thornton, G B; Moriarty, A.

    1988-01-01

    Previous studies located T-cell recognition of the nucleocapsid of the hepatitis B virus (HBcAg) to residues 120-140 in mice bearing the H-2s or H-2b haplotypes. Herein, we demonstrate that B10.S (H-2s) and B10 (H-2b) H-2 congenic strains recognize distinct T-cell sites within the p120-140 (a synthetic peptide corresponding to residues 120-140 of HBcAg) sequence defined by p120-131 and p129-140, respectively. Peptide p120-131 stimulates B10.S HBcAg-primed T cells, and reciprocally p120-131-pr...

  9. Release of the cell-envelope-associated proteinase of Lactobacillus delbrueckii subspecies lactis CRL 581 is dependent upon pH and temperature.

    Science.gov (United States)

    Espeche Turbay, María B; Savoy de Giori, Graciela; Hebert, Elvira M

    2009-09-23

    The cell-envelope-associated proteinase of Lactobacillus delbrueckii subsp. lactis CRL 581 (PrtL) has an essential role in bacterial growth and contributes to the development of the organoleptic properties of hard cheeses and to the release of bioactive health-beneficial peptides from milk proteins. In this study, the effect of environmental pH on PrtL production by L. delbrueckii subsp. lactis CRL 581 in a chemically defined medium and the influence of pH, temperature, and Ca(2+) ions on PrtL activity, stability, and release from the cell envelope were analyzed. The maximum PrtL activity levels were observed in the middle of the exponential growth phase, with the values at constant pH of 5.5 and 6.0 being higher than those observed at pH 4.5 and 5.0. At pH 4.5, PrtL remained mainly associated with the cell envelope, whereas at pH values of 5.5 or higher, approximately 40% of PrtL was found in the medium. In addition, the PrtL activity was stable for 24 h at 4 and 25 degrees C, and its release at 4, 25, and 40 degrees C was time-dependent. PrtL activity, stability, and release were independent of the presence of Ca(2+) ions in the medium. These results indicated that, at pH and temperature conditions found during the manufacture of hard cheeses, PrtL would remain active either bound to the cell or released in the supernatant contributing to the organoleptic characteristics and beneficial health effects of the fermented milk products. PMID:19754175

  10. Tol-Pal proteins are critical cell envelope components of Erwinia chrysanthemi affecting cell morphology and virulence.

    Science.gov (United States)

    Dubuisson, Jean-François; Vianney, Anne; Hugouvieux-Cotte-Pattat, Nicole; Lazzaroni, Jean Claude

    2005-10-01

    The tol-pal genes are necessary for maintaining the outer-membrane integrity of Gram-negative bacteria. These genes were first described in Escherichia coli, and more recently in several other species. They are involved in the pathogenesis of E. coli, Haemophilus ducreyi, Vibrio cholerae and Salmonella enterica. The role of the tol-pal genes in bacterial pathogenesis was investigated in the phytopathogenic enterobacterium Erwinia chrysanthemi, assuming that this organism might be a good model for such a study. The whole Er. chrysanthemi tol-pal region was characterized. Tol-Pal proteins, except TolA, showed high identity scores with their E. coli homologues. Er. chrysanthemi mutants were constructed by introducing a uidA-kan cassette in the ybgC, tolQ, tolA, tolB, pal and ybgF genes. All the mutants were hypersensitive to bile salts. Mutations in tolQ, tolA, tolB and pal were deleterious for the bacteria, which required high concentrations of sugars or osmoprotectants for their viability. Consistent with this observation, they were greatly impaired in their cell morphology and division, which was evidenced by observations of cell filaments, spherical forms, membrane blebbing and mislocalized bacterial septa. Moreover, tol-pal mutants showed a reduced virulence in a potato tuber model and on chicory leaves. This could be explained by a combination of impaired phenotypes in the tol-pal mutants, such as reduced growth and motility and a decreased production of pectate lyases, the major virulence factor of Er. chrysanthemi.

  11. Therapeutic envelope vaccination in combination with antiretroviral therapy temporarily rescues SIV-specific CD4⁺ T-cell-dependent natural killer cell effector responses in chronically infected rhesus macaques.

    Science.gov (United States)

    Vargas-Inchaustegui, Diego A; Xiao, Peng; Demberg, Thorsten; Pal, Ranajit; Robert-Guroff, Marjorie

    2015-06-01

    Natural killer (NK) cells are essential components of the immune system, and due to their rapid response potential, can have a great impact during early anti-viral immune responses. We have previously shown that interleukin-2-dependent NK and CD4(+) T-cell co-operative immune responses exist in long-term simian immunodeficiency virus (SIV) -infected controlling macaques and can be rescued in SIV-infected non-controlling macaques by a short course of antiretroviral therapy (ART). Given that co-operative responses may play an important role in disease prevention and therapeutic treatment, in the present study we sought to determine if these responses can be enhanced in chronically SIV-infected macaques by vaccination with a single-dose of envelope protein given during ART. To this end, we treated 14 chronically SIV-infected macaques with ART for 11 weeks and gave 10 of these macaques a single intramuscular dose of SIV gp120 at week 9 of treatment. ART significantly decreased plasma and mucosal viral loads, increased the numbers of circulating CD4(+) T cells in all macaques, and increased T-cell-dependent envelope- and gag-specific interferon-γ and tumour necrosis factor-α production by circulatory CD56(+) NK cells. The therapeutic envelope immunization resulted in higher envelope-specific responses compared with those in macaques that received ART only. Functional T-cell responses restored by ART and therapeutic Env immunization were correlated with transiently reduced plasma viraemia levels following ART release. Collectively our results indicate that SIV-specific T-cell-dependent NK cell responses can be efficiently rescued by ART in chronically SIV-infected macaques and that therapeutic immunization may be beneficial in previously vaccinated individuals. PMID:25626488

  12. Influence of Disulfide-Stabilized Structure on the Specificity of Helper T-Cell and Antibody Responses to HIV Envelope Glycoprotein gp120▿ †

    Science.gov (United States)

    Mirano-Bascos, Denise; Steede, N. Kalaya; Robinson, James E.; Landry, Samuel J.

    2010-01-01

    CD4+ helper T cells specific for human immunodeficiency virus type 1 (HIV-1) are associated with control of viremia. Nevertheless, vaccines have had limited effectiveness thus far, in part because sequence variability and other structural features of the HIV envelope glycoprotein deflect the immune response. Previous studies indicated that CD4+ T-cell epitope dominance is controlled by antigen three-dimensional structure through its influence on antigen processing and presentation. In this work, three disulfide bonds in the outer domain of gp120 were individually deleted in order to destabilize the local three-dimensional structure and enhance the presentation of nearby weakly immunogenic epitopes. However, upon immunization of groups of BALB/c mice, the CD4+ T-cell response was broadly reduced for all three variants, and distinct epitope profiles emerged. For one variant, antibody titers were sharply increased, and the antibody exhibited significant CD4-blocking activity. PMID:20089653

  13. Critical role of a ferritin-like protein in the control of Listeria monocytogenes cell envelope structure and stability under β-lactam pressure.

    Directory of Open Access Journals (Sweden)

    Agata Krawczyk-Balska

    Full Text Available The human pathogen Listeria monocytogenes is susceptible to the β-lactam antibiotics penicillin G and ampicillin, and these are the drugs of choice for the treatment of listerial infections. However, these antibiotics exert only a bacteriostatic effect on this bacterium and consequently, L. monocytogenes is regarded as β-lactam tolerant. It is widely accepted that the phenomenon of bacterial tolerance to β-lactams is due to the lack of adequate autolysin activity, but the mechanisms of L. monocytogenes tolerance to this class of antibiotics are poorly characterized. A ferritin-like protein (Fri was recently identified as a mediator of β-lactam tolerance in L. monocytogenes, but its function in this process remains unknown. The present study was undertaken to improve our understanding of L. monocytogenes tolerance to β-lactams and to characterize the role of Fri in this phenomenon. A comparative physiological analysis of wild-type L. monocytogenes and a fri deletion mutant provided evidence of a multilevel mechanism controlling autolysin activity in cells grown under β-lactam pressure, which leads to a reduction in the level and/or activity of cell wall-associated autolysins. This is accompanied by increases in the amount of teichoic acids, cell wall thickness and cell envelope integrity of L. monocytogenes grown in the presence of penicillin G, and provides the basis for the innate β-lactam tolerance of this bacterium. Furthermore, this study revealed the inability of the L. monocytogenes Δ fri mutant to deplete autolysins from the cell wall, to adjust the content of teichoic acids and to maintain their D-alanylation at the correct level when treated with penicillin G, thus providing further evidence that Fri is involved in the control of L. monocytogenes cell envelope structure and stability under β-lactam pressure.

  14. Involvement of viral envelope GP2 in Ebola virus entry into cells expressing the macrophage galactose-type C-type lectin

    International Nuclear Information System (INIS)

    Highlights: → Ebola virus infection is mediated by binding to and fusion with the target cells. → Structural feature of the viral glycoprotein determines the infectivity. → Surface C-type lectin, MGL, of macrophages and dendritic cells mediate the infection. → GP2, one of glycoprotein subunits, plays an essential role in MGL-mediated infection. → There is a critical amino acid residue involved in high infectivity. -- Abstract: Ebola virus (EBOV) infection is initiated by the interaction of the viral surface envelope glycoprotein (GP) with the binding sites on target cells. Differences in the mortality among different species of the Ebola viruses, i.e., Zaire ebolavirus (ZEBOV) and Reston ebolavirus (REBOV), correspond to the in vitro infectivity of the pseudo-typed virus constructed with the GPs in cells expressing macrophage galactose-type calcium-type lectin (MGL/CD301). Through mutagenesis of GP2, the transmembrane-anchored subunit of GP, we found that residues 502-527 of the GP2 sequence determined the different infectivity between VSV-ZEBOV GP and -REBOV GP in MGL/CD301-expressing cells and a histidine residue at position 516 of ZEBOV GP2 appeared essential in the differential infectivity. These findings may provide a clue to clarify a molecular basis of different pathogenicity among EBOV species.

  15. Involvement of viral envelope GP2 in Ebola virus entry into cells expressing the macrophage galactose-type C-type lectin

    Energy Technology Data Exchange (ETDEWEB)

    Usami, Katsuaki [Laboratory of Cancer Biology and Molecular Immunology, Graduate School of Pharmaceutical Sciences, University of Tokyo, Tokyo 113-0033 (Japan); Matsuno, Keita; Igarashi, Manabu [Department of Global Epidemiology, Hokkaido University Research Center for Zoonosis Control, Sapporo 001-0020 (Japan); Denda-Nagai, Kaori [Laboratory of Cancer Biology and Molecular Immunology, Graduate School of Pharmaceutical Sciences, University of Tokyo, Tokyo 113-0033 (Japan); Takada, Ayato [Department of Global Epidemiology, Hokkaido University Research Center for Zoonosis Control, Sapporo 001-0020 (Japan); Irimura, Tatsuro, E-mail: irimura@mol.f.u-tokyo.ac.jp [Laboratory of Cancer Biology and Molecular Immunology, Graduate School of Pharmaceutical Sciences, University of Tokyo, Tokyo 113-0033 (Japan)

    2011-04-01

    Highlights: {yields} Ebola virus infection is mediated by binding to and fusion with the target cells. {yields} Structural feature of the viral glycoprotein determines the infectivity. {yields} Surface C-type lectin, MGL, of macrophages and dendritic cells mediate the infection. {yields} GP2, one of glycoprotein subunits, plays an essential role in MGL-mediated infection. {yields} There is a critical amino acid residue involved in high infectivity. -- Abstract: Ebola virus (EBOV) infection is initiated by the interaction of the viral surface envelope glycoprotein (GP) with the binding sites on target cells. Differences in the mortality among different species of the Ebola viruses, i.e., Zaire ebolavirus (ZEBOV) and Reston ebolavirus (REBOV), correspond to the in vitro infectivity of the pseudo-typed virus constructed with the GPs in cells expressing macrophage galactose-type calcium-type lectin (MGL/CD301). Through mutagenesis of GP2, the transmembrane-anchored subunit of GP, we found that residues 502-527 of the GP2 sequence determined the different infectivity between VSV-ZEBOV GP and -REBOV GP in MGL/CD301-expressing cells and a histidine residue at position 516 of ZEBOV GP2 appeared essential in the differential infectivity. These findings may provide a clue to clarify a molecular basis of different pathogenicity among EBOV species.

  16. Envelopes of Commutative Rings

    Institute of Scientific and Technical Information of China (English)

    Rafael PARRA; Manuel SAOR(I)N

    2012-01-01

    Given a significative class F of commutative rings,we study the precise conditions under which a commutative ring R has an F-envelope.A full answer is obtained when.F is the class of fields,semisimple commutative rings or integral domains.When F is the class of Noetherian rings,we give a full answer when the Krull dimension of R is zero and when the envelope is required to be epimorphic.The general problem is reduced to identifying the class of non-Noetherian rings having a monomorphic Noetherian envelope,which we conjecture is the empty class.

  17. The Immunodominance Change and Protection of CD4+ T-Cell Responses Elicited by an Envelope Protein Domain III-Based Tetravalent Dengue Vaccine in Mice.

    Directory of Open Access Journals (Sweden)

    Hsin-Wei Chen

    Full Text Available Dengue is the leading cause of mosquito-borne viral infections and no vaccine is available now. Envelope protein domain III (ED3 is the major target for the binding of dengue virus neutralizing antibodies; however, the ED3-specifc T-cell response is less well understood. To investigate the T-cell responses to four serotypes of dengue virus (DENV-1 to 4, we immunized mice using either a tetravalent ED3-based DNA or protein vaccine, or combined both as a DNA prime-protein boost strategy (prime-boost. A significant serotype-dependent IFN-γ or IL-4 response was observed in mice immunized with either the DNA or protein vaccine. The IFN-γ response was dominant to DENV-1 to 3, whereas the IL-4 response was dominant to DENV-4. Although the similar IgG titers for the four serotypes were observed in mice immunized with the tetravalent vaccines, the neutralizing antibody titers varied and followed the order of 2 = 3>1>4. Interestingly, the lower IFN-γ response to DENV-4 is attributable to the immunodominance change between two CD4+ T-cell epitopes; one T-cell epitope located at E349-363 of DENV-1 to 3 was more immunogenic than the DENV-4 epitope E313-327. Despite DENV-4 specific IFN-γ responses were suppressed by immunodominance change, either DENV-4-specific IFN-γ or neutralizing antibody responses were still recalled after DENV-4 challenge and contributed to virus clearance. Immunization with the prime-boost elicited both IFN-γ and neutralizing antibody responses and provided better protection than either DNA or protein immunization. Our findings shed light on how ED3-based tetravalent dengue vaccines sharpen host CD4 T-cell responses and contribute to protection against dengue virus.

  18. Conformation-specific antibodies targeting the trimer-of-hairpins motif of the human T-cell leukemia virus type 1 transmembrane glycoprotein recognize the viral envelope but fail to neutralize viral entry.

    Science.gov (United States)

    Mirsaliotis, Antonis; Nurkiyanova, Kulpash; Lamb, Daniel; Woof, Jenny M; Brighty, David W

    2007-06-01

    Human T-cell leukemia virus type 1 (HTLV-1) entry into cells is dependent upon the viral envelope glycoprotein-catalyzed fusion of the viral and cellular membranes. Following receptor activation of the envelope, the transmembrane glycoprotein (TM) is thought to undergo a series of fusogenic conformational transitions through a rod-like prehairpin intermediate to a compact trimer-of-hairpins structure. Importantly, synthetic peptides that interfere with the conformational changes of TM are potent inhibitors of membrane fusion and HTLV-1 entry, suggesting that TM is a valid target for antiviral therapy. To assess the utility of TM as a vaccine target and to explore further the function of TM in HTLV-1 pathogenesis, we have begun to examine the immunological properties of TM. Here we demonstrate that a recombinant trimer-of-hairpins form of the TM ectodomain is strongly immunogenic. Monoclonal antibodies raised against the TM immunogen specifically bind to trimeric forms of TM, including structures thought to be important for membrane fusion. Importantly, these antibodies recognize the envelope on virally infected cells but, surprisingly, fail to neutralize envelope-mediated membrane fusion or infection by pseudotyped viral particles. Our data imply that, even in the absence of overt membrane fusion, there are multiple forms of TM on virally infected cells and that some of these display fusion-associated structures. Finally, we demonstrate that many of the antibodies possess the ability to recruit complement to TM, suggesting that envelope-derived immunogens capable of eliciting a combination of neutralizing and complement-fixing antibodies would be of value as subunit vaccines for intervention in HTLV infections. PMID:17376912

  19. Secretion of dengue virus envelope protein ectodomain from mammalian cells is dependent on domain II serotype and affects the immune response upon DNA vaccination.

    Science.gov (United States)

    Slon Campos, J L; Poggianella, M; Marchese, S; Bestagno, M; Burrone, O R

    2015-11-01

    Dengue virus (DENV) is currently among the most important human pathogens and affects millions of people throughout the tropical and subtropical regions of the world. Although it has been a World Health Organization priority for several years, there is still no efficient vaccine available to prevent infection. The envelope glycoprotein (E), exposed on the surface on infective viral particles, is the main target of neutralizing antibodies. For this reason it has been used as the antigen of choice for vaccine development efforts. Here we show a detailed analysis of factors involved in the expression, secretion and folding of E ectodomain from all four DENV serotypes in mammalian cells, and how this affects their ability to induce neutralizing antibody responses in DNA-vaccinated mice. Proper folding of E domain II (DII) is essential for efficient E ectodomain secretion, with DIII playing a significant role in stabilizing soluble dimers. We also show that the level of protein secreted from transfected cells determines the strength and efficiency of antibody responses in the context of DNA vaccination and should be considered a pivotal feature for the development of E-based DNA vaccines against DENV. PMID:26358704

  20. Use of silver nanoparticles increased inhibition of cell-associated HIV-1 infection by neutralizing antibodies developed against HIV-1 envelope proteins

    Directory of Open Access Journals (Sweden)

    Garza Treviño Elsa N

    2011-09-01

    Full Text Available Abstract Background HIV/AIDS pandemic is a worldwide public health issue. There is a need for new approaches to develop new antiviral compounds or other therapeutic strategies to limit viral transmission. The envelope glycoproteins gp120 and gp41 of HIV are the main targets for both silver nanoparticles (AgNPs and neutralizing antibodies. There is an urgency to optimize the efficiency of the neutralizing antibodies (NABs. In this study, we demonstrated that there is an additive effect between the four NABs and AgNPs when combined against cell-associated HIV-1 infection in vitro Results Four NABs (Monoclonal antibody to HIV-1 gp41 126-7, HIV-1 gp120 Antiserum PB1 Sub 2, HIV-1 gp120 Antiserum PB1, HIV-1 gp120 Monoclonal Antibody F425 B4e8 with or without AgNPs of 30-50 nm in size were tested against cell free and cell-associated HIVIIIB virus. All NABs inhibited HIV-1 cell free infection at a dose response manner, but with AgNPs an antiviral additive effect was not achieved Although there was no inhibition of infection with cell-associated virus by the NABs itself, AgNPs alone were able to inhibit cell associated virus infection and more importantly, when mixed together with NABs they inhibited the HIV-1 cell associated infection in an additive manner. Discussion The most attractive strategies to deal with the HIV problem are the development of a prophylactic vaccine and the development of effective topical vaginal microbicide. For two decades a potent vaccine that inhibits transmission of infection of HIV has been searched. There are vaccines that elicit NABs but none of them has the efficacy to stop transmission of HIV-1 infection. We propose that with the addition of AgNPs, NABs will have an additive effect and become more potent to inhibit cell-associated HIV-1 transmission/infection. Conclusions The addition of AgNPs to NABs has significantly increased the neutralizing potency of NABs in prevention of cell-associated HIV-1 transmission

  1. Dynamic remodeling of the plastid envelope membranes – a tool for chloroplast envelope in vivo localizations

    Directory of Open Access Journals (Sweden)

    Frederique KH Breuers

    2012-01-01

    Full Text Available Two envelope membranes delimit plastids, the defining organelles of plant cells. The inner and outer envelope membranes are unique in their protein and lipid composition. Several studies have attempted to establish the proteome of these two membranes; however, differentiating between them is difficult due to their close proximity. Here, we describe a novel approach to distinguish the localization of proteins between the two membranes using a straightforward approach based on live cell imaging coupled with transient expression. We base our approach on analyses of the distribution of GFP-fusions, which were aimed to verify outer-envelope-membrane proteomics data. To distinguish between outer envelope and inner envelope protein localization, we used AtTOC64-GFP and AtTIC40-GFP, as respective controls. During our analyses, we observed membrane proliferations and loss of chloroplast shape in conditions of protein overexpression. The morphology of the proliferations varied in correlation with the suborganellar distribution of the overexpressed proteins. In particular, while layers of membranes built up in the inner envelope membrane, the outer envelope formed long extensions into the cytosol. Using electron microscopy, we showed that these extensions were stromules, a dynamic feature of plastids. Since the behavior of the membranes is different and is related to the protein localization, we propose that in vivo studies based on the analysis of morphological differences of the membranes can be used to distinguish between inner and outer envelope localizations of proteins. To demonstrate the applicability of this approach, we demonstrated the localization of AtLACS9 to the outer envelope membrane. We also discuss protein impact on membrane behavior and regulation of protein insertion into membranes, and provide new hypotheses on the formation of stromules.

  2. Multiple Roles for Enterococcus faecalis Glycosyltransferases in Biofilm-Associated Antibiotic Resistance, Cell Envelope Integrity, and Conjugative Transfer

    OpenAIRE

    Dale, Jennifer L.; Cagnazzo, Julian; Phan, Chi Q.; Barnes, Aaron M. T.; Dunny, Gary M.

    2015-01-01

    The emergence of multidrug-resistant bacteria and the limited availability of new antibiotics are of increasing clinical concern. A compounding factor is the ability of microorganisms to form biofilms (communities of cells encased in a protective extracellular matrix) that are intrinsically resistant to antibiotics. Enterococcus faecalis is an opportunistic pathogen that readily forms biofilms and also has the propensity to acquire resistance determinants via horizontal gene transfer. There i...

  3. Thermal Activated Envelope

    DEFF Research Database (Denmark)

    Foged, Isak Worre; Pasold, Anke

    2015-01-01

    search procedure, the combination of materials and their bonding temperature is found in relation to the envelope effect on a thermal environment inside a defined space. This allows the designer to articulate dynamic composites with time-based thermal functionality, related to the material dynamics...

  4. Elliptic stable envelope

    CERN Document Server

    Aganagic, Mina

    2016-01-01

    We construct stable envelopes in equivariant elliptic cohomology of Nakajima quiver varieties. In particular, this gives an elliptic generalization of the results of arXiv:1211.1287. We apply them to the computation of the monodromy of $q$-difference equations arising the enumerative K-theory of rational curves in Nakajima varieties, including the quantum Knizhnik-Zamolodchikov equations.

  5. Total and Envelope Protein-Specific Antibody-Secreting Cell Response in Pediatric Dengue Is Highly Modulated by Age and Subsequent Infections.

    Science.gov (United States)

    Toro, Jessica F; Salgado, Doris M; Vega, Rocío; Rodríguez, Jairo A; Rodríguez, Luz-Stella; Angel, Juana; Franco, Manuel A; Greenberg, Harry B; Narváez, Carlos F

    2016-01-01

    The response of antibody-secreting cells (ASC) induced by dengue has only recently started to be characterized. We propose that young age and previous infections could be simple factors that affect this response. Here, we evaluated the primary and secondary responses of circulating ASC in infants (6-12 months old) and children (1-14 years old) infected with dengue showing different degrees of clinical severity. The ASC response was delayed and of lower magnitude in infants, compared with older children. In primary infection (PI), the total and envelope (E) protein-specific IgM ASC were dominant in infants but not in children, and a negative correlation was found between age and the number of IgM ASC (rho = -0.59, P = 0.03). However, infants with plasma dengue-specific IgG detectable in the acute phase developed an intense ASC response largely dominated by IgG and comparable to that of children with secondary infection (SI). IgM and IgG produced by ASC circulating in PI or SI were highly cross-reactive among the four serotypes. Dengue infection caused the disturbance of B cell subsets, particularly a decrease in the relative frequency of naïve B cells. Higher frequencies of total and E protein-specific IgM ASC in the infants and IgG in the children were associated with clinically severe forms of infection. Therefore, the ASC response induced by dengue is highly influenced by the age at which infection occurs and previous immune status, and its magnitude is a relevant element in the clinical outcome. These results are important in the search for correlates of protection and for determining the ideal age for vaccinating against dengue. PMID:27560782

  6. Total and Envelope Protein-Specific Antibody-Secreting Cell Response in Pediatric Dengue Is Highly Modulated by Age and Subsequent Infections

    Science.gov (United States)

    Toro, Jessica F.; Salgado, Doris M.; Vega, Rocío; Rodríguez, Jairo A.; Rodríguez, Luz-Stella; Angel, Juana; Franco, Manuel A.; Greenberg, Harry B.; Narváez, Carlos F.

    2016-01-01

    The response of antibody-secreting cells (ASC) induced by dengue has only recently started to be characterized. We propose that young age and previous infections could be simple factors that affect this response. Here, we evaluated the primary and secondary responses of circulating ASC in infants (6–12 months old) and children (1–14 years old) infected with dengue showing different degrees of clinical severity. The ASC response was delayed and of lower magnitude in infants, compared with older children. In primary infection (PI), the total and envelope (E) protein-specific IgM ASC were dominant in infants but not in children, and a negative correlation was found between age and the number of IgM ASC (rho = −0.59, P = 0.03). However, infants with plasma dengue-specific IgG detectable in the acute phase developed an intense ASC response largely dominated by IgG and comparable to that of children with secondary infection (SI). IgM and IgG produced by ASC circulating in PI or SI were highly cross-reactive among the four serotypes. Dengue infection caused the disturbance of B cell subsets, particularly a decrease in the relative frequency of naïve B cells. Higher frequencies of total and E protein-specific IgM ASC in the infants and IgG in the children were associated with clinically severe forms of infection. Therefore, the ASC response induced by dengue is highly influenced by the age at which infection occurs and previous immune status, and its magnitude is a relevant element in the clinical outcome. These results are important in the search for correlates of protection and for determining the ideal age for vaccinating against dengue. PMID:27560782

  7. Lamin b1 polymorphism influences morphology of the nuclear envelope, cell cycle progression, and risk of neural tube defects in mice.

    Directory of Open Access Journals (Sweden)

    Sandra C P De Castro

    in maintaining integrity of the nuclear envelope and ensuring normal cell cycle progression.

  8. Selective induction of cell-mediated immunity and protection of rhesus macaques from chronic SHIVKU2 infection by prophylactic vaccination with a conserved HIV-1 envelope peptide-cocktail

    International Nuclear Information System (INIS)

    Infection of Indian-origin rhesus macaques by the simian human immunodeficiency virus (SHIV) is considered to be a suitable preclinical model for directly testing efficacy of vaccine candidates based on the HIV-1 envelope. We used this model for prophylactic vaccination with a peptide-cocktail comprised of highly conserved HIV-1 envelope sequences immunogenic/antigenic in macaques and humans. Separate groups of macaques were immunized with the peptide-cocktail by intravenous and subcutaneous routes using autologous dendritic cells (DC) and Freund's adjuvant, respectively. The vaccine elicited antigen specific IFN-γ-producing cells and T-cell proliferation, but not HIV-neutralizing antibodies. The vaccinated animals also exhibited efficient cross-clade cytolytic activity against target cells expressing envelope proteins corresponding to HIV-1 strains representative of multiple clades that increased after intravenous challenge with pathogenic SHIVKU2. Virus-neutralizing antibodies were either undetectable or present only transiently at low levels in the control as well as vaccinated monkeys after infection. Significant control of plasma viremia leading to undetectable levels was achieved in majority of vaccinated monkeys compared to mock-vaccinated controls. Monkeys vaccinated with the peptide-cocktail using autologous DC, compared to Freund's adjuvant, and the mock-vaccinated animals, showed significantly higher IFN-γ production, higher levels of vaccine-specific IFN-γ producing CD4+ cells and significant control of plasma viremia. These results support DC-based vaccine delivery and the utility of the conserved HIV-1 envelope peptide-cocktail, capable of priming strong cell-mediated immunity, for potential inclusion in HIV vaccination strategies

  9. Nuclear envelope proteins Nesprin2 and LaminA regulate proliferation and apoptosis of vascular endothelial cells in response to shear stress.

    Science.gov (United States)

    Han, Yue; Wang, Lu; Yao, Qing-Ping; Zhang, Ping; Liu, Bo; Wang, Guo-Liang; Shen, Bao-Rong; Cheng, Binbin; Wang, Yingxiao; Jiang, Zong-Lai; Qi, Ying-Xin

    2015-05-01

    The dysfunction of vascular endothelial cells (ECs) influenced by flow shear stress is crucial for vascular remodeling. However, the roles of nuclear envelope (NE) proteins in shear stress-induced EC dysfunction are still unknown. Our results indicated that, compared with normal shear stress (NSS), low shear stress (LowSS) suppressed the expression of two types of NE proteins, Nesprin2 and LaminA, and increased the proliferation and apoptosis of ECs. Targeted small interfering RNA (siRNA) and gene overexpression plasmid transfection revealed that Nesprin2 and LaminA participate in the regulation of EC proliferation and apoptosis. A protein/DNA array was further used to detect the activation of transcription factors in ECs following transfection with target siRNAs and overexpression plasmids. The regulation of AP-2 and TFIID mediated by Nesprin2 and the activation of Stat-1, Stat-3, Stat-5 and Stat-6 by LaminA were verified under shear stress. Furthermore, using Ingenuity Pathway Analysis software and real-time RT-PCR, the effects of Nesprin2 or LaminA on the downstream target genes of AP-2, TFIID, and Stat-1, Stat-3, Stat-5 and Stat-6, respectively, were investigated under LowSS. Our study has revealed that NE proteins are novel mechano-sensitive molecules in ECs. LowSS suppresses the expression of Nesprin2 and LaminA, which may subsequently modulate the activation of important transcription factors and eventually lead to EC dysfunction.

  10. Revealing fosfomycin primary effect on Staphylococcus aureus transcriptome: modulation of cell envelope biosynthesis and phosphoenolpyruvate induced starvation

    Directory of Open Access Journals (Sweden)

    Gruden Kristina

    2010-06-01

    Full Text Available Abstract Background Staphylococcus aureus is a highly adaptable human pathogen and there is a constant search for effective antibiotics. Fosfomycin is a potent irreversible inhibitor of MurA, an enolpyruvyl transferase that uses phosphoenolpyruvate as substrate. The goal of this study was to identify the pathways and processes primarily affected by fosfomycin at the genome-wide transcriptome level to aid development of new drugs. Results S. aureus ATCC 29213 cells were treated with sub-MIC concentrations of fosfomycin and harvested at 10, 20 and 40 minutes after treatment. S. aureus GeneChip statistical data analysis was complemented by gene set enrichment analysis. A visualization tool for mapping gene expression data into biological pathways was developed in order to identify the metabolic processes affected by fosfomycin. We have shown that the number of significantly differentially expressed genes in treated cultures increased with time and with increasing fosfomycin concentration. The target pathway - peptidoglycan biosynthesis - was upregulated following fosfomycin treatment. Modulation of transport processes, cofactor biosynthesis, energy metabolism and nucleic acid biosynthesis was also observed. Conclusions Several pathways and genes downregulated by fosfomycin have been identified, in contrast to previously described cell wall active antibiotics, and was explained by starvation response induced by phosphoenolpyruvate accumulation. Transcriptomic profiling, in combination with meta-analysis, has been shown to be a valuable tool in determining bacterial response to a specific antibiotic.

  11. Immunization of rabbits with highly purified, soluble, trimeric human immunodeficiency virus type 1 envelope glycoprotein induces a vigorous B cell response and broadly cross-reactive neutralization.

    Directory of Open Access Journals (Sweden)

    Gerald V Quinnan

    Full Text Available Previously we described induction of cross-reactive HIV-1 neutralizing antibody responses in rabbits using a soluble HIV-1 gp140 envelope glycoprotein (Env in an adjuvant containing monophosphoryl lipid A (MPL and QS21 (AS02A. Here, we compared different forms of the same HIV-1 strain R2 Env for antigenic and biophysical characteristics, and in rabbits characterized the extent of B cell induction for specific antibody expression and secretion and neutralizing responses. The forms of this Env that were produced in and purified from stably transformed 293T cells included a primarily dimeric gp140, a trimeric gp140 appended to a GCN4 trimerization domain (gp140-GCN4, gp140-GCN4 with a 15 amino acid flexible linker between the gp120 and gp41 ectodomain (gp140-GCN4-L, also trimeric, and a gp140 with the flexible linker purified from cell culture supernatants as either dimer (gp140-L(D or monomer (gp140-L(M. Multimeric states of the Env proteins were assessed by native gel electrophoresis and analytical ultracentrifugation. The different forms of gp140 bound broadly cross-reactive neutralizing (BCN human monoclonal antibodies (mAbs similarly in ELISA and immunoprecipitation assays. All Envs bound CD4i mAbs in the presence and absence of sCD4, as reported for the R2 Env. Weak neutralization of some strains of HIV-1 was seen after two additional doses in AS02A. Rabbits that were given a seventh dose of gp140-GCN4-L developed BCN responses that were weak to moderate, similar to our previous report. The specificity of these responses did not appear similar to that of any of the known BCN human mAbs. Induction of spleen B cell and plasma cells producing immunoglobulins that bound trimeric gp140-GCN4-L was vigorous, based on ELISpot and flow cytometry analyses. The results demonstrate that highly purified gp140-GCN4-L trimer in adjuvant elicits BCN responses in rabbits accompanied by vigorous B cell induction.

  12. (Quasi-)Poisson enveloping algebras

    OpenAIRE

    Yang, Yan-Hong; Yuan YAO; Ye, Yu

    2010-01-01

    We introduce the quasi-Poisson enveloping algebra and Poisson enveloping algebra for a non-commutative Poisson algebra. We prove that for a non-commutative Poisson algebra, the category of quasi-Poisson modules is equivalent to the category of left modules over its quasi-Poisson enveloping algebra, and the category of Poisson modules is equivalent to the category of left modules over its Poisson enveloping algebra.

  13. Characterization of the Pattern of αs1- and β-Casein Breakdown and Release of a Bioactive Peptide by a Cell Envelope Proteinase from Lactobacillus delbrueckii subsp. lactis CRL 581▿

    OpenAIRE

    Hebert, Elvira María; Mamone, Gianfranco; Picariello, Gianluca; Raya, Raúl R.; Savoy, Graciela; Ferranti, Pasquale; Addeo, Francesco

    2008-01-01

    The cell envelope-associated proteinases (CEPs) of the lactobacilli have key roles in bacterial nutrition and contribute to the development of the organoleptic properties of fermented milk products as well, as they can release bioactive health-beneficial peptides from milk proteins. The influence of the peptide supply, carbohydrate source, and osmolites on the CEP activity of the cheese starter Lactobacillus delbrueckii subsp. lactis CRL 581 was investigated. The CEP activity levels were cont...

  14. URGENT - Internal Mail Envelopes

    CERN Multimedia

    2007-01-01

    Internal mail envelopes often finish up in large piles in certain offices, thus creating a shortage for other users of the mail service, who would be grateful if everyone with an unused stock could deposit them in their mail box, after attaching them together with an elastic band or piece of string. The messengers will then collect them so that the Mail Office can put them back in circulation. Thank you for your understanding and collaboration. Mail Office

  15. Internal mail envelopes

    CERN Multimedia

    2003-01-01

    Internal mail envelopes often finish up in large piles in certain offices, thus creating a shortage for other users of the mail service, who would be grateful if everyone with an unusual stock could deposit them in their mail box, after attaching them together with an elastic band or piece of string. The messengers will then collect them so that the Mail Office can put them back in circulation. Thank you for your understanding and collaboration. Mail Office

  16. Data envelopment analysis

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    This review introduces the history and present status of data envelopment analysis (DEA) research, particularly the evaluation process. And extensions of some DEA models are also described. It is pointed out that mathematics, economics and management science are the main forces in the DEA development, optimization provides the fundamental method for the DEA research, and the wide range of applications enforces the rapid development of DEA.

  17. INTERNAL MAIL ENVELOPES

    CERN Multimedia

    Mail Office

    2001-01-01

    Internal mail envelopes often finish up in large piles in certain offices, thus creating a shortage for other users of the mail service, who would be grateful if everyone with an unused stock could deposit them in their mail box, after attaching them together with an elastic band or piece of string. The messengers will then collect them so that the Mail Office can put them back in circulation. Thank you for your understanding and collaboration.

  18. INTERNAL MAIL ENVELOPES

    CERN Multimedia

    Mail Office

    2002-01-01

    Internal mail envelopes often finish up in large piles in certain offices, thus creating a shortage for other users of the mail service, who would be grateful if everyone with an unused stock could deposit them in their mail box, after attaching them together with an elastic band or piece of string. The messengers will then collect them so that the Mail Office can put them back in circulation. Thank you for your understanding and collaboration. Mail Office

  19. INTERNAL MAIL ENVELOPES

    CERN Multimedia

    Mail Office

    2002-01-01

    Internal mail envelopes often finish up in large piles in certain offices, thus creating a shortage for other users of the mail service, who would be grateful if everyone with an unused stock could deposit them in their mail box, after attaching them together with an elastic band or piece of string. The messengers will then collect them so that the Mail Office can put them back in circulation. Thank you for your understanding and collaboration.   Mail Office

  20. INTERNAL MAIL ENVELOPES

    CERN Multimedia

    Mail Office

    2002-01-01

    Internal mail envelopes often finish up in large piles in certain offices, thus creating a shortage for other users of the mail service, who would be grateful if everyone with an unused stock could deposit them in their mail box, after attaching them together with an elastic band or piece of string. The messengers will then collect them so that the Mail Office can put them back in circulation. Thank you for your understanding and collaboration.

  1. INTERNAL CIRCULATION ENVELOPES

    CERN Multimedia

    Mail Office

    2001-01-01

    Internal mail envelopes often finish up in large piles in certain offices, thus creating a shortage for other users of the mail service, who would be grateful if everyone with an unused stock could deposit them in their mail box, after attaching them together with an elastic band or a piece of string. The messengers will then collect them so that the Mail Office can put them back in circulation. Thank you for your understanding and collaboration.

  2. URGENT - Internal Mail Envelopes

    CERN Multimedia

    Mail Office

    2004-01-01

    Internal mail envelopes often finish up in large piles in certain offices, thus creating a shortage for other users of the mail service, who would be grateful if everyone with an unused stock could deposit them in their mail box, after attaching them together with an elastic band or piece of string. The messengers will then collect them so that the Mail Office can put them back in circulation. Thank you for your understanding and collaboration. Mail Office

  3. Uncertain data envelopment analysis

    CERN Document Server

    Wen, Meilin

    2014-01-01

    This book is intended to present the milestones in the progression of uncertain Data envelopment analysis (DEA). Chapter 1 gives some basic introduction to uncertain theories, including probability theory, credibility theory, uncertainty theory and chance theory. Chapter 2 presents a comprehensive review and discussion of basic DEA models. The stochastic DEA is introduced in Chapter 3, in which the inputs and outputs are assumed to be random variables. To obtain the probability distribution of a random variable, a lot of samples are needed to apply the statistics inference approach. Chapter 4

  4. Tegument Assembly and Secondary Envelopment of Alphaherpesviruses

    Directory of Open Access Journals (Sweden)

    Danielle J. Owen

    2015-09-01

    Full Text Available Alphaherpesviruses like herpes simplex virus are large DNA viruses characterized by their ability to establish lifelong latent infection in neurons. As for all herpesviruses, alphaherpesvirus virions contain a protein-rich layer called “tegument” that links the DNA-containing capsid to the glycoprotein-studded membrane envelope. Tegument proteins mediate a diverse range of functions during the virus lifecycle, including modulation of the host-cell environment immediately after entry, transport of virus capsids to the nucleus during infection, and wrapping of cytoplasmic capsids with membranes (secondary envelopment during virion assembly. Eleven tegument proteins that are conserved across alphaherpesviruses have been implicated in the formation of the tegument layer or in secondary envelopment. Tegument is assembled via a dense network of interactions between tegument proteins, with the redundancy of these interactions making it challenging to determine the precise function of any specific tegument protein. However, recent studies have made great headway in defining the interactions between tegument proteins, conserved across alphaherpesviruses, which facilitate tegument assembly and secondary envelopment. We summarize these recent advances and review what remains to be learned about the molecular interactions required to assemble mature alphaherpesvirus virions following the release of capsids from infected cell nuclei.

  5. Shaping T Cell – B Cell Collaboration in the Response to Human Immunodeficiency Virus Type 1 Envelope Glycoprotein gp120 by Peptide Priming

    OpenAIRE

    N Kalaya Steede; Rust, Blake J.; Hossain, Mohammad M.; Freytag, Lucy C.; Robinson, James E.; Landry, Samuel J.

    2013-01-01

    Prime-boost vaccination regimes have shown promise for obtaining protective immunity to HIV. Poorly understood mechanisms of cellular immunity could be responsible for improved humoral responses. Although CD4+ T-cell help promotes B-cell development, the relationship of CD4+ T-cell specificity to antibody specificity has not been systematically investigated. Here, protein and peptide-specific immune responses to HIV-1 gp120 were characterized in groups of ten mucosally immunized BALB/c mice. ...

  6. Shaping T Cell – B Cell Collaboration in the Response to Human Immunodeficiency Virus Type 1 Envelope Glycoprotein gp120 by Peptide Priming

    Science.gov (United States)

    Steede, N. Kalaya; Rust, Blake J.; Hossain, Mohammad M.; Freytag, Lucy C.; Robinson, James E.; Landry, Samuel J.

    2013-01-01

    Prime-boost vaccination regimes have shown promise for obtaining protective immunity to HIV. Poorly understood mechanisms of cellular immunity could be responsible for improved humoral responses. Although CD4+ T-cell help promotes B-cell development, the relationship of CD4+ T-cell specificity to antibody specificity has not been systematically investigated. Here, protein and peptide-specific immune responses to HIV-1 gp120 were characterized in groups of ten mucosally immunized BALB/c mice. Protein and peptide reactivity of serum antibody was tested for correlation with cytokine secretion by splenocytes restimulated with individual gp120 peptides. Antibody titer for gp120 correlated poorly with the peptide-stimulated T-cell response. In contrast, titers for conformational epitopes, measured as crossreactivity or CD4-blocking, correlated with average interleukin-2 and interleukin-5 production in response to gp120 peptides. Antibodies specific for conformational epitopes and individual gp120 peptides typically correlated with T-cell responses to several peptides. In order to modify the specificity of immune responses, animals were primed with a gp120 peptide prior to immunization with protein. Priming induced distinct peptide-specific correlations of antibodies and T-cells. The majority of correlated antibodies were specific for the primed peptides or other peptides nearby in the gp120 sequence. These studies suggest that the dominant B-cell subsets recruit the dominant T-cell subsets and that T-B collaborations can be shaped by epitope-specific priming. PMID:23776539

  7. Shaping T cell - B cell collaboration in the response to human immunodeficiency virus type 1 envelope glycoprotein gp120 by peptide priming.

    Directory of Open Access Journals (Sweden)

    N Kalaya Steede

    Full Text Available Prime-boost vaccination regimes have shown promise for obtaining protective immunity to HIV. Poorly understood mechanisms of cellular immunity could be responsible for improved humoral responses. Although CD4+ T-cell help promotes B-cell development, the relationship of CD4+ T-cell specificity to antibody specificity has not been systematically investigated. Here, protein and peptide-specific immune responses to HIV-1 gp120 were characterized in groups of ten mucosally immunized BALB/c mice. Protein and peptide reactivity of serum antibody was tested for correlation with cytokine secretion by splenocytes restimulated with individual gp120 peptides. Antibody titer for gp120 correlated poorly with the peptide-stimulated T-cell response. In contrast, titers for conformational epitopes, measured as crossreactivity or CD4-blocking, correlated with average interleukin-2 and interleukin-5 production in response to gp120 peptides. Antibodies specific for conformational epitopes and individual gp120 peptides typically correlated with T-cell responses to several peptides. In order to modify the specificity of immune responses, animals were primed with a gp120 peptide prior to immunization with protein. Priming induced distinct peptide-specific correlations of antibodies and T-cells. The majority of correlated antibodies were specific for the primed peptides or other peptides nearby in the gp120 sequence. These studies suggest that the dominant B-cell subsets recruit the dominant T-cell subsets and that T-B collaborations can be shaped by epitope-specific priming.

  8. Optimization of Extraction of Cell-envelope Proteinase from Lactobacillus acidophilus%嗜酸乳杆菌细胞壁蛋白酶的提取优化

    Institute of Scientific and Technical Information of China (English)

    李敏; 潘道东

    2011-01-01

    In this study,the extraction of cell-envelope proteinase(CEP) from Lactobacillus acidophilus was optimized.A comparison of ultrasonic treatment,Ca2+-free treatment and lysozyme lysis for their effectiveness in Lactobacillus acidophilus cell disruption was performed to determine lysozyme lysis as the best method among the three.Further,process conditions optimization for CEP extraction from Lactobacillus acidophilus by lysozyme lysis was carried out using orthogonal array design based on one-factor-at-a-time experiments.The best extraction results were obtained by 3 h incubation at 37 ℃ of Lactobacillus acidophilus cells in pH 7.8 lysozyme lysis buffer containing 50 mmol/L Tris-HCl,100 mmol/L NaCl,1% TritonX-100 and 1.5 mg/mL lysozyme and then centrifugation at 4500 r/min and 4 ℃ for 20 min,and the resulting supernatant was collected as CEP.In addition,lysozyme concentration had the largest impact on extraction efficiency of CEP followed by pH,Tirton X-100 concentration and incubation time.%为了获得较高酶活力的嗜酸乳杆菌细胞壁蛋白酶(CEP),对嗜酸乳杆菌CEP的提取方法进行优化。经过比较超声波破碎法、Ca2+-free法、溶菌酶裂解3种方法,确认溶菌酶裂解法结合使用非离子清洁剂破壁是提取嗜酸乳杆菌CEP的最佳方法。在单因素试验的基础上,采用正交试验对嗜酸乳杆菌CEP的提取工艺进行优化,得出嗜酸乳杆菌CEP的最佳提取方法:用裂解液(50mmol/L Tris-HCl、100mmol/L NaCl、TritonX-100添加量1%、1.5mg/mL溶菌酶,pH 7.8)悬浮菌体(20mL/g),37℃保温3h,4℃、4500r/min离心20min,取上清液。溶菌酶裂解法提取CEP过程中各因素对CEP提取效果的影响依次为:溶菌酶质量浓度〉裂解pH值〉TirtonX-100添加量〉保温时间。

  9. Adaptive Architectural Envelope

    DEFF Research Database (Denmark)

    Foged, Isak Worre; Kirkegaard, Poul Henning

    2010-01-01

    Recent years have seen an increasing variety of applications of adaptive architectural structures for improvement of structural performance by recognizing changes in their environments and loads, adapting to meet goals, and using past events to improve future performance or maintain serviceability....... The general scopes of this paper are to develop a new adaptive kinetic architectural structure, particularly a reconfigurable architectural structure which can transform body shape from planar geometries to hyper-surfaces using different control strategies, i.e. a transformation into more than one or two...... different shape alternatives. The adaptive structure is a proposal for a responsive building envelope which is an idea of a first level operational framework for present and future investigations towards performance based responsive architectures through a set of responsive typologies. A mock- up concept...

  10. Thermal Responsive Envelope

    DEFF Research Database (Denmark)

    Foged, Isak Worre; Pasold, Anke

    2015-01-01

    The paper presents an architectural computational method and model, which, through additive and subtractive processes, create composite elements with bending behaviour based on thermal variations in the surrounding climatic environment. The present effort is focused on the manipulation of assembly...... composite layers and their relative layer lengths thereby embedding the merged material effect to create a responsive behavioural architectural envelope. Copper and polypropylene are used as base materials for the composite structure due to their high differences in thermal expansion, surface emissivity...... alterations, their respective durability and copper’s architectural (visual and transformative) aesthetic qualities. Through the use of an evolutionary solver, the composite structure of the elements are organised to find the bending behaviour specified by and for the thermal environments. The entire model...

  11. Retinoid suppression of transglutaminase activity and envelope competence in cultured human epidermal carcinoma cells: Hydrocortisone is a potent antagonist of retinyl acetate but not retinoic acid

    OpenAIRE

    Rice, Rh; Thacher, SM; Coe, EL

    1985-01-01

    Growth of SCC-13 squamous carcinoma cultures in the presence of retinoids considerably reduced the expression of two differentiation markers, the cellular capability to form cross-linked envelopes, and the enzyme transglutaminase required for cross-linking. A limited survey of retinoids showed that all-trans retinoic acid, 13-cis retinoic acid, and arotinoid Ro 13-6298 were highly effective in the absence of hydrocortisone and were only slightly antagonized by its presence in the medium. In c...

  12. Membrane topology and mutational analysis of the TolQ protein of Escherichia coli required for the uptake of macromolecules and cell envelope integrity.

    OpenAIRE

    Vianney, A; Lewin, T M; Beyer, W F; Lazzaroni, J C; Portalier, R; Webster, R E

    1994-01-01

    TolQ is a 230-amino-acid protein required to maintain the integrity of the bacterial envelope and to facilitate the import of both filamentous bacteriophage and group A colicins. Cellular fractionation experiments showed TolQ to be localized to the cytoplasmic membrane. Bacteria expressing a series of TolQ-beta-galactosidase and TolQ-alkaline phosphatase fusion proteins were analyzed for the appropriate enzyme activity, membrane location, and sensitivity to exogenously added protease. The res...

  13. Effects of lyophilization on the infectivity of enveloped and non-enveloped viruses in bone tissue.

    Science.gov (United States)

    Uhlenhaut, Christine; Dörner, Thomas; Pauli, Georg; Pruss, Axel

    2005-11-01

    Recently reported qualitative experiments proved that retroviral infectivity is not destroyed by lyophilization performed on systemically infected bone and tendon. The now accomplished quantitative determination of residual infectivity for enveloped and non-enveloped viruses allows a validation of the production process regarding viral safety in freeze-dried bone transplants. The lyophilization effect on the infectivity of two non-enveloped viruses (Maus Elberfeld virus, MEV; Porcine parvovirus, PPV) and one enveloped virus (Vesicular Stomatitis virus, VSV) was examined for virus-spiked bone material in comparison to lyophilized viruses, original virus stock, and air-dried viruses. All experiments were carried out with both cell-free and cell-associated virus. Significant differences were observed regarding the reduction of virus titers (TCID50). Infectivity of VSV was reduced by about 3-4 log10 using lyophilization in presence of bone matrix and of MEV by 6-7 log10, while no substantial reduction in virus titers was observed for PPV. Lyophilization of cell-free or cell-associated virus is not sufficient to inactivate viruses completely. However, lyophilization could have an additive effect in line with other production steps used in the manufacturing process.

  14. Categories with envelopes and imprints

    CERN Document Server

    Akbarov, Sergei

    2011-01-01

    An envelope in a category is a construction generalizing operations of "exterior completion", like completion of a locally convex space. Dually, an imprint generalizes operations of "interior enrichment", like saturation of a locally convex space. We give abstract definition for envelopes and imprints, prove existence of these objects in the categories of stereotype spaces and of stereotype algebras, and give some examples.

  15. A novel strategy to isolate cell-envelope mutants resistant to phage infection: bacteriophage mEp213 requires lipopolysaccharides in addition to FhuA to enter Escherichia coli K-12.

    Science.gov (United States)

    Reyes-Cortés, Ruth; Martínez-Peñafiel, Eva; Martínez-Pérez, Francisco; de la Garza, Mireya; Kameyama, Luis

    2012-12-01

    We have developed a direct and efficient strategy, based on a three-step method, to select bacterial cell-envelope mutants resistant to bacteriophage infection. Escherichia coli K-12 strain W3110 underwent classical transposon mutagenesis followed by replica plating and selection for mutants resistant to infection by coliphage mEp213. To verify that phage resistance was due to mutations in the cell envelope, we transformed host cells with the viral genome using electroporation and selected those in which virions were subsequently detected in the supernatant. Among the nine mutants resistant to coliphage infection that we selected, six were in the fhuA gene, two were mutated in the waaC gene, and one was mutated in the gmhD gene. The latter two gene products are involved in the synthesis of lipopolysaccharide (LPS). The efficiency of plating and adsorption of phage mEp213 was affected in these mutants. We verified that LPS is required for the efficient infection of phage λ as well. We propose that this mutation-and-selection strategy can be used to find host factors involved in the initial steps of phage infection for any cognate pair of phage and bacteria.

  16. Multifamily Envelope Leakage Model

    Energy Technology Data Exchange (ETDEWEB)

    Faakye, Omari [Consortium for Advanced Residential Buildings, Norwalk, CT (United States); Griffiths, Dianne [Consortium for Advanced Residential Buildings, Norwalk, CT (United States)

    2015-05-08

    “The cost for blower testing is high, because it is labor intensive, and it may disrupt occupants in multiple units. This high cost and disruption deter program participants, and dissuade them from pursuing energy improvements that would trigger air leakage testing, such as improvements to the building envelope.” This statement found in a 2012 report by Heschong Mahone Group for several California interests emphasizes the importance of reducing the cost and complexity of blower testing in multifamily buildings. Energy efficiency opportunities are being bypassed. The cost of single blower testing is on the order of $300. The cost for guarded blower door testing—the more appropriate test for assessing energy savings opportunities—could easily be six times that, and that’s only if you have the equipment and simultaneous access to multiple apartments. Thus, the proper test is simply not performed. This research seeks to provide an algorithm for predicting the guarded blower door test result based upon a single, total blower door test.

  17. The LHC in an envelope

    CERN Document Server

    2007-01-01

    The series of envelopes featuring CERN issued this summer was a huge success. The French postal services of the Pays de Gex will shortly be launching the second set of pre-paid envelopes issued in collaboration with the Laboratory this year, this time highlighting the LHC. Five thousand envelopes describing the accelerator’s capabilities will go on sale on 12 November, and some of the packs will even contain a small sample of the cables from the heart of the LHC magnets. The sets of ten pre-paid envelopes will tell you everything about CERN’s flagship accelerator, from its astounding technical capabilities to its spin-offs in the fields of technology and human resources. Each envelope will feature a different attribute or spin-off of the LHC. People will be invited to consult CERN’s public website for more detailed explanations if they want to know more. The new envelopes will be available from five post offices in the Pays de Gex (Ferney-Voltaire, Prévessin...

  18. The LHC on an envelope

    CERN Multimedia

    2007-01-01

    The series of envelopes featuring CERN issued this summer was a huge success. The French postal services of the Pays de Gex will shortly be launching the second set of pre-paid envelopes issued in collaboration with the Laboratory this year, this time highlighting the LHC. Five thousand envelopes describing the accelerator’s capabilities will go on sale on 12 November, and some of the packs will even contain a small sample of the cables from the heart of the LHC magnets. The sets of ten pre-paid envelopes will tell you everything about CERN’s flagship accelerator, from its astounding technical capabilities to its spin-offs in the fields of technology and human resources. Each envelope will feature a different attribute or spin-off of the LHC. People will be invited to consult CERN’s public website for more detailed explanations if they want to know more. The new envelopes will be available from five post offices in the Pays ...

  19. Parasitic Events in Envelope Analysis

    Directory of Open Access Journals (Sweden)

    J. Doubek

    2001-01-01

    Full Text Available Envelope analysis allows fast fault location of individual gearboxes and parts of bearings by repetition frequency determination of the mechanical catch of an amplitude-modulated signal. Systematic faults arise when using envelope analysis on a signal with strong changes. The source of these events is the range of function definition of used in convolution integral definition. This integral is used for Hilbert image calculation of analyzed signal. Overshoots (almost similar to Gibbs events on a synthetic signal using the Fourier series are result from these faults. Overshoots are caused by parasitic spectral lines in the frequency domain, which can produce faulty diagnostic analysis.This paper describes systematic arising during faults rising by signal numerical calculation using envelope analysis with Hilbert transform. It goes on to offer a mathematical analysis of these systematic faults.

  20. Moisture dynamics in building envelopes

    Energy Technology Data Exchange (ETDEWEB)

    Peuhkuri, R.

    2003-07-01

    The overall scope of this Thesis 'Moisture dynamics in building envelopes' has been to characterise how the various porous insulation materials investigated performed hygro thermally under conditions similar to those in a typical building envelope. As a result of the changing temperature and moisture conditions in the exterior weather and indoor climate the materials dynamically absorb and release moisture. The complexity of the impact of these conditions on the resulting moisture transport and content of the materials has been studied in this Thesis with controlled laboratory tests. (au)

  1. An HIV-1 envelope immunogen with W427S mutation in CD4 binding site induced more T follicular helper memory cells and reduced non-specific antibody responses.

    Directory of Open Access Journals (Sweden)

    Hao-Tong Yu

    Full Text Available The CD4 binding site (CD4BS of the HIV-1 envelope glycoprotein (Env contains epitopes for broadly neutralizing antibody (nAb and is the target for the vaccine development. However, the CD4BS core including residues 425-430 overlaps the B cell superantigen site and may be related to B cell exhaustion in HIV-1 infection. Furthermore, production of nAb and high-affinity plasma cells needs germinal center reaction and the help of T follicular helper (Tfh cells. We believe that strengthening the ability of Env CD4BS in inducing Tfh response and decreasing the effects of the superantigen are the strategies for eliciting nAb and development of HIV-1 vaccine. We constructed a gp120 mutant W427S of an HIV-1 primary R5 strain and examined its ability in the elicitation of Ab and the production of Tfh by immunization of BALB/c mice. We found that the trimeric wild-type gp120 can induce more non-specific antibody-secreting plasma cells, higher serum IgG secretion, and more Tfh cells by splenocyte. The modified W427S gp120 elicits higher levels of specific binding antibodies as well as nAbs though it produces less Tfh cells. Furthermore, higher Tfh cell frequency does not correlate to the specific binding Abs or nAbs indicating that the wild-type gp120 induced some non-specific Tfh that did not contribute to the production of specific Abs. This gp120 mutant led to more memory Tfh production, especially, the effector memory Tfh cells. Taken together, W427S gp120 could induce higher level of specific binding and neutralizing Ab production that may be associated with the reduction of non-specific Tfh but strengthening of the memory Tfh.

  2. Structural plasticity of the nuclear envelope and the endoplasmic reticulum

    Directory of Open Access Journals (Sweden)

    Sheval E. V.

    2014-09-01

    Full Text Available The nuclear envelope is a double membrane structure, continuous with endoplasmic reticulum, and the morphological organization of both these structures is quite conservative. However, nuclear envelope and endoplasmic reticulum demonstrate distinct structural plasticity, i. e., based on common organization, cells may form various non-canonical membrane structures that are observed only in specialized types of cells or appear in different pathologies. In this review, we will discuss the mechanisms of the biogenesis of such non-canonical structures, and the possible role of this plasticity in the development of pathological processes.

  3. Several novel nuclear envelope transmembrane proteins identified in skeletal muscle have cytoskeletal associations.

    Science.gov (United States)

    Wilkie, Gavin S; Korfali, Nadia; Swanson, Selene K; Malik, Poonam; Srsen, Vlastimil; Batrakou, Dzmitry G; de las Heras, Jose; Zuleger, Nikolaj; Kerr, Alastair R W; Florens, Laurence; Schirmer, Eric C

    2011-01-01

    Nuclear envelopes from liver and a neuroblastoma cell line have previously been analyzed by proteomics; however, most diseases associated with the nuclear envelope affect muscle. To determine whether muscle has unique nuclear envelope proteins, rat skeletal muscle nuclear envelopes were prepared and analyzed by multidimensional protein identification technology. Many novel muscle-specific proteins were identified that did not appear in previous nuclear envelope data sets. Nuclear envelope residence was confirmed for 11 of these by expression of fusion proteins and by antibody staining of muscle tissue cryosections. Moreover, transcript levels for several of the newly identified nuclear envelope transmembrane proteins increased during muscle differentiation using mouse and human in vitro model systems. Some of these proteins tracked with microtubules at the nuclear surface in interphase cells and accumulated at the base of the microtubule spindle in mitotic cells, suggesting they may associate with complexes that connect the nucleus to the cytoskeleton. The finding of tissue-specific proteins in the skeletal muscle nuclear envelope proteome argues the importance of analyzing nuclear envelopes from all tissues linked to disease and suggests that general investigation of tissue differences in organellar proteomes might yield critical insights. PMID:20876400

  4. Energy efficiency of building envelope

    OpenAIRE

    V.M. Yakubson

    2014-01-01

    November, 12-13th, in Saint-Petersburg the 7th International congress "Energy efficiency. XXI century" took place. The reports were done in breakuo groups according to the various aspects of energy efficiency challenge: HVAC systems, water supply and sewerage systems, gas supply, energy metering. One of the grourps was devoted to thermophysics of buildings and energy effective design of building envelope.

  5. Outliers In Data Envelopment Analysis

    Directory of Open Access Journals (Sweden)

    Shaik Khaleel Ahamed

    2015-06-01

    Full Text Available Data Envelopment Analysis is a linear programming technique that assigns efficiency scores to firms engaged in producing similar outputs employing similar inputs. Extremely efficient firms are potential Outliers. The method developed detects Outliers, implementing Stochastic Threshold Value, with computational ease. It is useful in data filtering in BIG DATA problems.

  6. Identification of immunodominant regions and linear B cell epitopes of the gE envelope protein of varicella-zoster virus.

    Science.gov (United States)

    Fowler, W J; Garcia-Valcarcel, M; Hill-Perkins, M S; Murphy, G; Harper, D R; Jeffries, D J; Burns, N R; Adams, S E; Kingsman, A J; Layton, G T

    1995-12-20

    The envelope proteins of varicella-zoster virus (VZV) are highly immunogenic and one of the most abundant is glycoprotein E (gE). However, its immunodominant regions and epitopes have not been identified. In this study, using human sera from individuals with recent varicella or zoster infections, we have localized antigenic sequences of gE using recombinant hybrid Ty-virus-like particles (VLPs) carrying overlapping fragments of the gE protein. gE(1-134)-VLPs (particles carrying amino acids 1-134 of gE) and, to a lesser extent, gE(101-161)-VLPs were found to be the most antigenic when tested by Western blotting and ELISA. Other fragments of gE (spanning residues 161-623) showed weak or no antigenicity. Pepscan analysis of human sera on overlapping synthetic peptides representing residues 1-135 of gE revealed that the most antigenic region was between residues 50 and 135. Three immunodominant sequences (residues 86-105, 116-135, and, to a lesser extent, 56-75) were detected using sera from both varicella and zoster patients. All sera from varicella, but not zoster, patients reacted strongly with an epitope in peptide 66-85. Other epitopes were recognized weakly by some varicella or zoster sera. More sera need to be tested to assess the potential disease specificity of these epitopes. The neutralizing monoclonal antibody (MAb) IF-B9 reacted with residues 71-90; however, another neutralizing MAb, SG1A, which bound to both gE(1-134)-VLPs and gE(101-161)-VLPs did not bind to any peptide. The identification of immunodominant sequences of gE will help toward the development of a subunit VZV vaccine. PMID:8553555

  7. Functional organization of the HIV lipid envelope

    Science.gov (United States)

    Huarte, Nerea; Carravilla, Pablo; Cruz, Antonio; Lorizate, Maier; Nieto-Garai, Jon A.; Kräusslich, Hans-Georg; Pérez-Gil, Jesús; Requejo-Isidro, Jose; Nieva, José L.

    2016-01-01

    The chemical composition of the human immunodeficiency virus type 1 (HIV-1) membrane is critical for fusion and entry into target cells, suggesting that preservation of a functional lipid bilayer organization may be required for efficient infection. HIV-1 acquires its envelope from the host cell plasma membrane at sites enriched in raft-type lipids. Furthermore, infectious particles display aminophospholipids on their surface, indicative of dissipation of the inter-leaflet lipid asymmetry metabolically generated at cellular membranes. By combining two-photon excited Laurdan fluorescence imaging and atomic force microscopy, we have obtained unprecedented insights into the phase state of membranes reconstituted from viral lipids (i.e., extracted from infectious HIV-1 particles), established the role played by the different specimens in the mixtures, and characterized the effects of membrane-active virucidal agents on membrane organization. In determining the molecular basis underlying lipid packing and lateral heterogeneity of the HIV-1 membrane, our results may help develop compounds with antiviral activity acting by perturbing the functional organization of the lipid envelope. PMID:27678107

  8. Marking 100 years since Rudolf Höber’s discovery of the insulating envelope surrounding cells and of the beta-dispersion exhibited by tissue

    Directory of Open Access Journals (Sweden)

    Ronald Pethig

    2012-11-01

    Full Text Available Between 1910 and 1913 Rudolf Höber presented proof that the interiors of red blood cells and muscle cells contain conducting electrolytes, and that each conducting core is contained within an insulating membrane.  He did this by demonstrating, in a series of remarkable electrical experiments, that the conductivity of compacted cell samples at low frequencies (~150 Hz was about ten-times less than the value obtained at ~5 MHz.  On perforation of the membrane, the low-frequency conductivity increased to a value approaching that exhibited at MHz frequencies. Apart from representing a major milestone in the development of cell biology and electrophysiology, Höber’s work was the first description of what we now call the dielectric b-dispersion exhibited by cell suspensions and fresh tissue.

  9. Moisture Dynamics in Building Envelopes

    DEFF Research Database (Denmark)

    Peuhkuri, Ruut Hannele

    2003-01-01

    and moisture conditions in the exterior weather and indoor climate the materials dynamically absorb and release moisture. The complexity of the impact of these conditions on the resulting moisture transport and content of the materials has been studied in this Thesis with controlled laboratory tests. The first...... part of the Thesis consists of a theory and literature review on the moisture storage and transport processes (Chapter 2), on the non-Fickian moisture transport (Chapter 3)and on the methods for determining the moisture properties (Chapter 4). In the second part, the conducted experimental work......The overall scope of this Thesis "Moisture dynamics in building envelopes" has been to characterise how the various porous insulation materials investigated performed hygrothermally under conditions similar to those in a typical building envelope. As a result of the changing temperature...

  10. Chemical Models of Collapsing Envelopes

    CERN Document Server

    Bergin, E A

    1999-01-01

    We discuss recent models of chemical evolution in the developing and collapsing protostellar envelopes associated with low-mass star formation. In particular, the effects of depletion of gas-phase molecules onto grain surfaces is considered. We show that during the middle to late evolutionary stages, prior to the formation of a protostar, various species selectively deplete from the gas phase. The principal pattern of selective depletions is the depletion of sulfur-bearing molecules relative to nitrogen-bearing species: NH3 and N2H+. This pattern is shown to be insensitive to the details of the dynamics and marginally sensitive to whether the grain mantle is dominated by polar or non-polar molecules. Based on these results we suggest that molecular ions are good tracers of collapsing envelopes. The effects of coupling chemistry and dynamics on the resulting physical evolution are also examined. Particular attention is paid to comparisons between models and observations.

  11. Conformational instability governed by disulfide bonds partitions the dominant from subdominant helper T-cell responses specific for HIV-1 envelope glycoprotein gp120

    OpenAIRE

    Nguyen, Hong-Nam P.; Steede, N. Kalaya; Robinson, James E.; Landry, Samuel J.

    2015-01-01

    Most individuals infected with human immunodeficiency virus type 1 (HIV-1) generate a CD4+ T-cell response that is dominated by a few epitopes. Immunodominance may be counterproductive because a broad CD4+ T-cell response is associated with reduced viral load. Previous studies indicated that antigen three-dimensional structure controls antigen processing and presentation and therefore CD4+ T-cell epitope dominance. Dominant epitopes occur adjacent to the V1-V2, V3, and V4 loops because proteo...

  12. Safeguards Envelope Progress FY08

    Energy Technology Data Exchange (ETDEWEB)

    Robert Bean; Richard Metcalf; Aaron Bevill

    2008-09-01

    The Safeguards Envelope Project met its milestones by creating a rudimentary safeguards envelope, proving the value of the approach on a small scale, and determining the most appropriate path forward. The Idaho Chemical Processing Plant’s large cache of reprocessing process monitoring data, dubbed UBER Data, was recovered and used in the analysis. A probabilistic Z test was used on a Markov Monte Carlo simulation of expected diversion data when compared with normal operating data. The data regarding a fully transient event in a tank was used to create a simple requirement, representative of a safeguards envelope, whose impact was a decrease in operating efficiency by 1.3% but an increase in material balance period of 26%. This approach is operator, state, and international safeguards friendly and should be applied to future reprocessing plants. Future requirements include tank-to-tank correlations in reprocessing facilities, detailed operations impact studies, simulation inclusion, automated optimization, advanced statistics analysis, and multi-attribute utility analysis.

  13. Genomewide screening for fusogenic human endogenous retrovirus envelopes identifies syncytin 2, a gene conserved on primate evolution

    OpenAIRE

    Blaise, Sandra; de Parseval, Nathalie; Bénit, Laurence; Heidmann, Thierry

    2003-01-01

    Screening human sequence databases for endogenous retroviral elements with coding envelope genes has revealed 16 candidate genes that we assayed for their fusogenic properties. All 16 genes were cloned in a eukaryotic expression vector and assayed for cell–cell fusion by using a large panel of mammalian cells in transient transfection assays. Fusion was observed for two human endogenous retrovirus (HERV) envelopes, the previously characterized HERV-W envelope, also called syncytin, and a prev...

  14. Conformational instability governed by disulfide bonds partitions the dominant from subdominant helper T-cell responses specific for HIV-1 envelope glycoprotein gp120

    Science.gov (United States)

    Nguyen, Hong-Nam P.; Steede, N. Kalaya; Robinson, James E.; Landry, Samuel J.

    2015-01-01

    Most individuals infected with human immunodeficiency virus type 1 (HIV-1) generate a CD4+ T-cell response that is dominated by a few epitopes. Immunodominance may be counterproductive because a broad CD4+ T-cell response is associated with reduced viral load. Previous studies indicated that antigen three-dimensional structure controls antigen processing and presentation and therefore CD4+ T-cell epitope dominance. Dominant epitopes occur adjacent to the V1-V2, V3, and V4 loops because proteolytic antigen processing in the loops promotes presentation of adjacent sequences. In this study, three gp120 (strain JR-FL) variants were constructed, in which deletions of single outer-domain disulfide bonds were expected to introduce local conformational flexibility and promote presentation of additional CD4+ T-cell epitopes. Following mucosal immunization of C57BL/6 mice with wild-type or variant gp120 lacking the V3-flanking disulfide bond, the typical pattern of dominant epitopes was observed, suggesting that the disulfide bond posed no barrier to antigen presentation. In mice that lacked gamma interferoninducible lysosomal thioreductase (GILT), proliferative responses to the typically dominant epitopes of gp120 were selectively depressed, and the dominance pattern was rearranged. Deletion of the V3-flanking disulfide bond or one of the V4-flanking disulfide bonds partially restored highly proliferative responses to the typically dominant epitopes. These results reveal an acute dependence of dominant CD4+ T-cell responses on the native gp120 conformation. PMID:25944298

  15. Introducing the Adaptive Convex Enveloping

    CERN Document Server

    Yu, Sheng

    2011-01-01

    Convexity, though extremely important in mathematical programming, has not drawn enough attention in the field of dynamic programming. This paper gives conditions for verifying convexity of the cost-to-go functions, and introduces an accurate, fast and reliable algorithm for solving convex dynamic programs with multivariate continuous states and actions, called Adaptive Convex Enveloping. This is a short introduction of the core technique created and used in my dissertation, so it is less formal, and misses some parts, such as literature review and reference, compared to a full journal paper.

  16. Absence of cytotoxic antibody to human immunodeficiency virus-infected cells in humans and its induction in animals after infection or immunization with purified envelope glycoprotein gp120

    International Nuclear Information System (INIS)

    The presence of antibody-dependent complement-mediated cytotoxicity (ACC) was assessed in humans and chimpanzees, which are capable of infection with human immunodeficiency virus isolate HTLV-IIIb, and examined in the goat after immunization with the major viral glycoprotein (gp120) of HTLV-IIIb. In infected humans no antibody mediating ACC was observed regardless of the status of disease. Even healthy individuals with high-titer, broadly reactive, neutralizing antibodies has no ACC. In contrast, chimpanzees infected with HTLV-IIIb, from whom virus could be isolated, not only had neutralizing antibody but also antibodies broadly reactive in ACC, even against distantly related human immunodeficiency virus isolates, as well as against their own reisolated virus. In the goat, the gp120 of HTLV-IIIb induced a highly type-specific response as measured by both ACC and flow cytofluorometry of live infected H9 cells. Normal human cells were not subject to ACC by animal anti-HTLV-III gp120-specific sera. Induction of ACC and neutralizing antibody were closely correlated in the animal experimental models but not in humans. The presence of ACC in gp120-inoculated goats and HTLV-III-infected chimpanzees represent a qualitative difference that may be important in the quest for the elicitation of a protective immunity in humans

  17. Elimination of human T cell leukemia virus type-1-infected cells by neutralizing and antibody-dependent cellular cytotoxicity-inducing antibodies against human t cell leukemia virus type-1 envelope gp46.

    Science.gov (United States)

    Tanaka, Yuetsu; Takahashi, Yoshiaki; Tanaka, Reiko; Kodama, Akira; Fujii, Hideki; Hasegawa, Atsuhiko; Kannagi, Mari; Ansari, Aftab A; Saito, Mineki

    2014-06-01

    Human T cell leukemia virus type-1 (HTLV-1) is prevalent worldwide with foci of high prevalence. However, to date no effective vaccine or drug against HTLV-1 infection has been developed. In efforts to define the role of antibodies in the control of HTLV-1 infection, we capitalized on the use of our previously defined anti-gp46 neutralizing monoclonal antibody (mAb) (clone LAT-27) and high titers of human anti-HTLV-1 IgG purified from HAM/TSP patients (HAM-IgG). LAT-27 and HAM-IgG completely blocked syncytium formation and T cell immortalization mediated by HTLV-1 in vitro. The addition of these antibodies to cultures of CD8(+) T cell-depleted peripheral blood mononuclear cells (PBMCs) from HAM/TSP patients at the initiation of culture not only decreased the numbers of Tax-expressing cells and the production of HTLV-1 p24 but also inhibited the spontaneous immortalization of T cells. Coculture of in vitro-HTLV-1-immortalized T cell lines with autologous PBMCs in the presence of LAT-27 or HAM-IgG, but not an F(ab')2 fragment of LAT-27 or nonneutralizing anti-gp46 mAbs, resulted in depletion of HTLV-1-infected cells. A 24-h (51)Cr release assay showed the presence of significant antibody-dependent cellular cytotoxicity (ADCC) activity in LAT-27 and HAM-IgG, but not F(ab')2 of LAT-27, resulting in the depletion of HTLV-1-infected T cells by autologous PBMCs. The depletion of natural killer (NK) cells from the effector PBMCs reduced this ADCC activity. Altogether, the present data demonstrate that the neutralizing and ADCC-inducing activities of anti-HTLV-1 antibodies are capable of reducing infection and eliminating HTLV-1-infected cells in the presence of autologous PBMCs. PMID:24524420

  18. Safeguards Envelope Progress FY10

    Energy Technology Data Exchange (ETDEWEB)

    Richard Metcalf

    2010-10-01

    The Safeguards Envelope is a strategy to determine a set of specific operating parameters within which nuclear facilities may operate to maximize safeguards effectiveness without sacrificing safety or plant efficiency. This paper details the additions to the advanced operating techniques that will be applied to real plant process monitoring (PM) data from the Idaho Chemical Processing Plant (ICPP). Research this year focused on combining disparate pieces of data together to maximize operating time with minimal downtime due to safeguards. A Chi-Square and Croiser's cumulative sum were both included as part of the new analysis. Because of a major issue with the original data, the implementation of the two new tests did not add to the existing set of tests, though limited one-variable optimization made a small increase in detection probability. Additional analysis was performed to determine if prior analysis would have caused a major security or safety operating envelope issue. It was determined that a safety issue would have resulted from the prior research, but that the security may have been increased under certain conditions.

  19. Circumplanetary disc or circumplanetary envelope?

    Science.gov (United States)

    Szulágyi, J.; Masset, F.; Lega, E.; Crida, A.; Morbidelli, A.; Guillot, T.

    2016-08-01

    We present three-dimensional simulations with nested meshes of the dynamics of the gas around a Jupiter mass planet with the JUPITER and FARGOCA codes. We implemented a radiative transfer module into the JUPITER code to account for realistic heating and cooling of the gas. We focus on the circumplanetary gas flow, determining its characteristics at very high resolution (80 per cent of Jupiter's diameter). In our nominal simulation where the temperature evolves freely by the radiative module and reaches 13000 K at the planet, a circumplanetary envelope was formed filling the entire Roche lobe. Because of our equation of state is simplified and probably overestimates the temperature, we also performed simulations with limited maximal temperatures in the planet region (1000, 1500, and 2000 K). In these fixed temperature cases circumplanetary discs (CPDs) were formed. This suggests that the capability to form a CPD is not simply linked to the mass of the planet and its ability to open a gap. Instead, the gas temperature at the planet's location, which depends on its accretion history, plays also fundamental role. The CPDs in the simulations are hot and cooling very slowly, they have very steep temperature and density profiles, and are strongly sub-Keplerian. Moreover, the CPDs are fed by a strong vertical influx, which shocks on the CPD surfaces creating a hot and luminous shock-front. In contrast, the pressure supported circumplanetary envelope is characterized by internal convection and almost stalled rotation.

  20. Envelope gene sequences encoding variable regions 3 and 4 are involved in macrophage tropism of feline immunodeficiency virus

    NARCIS (Netherlands)

    Horzinek, M.C.; Vahlenkamp, T.W.; Ronde, A. de; Schuurman, N.M.P.; Vliet, A.L.W. van; Drunen, J. van; Egberink, H.F.

    1999-01-01

    The envelope is of cardinal importance for the entry of feline immunodeficiency virus (FIV) into its host cells, which consist of cells of the immune system including macrophages. To characterize the envelope glycoprotein determinants involved in macrophage tropism, chimeric infectious molecular clo

  1. Evolution of envelope solitons of ionization waves

    International Nuclear Information System (INIS)

    The time evolution of a particle-like envelope soliton of ionization waves in plasma was investigated theoretically. The hydrodynamic equations of one spatial dimension were solved and the nonlinear dispersion relation was derived. For the amplitude of the wave the nonlinear Schroedinger equation was derived. Its soliton solution was interpreted as the envelope soliton which was experimentally found. The damping rate of the envelope soliton was estimated. (D.Gy.)

  2. Adaptive Flight Envelope Estimation and Protection Project

    Data.gov (United States)

    National Aeronautics and Space Administration — Impact Technologies, in collaboration with the Georgia Institute of Technology, proposes to develop and demonstrate an innovative flight envelope estimation and...

  3. Involucrin and envelope competence in human keratinocytes: Modulation by hydrocortisone, retinyl acetate and growth arrest

    OpenAIRE

    Rice, Rh; Cline, PR

    1983-01-01

    Involucrin accumulation and ionophore-assisted envelope for mation, markers of keratinocyte differentiation, were found to be highly dependent on culture conditions in the malignant epidermal keratinocyte line, SCC-13, derived from a human squamous cell carcinoma. In confluent cultures, approximately one-half of the cells were competent to form envelopes when grown in medium without hydrocortisone or retinyl acetate supplementation. Ad dition of hydrocortisone to the medi...

  4. Glycosylation of a Streptomyces coelicolor A3(2) cell envelope protein is required for infection by bacteriophage phi C31.

    Science.gov (United States)

    Cowlishaw, D A; Smith, M C

    2001-08-01

    Mutants of Streptomyces coelicolor A3(2) J1929 (Delta pglY) were isolated that were resistant to the Streptomyces temperate phage phi C31. These strains could be transfected with phi C31 DNA, but could not act as infective centres after exposure to phage. Thus, it was concluded that infection was blocked at the adsorption/DNA injection step. The mutants fell into three classes. Class I mutants were complemented by a gene, SCE87.05, isolated from the cosmid library of S. coelicolor A3(2). The product of SCE87.05 had good overall homology to a Mycobacterium tuberculosis hypothetical protein and regions with similarity to dolichol phosphate-D-mannose:protein O-D-mannosyltransferases. Concanavalin A (ConA) inhibited phi C31 infection of S. coelicolor J1929, and this could be partially reversed by the addition of the sugar, alpha-D-methyl-pyranoside. Moreover, glycosylated proteins from J1929, but not from the class I mutant DT1017, were detected using ConA as a probe in Western blots. Class I and II mutants were sensitive to phi C31hc, a previously isolated phage exhibiting an extended host range phenotype, conferred by h. A phage with the same phenotype, phi DT4002, was isolated independently, and a missense mutation was found in a putative tail gene. It is proposed that the phi C31 receptor is a cell wall glycoprotein, and that the phi C31h mutation compensates for the lack of glycosylation of the receptor.

  5. Flexibility of cold- and heat-adapted subtilisin-like serine proteinases evaluated with fluorescence quenching and molecular dynamics

    DEFF Research Database (Denmark)

    Sigtryggsdóttir, Asta Rós; Papaleo, Elena; Thorbjarnardóttir, Sigríður H.;

    2014-01-01

    activity of cold adapted enzymes when compared to homologues from thermophiles, reflects their higher molecular flexibility. To assess a potential difference in molecular flexibility between the two homologous proteinases, we have measured their Trp fluorescence quenching by acrylamide at different...... have similar flexibility profiles, the cold adapted VPR displays higher flexibility in most regions of the protein structure. Some of these regions contain or are in proximity to some of the Trp residues (Trp6, Trp114 and Trp208) in the proteins. Thus, we observe an overall agreement between...

  6. Different evolutionary patterns of classical swine fever virus envelope proteins.

    Science.gov (United States)

    Li, Yan; Yang, Zexiao; Zhang, Mingwang

    2016-03-01

    Classical swine fever virus (CSFV) is the causative agent of classical swine fever, which is a highly contagious disease of the domestic pig as well as wild boar. The proteins E(rns), E1, and E2 are components of the viral envelope membrane. They are also implicated in virus attachment and entry, replication, and (or) anti-immune response. Here, we studied the genetic variations of these envelope proteins in the evolution of CSFV. The results reveal that the envelope proteins underwent different evolutionary fates. In E(rns) and E1, but not E2, a number of amino acid sites experienced functional divergence. Furthermore, the diversification in E(rns) and E1 was generally episodic because the divergence-related changes of E1 only occurred with the separation of 2 major groups of CSFV and that of E(rns) took place with the division of 1 major group. The major divergence-related sites of E(rns) are located on one of the substrate-binding regions of the RNase domain and C-terminal extension. These functional domains have been reported to block activation of the innate immune system and attachment and entry into host cells, respectively. Our results may shed some light on the divergent roles of the envelope proteins. PMID:26911308

  7. Reach Envelope of Human Extremities

    Institute of Scientific and Technical Information of China (English)

    YANG Jingzhou(杨景周); ZHANG Yunqing(张云清); CHEN Liping(陈立平); ABDEL-MALEK Karim

    2004-01-01

    Significant attention in recent years has been given to obtain a better understanding of human joint ranges, measurement, and functionality, especially in conjunction with commands issued by the central nervous system. While researchers have studied motor commands needed to drive a limb to follow a path trajectory, various computer algorithms have been reported that provide adequate analysis of limb modeling and motion. This paper uses a rigorous mathematical formulation to model human limbs, understand their reach envelope, delineate barriers therein where a trajectory becomes difficult to control, and help visualize these barriers. Workspaces of a typical forearm with 9 degrees of freedom, a typical finger modeled as a 4- degree-of-freedom system, and a lower extremity with 4 degrees of freedom are discussed. The results show that using the proposed formulation, joint limits play an important role in distinguishing the barriers.

  8. Characterization of the pattern of alphas1- and beta-casein breakdown and release of a bioactive peptide by a cell envelope proteinase from Lactobacillus delbrueckii subsp. lactis CRL 581.

    Science.gov (United States)

    Hebert, Elvira María; Mamone, Gianfranco; Picariello, Gianluca; Raya, Raúl R; Savoy, Graciela; Ferranti, Pasquale; Addeo, Francesco

    2008-06-01

    The cell envelope-associated proteinases (CEPs) of the lactobacilli have key roles in bacterial nutrition and contribute to the development of the organoleptic properties of fermented milk products as well, as they can release bioactive health-beneficial peptides from milk proteins. The influence of the peptide supply, carbohydrate source, and osmolites on the CEP activity of the cheese starter Lactobacillus delbrueckii subsp. lactis CRL 581 was investigated. The CEP activity levels were controlled by the peptide content of the growth medium. The maximum activity was observed in a basal minimal defined medium, whereas in the presence of Casitone, Casamino Acids, or yeast extract, the synthesis of CEP was inhibited 99-, 70-, and 68-fold, respectively. The addition of specific di- or tripeptides containing branched-chain amino acids, such as leucylleucine, prolylleucine, leucylglycylglycine, or leucylproline, to the growth medium negatively affected CEP activity, whereas dipeptides without branched-chain amino acids had no effect on the enzyme's production. The carbon source and osmolites did not affect CEP activity. The CEP of L. delbrueckii subsp. lactis CRL 581 exhibited a mixed-type CEP(I/III) variant caseinolytic specificity. Mass-spectrometric screening of the main peptide peaks isolated by reverse-phase high-pressure liquid chromatography allowed the identification of 33 and 32 peptides in the alpha(s1)- and beta-casein hydrolysates, respectively. By characterizing the peptide sequence in these hydrolysates, a pattern of alpha(s1)- and beta-casein breakdown was defined and is reported herein, this being the first report for a CEP of L. delbrueckii subsp. lactis. In this pattern, a series of potentially bioactive peptides (antihypertensive and phosphopeptides) which are encrypted within the precursor protein could be visualized. PMID:18424544

  9. 14 CFR 23.333 - Flight envelope.

    Science.gov (United States)

    2010-01-01

    ... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Flight envelope. 23.333 Section 23.333... STANDARDS: NORMAL, UTILITY, ACROBATIC, AND COMMUTER CATEGORY AIRPLANES Structure Flight Loads § 23.333 Flight envelope. (a) General. Compliance with the strength requirements of this subpart must be shown...

  10. Efflux of RNA from resealed nuclear envelope ghosts.

    Science.gov (United States)

    Prochnow, D; Thomson, M; Schröder, H C; Müller, W E; Agutter, P S

    1994-08-01

    mRNA translocation across the nuclear envelope and the appropriate signal-receptor interactions have been studied using resealed rat liver nuclear envelope ghosts (RNEG). We compared export kinetics of nonadenylated (tRNAs, histone-2 poly(A)- mRNA), and adenylated RNAs (poly(A)+ tRNAs, synthetic histone-2 poly(A) +mRNA, albumin mRNA, beta-globin poly(A) +mRNA and a total poly(A) + mRNA extract from rat liver cells). ATP-dependent export of mRNAs and of total poly(A)+ RNA was prevented by inhibitors of a nuclear envelope NTPase. All adenylated RNA species competed with each other for export, but nonadenylated RNAs did not. This indicates the existence of different translocation mechanisms for different RNA species with their appropriate nuclear envelope associated RNA receptors involved in export. The attachment of a poly(A)250 sequence at the 3'-end of tRNA or histone messenger masks the intrinsic RNA export signal of nonadenylated RNAs and results in efflux comparable to that of beta-globin poly(A)+ mRNA. The attachment on oligo(A)5 does not have any comparable effect of nonadenylated RNA translocation. Export of all polyadenylated RNAs from RNEGs is blocked by a monoclonal antibody, which is directed against an intranuclear envelope poly(A) binding protein. The results suggest that the pore complexes do not select RNAs for export to the cytoplasm and are therefore not responsible for nuclear restriction of mRNA precursors.

  11. Simulating Convection in Stellar Envelopes

    Science.gov (United States)

    Tanner, Joel

    Understanding convection in stellar envelopes, and providing a mathematical description of it, would represent a substantial advance in stellar astrophysics. As one of the largest sources of uncertainty in stellar models, existing treatments of convection fail to account for many of the dynamical effects of convection, such as turbulent pressure and asymmetry in the velocity field. To better understand stellar convection, we must be able to study and examine it in detail, and one of the best tools for doing so is numerical simulation. Near the stellar surface, both convective and radiative process play a critical role in determining the structure and gas dynamics. By following these processes from first principles, convection can be simulated self-consistently and accurately, even in regions of inefficient energy transport where existing descriptions of convection fail. Our simulation code includes two radiative transfer solvers that are based on different assumptions and approximations. By comparing simulations that differ only in their respective radiative transfer methods, we are able to isolate the effect that radiative efficiency has on the structure of the superadiabatic layer. We find the simulations to be in good general agreement, but they show distinct differences in the thermal structure in the superadiabatic layer and atmosphere. Using the code to construct a grid of three-dimensional radiation hydrodynamic simulations, we investigate the link between convection and various chemical compositions. The stellar parameters correspond to main-sequence stars at several surface gravities, and span a range in effective temperatures (4500 matches the thermodynamics of the simulations. In particular, we consider adjusting the mixing length parameter such that the specific entropy of the model matches that of an equivalent simulation eliminates the need to arbitrarily set the parameter, and in principle will produce stellar models with more accurate radii. By

  12. The microtubule aster formation and its role in nuclear envelope assembly around the sperm chromatin in Xenopus egg extracts

    Institute of Scientific and Technical Information of China (English)

    YANG Ning; CHEN Zhongcai; LU Ping; ZHANG Chuanmao; ZHAI Zhonghe; TANG Xiaowei

    2003-01-01

    Nuclear envelope is a dynamic structure in the cell cycle. At the beginning of mitosis, nuclear envelope breaks down and its components disperse into the cytoplasm. At the end of mitosis, nuclear envelope reassembles using the dispersed components. Searching for the mechanisms of the nuclear disassembly and reassembly has for a long time been one of the key projects for cell biologists. In this report we show that microtubules take a role in the nuclear envelope assembly around the sperm chromatin in Xenopus egg extracts. Microtubule cytoskeleton has been demonstrated to take roles in the transport of intracellular membranes such as Golgi and ER vesicles. We found that the nuclear envelope assembly needs functional microtubules. At the beginning of the nuclear assembly, microtubules nucleated to form a microtubule aster around the centrosome at the base of the sperm head. Using the microtubule drug colchicine to disrupt the microtubule nucleation, nuclear envelope reassembly was seriously inhibited. If the microtubules were stabilized by taxol, another microtubule drug, the nuclear envelope reassembly was also interfered, although a significantly large aster formed around the chromatin. Based on these observations, we propose that microtubules play an important role in the nuclear envelope reassembly maybe by transporting the nuclear envelope precursors to the chromatin surfaces.

  13. Spectral Envelopes - A Preliminary Report

    CERN Document Server

    Lawton, Wayne

    2012-01-01

    The spectral envelope S(F) of a subset of integers is the set of probability measures on the circle group that are weak star limits of squared moduli of trigonometric polynomials with frequencies in F. Fourier transforms of these measures are positive and supported in F - F but the converse generally fails. The characteristic function chiF of F is a binary sequence whose orbit closure gives a symbolic dynamical system O(F). Analytic properties of S(F) are related to dynamical properties of chiF. The Riemann-Lebesque lemma implies that if chiF is minimal, then S(F) is convex and hence S(F) is the closure of the convex hull of its extreme points Se(F). In this paper we (i) review the relationship between these concepts and the special case of the still open 1959 Kadison-Singer problem called Feichtinger's conjecture for exponential functions, (ii) partially characterize of elements in Se(F), for minimal chiF, in terms of ergodic properties of (O(F),lambda) where lambda is a shift invariant probability measure w...

  14. Circumplanetary disk or circumplanetary envelope?

    CERN Document Server

    Szulágyi, J; Lega, E; Crida, A; Morbidelli, A; Guillot, T

    2016-01-01

    We present three-dimensional simulations with nested meshes of the dynamics of the gas around a Jupiter mass planet with the JUPITER and FARGOCA codes. We implemented a radiative transfer module into the JUPITER code to account for realistic heating and cooling of the gas. We focus on the circumplanetary gas flow, determining its characteristics at very high resolution ($80\\%$ of Jupiter's diameter). In our nominal simulation where the temperature evolves freely by the radiative module and reaches 13000 K at the planet, a circumplanetary envelope was formed filling the entire Roche-lobe. Because of our equation of state is simplified and probably overestimates the temperature, we also performed simulations with limited maximal temperatures in the planet region (1000 K, 1500 K, and 2000 K). In these fixed temperature cases circumplanetary disks (CPDs) were formed. This suggests that the capability to form a circumplanetary disk is not simply linked to the mass of the planet and its ability to open a gap. Inste...

  15. Injection envelope matching in storage rings

    International Nuclear Information System (INIS)

    The shape and size of the transverse phase space injected into a storage ring can be deduced from turn-by-turn measurements of the transient behavior of the beam envelope in the ring. Envelope oscillations at 2 x the β-tron frequency indicate the presence of a β-mismatch, while envelope oscillations at the β-tron frequency are the signature of a dispersion function mismatch. Experiments in injection optimization using synchrotron radiation imaging of the beam and a fast-gated camera at the SLC damping rings are reported

  16. Functional dissection of the Moloney murine leukemia virus envelope protein gp70.

    OpenAIRE

    Bae, Y.; Kingsman, S M; Kingsman, A J

    1997-01-01

    The envelope protein of Moloney murine leukemia virus (Mo-MLV) is a complex glycoprotein that mediates receptor binding and entry via fusion with cell membranes. By using a series of substitution mutations and truncations in the Mo-MLV external envelope surface protein gp70, we have identified regions important for these processes. Firstly, truncations of gp70 revealed that the minimal continuous receptor-binding region is amino acids 9 to 230, in broad agreement with other studies. Secondly,...

  17. 干酪乳杆菌DI-1发酵产胞壁蛋白酶的培养基优化%Optimization of Culture Medium for the Production of Cell Envelope Proteinase by Lactobacillus Casei DI-1

    Institute of Scientific and Technical Information of China (English)

    吴振; 潘道东

    2013-01-01

    采用Plackett-Burman和Box-Behnken方案,对影响干酪乳杆菌DI-1产胞壁蛋白酶(CEP)的MRS培养基成分进行筛选,结果表明,当在MRS培养基中添加磷酸氢二钾2.78 g/L,柠檬酸二铵2.92 g/L和乙酸钠4.36g/L时,CEP活性显著提高,此时酶活性为11.36U/mL,比基本MRS培养基提高了63.68%.在氨基酸和鸭肉水解肽添加试验中,当基础培养基中分别添加0.1 g/L的精氨酸、甘氨酸、异亮氨酸、丝氨酸、丙氨酸和谷氨酰胺时,CEP的活性从6.94 U/mL提高到11.11 U/mL;当添加木瓜风味复合蛋白酶水解鸭肉蛋白多肽时,CEP活力提高到13.89 U/mL.%In the present study, Plackett-Burman and Box-Behnken design were adopted to analyze the basal MRS medium components that significantly influenced the CEP production. K2HPO4, diamine hydrogen citrate and CH3C00Na were screened as the three main factors for effection the production of cell envelope proteinase (CEP) of Lactobacillus ca-sei DI-1. The optimized concentrations of K2HPO4, diamine hydrogen citrate and CH3CO0Na in the media were 2.78, 2.92 and 4.36 g/L, respectively. The maximum activity of CEP in the media was 11.36 U/mL, which was 63.68% higher than that of basal MRS medium. Furthermore, the CEP activity increased from 6.94 to 11.11 U/mL when adding 0.10 g/L of L-arginine, glycine, L-isoleucine, L-serine, L-alanine and L-glutamine to the MRS medium respectively, and the CEP activity increased from 6.94 to 13.89 U/mL when adding peptides from the duck protein hydrolysate produced by papaya-flavour compund enzyme.

  18. Multiscale Analysis of RMS Envelope Dynamics

    CERN Document Server

    Fedorova, A N; Fedorova, Antonina N.; Zeitlin, Michael G.

    2000-01-01

    We present applications of variational -- wavelet approach to different forms of nonlinear (rational) rms envelope equations. We have the representation for beam bunch oscillations as a multiresolution (multiscales) expansion in the base of compactly supported wavelet bases.

  19. Local Analysis of Nonlinear RMS Envelope Dynamics

    CERN Document Server

    Fedorova, A N; Fedorova, Antonina N.; Zeitlin, Michael G.

    2000-01-01

    We present applications of variational -- wavelet approach to nonlinear (rational) rms envelope dynamics. We have the solution as a multiresolution (multiscales) expansion in the base of compactly supported wavelet basis.

  20. Diffusive heat blanketing envelopes of neutron stars

    CERN Document Server

    Beznogov, M V; Yakovlev, D G

    2016-01-01

    We construct new models of outer heat blanketing envelopes of neutron stars composed of binary ion mixtures (H - He, He - C, C - Fe) in and out of diffusive equilibrium. To this aim, we generalize our previous work on diffusion of ions in isothermal gaseous or Coulomb liquid plasmas to handle non-isothermal systems. We calculate the relations between the effective surface temperature Ts and the temperature Tb at the bottom of heat blanketing envelopes (at a density rhob= 1e8 -- 1e10 g/cc) for diffusively equilibrated and non-equilibrated distributions of ion species at different masses DeltaM of lighter ions in the envelope. Our principal result is that the Ts - Tb relations are fairly insensitive to detailed distribution of ion fractions over the envelope (diffusively equilibrated or not) and depend almost solely on DeltaM. The obtained relations are approximated by analytic expressions which are convenient for modeling the evolution of neutron stars.

  1. Enveloping Relief Surfaces of Landslide Terrain

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    Two relief surfaces that envelop the rock fall region in a part of Garhwal Himalayas around Chamoli have been identified. Relative relief and absolute relief have been analyzed and the enveloping surfaces recorded at two levels of relief in the landscape. All landslide activity lies within these surfaces. The lower enveloping surface (800 m) dips due south by 7-8 degrees, due to an elevation rise of 100 meters within 12 km from south to north, i.e., a gradient of 8 percent. The nature of the surface is smooth. The upper enveloping surface (> 2500 m) is almost parallel to the lower one but its surface is undulatory due to landslides and denudation. The area has been a seismically active region and has undergone seismic activity up until recently, as evidenced by the Chamoli earthquake of 29th March 1999. The effects of earthquakes are seen at higher levels in the form of landslide imprints on the terrain.

  2. Solar envelope concepts: moderate density building applications

    Science.gov (United States)

    Knowles, R. L.; Berry, R. D.

    1980-04-01

    The public policy mechanism for guaranteeing solar access is conceptualized as a solar zoning envelope that allows the largest possible building bulk on a land parcel without shadowing neighboring properties during specified times. Step-by-step methods for generating solar envelopes are described with extensive drawings, showing a variety of urban platting and lot configurations. Development and design possibilities are examined on a selected set of Los Angeles sites with typically diverse urban characteristics. Envelope attributes suitable for encouraging moderate-density commercial and residential building are examined in the context of two hypothetical but realistic development programs: one for speculative office buildings and one for condominium housing. Numerous illustrations of envelope forms and prototypical building designs are provided.

  3. Survival of an Enveloped Virus on Toys.

    Science.gov (United States)

    Bearden, Richard L; Casanova, Lisa M

    2016-08-01

    Children's toys may carry respiratory viruses. Inactivation of a lipid-enveloped bacteriophage, Φ6, was measured on a nonporous toy at indoor temperature and relative humidity (RH). Inactivation was approximately 2log10 after 24 hours at 60% RH and 6.8log10 at 10 hours at 40% RH. Enveloped viruses can potentially survive on toys long enough to result in exposures. PMID:27144972

  4. The Envelope of Projectile Trajectories in Midair

    CERN Document Server

    Chudinov, P

    2005-01-01

    A classic problem of the motion of a point mass (projectile) thrown at an angle to the horizon is reviewed. The air drag force is taken into account with the drag factor assumed to be constant. Analytic approach is used for investigation. Simple analytical formulas are used for the constructing the envelope of the family of the point mass trajectories. The equation of envelope is applied for determination of maximum range of flight. The motion of a baseball is presented as an example.

  5. Cooling of neutron stars with diffusive envelopes

    CERN Document Server

    Beznogov, M V; Haensel, P; Yakovlev, D G; Zdunik, J L

    2016-01-01

    We study the effects of heat blanketing envelopes of neutron stars on their cooling. To this aim, we perform cooling simulations using newly constructed models of the envelopes composed of binary ion mixtures (H--He, He--C, C--Fe) varying the mass of lighter ions (H, He or C) in the envelope. The results are compared with those calculated using the standard models of the envelopes which contain the layers of lighter (accreted) elements (H, He and C) on top of the Fe layer, varying the mass of accreted elements. The main effect is that the chemical composition of the envelopes influences their thermal conductivity and, hence, thermal insulation of the star. For illustration, we apply these results to estimate the internal temperature of the Vela pulsar and to study the cooling of neutron stars of ages of 0.1 - 1 Myr at the photon cooling stage. The uncertainties of the cooling models associated with our poor knowledge of chemical composition of the heat insulating envelopes strongly complicate theoretical reco...

  6. Genetic Diversity of Koala Retroviral Envelopes

    Directory of Open Access Journals (Sweden)

    Wenqin Xu

    2015-03-01

    Full Text Available Genetic diversity, attributable to the low fidelity of reverse transcription, recombination and mutation, is an important feature of infectious retroviruses. Under selective pressure, such as that imposed by superinfection interference, gammaretroviruses commonly adapt their envelope proteins to use alternative receptors to overcome this entry block. The first characterized koala retroviruses KoRV subgroup A (KoRV-A were remarkable in their absence of envelope genetic variability. Once it was determined that KoRV-A was present in all koalas in US zoos, regardless of their disease status, we sought to isolate a KoRV variant whose presence correlated with neoplastic malignancies. More than a decade after the identification of KoRV-A, we isolated a second subgroup of KoRV, KoRV-B from koalas with lymphomas. The envelope proteins of KoRV-A and KoRV-B are sufficiently divergent to confer the ability to bind and employ distinct receptors for infection. We have now obtained a number of additional KoRV envelope variants. In the present studies we report these variants, and show that they differ from KoRV-A and KoRV-B envelopes in their host range and superinfection interference properties. Thus, there appears to be considerable variation among KoRVs envelope genes suggesting genetic diversity is a factor following the KoRV-A infection process.

  7. Genetic diversity of koala retroviral envelopes.

    Science.gov (United States)

    Xu, Wenqin; Gorman, Kristen; Santiago, Jan Clement; Kluska, Kristen; Eiden, Maribeth V

    2015-03-01

    Genetic diversity, attributable to the low fidelity of reverse transcription, recombination and mutation, is an important feature of infectious retroviruses. Under selective pressure, such as that imposed by superinfection interference, gammaretroviruses commonly adapt their envelope proteins to use alternative receptors to overcome this entry block. The first characterized koala retroviruses KoRV subgroup A (KoRV-A) were remarkable in their absence of envelope genetic variability. Once it was determined that KoRV-A was present in all koalas in US zoos, regardless of their disease status, we sought to isolate a KoRV variant whose presence correlated with neoplastic malignancies. More than a decade after the identification of KoRV-A, we isolated a second subgroup of KoRV, KoRV-B from koalas with lymphomas. The envelope proteins of KoRV-A and KoRV-B are sufficiently divergent to confer the ability to bind and employ distinct receptors for infection. We have now obtained a number of additional KoRV envelope variants. In the present studies we report these variants, and show that they differ from KoRV-A and KoRV-B envelopes in their host range and superinfection interference properties. Thus, there appears to be considerable variation among KoRVs envelope genes suggesting genetic diversity is a factor following the KoRV-A infection process.

  8. All the Universe in an envelope

    CERN Multimedia

    2007-01-01

    Do you know which force is hidden in an envelope or how many billions of years old are the atoms it contains? You will find the answers to these (curious) questions in a post office in the Pays de Gex. The French postal services of the Pays de Gex are again issuing pre-paid envelopes in collaboration with CERN (see Bulletin No. 24/2006). The new series presents some of the concepts of modern physics in an amazing way by showing what you can learn about the Universe with a single envelope. Packets of ten pre-stamped envelopes, each carrying a statement on fundamental physics, will be on sale from 7 July onwards. To learn more about the physics issues presented on the envelopes, people are invited to go to the CERN Web site where they will find the explanations. Five thousand envelopes will be put on sale in July and five thousand more during the French "Fête de la science" in October. They will be available from five post offices in the Pays de Gex (F...

  9. Pushing the Envelope: Dengue Viral Membrane Coaxed into Shape by Molecular Simulations.

    Science.gov (United States)

    Marzinek, Jan K; Holdbrook, Daniel A; Huber, Roland G; Verma, Chandra; Bond, Peter J

    2016-08-01

    Dengue virus is a flavivirus responsible for millions of infections per year. Its surface contains a phospholipid bilayer, within which are embedded the envelope (E) and membrane (M) proteins, arranged with icosahedral geometry. Exposure to low pH triggers the E proteins to undergo conformational changes, which precede fusion with the host cell membrane and release of the viral genome. The flavivirus membrane exhibits significant local curvature and deformation, as revealed by cryoelectron microscopy (cryo-EM), but its precise structure and interactions with envelope components remain unclear. We now report simulations of the dengue viral particle that refine its envelope structure in unprecedented detail. Our final models are morphologically consistent with cryo-EM data, and reveal the structural basis for membrane curvature. Electrostatic interactions increased envelope complex stability; this coupling has potential functional significance in the context of the viral fusion mechanism and infective states. PMID:27396828

  10. Morphologically complex protostellar envelopes : structure and kinematics

    Science.gov (United States)

    Tobin, John J.

    I present an in-depth study of protostars and their surrounding envelopes of dense gas and dust, using a multitude of observational methods to reveal new details of the star formation process. I use mid-infrared imaging from the Spitzer Space Telescope, combined with photometry spanning the near-infrared to millimeter wavelengths, to construct a model of the L1527 protostellar system. I modeled both the spectral energy distribution and resolved scattered light images to determine physical properties of the protostellar system. The nature of the apparent central point source in the Spitzer images was uncertain until high-resolution L-band imaging from the Gemini observatory resolved the point source into a disk in scattered light, having a radius of 200 AU. Protostellar envelopes are also often found to cast shadows against the 8 micron Galactic background in Spitzer imaging, enabling direct probes of envelope structure. The shadow images show that the dense envelopes around twenty-two Class 0 protostars are generally morphologically complex from 0.1 pc scales down to ˜1000 AU; they are often filamentary, and frequently non-axisymmetric. The observed envelope structure indicates a likely origin in turbulent cloud structure rather than a quasi-static/equilibrium formation. The complex envelope structure also may indicate an increased likelihood of fragmentation during collapse, forming close binaries. To further characterize these envelopes, I have observed them in the dense molecular gas tracers nthp and nht, both of which closely follow the 8 micron extinction morphology. The magnitude of the velocity gradients and envelope complexity on ˜10000 AU scales indicates that the velocity structure may reflect large-scale infall in addition to the often assumed rotation. Comparisons with three-dimensional filamentary and symmetric rotating collapse models reinforce the interpretation of velocities reflecting large-scale infall, showing that the structure of the envelope

  11. Immunological responses to envelope glycoprotein 120 from subtypes of human immunodeficiency virus type 1.

    Science.gov (United States)

    Gilljam, G; Svensson, A; Ekström, A; Wahren, B

    1999-07-01

    The outer envelope glycoprotein (gp120) from subtypes A-E of HIV-1 was purified using a specific high mannose-binding lectin, Galanthus nivalis agglutinin. All isolates were grown in peripheral blood lymphocyte cells in order to avoid selection in cell lines. A comparison of the reactivities of the envelope proteins was made using sera from patients infected with the different subtypes. In this study, the B and C subtype envelope glycoproteins showed the strongest immunological reactivity, when reacted with sera from patients infected with the same subtype of virus. On the other hand, sera of patients infected with subtype A or C virus had the strongest and broadest reactivities, to envelope glycoproteins of many subtypes. The purified gp120 proteins from all five subtypes stimulated mononuclear cells from HIV-1 (subtype B)-infected patients, indicating conserved T cell-activating epitopes. The immunological reactivities indicate that strong antigenicity does not always predict the broadest immunogenicity of an envelope glycoprotein. Glycoprotein 120 from foreign subtypes may serve to induce strong cross-reactive immune responses.

  12. Inhibition of enveloped viruses infectivity by curcumin.

    Directory of Open Access Journals (Sweden)

    Tzu-Yen Chen

    Full Text Available Curcumin, a natural compound and ingredient in curry, has antiinflammatory, antioxidant, and anticarcinogenic properties. Previously, we reported that curcumin abrogated influenza virus infectivity by inhibiting hemagglutination (HA activity. This study demonstrates a novel mechanism by which curcumin inhibits the infectivity of enveloped viruses. In all analyzed enveloped viruses, including the influenza virus, curcumin inhibited plaque formation. In contrast, the nonenveloped enterovirus 71 remained unaffected by curcumin treatment. We evaluated the effects of curcumin on the membrane structure using fluorescent dye (sulforhodamine B; SRB-containing liposomes that mimic the viral envelope. Curcumin treatment induced the leakage of SRB from these liposomes and the addition of the influenza virus reduced the leakage, indicating that curcumin disrupts the integrity of the membranes of viral envelopes and of liposomes. When testing liposomes of various diameters, we detected higher levels of SRB leakage from the smaller-sized liposomes than from the larger liposomes. Interestingly, the curcumin concentration required to reduce plaque formation was lower for the influenza virus (approximately 100 nm in diameter than for the pseudorabies virus (approximately 180 nm and the vaccinia virus (roughly 335 × 200 × 200 nm. These data provide insights on the molecular antiviral mechanisms of curcumin and its potential use as an antiviral agent for enveloped viruses.

  13. Purification and Enzymatic Characterization of Cell-envelope Proteinase from Lactobacillus Acidophilus%嗜酸乳杆菌细胞壁蛋白酶的分离纯化及酶学性质的研究

    Institute of Scientific and Technical Information of China (English)

    潘道东; 李敏

    2012-01-01

    Cell-envelope Proteinase (CEP) purification methods were optimized, using PEG-20000 concentre the crude enzyme solution, and filter the enzyme solution using ultrafiltration tube. Collection the dcpositon in the ammonium sulfate fractionation between 40% to 60%, and purification on Sephacryl-S-300 HR chromatogram, obtained pure enzyme by recovery from Native-PAGE gel. The molecular weight and activity of CEP were 28.3 ku and 62.066 U/mg, respectively. Optimum temperature and pH of CEP are 32 ℃ and 6.5, respectively. Heat resistance of CEP is strong, acid resistance is better than alkali resistance. The CEP can be activated by Co2+, Mg2+, Ca2+; Ba2+, Mn2+, K+, Na+ has little effect on the activity of CEP; Zn2+, Ni2+ showed a strong CEP activity inhibition; EDTA inhibited the CEP activity, indicating that CHIP is a metal ion activation peptidase; PMSF showed significant inhibition of CEP, indicating that the CEP is a serine protease. Whey protein hydrolyzed with CEP of Lactobacillus acidophilus showed ACE inhibition, ACE inhibition rate was 56.31%, indicating that CEP of LactobaciUus acidophilus can hydrolyzc whey protein and produce ACE inhibitory peptides.%为优化CEP的分离纯化方法,采用聚乙二醇(PEG)-20000浓缩粗酶液,用超滤离心管过滤酶液,40%~60%硫酸铵盐析分级沉淀,Sephacryl-S-300 HR纯化,并通过Native-PAGE切胶回收得到纯酶.所得CEP的分子质量为28.3 ku,比酶活力62.066 U/mg,最适温度32℃,最适pH 6.5,耐热性比较强,耐酸性明显好于耐碱性.Co2+、Mg2+、Ca2+对CEP有激活作用;Ba2+、Mn2+、K+、Na对CEP的活力影响不大;Zn2+、Ni2+则表现出较强的抑制CEP活性作用;EDTA对CEP活性有抑制作用,表明CEP是一种金属离子激活酶;PMSF对CEP有显著抑制作用,表明CEP是一种丝氨酸蛋白酶.用嗜酸乳杆菌CEP水解乳清蛋白,其酶解液对ACE的抑制率为56.31%,表明CEP水解乳清蛋白可以产生ACE抑制肽.

  14. A Point Mutation in the Binding Subunit of a Retroviral Envelope Protein Arrests Virus Entry at Hemifusion

    OpenAIRE

    Zavorotinskaya, Tatiana; Qian, Zhaohui; Franks, John; Albritton, Lorraine M.

    2004-01-01

    The transmembrane subunits of viral envelope proteins are thought to perform all of the functions required for membrane fusion during entry of enveloped viruses. However, changes in a conserved SPHQ motif near the N terminus of the receptor binding subunit of a murine leukemia virus (MLV) envelope protein block infection and induction of cell-cell fusion but not receptor binding. Here we report evidence that a histidine-to-arginine change at position 8 (H8R) in the SPHQ motif of Moloney MLV b...

  15. Investment Costs of the Building Envelope Reconstructions

    Directory of Open Access Journals (Sweden)

    Výskala Miloslav

    2014-12-01

    Full Text Available The article is aimed at the design of the measurements improving the thermal-technical properties of the building envelope from the point of view of the economic evaluation. The starting point for the evaluation of economic aspects is the quantification of the partial and total costs according to the individual constructions of the building envelope in relation to the earlier requirements. The result is the determination of the minimal thickness of the thermal insulation i.e. the determination of the corresponding properties of the building envelope. Described procedure represents the first step for the consecutive modelling of the potential investment options while comply with the optimal level according to Directive 2010/31/ES (EPBD II.

  16. Simulating the Onset of Grazing Envelope Evolution

    CERN Document Server

    Shiber, Sagiv; Soker, Noam

    2016-01-01

    We present the first three-dimensional gas-dynamical simulations of the grazing envelope evolution (GEE), with the goal of exploring the basic flow properties and the role of jets at the onset of the GEE. In the simulated runs, a secondary main-sequence star grazes the envelope of the primary asymptotic giant branch (AGB) star. The orbit is circular at the radius of the AGB primary star on its equator. We inject two opposite jets perpendicular to the equatorial plane from the location of the secondary star, and follow the evolution for several orbital periods. We explore the flow pattern by which the jets eject the outskirts of the AGB envelope. After one orbit the jets start to interact with gas ejected in previous orbits and inflate hot low-density bubbles.

  17. Convection in stellar envelopes a changing paradigm

    CERN Document Server

    Spruit, H C

    1996-01-01

    Progress in the theory of stellar convection over the past decade is reviewed. The similarities and differences between convection in stellar envelopes and laboratory convection at high Rayleigh numbers are discussed. Direct numerical simulation of the solar surface layers, with no other input than atomic physics, the equations of hydrodynamics and radiative transfer is now capable of reproducing the observed heat flux, convection velocities, granulation patterns and line profiles with remarkably accuracy. These results show that convection in stellar envelopes is an essentially non-local process, being driven by cooling at the surface. This differs distinctly from the traditional view of stellar convection in terms of local concepts such as cascades of eddies in a mean superadiabatic gradient. The consequences this has for our physical picture of processes in the convective envelope are illustrated with the problems of sunspot heat flux blocking, the eruption of magnetic flux from the base of the convection ...

  18. Envelope Solitons in Acoustically Dispersive Vitreous Silica

    Science.gov (United States)

    Cantrell, John H.; Yost, William T.

    2012-01-01

    Acoustic radiation-induced static strains, displacements, and stresses are manifested as rectified or dc waveforms linked to the energy density of an acoustic wave or vibrational mode via the mode nonlinearity parameter of the material. An analytical model is developed for acoustically dispersive media that predicts the evolution of the energy density of an initial waveform into a series of energy solitons that generates a corresponding series of radiation-induced static strains (envelope solitons). The evolutionary characteristics of the envelope solitons are confirmed experimentally in Suprasil W1 vitreous silica. The value (-11.9 plus or minus 1.43) for the nonlinearity parameter, determined from displacement measurements of the envelope solitons via a capacitive transducer, is in good agreement with the value (-11.6 plus or minus 1.16) obtained independently from acoustic harmonic generation measurements. The agreement provides strong, quantitative evidence for the validity of the model.

  19. Single genome amplification and standard bulk PCR yield HIV-1 envelope products with similar genotypic and phenotypic characteristics.

    Science.gov (United States)

    Etemad, Behzad; Ghulam-Smith, Melissa; Gonzalez, Oscar; White, Laura F; Sagar, Manish

    2015-03-01

    Recent studies suggest that single genome amplification (SGA) as compared to standard bulk PCR and virus stocks from 293T transfection versus short term passage in peripheral blood mononuclear cells (PBMC) yield a less biased representation of HIV-1 envelope characteristics. In 9 different subjects, genetic diversity, divergence, and population structure were not significantly different among SGA or bulk PCR amplified envelope V1-V3 segments. In these subjects, 293T transfection derived virus stocks with SGA or bulk PCR amplified envelopes have similar infectivity, replication kinetics, co-receptor usage, and neutralization susceptibility. While PBMC passage as compared to the 293T derived virus stocks had similar co-receptor usage, PBMC viruses were less neutralization susceptible to some specific antibodies. Our results suggest that the method of envelope sequence amplification, either SGA or bulk PCR, does not have a significant impact on the genotypic and phenotypic properties of the virus envelope quasispecies. PMID:25681527

  20. Functional incorporation of green fluorescent protein into hepatitis B virus envelope particles

    International Nuclear Information System (INIS)

    The envelope of hepatitis B virus (HBV), containing the L, M, and S proteins, is essential for virus entry and maturation. For direct visualization of HBV, we determined whether envelope assembly could accommodate the green fluorescent protein (GFP). While the C-terminal addition of GFP to S trans-dominant negatively inhibited empty envelope particle secretion, the N-terminal GFP fusion to S (GFP.S) was co-integrated into the envelope, giving rise to fluorescent particles. Microscopy and topogenesis analyses demonstrated that the proper intracellular distribution and folding of GFP.S, required for particle export were rescued by interprotein interactions with wild-type S. Thereby, a dual location of GFP, inside and outside the envelope, was observed. GFP.S was also efficiently packaged into the viral envelope, and these GFP-tagged virions retained the capacity for attachment to HBV receptor-positive cells in vitro. Together, GFP-tagged virions should be suitable to monitor HBV uptake and egress in live hepatocytes

  1. Inversion of Auditory Spectrograms, Traditional Spectrograms, and Other Envelope Representations

    DEFF Research Database (Denmark)

    Decorsière, Remi Julien Blaise; Søndergaard, Peter Lempel; MacDonald, Ewen;

    2015-01-01

    implementations of this framework are presented for auditory spectrograms, where the filterbank is based on the behavior of the basilar membrane and envelope extraction is modeled on the response of inner hair cells. One implementation is direct while the other is a two-stage approach that is computationally...... simpler. While both can accurately invert an auditory spectrogram, the two-stage approach performs better on time-domain metrics. The same framework is applied to traditional spectrograms based on the magnitude of the short-time Fourier transform. Inspired by human perception of loudness, a modification...

  2. Envelope tracking power amplifiers for wireless communications

    CERN Document Server

    Wang, Zhancang

    2014-01-01

    Envelope tracking technology is seen as the most promising efficiency enhancement technology for RF power amplifiers for 4G and beyond wireless communications. More and more organizations are investing and researching on this topic with huge potential in academic and commercial areas.This is the first book on the market to offer complete introduction, theory, and design considerations on envelope tracking for wireless communications. This resource presents you with a full introduction to the subject and covers underlying theory and practical design considerations.

  3. Herpesvirus nuclear egress: Pseudorabies Virus can simultaneously induce nuclear envelope breakdown and exit the nucleus via the envelopment-deenvelopment-pathway.

    Science.gov (United States)

    Schulz, Katharina S; Klupp, Barbara G; Granzow, Harald; Passvogel, Lars; Mettenleiter, Thomas C

    2015-11-01

    Herpesvirus replication takes place in the nucleus and in the cytosol. After entering the cell, nucleocapsids are transported to nuclear pores where viral DNA is released into the nucleus. After gene expression and DNA replication new nucleocapsids are assembled which have to exit the nucleus for virion formation in the cytosol. Since nuclear pores are not wide enough to allow passage of the nucleocapsid, nuclear egress occurs by vesicle-mediated transport through the nuclear envelope. To this end, nucleocapsids bud at the inner nuclear membrane (INM) recruiting a primary envelope which then fuses with the outer nuclear membrane (ONM). In the absence of this regulated nuclear egress, mutants of the alphaherpesvirus pseudorabies virus have been described that escape from the nucleus after virus-induced nuclear envelope breakdown. Here we review these exit pathways and demonstrate that both can occur simultaneously under appropriate conditions. PMID:25678269

  4. Mutations altering the gammaretrovirus endoproteolytic motif affect glycosylation of the envelope glycoprotein and early events of the virus life cycle

    Energy Technology Data Exchange (ETDEWEB)

    Argaw, Takele; Wilson, Carolyn A., E-mail: carolyn.wilson@fda.hhs.gov

    2015-01-15

    Previously, we found that mutation of glutamine to proline in the endoproteolytic cleavage signal of the PERV-C envelope (RQKK to RPKK) resulted in non-infectious vectors. Here, we show that RPKK results in a non-infectious vector when placed in not only a PERV envelope, but also the envelope of a related gammaretrovirus, FeLV-B. The amino acid substitutions do not prevent envelope precursor cleavage, viral core and genome assembly, or receptor binding. Rather, the mutations result in the formation of hyperglycosylated glycoprotein and a reduction in the reverse transcribed minus strand synthesis and undetectable 2-LTR circular DNA in cells exposed to vectors with these mutated envelopes. Our findings suggest novel functions associated with the cleavage signal sequence that may affect trafficking through the glycosylation machinery of the cell. Further, the glycosylation status of the envelope appears to impact post-binding events of the viral life cycle, either membrane fusion, internalization, or reverse transcription. - Highlights: • Env cleavage signal impacts infectivity of gammaretroviruses. • Non-infectious mutants have hyper-glycosylated envelope that bind target cells. • Non-infectious mutants have defects in the formation of the double-stranded DNA. • Env cleavage motif has functions beyond cleavage of the env precursor.

  5. Tone-in-noise detection using envelope cues: comparison of signal-processing-based and physiological models.

    Science.gov (United States)

    Mao, Junwen; Carney, Laurel H

    2015-02-01

    Tone-in-noise detection tasks with reproducible noise maskers have been used to identify cues that listeners use to detect signals in noisy environments. Previous studies have shown that energy, envelope, and fine-structure cues are significantly correlated to listeners' performance for detection of a 500-Hz tone in noise. In this study, envelope cues were examined for both diotic and dichotic tone-in-noise detection using both stimulus-based signal processing and physiological models. For stimulus-based envelope cues, a modified envelope slope model was used for the diotic condition and the binaural slope of the interaural envelope difference model for the dichotic condition. Stimulus-based models do not include key nonlinear transformations in the auditory periphery such as compression, rate and dynamic range adaptation, and rate saturation, all of which affect the encoding of the stimulus envelope. For physiological envelope cues, stimuli were passed through models for the auditory nerve (AN), cochlear nucleus, and inferior colliculus (IC). The AN and cochlear nucleus models included appropriate modulation gain, another transformation of the stimulus envelope that is not typically included in stimulus-based models. A model IC cell was simulated with a linear band-pass modulation filter. The average discharge rate and response fluctuations of the model IC cell were compared to human performance. Previous studies have predicted a significant amount of the variance across reproducible noise maskers in listeners' detection using stimulus-based envelope cues. In this study, a physiological model that includes neural mechanisms that affect encoding of the stimulus envelope predicts a similar amount of the variance in listeners' performance across noise maskers. PMID:25266265

  6. Focal Targeting of the Bacterial Envelope by Antimicrobial Peptides

    Directory of Open Access Journals (Sweden)

    Rafi eRashid

    2016-06-01

    Full Text Available Antimicrobial peptides (AMPs are utilized by both eukaryotic and prokaryotic organisms. AMPs such as the human beta defensins, human neutrophil peptides, human cathelicidin, and many bacterial bacteriocins are cationic and capable of binding to anionic regions of the bacterial surface. Cationic AMPs (CAMPs target anionic lipids (e.g. phosphatidylglycerol (PG and cardiolipins (CL in the cell membrane and anionic components (e.g. lipopolysaccharide (LPS and lipoteichoic acid (LTA of the cell envelope. Bacteria have evolved mechanisms to modify these same targets in order to resist CAMP killing, e.g. lysinylation of PG to yield cationic lysyl-PG and alanylation of LTA. Since CAMPs offer a promising therapeutic alternative to conventional antibiotics, which are becoming less effective due to rapidly emerging antibiotic resistance, there is a strong need to improve our understanding about the AMP mechanism of action. Recent literature suggests that AMPs often interact with the bacterial cell envelope at discrete foci. Here we review recent AMP literature, with an emphasis on focal interactions with bacteria, including (1 CAMP disruption mechanisms, (2 delocalization of membrane proteins and lipids by CAMPs, and (3 CAMP sensing systems and resistance mechanisms. We conclude with new approaches for studying the bacterial membrane, e.g., lipidomics, high resolution imaging and non-detergent-based membrane domain extraction.

  7. Focal Targeting of the Bacterial Envelope by Antimicrobial Peptides.

    Science.gov (United States)

    Rashid, Rafi; Veleba, Mark; Kline, Kimberly A

    2016-01-01

    Antimicrobial peptides (AMPs) are utilized by both eukaryotic and prokaryotic organisms. AMPs such as the human beta defensins, human neutrophil peptides, human cathelicidin, and many bacterial bacteriocins are cationic and capable of binding to anionic regions of the bacterial surface. Cationic AMPs (CAMPs) target anionic lipids [e.g., phosphatidylglycerol (PG) and cardiolipins (CL)] in the cell membrane and anionic components [e.g., lipopolysaccharide (LPS) and lipoteichoic acid (LTA)] of the cell envelope. Bacteria have evolved mechanisms to modify these same targets in order to resist CAMP killing, e.g., lysinylation of PG to yield cationic lysyl-PG and alanylation of LTA. Since CAMPs offer a promising therapeutic alternative to conventional antibiotics, which are becoming less effective due to rapidly emerging antibiotic resistance, there is a strong need to improve our understanding about the AMP mechanism of action. Recent literature suggests that AMPs often interact with the bacterial cell envelope at discrete foci. Here we review recent AMP literature, with an emphasis on focal interactions with bacteria, including (1) CAMP disruption mechanisms, (2) delocalization of membrane proteins and lipids by CAMPs, and (3) CAMP sensing systems and resistance mechanisms. We conclude with new approaches for studying the bacterial membrane, e.g., lipidomics, high resolution imaging, and non-detergent-based membrane domain extraction. PMID:27376064

  8. Relation between nuclear envelope and nuclear lamina in nuclear assembly in vitro

    Institute of Scientific and Technical Information of China (English)

    蔡树涛; 翟中和

    1997-01-01

    Xenopus laevis egg extracts cell-free nuclear assembly system was used as an experimental model to study the process of nuclear lamina assembly in nuclear reconstitution in vitro. The experimental results showed that lamin was involved in the nuclear assembly in vitro. The assembly of nuclear lamina was preceded by the assembly of nuclear matrix, and probably, inner nuclear matrix assembly provided the basis for nuclear lamina assembly. Inhibition of normal assembly of nuclear lamina, by preincubating egg extracts cell-free system with anti-lamin antibodies, resulted in abnormal assembly of nuclear envelope, suggesting that nuclear envelope assembly is closely associated with nuclear lamina assembly.

  9. Proprotein convertase furin regulates apoptosis and proliferation of granulosa cells in the rat ovary.

    Directory of Open Access Journals (Sweden)

    Xiaokui Yang

    Full Text Available Folliculogenesis is tightly controlled by a series of hormones, growth factors and cytokines, many of which are secreted as proproteins and require processing by proteases before becoming functional. Furin is a member of the subtilisin-like proteases that activate large numbers of proprotein substrates and is ubiquitously expressed and implicated in many physiological and pathological processes. However, the precise role of furin during folliculogenesis has not been thoroughly investigated. The goal of the present work is to identify the role of furin in the development of granulosa cells during folliculogenesis, using immunohistochemistry, RT-PCR, Western blot and functional studies in primary cultured rat granulosa cells. Our results demonstrate that furin is highly expressed in granulosa cells and oocytes of the ovary with very limited expression in other ovarian cells such as the epithelial, stromal or theca cells. Furin siRNA significantly increases apoptosis of the granulosa cells from large antral/preovulatory follicles, in part via downregulation of the anti-apoptotic proteins, XIAP and p-AKT. On the contrary, furin siRNA markedly decreases proliferation of granulosa cells based on the downregulation of proliferation cell nuclear antigen (PCNA. Taken together, these data suggest that furin may play an important role in regulating apoptosis and proliferation of granulosa cells.

  10. An additional simple denitrification bioreactor using packed gel envelopes applicable to industrial wastewater treatment.

    Science.gov (United States)

    Morita, Masahiko; Uemoto, Hiroaki; Watanabe, Atsushi

    2007-08-15

    A simple denitrification bioreactor for nitrate-containing wastewater without organic compounds was developed. This bioreactor consisted of packed gel envelopes in a single tank. Each envelope comprised two plates of gels containing Paracoccus denitrificans cells with an internal space between the plates. As an electron donor for denitrification, ethanol was injected into the internal space and not directly into the wastewater. P. denitrificans cells in the gel reduced nitrate to nitrogen gas by using the injected ethanol. Nitrate-containing desulfurization wastewater derived from a coal-fired thermal power plant was continuously treated with 20 packed gel envelopes (size, 1,000 x 900 x 12 mm; surface area, 1.44 m(2)) in a reactor tank (volume 1.5 m(3)). When the total nitrogen concentration in the inflow was around 150 mg-N x L(-1), the envelopes removed approximately 60-80% of the total nitrogen, and the maximum nitrogen removal rate was 5.0 g-N x day(-1) per square meter of the gel surface. This value corresponded to the volumetric nitrogen removal performance of 0.109 kg-N x m(-3) x day(-1). In each envelope, a high utilization efficiency of the electron donor was attained, although more than the double amount of the electron donor was empirically injected in the present activated sludge system to achieve denitrification when compared with the theoretical value. The bioreactor using the envelopes would be extremely effective as an additional denitrification system because these envelopes can be easily installed in the vacant spaces of preinstalled water treatment systems, without requiring additional facilities for removing surplus ethanol and sludge. PMID:17252606

  11. Ozone Reductions Using Residential Building Envelopes

    Energy Technology Data Exchange (ETDEWEB)

    Walker, Iain S.; Sherman, Max; Nazaroff, William W.

    2009-02-01

    Ozone is an air pollutant with that can have significant health effects and a significant source of ozone in some regions of California is outdoor air. Because people spend the vast majority of their time indoors, reduction in indoor levels of ozone could lead to improved health for many California residents. Ozone is removed from indoor air by surface reactions and can also be filtered by building envelopes. The magnitude of the envelope impact depends on the specific building materials that the air flows over and the geometry of the air flow paths through the envelope that can be changes by mechanical ventilation operation. The 2008 Residential Building Standards in California include minimum requirements for mechanical ventilation by referencing ASHRAE Standard 62.2. This study examines the changes in indoor ozone depending on the mechanical ventilation system selected to meet these requirements. This study used detailed simulations of ventilation in a house to examine the impacts of different ventilation systems on indoor ozone concentrations. The simulation results showed that staying indoors reduces exposure to ozone by 80percent to 90percent, that exhaust ventilation systems lead to lower indoor ozone concentrations, that opening of windows should be avoided at times of high outdoor ozone, and that changing the time at which mechanical ventilation occurs has the ability to halve exposure to ozone. Future work should focus on the products of ozone reactions in the building envelope and the fate of these products with respect to indoor exposures.

  12. The Story of the Red Envelopes.

    Science.gov (United States)

    Lew, Gordon

    This is one of a series of elementary readers written in Cantonese and English and designed to familiarize children with the traditional major Chinese festivals celebrated by the Chinese in America. This booklet describes in narrative form the meaning of the red envelopes given with money gifts at Chinese New Year and other festivities. A page of…

  13. Multi-layered breathing architectural envelope

    DEFF Research Database (Denmark)

    Lund Larsen, Andreas; Foged, Isak Worre; Jensen, Rasmus Lund

    2014-01-01

    A multi layered breathing envelope is developed as a method of natural ventilation. The two main layers consist of mineral wool and air permeable concrete. The mineral wool works as a dynamic insulation and the permeable concrete as a heat recovery system with a high thermal mass for heat storage...

  14. Playing with the enveloping algebra of supersymmetry

    CERN Document Server

    Cattaruzza, E

    2016-01-01

    In this paper we show how to obtain from a scalar superfield its first component via a similarity transformation. We prove that in D=4 the generators of this similarity transformation live in the enveloping algebra of supersymmetry while for D=1 they belong to the basic algebra.

  15. SAFEGUARDS ENVELOPE: PREVIOUS WORK AND EXAMPLES

    Energy Technology Data Exchange (ETDEWEB)

    Richard Metcalf; Aaron Bevill; William Charlton; Robert Bean

    2008-07-01

    The future expansion of nuclear power will require not just electricity production but fuel cycle facilities such as fuel fabrication and reprocessing plants. As large reprocessing facilities are built in various states, they must be built and operated in a manner to minimize the risk of nuclear proliferation. Process monitoring has returned to the spotlight as an added measure that can increase confidence in the safeguards of special nuclear material (SNM). Process monitoring can be demonstrated to lengthen the allowable inventory period by reducing accountancy requirements, and to reduce the false positive indications. The next logical step is the creation of a Safeguards Envelope, a set of operational parameters and models to maximize anomaly detection and inventory period by process monitoring while minimizing operator impact and false positive rates. A brief example of a rudimentary Safeguards Envelope is presented, and shown to detect synthetic diversions overlaying a measured processing plant data set. This demonstration Safeguards Envelope is shown to increase the confidence that no SNM has been diverted with minimal operator impact, even though it is based on an information sparse environment. While the foundation on which a full Safeguards Envelope can be built has been presented in historical demonstrations of process monitoring, several requirements remain yet unfulfilled. Future work will require reprocessing plant transient models, inclusion of “non-traditional” operating data, and exploration of new methods of identifying subtle events in transient processes.

  16. Discriminating Dysarthria Type from Envelope Modulation Spectra

    Science.gov (United States)

    Liss, Julie M.; LeGendre, Sue; Lotto, Andrew J.

    2010-01-01

    Purpose: Previous research demonstrated the ability of temporally based rhythm metrics to distinguish among dysarthrias with different prosodic deficit profiles (J. M. Liss et al., 2009). The authors examined whether comparable results could be obtained by an automated analysis of speech envelope modulation spectra (EMS), which quantifies the…

  17. Implications of Time Bomb model of ookinete invasion of midgut cells.

    Science.gov (United States)

    Han, Yeon Soo; Barillas-Mury, Carolina

    2002-10-01

    In this review, we describe the experimental observations that led us to propose the Time Bomb model of ookinete midgut invasion and discuss potential implications of this model when considering malaria transmission-blocking strategies aimed at arresting parasite development within midgut cells. A detailed analysis of the molecular interactions between Anopheles stephensi midgut epithelial cells and Plasmodium berghei parasites, as they migrate through midgut cells, revealed that ookinetes induce nitric oxide synthase (NOS) expression, remodeling of the actin cytoskeleton and characteristic morphological changes in the invaded epithelial cells. Parasites inflict extensive damage that ultimately leads to genome fragmentation and cell death. During their migration through the cytoplasm, ookinetes release a subtilisin-like protease (PbSub2) and the surface protein (Pbs21). The model proposes that ookinetes must escape rapidly from the invaded cells, as the responses mediating cell death could be potentially lethal to the parasites. In other words, the physical and/or chemical damage triggered by the parasite can be thought of as a 'lethal bomb'. Once this cascade of events is initiated, the parasite must leave the cellular compartment within a limited time to escape unharmed from the 'bomb' it has activated. The midgut epithelium has the ability to heal rapidly by 'budding off' the damaged cells to the midgut lumen without losing its integrity. PMID:12225921

  18. Cytoskeletal Interactions at the Nuclear Envelope Mediated by Nesprins

    Directory of Open Access Journals (Sweden)

    Surayya Taranum

    2012-01-01

    Full Text Available Nesprin-1 is a giant tail-anchored nuclear envelope protein composed of an N-terminal F-actin binding domain, a long linker region formed by multiple spectrin repeats and a C-terminal transmembrane domain. Based on this structure, it connects the nucleus to the actin cytoskeleton. Earlier reports had shown that Nesprin-1 binds to nuclear envelope proteins emerin and lamin through C-terminal spectrin repeats. These repeats can also self-associate. We focus on the N-terminal Nesprin-1 sequences and show that they interact with Nesprin-3, a further member of the Nesprin family, which connects the nucleus to the intermediate filament network. We show that upon ectopic expression of Nesprin-3 in COS7 cells, which are nearly devoid of Nesprin-3 in vitro, vimentin filaments are recruited to the nucleus and provide evidence for an F-actin interaction of Nesprin-3 in vitro. We propose that Nesprins through interactions amongst themselves and amongst the various Nesprins form a network around the nucleus and connect the nucleus to several cytoskeletal networks of the cell.

  19. The universal enveloping TRO of a JB*-triple system

    CERN Document Server

    Bohle, Dennis

    2010-01-01

    We associate to every JB*-triple system a so-called universal enveloping TRO and show some functorial properties of this correspondence. We compute the universal enveloping TROs of the finite dimensional Cartan factors.

  20. Novel Real-Time Flight Envelope Monitoring System Project

    Data.gov (United States)

    National Aeronautics and Space Administration — The proposed innovation is an aircraft flight envelope monitoring system that will provide real-time in-cockpit estimations of aircraft flight envelope boundaries....

  1. Novel Real-Time Flight Envelope Monitoring System Project

    Data.gov (United States)

    National Aeronautics and Space Administration — The proposed innovation is an aircraft flight envelope monitoring system that will provide real-time in-cockpit estimations of aircraft flight envelope boundaries,...

  2. African Swine Fever Virus Undergoes Outer Envelope Disruption, Capsid Disassembly and Inner Envelope Fusion before Core Release from Multivesicular Endosomes.

    Directory of Open Access Journals (Sweden)

    Bruno Hernáez

    2016-04-01

    Full Text Available African swine fever virus (ASFV is a nucleocytoplasmic large DNA virus (NCLDV that causes a highly lethal disease in domestic pigs. As other NCLDVs, the extracellular form of ASFV possesses a multilayered structure consisting of a genome-containing nucleoid successively wrapped by a thick protein core shell, an inner lipid membrane, an icosahedral protein capsid and an outer lipid envelope. This structural complexity suggests an intricate mechanism of internalization in order to deliver the virus genome into the cytoplasm. By using flow cytometry in combination with pharmacological entry inhibitors, as well as fluorescence and electron microscopy approaches, we have dissected the entry and uncoating pathway used by ASFV to infect the macrophage, its natural host cell. We found that purified extracellular ASFV is internalized by both constitutive macropinocytosis and clathrin-mediated endocytosis. Once inside the cell, ASFV particles move from early endosomes or macropinosomes to late, multivesicular endosomes where they become uncoated. Virus uncoating requires acidic pH and involves the disruption of the outer membrane as well as of the protein capsid. As a consequence, the inner viral membrane becomes exposed and fuses with the limiting endosomal membrane to release the viral core into the cytosol. Interestingly, virus fusion is dependent on virus protein pE248R, a transmembrane polypeptide of the inner envelope that shares sequence similarity with some members of the poxviral entry/fusion complex. Collective evidence supports an entry model for ASFV that might also explain the uncoating of other multienveloped icosahedral NCLDVs.

  3. African Swine Fever Virus Undergoes Outer Envelope Disruption, Capsid Disassembly and Inner Envelope Fusion before Core Release from Multivesicular Endosomes.

    Science.gov (United States)

    Hernáez, Bruno; Guerra, Milagros; Salas, María L; Andrés, Germán

    2016-04-01

    African swine fever virus (ASFV) is a nucleocytoplasmic large DNA virus (NCLDV) that causes a highly lethal disease in domestic pigs. As other NCLDVs, the extracellular form of ASFV possesses a multilayered structure consisting of a genome-containing nucleoid successively wrapped by a thick protein core shell, an inner lipid membrane, an icosahedral protein capsid and an outer lipid envelope. This structural complexity suggests an intricate mechanism of internalization in order to deliver the virus genome into the cytoplasm. By using flow cytometry in combination with pharmacological entry inhibitors, as well as fluorescence and electron microscopy approaches, we have dissected the entry and uncoating pathway used by ASFV to infect the macrophage, its natural host cell. We found that purified extracellular ASFV is internalized by both constitutive macropinocytosis and clathrin-mediated endocytosis. Once inside the cell, ASFV particles move from early endosomes or macropinosomes to late, multivesicular endosomes where they become uncoated. Virus uncoating requires acidic pH and involves the disruption of the outer membrane as well as of the protein capsid. As a consequence, the inner viral membrane becomes exposed and fuses with the limiting endosomal membrane to release the viral core into the cytosol. Interestingly, virus fusion is dependent on virus protein pE248R, a transmembrane polypeptide of the inner envelope that shares sequence similarity with some members of the poxviral entry/fusion complex. Collective evidence supports an entry model for ASFV that might also explain the uncoating of other multienveloped icosahedral NCLDVs. PMID:27110717

  4. y Human herpesvirus 6 envelope components enriched in lipid rafts: evidence for virion-associated lipid rafts

    Directory of Open Access Journals (Sweden)

    Yamanishi Koichi

    2009-08-01

    Full Text Available Abstract In general, enveloped viruses are highly dependent on their lipid envelope for entry into host cells. Here, we demonstrated that during the course of virus maturation, a significant proportion of human herpesvirus 6 (HHV-6 envelope proteins were selectively concentrated in the detergent-resistant glycosphingolipid- and cholesterol-rich membranes (rafts in HHV-6-infected cells. In addition, the ganglioside GM1, which is known to partition preferentially into lipid rafts, was detected in purified virions, along with viral envelope glycoproteins, gH, gL, gB, gQ1, gQ2 and gO indicating that at least one raft component was included in the viral particle during the assembly process.

  5. Analysis of Building Envelope Construction in 2003 CBECS

    Energy Technology Data Exchange (ETDEWEB)

    Winiarski, David W.; Halverson, Mark A.; Jiang, Wei

    2007-06-01

    The purpose of this analysis is to determine "typical" building envelope characteristics for buildings built after 1980. We address three envelope components in this paper - roofs, walls, and window area. These typical building envelope characteristics were used in the development of DOE’s Reference Buildings .

  6. Do projections from bioclimatic envelope models and climate change metrics match?

    DEFF Research Database (Denmark)

    Garcia, Raquel A.; Cabeza, Mar; Altwegg, Res;

    2016-01-01

    for sub-Saharan Africa with ensembles of bioclimatic envelope models for 2723 species of amphibians, snakes, mammals and birds. For each taxonomic group, we performed three comparisons between the two approaches: (1) is projected change in local climatic suitability (models) greater in grid cells...

  7. Cost Allocation and Convex Data Envelopment

    DEFF Research Database (Denmark)

    Hougaard, Jens Leth; Tind, Jørgen

    This paper considers allocation rules. First, we demonstrate that costs allocated by the Aumann-Shapley and the Friedman-Moulin cost allocation rules are easy to determine in practice using convex envelopment of registered cost data and parametric programming. Second, from the linear programming...... such as Data Envelopment Analysis (DEA). The convexity constraint of the BCC model introduces a non-zero slack in the objective function of the multiplier problem and we show that the cost allocation rules discussed in this paper can be used as candidates to allocate this slack value on to the input (or output...... problems involved it becomes clear that the allocation rules, technically speaking, allocate the non-zero value of the dual variable for a convexity constraint on to the output vector. Hence, the allocation rules can also be used to allocate inefficiencies in non-parametric efficiency measurement models...

  8. Development of High Specific Strength Envelope Materials

    Science.gov (United States)

    Komatsu, Keiji; Sano, Masa-Aki; Kakuta, Yoshiaki

    Progress in materials technology has produced a much more durable synthetic fabric envelope for the non-rigid airship. Flexible materials are required to form airship envelopes, ballonets, load curtains, gas bags and covering rigid structures. Polybenzoxazole fiber (Zylon) and polyalirate fiber (Vectran) show high specific tensile strength, so that we developed membrane using these high specific tensile strength fibers as a load carrier. The main material developed is a Zylon or Vectran load carrier sealed internally with a polyurethane bonded inner gas retention film (EVOH). The external surface provides weather protecting with, for instance, a titanium oxide integrated polyurethane or Tedlar film. The mechanical test results show that tensile strength 1,000 N/cm is attained with weight less than 230g/m2. In addition to the mechanical properties, temperature dependence of the joint strength and solar absorptivity and emissivity of the surface are measured. 

  9. Envelope Soliton in Solar Radio Emission

    Institute of Scientific and Technical Information of China (English)

    WANG De-Yu; Wangde; G. P. Chernov

    2000-01-01

    Several envelope soliton fine structures have been observed in solar radio metric-wave emission. We present amodel of 1ongitudinal modulational instability to explain these fine structures. It is found that this instability canonly occur in the condition of sound velocity being larger than Alfven velocity in corona. Therefore, the envelopesoliton fine structures should display in the coronal region with high temperature and low magnetic field, whichcorresponds to the solar radio emission in the region of meter and decameter wavelength.

  10. Transparent Helium in Stripped Envelope Supernovae

    OpenAIRE

    Piro, Anthony L.; Morozova, Viktoriya S.

    2014-01-01

    Using simple arguments based on photometric light curves and velocity evolution, we propose that some stripped envelope supernovae (SNe) show signs that a significant fraction of their helium is effectively transparent. The main pieces of evidence are the relatively low velocities with little velocity evolution, as are expected deep inside an exploding star, along with temperatures that are too low to ionize helium. This means that the helium should not contribute to the shaping of the main S...

  11. Digital image envelope: method and evaluation

    Science.gov (United States)

    Huang, H. K.; Cao, Fei; Zhou, Michael Z.; Mogel, Greg T.; Liu, Brent J.; Zhou, Xiaoqiang

    2003-05-01

    Health data security, characterized in terms of data privacy, authenticity, and integrity, is a vital issue when digital images and other patient information are transmitted through public networks in telehealth applications such as teleradiology. Mandates for ensuring health data security have been extensively discussed (for example The Health Insurance Portability and Accountability Act, HIPAA) and health informatics guidelines (such as the DICOM standard) are beginning to focus on issues of data continue to be published by organizing bodies in healthcare; however, there has not been a systematic method developed to ensure data security in medical imaging Because data privacy and authenticity are often managed primarily with firewall and password protection, we have focused our research and development on data integrity. We have developed a systematic method of ensuring medical image data integrity across public networks using the concept of the digital envelope. When a medical image is generated regardless of the modality, three processes are performed: the image signature is obtained, the DICOM image header is encrypted, and a digital envelope is formed by combining the signature and the encrypted header. The envelope is encrypted and embedded in the original image. This assures the security of both the image and the patient ID. The embedded image is encrypted again and transmitted across the network. The reverse process is performed at the receiving site. The result is two digital signatures, one from the original image before transmission, and second from the image after transmission. If the signatures are identical, there has been no alteration of the image. This paper concentrates in the method and evaluation of the digital image envelope.

  12. Properties of mammalian nuclear-envelope nucleoside triphosphatase.

    Science.gov (United States)

    Agutter, P S; Cockrill, J B; Lavine, J E; McCaldin, B; Sim, R B

    1979-09-01

    The nucleoside triphosphatase activities of the nuclear envelopes from rat liver, pig liver and simian-virus-40-transformed mouse-embryo 3T3 cells were shown to exhibit similar parperties. All three preparations hydrolyse ATP, 2'-dATP, 3'-dATP, GTP, CTP and UTP in the presence of Mg2+, Ca2+, Mn2+ and Co2+ with a pH optimum of 8.0, are sensitive to inhibition by mercurials, arsenicals, quercetin, proflavin and adenosine 5'-[gamma-thio]triphosphate and are partially inactivated by exposure to high ionic strength. The kinetic behaviour is similar for all substrates irrespective of the source of material. The typical Eadie-Hofstee plot, which is concave upwards at pH 8.0 when the ionic strength is 20mM, becomes linear when the pH is increased to 8.5 or the ionic strength to 160mM. The overall evidence, particularly the labelling of only one polypeptide by [gamma-32P]ATP, suggests that under the conditions of preparation and assay used only one class of nucleoside triphosphatase active sites is detectable in nuclear envelopes. The importance of these results for an understanding of the role of the enzyme in vivo is discussed.

  13. Antiviral Activity of Graphene–Silver Nanocomposites against Non-Enveloped and Enveloped Viruses

    Directory of Open Access Journals (Sweden)

    Yi-Ning Chen

    2016-04-01

    Full Text Available The discovery of novel antiviral materials is important because many infectious diseases are caused by viruses. Silver nanoparticles have demonstrated strong antiviral activity, and graphene is a potential antimicrobial material due to its large surface area, high carrier mobility, and biocompatibility. No studies on the antiviral activity of nanomaterials on non-enveloped viruses have been reported. To investigate the antiviral activity of graphene oxide (GO sheets and GO sheets with silver particles (GO-Ag against enveloped and non-enveloped viruses, feline coronavirus (FCoV with an envelope and infectious bursal disease virus (IBDV without an envelope were chosen. The morphology and sizes of GO and GO-Ag were characterized by transmission, scanning electron microscopy, and X-ray diffraction. A virus inhibition assay was used to identify the antiviral activity of GO and GO-Ag. Go-Ag inhibited 25% of infection by FCoV and 23% by IBDV, whereas GO only inhibited 16% of infection by FCoV but showed no antiviral activity against the infection by IBDV. Further application of GO and GO-Ag can be considered for personal protection equipment to decrease the transmission of viruses.

  14. Molecular interactions between Anopheles stephensi midgut cells and Plasmodium berghei: the time bomb theory of ookinete invasion of mosquitoes.

    Science.gov (United States)

    Han, Y S; Thompson, J; Kafatos, F C; Barillas-Mury, C

    2000-11-15

    We present a detailed analysis of the interactions between Anopheles stephensi midgut epithelial cells and Plasmodium berghei ookinetes during invasion of the mosquito by the parasite. In this mosquito, P. berghei ookinetes invade polarized columnar epithelial cells with microvilli, which do not express high levels of vesicular ATPase. The invaded cells are damaged, protrude towards the midgut lumen and suffer other characteristic changes, including induction of nitric oxide synthase (NOS) expression, a substantial loss of microvilli and genomic DNA fragmentation. Our results indicate that the parasite inflicts extensive damage leading to subsequent death of the invaded cell. Ookinetes were found to be remarkably plastic, to secrete a subtilisin-like serine protease and the GPI-anchored surface protein Pbs21 into the cytoplasm of invaded cells, and to be capable of extensive lateral movement between cells. The epithelial damage inflicted is repaired efficiently by an actin purse-string-mediated restitution mechanism, which allows the epithelium to 'bud off' the damaged cells without losing its integrity. A new model, the time bomb theory of ookinete invasion, is proposed and its implications are discussed. PMID:11080150

  15. Polymers in cell encapsulation from an enveloped cell perspective

    NARCIS (Netherlands)

    de Vos, Paul; Lazarjani, Hamideh Aghajani; Poncelet, Denis; Faas, Marijke M.

    2014-01-01

    In the past two decades, many polymers have been proposed for producing immunoprotective capsules. Examples include the natural polymers alginate, agarose, chitosan, cellulose, collagen, and xanthan and synthetic polymers poly(ethylene glycol), polyvinyl alcohol, polyurethane, poly(ether-sulfone), p

  16. Identification of the Receptor Binding Domain of the Mouse Mammary Tumor Virus Envelope Protein

    OpenAIRE

    Zhang, Yuanming; Rassa, John C.; deObaldia, Maria Elena; Albritton, Lorraine M.; Susan R Ross

    2003-01-01

    Mouse mammary tumor virus (MMTV) is a betaretrovirus that infects rodent cells and uses mouse transferrin receptor 1 for cell entry. To characterize the interaction of MMTV with its receptor, we aligned the MMTV envelope surface (SU) protein with that of Friend murine leukemia virus (F-MLV) and identified a putative receptor-binding domain (RBD) that included a receptor binding sequence (RBS) of five amino acids and a heparin-binding domain (HBD). Mutation of the HBD reduced virus infectivity...

  17. Hepatitis C Virus E2 Envelope Glycoprotein Core Structure

    Energy Technology Data Exchange (ETDEWEB)

    Kong, Leopold; Giang, Erick; Nieusma, Travis; Kadam, Rameshwar U.; Cogburn, Kristin E.; Hua, Yuanzi; Dai, Xiaoping; Stanfield, Robyn L.; Burton, Dennis R.; Ward, Andrew B.; Wilson, Ian A.; Law, Mansun

    2014-08-26

    Hepatitis C virus (HCV), a Hepacivirus, is a major cause of viral hepatitis, liver cirrhosis, and hepatocellular carcinoma. HCV envelope glycoproteins E1 and E2 mediate fusion and entry into host cells and are the primary targets of the humoral immune response. The crystal structure of the E2 core bound to broadly neutralizing antibody AR3C at 2.65 angstroms reveals a compact architecture composed of a central immunoglobulin-fold β sandwich flanked by two additional protein layers. The CD81 receptor binding site was identified by electron microscopy and site-directed mutagenesis and overlaps with the AR3C epitope. The x-ray and electron microscopy E2 structures differ markedly from predictions of an extended, three-domain, class II fusion protein fold and therefore provide valuable information for HCV drug and vaccine design.

  18. Detection and modeling of rough component envelopes

    Science.gov (United States)

    Peacock, Matthew; Dluzniak, Richard; Thompson, William

    1995-08-01

    This paper describes an imaging technique for the determination of rough component envelopes of cast and forged components. The paper includes several image acquisition methods currently used in this area but concentrates in detail on the method known as the light stripe method. Results presented show the advantages of the light stripe method to obtain a fast and accurate 3D description of the cast and forged components. The research is part of a larger project on intelligent manufacturing systems and is being conducted at the CIM Centre, Swinburne University of Technology, Hawthorn, Victoria, Australia.

  19. Enveloping algebras of some quantum Lie algebras

    OpenAIRE

    Pourkia, Arash

    2014-01-01

    We define a family of Hopf algebra objects, $H$, in the braided category of $\\mathbb{Z}_n$-modules (known as anyonic vector spaces), for which the property $\\psi^2_{H\\otimes H}=id_{H\\otimes H}$ holds. We will show that these anyonic Hopf algebras are, in fact, the enveloping (Hopf) algebras of particular quantum Lie algebras, also with the property $\\psi^2=id$. Then we compute the braided periodic Hopf cyclic cohomology of these Hopf algebras. For that, we will show the following fact: analog...

  20. Shape Control of Responsive Building Envelopes

    DEFF Research Database (Denmark)

    Worre Foged, Isak; Kirkegaard, Poul Henning; Christensen, Jesper Thøger;

    2010-01-01

    of the paper are to develop a new adaptive kinetic architectural structure, particularly a reconfigurable architectural structure which can transform body shape from planar geometries to hyper-surfaces using different control strategies, i.e. a transformation into more than one or two different shape...... alternatives. The adaptive structure is a proposal for a responsive building envelope which is an idea of a first level operational framework for present and future investigations towards performance based responsive architectures through a set of responsive typologies. A mock-up concept of a secondary...

  1. Computer Language Effciency via Data Envelopment Analysis

    Directory of Open Access Journals (Sweden)

    Andrea Ellero

    2011-01-01

    Full Text Available The selection of the computer language to adopt is usually driven by intuition and expertise, since it is very diffcult to compare languages taking into account all their characteristics. In this paper, we analyze the effciency of programming languages through Data Envelopment Analysis. We collected the input data from The Computer Language Benchmarks Game: we consider a large set of languages in terms of computational time, memory usage, and source code size. Various benchmark problems are tackled. We analyze the results first of all considering programming languages individually. Then, we evaluate families of them sharing some characteristics, for example, being compiled or interpreted.

  2. Envelope as Climate Negotiator: Evaluating adaptive building envelope's capacity to moderate indoor climate and energy

    Science.gov (United States)

    Erickson, James

    Through manipulation of adaptable opportunities available within a given environment, individuals become active participants in managing personal comfort requirements, by exercising control over their comfort without the assistance of mechanical heating and cooling systems. Similarly, continuous manipulation of a building skin's form, insulation, porosity, and transmissivity qualities exerts control over the energy exchanged between indoor and outdoor environments. This research uses four adaptive response variables in a modified software algorithm to explore an adaptive building skin's potential in reacting to environmental stimuli with the purpose of minimizing energy use without sacrificing occupant comfort. Results illustrate that significant energy savings can be realized with adaptive envelopes over static building envelopes even under extreme summer and winter climate conditions; that the magnitude of these savings are dependent on climate and orientation; and that occupant thermal comfort can be improved consistently over comfort levels achieved by optimized static building envelopes. The resulting adaptive envelope's unique climate-specific behavior could inform designers in creating an intelligent kinetic aesthetic that helps facilitate adaptability and resiliency in architecture.

  3. TRANSPARENT HELIUM IN STRIPPED ENVELOPE SUPERNOVAE

    International Nuclear Information System (INIS)

    Using simple arguments based on photometric light curves and velocity evolution, we propose that some stripped envelope supernovae (SNe) show signs that a significant fraction of their helium is effectively transparent. The main pieces of evidence are the relatively low velocities with little velocity evolution, as are expected deep inside an exploding star, along with temperatures that are too low to ionize helium. This means that the helium should not contribute to the shaping of the main SN light curve, and thus the total helium mass may be difficult to measure from simple light curve modeling. Conversely, such modeling may be more useful for constraining the mass of the carbon/oxygen core of the SN progenitor. Other stripped envelope SNe show higher velocities and larger velocity gradients, which require an additional opacity source (perhaps the mixing of heavier elements or radioactive nickel) to prevent the helium from being transparent. We discuss ways in which similar analysis can provide insights into the differences and similarities between SNe Ib and Ic, which will lead to a better understanding of their respective formation mechanisms

  4. Transparent Helium in Stripped Envelope Supernovae

    CERN Document Server

    Piro, Anthony L

    2014-01-01

    The light curves and velocity evolution of core-collapse supernovae (SNe) provide important clues to help constrain their progenitors. This may be especially important for stripped envelope SNe (Type Ib, Ic, and IIb), which have been elusive in providing direct connections with the massive stars that give rise to these explosions. Using simple arguments based on photometric light curves, we propose that many of these stripped envelope SNe show evidence that a significant fraction their helium is effectively transparent during the majority of their light curve evolution. This means that the helium should not contribute to the shaping of the main SN light curve and thus the total helium mass may be difficult to constrain from simple light curve modeling. Conversely, such modeling may be more useful for constraining the mass of the carbon/oxygen core of the SN progenitor. We discuss ways in which similar analysis can provide insights into the differences and similarities between SNe Ib and Ic, which will help le...

  5. Variability of mammalian liver nuclear-envelope preparations.

    Science.gov (United States)

    Agutter, P S; Gleed, C D

    1980-10-15

    The composition, density and enzymic activities of sheep liver nuclear-envelope preparations were found to vary markedly according to the concentrations of nuclei during the lysis stage. The effect of nuclear concentration on the properties of the purified envelopes could not be attributed to bound Mg2+ or to other ions, and appeared to result from some component of the nucleus which was not eluted during lysis. The implications of these findings for studies on the nuclear envelope are discussed.

  6. Solar active envelope module with an adjustable transmittance/absorptance

    OpenAIRE

    C. Villasante Villasante; I. del Hoyo; Pagola, I. (I.); Sanchez, M.; E. Aranzabe

    2015-01-01

    A solar active envelope module with a high flexibility degree is proposed in this paper. The transparent module controls the day-lighting of the room, improving the indoor environment, while absorbing the superfluous solar energy inside. That energy is used to increase the efficiency of heating, ventilation, and the air-conditioning (HVAC) system of the building. This is carried out through a fine control of the absorptance of the envelope module. The active envelope module consists of three ...

  7. Enveloping actions and Takai duality for partial actions

    OpenAIRE

    Abadie, Fernando

    2000-01-01

    We show that any continuous partial action on a topological space has a unique enveloping action, i.e. it is the restriction of a global action. In the case of C^*-algebras we prove that any partial action has an enveloping action up to Morita equivalence. The study of enveloping actions up to Morita equivalence reveals the form that Takai duality takes for partial actions.

  8. 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.

  9. Multislice behavioral modeling based on envelope domain for power amplifiers

    Institute of Scientific and Technical Information of China (English)

    Wang Huadong; Bao Jingfu; Wu Zhengde

    2009-01-01

    An envelope domain multislice behavioral modeling is introduced. The tradition AM-AM and AM-PM characteristics of power amplifiers are extended to envelope domain and base-band filter is applied to distortion complex envelope signal for description of the envelope memory effect. Using traditional one and two-tone tests, the coefficients of nonlinear model and the FIR filter can be extracted. At last the model has been applied to a 10 W WCDMA power amplifier to predict its output signal. And simulation results show that the model output conforms very well to the traditional transistor level simulation results.

  10. Semiparametric Power Envelopes for Tests of the Unit Root Hypothesis

    DEFF Research Database (Denmark)

    Jansson, Michael

    This paper derives asymptotic power envelopes for tests of the unit root hypothesis in a zero-mean AR(1) model. The power envelopes are derived using the limits of experiments approach and are semiparametric in the sense that the underlying error distribution is treated as an unknown infinitedime......This paper derives asymptotic power envelopes for tests of the unit root hypothesis in a zero-mean AR(1) model. The power envelopes are derived using the limits of experiments approach and are semiparametric in the sense that the underlying error distribution is treated as an unknown...

  11. From the Outside-In: the Francisella tularensis Envelope and Virulence

    Directory of Open Access Journals (Sweden)

    Hannah M. Rowe

    2015-12-01

    Full Text Available Francisella tularensis is a highly-infectious bacterium that causes the rapid, and often lethal disease, tularemia. Many studies have been performed to identify and characterize the virulence factors that F. tularensis uses to infect a wide variety of hosts and host cell types, evade immune defenses, and induce severe disease and death. This review focuses on the virulence factors that are present in the F. tularensis envelope, including capsule, LPS, outer membrane, periplasm, inner membrane, secretion systems, and various molecules in each of aforementioned sub-compartments. Whereas no single bacterial molecule or molecular complex single-handedly controls F. tularensis virulence, we review here how diverse bacterial systems work in conjunction to subvert the immune system, attach to and invade host cells, alter phagosome/lysosome maturation pathways, replicate in host cells without being detected, inhibit apoptosis, and induce host cell death for bacterial release and infection of adjacent cells. Given that the F. tularensis envelope is the outermost layer of the bacterium, we highlight herein how many of these molecules directly interact with the host to promote infection and disease. These and future envelope studies are important to advance our collective understanding of F. tularensis virulence mechanisms and offer targets for future vaccine development efforts.

  12. Secretion of hepatitis C virus envelope glycoproteins depends on assembly of apolipoprotein B positive lipoproteins.

    Directory of Open Access Journals (Sweden)

    Vinca Icard

    Full Text Available The density of circulating hepatitis C virus (HCV particles in the blood of chronically infected patients is very heterogeneous. The very low density of some particles has been attributed to an association of the virus with apolipoprotein B (apoB positive and triglyceride rich lipoproteins (TRL likely resulting in hybrid lipoproteins known as lipo-viro-particles (LVP containing the viral envelope glycoproteins E1 and E2, capsid and viral RNA. The specific infectivity of these particles has been shown to be higher than the infectivity of particles of higher density. The nature of the association of HCV particles with lipoproteins remains elusive and the role of apolipoproteins in the synthesis and assembly of the viral particles is unknown. The human intestinal Caco-2 cell line differentiates in vitro into polarized and apoB secreting cells during asymmetric culture on porous filters. By using this cell culture system, cells stably expressing E1 and E2 secreted the glycoproteins into the basal culture medium after one week of differentiation concomitantly with TRL secretion. Secreted glycoproteins were only detected in apoB containing density fractions. The E1-E2 and apoB containing particles were unique complexes bearing the envelope glycoproteins at their surface since apoB could be co-immunoprecipitated with E2-specific antibodies. Envelope protein secretion was reduced by inhibiting the lipidation of apoB with an inhibitor of the microsomal triglyceride transfer protein. HCV glycoproteins were similarly secreted in association with TRL from the human liver cell line HepG2 but not by Huh-7 and Huh-7.5 hepatoma cells that proved deficient for lipoprotein assembly. These data indicate that HCV envelope glycoproteins have the intrinsic capacity to utilize apoB synthesis and lipoprotein assembly machinery even in the absence of the other HCV proteins. A model for LVP assembly is proposed.

  13. Hydrolytic activity of Virgibacillus sp. SK37, a starter culture of fish sauce fermentation, and its cell-bound proteinases.

    Science.gov (United States)

    Sinsuwan, Sornchai; Rodtong, Sureelak; Yongsawatdigul, Jirawat

    2012-08-01

    Fish sauce production relies on a natural fermentation process requiring 12-18 months for process completion. Virgibacillus sp. SK37 has been shown to be a potential strain for fish sauce acceleration. However, hydrolytic activity of proteinases bound at cell surface of this strain has not been well elucidated. Addition of 0.2 % CaCl(2) (w/w) in conjunction with starter cultures of Virgibacillus sp. SK 37 increased protein hydrolysis as measured by α-amino group content throughout fermentation (P Virgibacillus sp. SK 37 were extracted into a free form by incubating the washed cells in Ca(2+)-free buffer at 37 °C for 2 h. Cell-bound proteinases revealed molecular mass of 19, 20, 22, 32, 34, and 44 kDa based on a synthetic peptide zymogram. The proteinases showed subtilisin-like serine characteristics with the highest activity at 50 °C and pH 8 and 11. Activity of the extracted proteinases increased ~4 times at ≥100 mM CaCl(2). In addition, CaCl(2) enhanced thermal stability of the extracted proteinases. Enzymes showed proteolytic activity in either the absence or presence of 10 and 25 % NaCl toward fish muscle, soy protein isolate, and casein substrates. Cell-bound proteinases were likely to play an important role in protein hydrolysis during fish sauce fermentation. PMID:22806191

  14. Characterization of the fusion core in zebrafish endogenous retroviral envelope protein

    Energy Technology Data Exchange (ETDEWEB)

    Shi, Jian [State Key Laboratory of Virology, College of Life Sciences, Wuhan University, Wuhan, Hubei 430072 (China); State Key Laboratory of Virology, Wuhan Institute of Virology, Chinese Academy of Sciences, Wuhan, Hubei 430071 (China); Zhang, Huaidong [CAS Key Laboratory of Special Pathogens and Biosafety, Wuhan Institute of Virology, Chinese Academy of Sciences, Wuhan, Hubei 430071 (China); Gong, Rui, E-mail: gongr@wh.iov.cn [CAS Key Laboratory of Special Pathogens and Biosafety, Wuhan Institute of Virology, Chinese Academy of Sciences, Wuhan, Hubei 430071 (China); Xiao, Gengfu, E-mail: xiaogf@wh.iov.cn [State Key Laboratory of Virology, College of Life Sciences, Wuhan University, Wuhan, Hubei 430072 (China); State Key Laboratory of Virology, Wuhan Institute of Virology, Chinese Academy of Sciences, Wuhan, Hubei 430071 (China)

    2015-05-08

    Zebrafish endogenous retrovirus (ZFERV) is the unique endogenous retrovirus in zebrafish, as yet, containing intact open reading frames of its envelope protein gene in zebrafish genome. Similarly, several envelope proteins of endogenous retroviruses in human and other mammalian animal genomes (such as syncytin-1 and 2 in human, syncytin-A and B in mouse) were identified and shown to be functional in induction of cell–cell fusion involved in placental development. ZFERV envelope protein (Env) gene appears to be also functional in vivo because it is expressible. After sequence alignment, we found ZFERV Env shares similar structural profiles with syncytin and other type I viral envelopes, especially in the regions of N- and C-terminal heptad repeats (NHR and CHR) which were crucial for membrane fusion. We expressed the regions of N + C protein in the ZFERV Env (residues 459–567, including predicted NHR and CHR) to characterize the fusion core structure. We found N + C protein could form a stable coiled-coil trimer that consists of three helical NHR regions forming a central trimeric core, and three helical CHR regions packing into the grooves on the surface of the central core. The structural characterization of the fusion core revealed the possible mechanism of fusion mediated by ZFERV Env. These results gave comprehensive explanation of how the ancient virus infects the zebrafish and integrates into the genome million years ago, and showed a rational clue for discovery of physiological significance (e.g., medicate cell–cell fusion). - Highlights: • ZFERV Env shares similar structural profiles with syncytin and other type I viral envelopes. • The fusion core of ZFERV Env forms stable coiled-coil trimer including three NHRs and three CHRs. • The structural mechanism of viral entry mediated by ZFERV Env is disclosed. • The results are helpful for further discovery of physiological function of ZFERV Env in zebrafish.

  15. Cryo electron tomography of herpes simplex virus during axonal transport and secondary envelopment in primary neurons.

    Directory of Open Access Journals (Sweden)

    Iosune Ibiricu

    2011-12-01

    Full Text Available During herpes simplex virus 1 (HSV1 egress in neurons, viral particles travel from the neuronal cell body along the axon towards the synapse. Whether HSV1 particles are transported as enveloped virions as proposed by the 'married' model or as non-enveloped capsids suggested by the 'separate' model is controversial. Specific viral proteins may form a recruitment platform for microtubule motors that catalyze such transport. However, their subviral location has remained elusive. Here we established a system to analyze herpesvirus egress by cryo electron tomography. At 16 h post infection, we observed intra-axonal transport of progeny HSV1 viral particles in dissociated hippocampal neurons by live-cell fluorescence microscopy. Cryo electron tomography of frozen-hydrated neurons revealed that most egressing capsids were transported independently of the viral envelope. Unexpectedly, we found not only DNA-containing capsids (cytosolic C-capsids, but also capsids lacking DNA (cytosolic A-/B-capsids in mid-axon regions. Subvolume averaging revealed lower amounts of tegument on cytosolic A-/B-capsids than on C-capsids. Nevertheless, all capsid types underwent active axonal transport. Therefore, even few tegument proteins on the capsid vertices seemed to suffice for transport. Secondary envelopment of capsids was observed at axon terminals. On their luminal face, the enveloping vesicles were studded with typical glycoprotein-like spikes. Furthermore, we noted an accretion of tegument density at the concave cytosolic face of the vesicle membrane in close proximity to the capsids. Three-dimensional analysis revealed that these assembly sites lacked cytoskeletal elements, but that filamentous actin surrounded them and formed an assembly compartment. Our data support the 'separate model' for HSV1 egress, i.e. progeny herpes viruses being transported along axons as subassemblies and not as complete virions within transport vesicles.

  16. Characterization of the fusion core in zebrafish endogenous retroviral envelope protein

    International Nuclear Information System (INIS)

    Zebrafish endogenous retrovirus (ZFERV) is the unique endogenous retrovirus in zebrafish, as yet, containing intact open reading frames of its envelope protein gene in zebrafish genome. Similarly, several envelope proteins of endogenous retroviruses in human and other mammalian animal genomes (such as syncytin-1 and 2 in human, syncytin-A and B in mouse) were identified and shown to be functional in induction of cell–cell fusion involved in placental development. ZFERV envelope protein (Env) gene appears to be also functional in vivo because it is expressible. After sequence alignment, we found ZFERV Env shares similar structural profiles with syncytin and other type I viral envelopes, especially in the regions of N- and C-terminal heptad repeats (NHR and CHR) which were crucial for membrane fusion. We expressed the regions of N + C protein in the ZFERV Env (residues 459–567, including predicted NHR and CHR) to characterize the fusion core structure. We found N + C protein could form a stable coiled-coil trimer that consists of three helical NHR regions forming a central trimeric core, and three helical CHR regions packing into the grooves on the surface of the central core. The structural characterization of the fusion core revealed the possible mechanism of fusion mediated by ZFERV Env. These results gave comprehensive explanation of how the ancient virus infects the zebrafish and integrates into the genome million years ago, and showed a rational clue for discovery of physiological significance (e.g., medicate cell–cell fusion). - Highlights: • ZFERV Env shares similar structural profiles with syncytin and other type I viral envelopes. • The fusion core of ZFERV Env forms stable coiled-coil trimer including three NHRs and three CHRs. • The structural mechanism of viral entry mediated by ZFERV Env is disclosed. • The results are helpful for further discovery of physiological function of ZFERV Env in zebrafish

  17. Early localization of NPA58, a rat nuclear pore-associated protein, to the reforming nuclear envelope during mitosis

    Indian Academy of Sciences (India)

    Radhika Ganeshan; Nandini Rangaraj; Veena K Parnaik

    2001-03-01

    We have studied the mitotic reassembly of the nuclear envelope, using antibodies to nuclear marker proteins and NPA58 in F-111 rat fibroblast cells. In earlier studies we have proposed that NPA58, a 58 kDa rat nuclear protein, is involved in nuclear protein import. In this report, NPA58 is shown to be localized on the cytoplasmic face of the envelope in interphase cells, in close association with nuclear pores. In mitotic cells NPA58 is dispersed in the cytoplasm till anaphase. The targeting of NPA58 to the reforming nuclear envelope in early telophase coincides with the recruitment of a well-characterized class of nuclear pore proteins recognized by the antibody mAb 414, and occurs prior to the incorporation of lamin B1 into the envelope. Significant protein import activity is detectable only after localization of NPA58 in the newly-formed envelope. The early targeting of NPA58 is consistent with its proposed role in nuclear transport.

  18. Enveloped virus-like particles as vaccines against pathogenic arboviruses.

    Science.gov (United States)

    Pijlman, Gorben P

    2015-05-01

    Arthropod-borne arboviruses form a continuous threat to human and animal health, but few arboviral vaccines are currently available. Advances in expression technology for complex, enveloped virus-like particles (eVLPs) create new opportunities to develop potent vaccines against pathogenic arboviruses. In this short review, I highlight the successes and challenges in eVLP production for members of the three major arbovirus families: Flaviviridae (e.g., dengue, West Nile, Japanese encephalitis); Bunyaviridae (e.g., Rift Valley fever); and Togaviridae (e.g., chikungunya). The results from pre-clinical testing will be discussed as well as specific constraints to the large-scale manufacture and purification of eVLPs, which are complex assemblies of membranes and viral glycoproteins. Insect cells emerge as ideal substrates for correct arboviral glycoprotein folding and posttranslational modification to yield high quality eVLPs. Furthermore, baculovirus expression in insect cell culture is scalable and has a proven safety record in industrial human and veterinary vaccine manufacturing. In conclusion, eVLPs produced in insect cells using modern biotechnology have a realistic potential to be used in novel vaccines against arboviral diseases.

  19. Enveloped virus-like particles as vaccines against pathogenic arboviruses.

    Science.gov (United States)

    Pijlman, Gorben P

    2015-05-01

    Arthropod-borne arboviruses form a continuous threat to human and animal health, but few arboviral vaccines are currently available. Advances in expression technology for complex, enveloped virus-like particles (eVLPs) create new opportunities to develop potent vaccines against pathogenic arboviruses. In this short review, I highlight the successes and challenges in eVLP production for members of the three major arbovirus families: Flaviviridae (e.g., dengue, West Nile, Japanese encephalitis); Bunyaviridae (e.g., Rift Valley fever); and Togaviridae (e.g., chikungunya). The results from pre-clinical testing will be discussed as well as specific constraints to the large-scale manufacture and purification of eVLPs, which are complex assemblies of membranes and viral glycoproteins. Insect cells emerge as ideal substrates for correct arboviral glycoprotein folding and posttranslational modification to yield high quality eVLPs. Furthermore, baculovirus expression in insect cell culture is scalable and has a proven safety record in industrial human and veterinary vaccine manufacturing. In conclusion, eVLPs produced in insect cells using modern biotechnology have a realistic potential to be used in novel vaccines against arboviral diseases. PMID:25692281

  20. Enveloping branes and brane-world singularities

    CERN Document Server

    Antoniadis, Ignatios; Klaoudatou, Ifigeneia

    2014-01-01

    The existence of envelopes is studied for systems of differential equations in connection with the method of asymptotic splittings which allows to determine the singularity structure of the solutions. The result is applied to braneworlds consisting of a 3-brane in a five-dimensional bulk, in the presence of an analog of a bulk perfect fluid parametrizing a generic class of bulk matter. We find that all flat brane solutions suffer from a finite distance singularity contrary to previous claims. We then study the possibility of avoiding finite distance singularities by cutting the bulk and gluing regular solutions at the position of the brane. Further imposing physical conditions such as finite Planck mass on the brane and positive energy conditions on the bulk fluid, excludes however this possibility, as well.

  1. Antireflection Pyrex envelopes for parabolic solar collectors

    Science.gov (United States)

    McCollister, H. L.; Pettit, R. B.

    1983-11-01

    Antireflective (AR) coatings, applied to the glass envelopes used in parabolic trough solar collectors around the receiver tube in order to reduce thermal losses, can increase solar transmittance by 7 percent. An AR surface has been formed on Pyrex by first heat treating the glass to cause a compositional phase separation, removing a surface layer after heat treatment through the use of a preetching solution, and finally etching in a solution that contains hydrofluorosilic and ammonium bifluoride acids. AR-coated samples with solar transmittance values of more than 0.97, by comparison to an untreated sample value of 0.91, have been obtained for the 560-630 C range of heat treatment temperatures. Optimum values have also been determined for the other processing parameters.

  2. Enveloping branes and brane-world singularities

    Energy Technology Data Exchange (ETDEWEB)

    Antoniadis, Ignatios; Cotsakis, Spiros [CERN-Theory Division, Department of Physics, Geneva 23 (Switzerland); Klaoudatou, Ifigeneia [University of the Aegean, Research Group of Geometry, Dynamical Systems and Cosmology, Department of Information and Communication Systems Engineering, Samos (Greece)

    2014-12-01

    The existence of envelopes is studied for systems of differential equations in connection with the method of asymptotic splittings which allows one to determine the singularity structure of the solutions. The result is applied to brane-worlds consisting of a 3-brane in a five-dimensional bulk, in the presence of an analog of a bulk perfect fluid parameterizing a generic class of bulk matter. We find that all flat brane solutions suffer from a finite-distance singularity contrary to previous claims. We then study the possibility of avoiding finite-distance singularities by cutting the bulk and gluing regular solutions at the position of the brane. Further imposing physical conditions such as finite Planck mass on the brane and positive energy conditions on the bulk fluid, excludes, however, this possibility as well. (orig.)

  3. The circumstellar envelope of AFGL 4106

    CERN Document Server

    Van Loon, J T; Van Winckel, H; Waters, L B F M; Loon, Jacco Th. van; Winckel, Hans van

    1999-01-01

    We present new imaging and spectroscopy of the post-red supergiant binary AFGL 4106. Coronographic imaging in H-alpha reveals the shape and extent of the ionized region in the circumstellar envelope (CSE). Echelle spectroscopy with the slit covering almost the entire extent of the CSE is used to derive the physical conditions in the ionized region and the optical depth of the dust contained within the CSE. The dust shell around AFGL 4106 is clumpy and mixed with ionized gas. H-alpha and [N II] emission is brightest from a thin bow-shaped layer just outside of the detached dust shell. On-going mass loss is traced by [Ca II] emission and blue-shifted absorption in lines of low-ionization species. A simple model is used to interpret the spatial distribution of the circumstellar extinction and the dust emission in a consistent way.

  4. Integrated Energy Design of the Building Envelope

    DEFF Research Database (Denmark)

    Nielsen, Martin Vraa

    project analysed how the implementation of technical knowledge early in the building design process can quantify the effect of a building’s façades on its energy efficiency and indoor climate and thereby facilitate a more qualified design development. The project was structured in the following way: 1......This thesis describes the outcome of the PhD project Integrated energy design of the building envelope carried out through a combination of scientific dissemination reported through peer-reviewed journals and a wide range of affiliated projects involved in at an architectural firm. The research...... layout, window geometry and transparency, design of the window aperture, etc. Through the wide range of affiliated project involved in at the architectural firm over the course of this project, this approach resulted in building designs with an energy demand at least 25% below the minimum requirements...

  5. Performance measurement with fuzzy data envelopment analysis

    CERN Document Server

    Tavana, Madjid

    2014-01-01

    The intensity of global competition and ever-increasing economic uncertainties has led organizations to search for more efficient and effective ways to manage their business operations.  Data envelopment analysis (DEA) has been widely used as a conceptually simple yet powerful tool for evaluating organizational productivity and performance. Fuzzy DEA (FDEA) is a promising extension of the conventional DEA proposed for dealing with imprecise and ambiguous data in performance measurement problems. This book is the first volume in the literature to present the state-of-the-art developments and applications of FDEA. It is designed for students, educators, researchers, consultants and practicing managers in business, industry, and government with a basic understanding of the DEA and fuzzy logic concepts.

  6. Data envelopment analysis of randomized ranks

    Directory of Open Access Journals (Sweden)

    Sant'Anna Annibal P.

    2002-01-01

    Full Text Available Probabilities and odds, derived from vectors of ranks, are here compared as measures of efficiency of decision-making units (DMUs. These measures are computed with the goal of providing preliminary information before starting a Data Envelopment Analysis (DEA or the application of any other evaluation or composition of preferences methodology. Preferences, quality and productivity evaluations are usually measured with errors or subject to influence of other random disturbances. Reducing evaluations to ranks and treating the ranks as estimates of location parameters of random variables, we are able to compute the probability of each DMU being classified as the best according to the consumption of each input and the production of each output. Employing the probabilities of being the best as efficiency measures, we stretch distances between the most efficient units. We combine these partial probabilities in a global efficiency score determined in terms of proximity to the efficiency frontier.

  7. DC-SIGN increases the affinity of HIV-1 envelope glycoprotein interaction with CD4.

    Directory of Open Access Journals (Sweden)

    Karolin Hijazi

    Full Text Available Mannose-binding C-type lectin receptors, expressed on Langerhans cells and subepithelial dendritic cells (DCs of cervico-vaginal tissues, play an important role in HIV-1 capture and subsequent dissemination to lymph nodes. DC-SIGN has been implicated in both productive infection of DCs and the DC-mediated trans infection of CD4(+ T cells that occurs in the absence of replication. However, the molecular events that underlie this efficient transmission have not been fully defined. In this study, we have examined the effect of the extracellular domains of DC-SIGN and Langerin on the stability of the interaction of the HIV-1 envelope glycoprotein with CD4 and also on replication in permissive cells. Surface plasmon resonance analysis showed that DC-SIGN increases the binding affinity of trimeric gp140 envelope glycoproteins to CD4. In contrast, Langerin had no effect on the stability of the gp140:CD4 complex. In vitro infection experiments to compare DC-SIGN enhancement of CD4-dependent and CD4-independent strains demonstrated significantly lower enhancement of the CD4-independent strain. In addition DC-SIGN increased the relative rate of infection of the CD4-dependent strain but had no effect on the CD4-independent strain. DC-SIGN binding to the HIV envelope protein effectively increases exposure of the CD4 binding site, which in turn contributes to enhancement of infection.

  8. Furin is involved in baculovirus envelope fusion protein activation

    NARCIS (Netherlands)

    Westenberg, M.; Wang, H.; IJkel, W.F.J.; Goldbach, R.W.; Vlak, J.M.; Zuidema, D.

    2002-01-01

    The Spodoptera exigua multicapsid nucleopolyhedrovirus (SeMNPV) Se8 gene was recently shown to encode the viral envelope fusion (F) protein. A 60-kDa C-terminal subunit (F1) of the 76-kDa primary translation product of this gene was found to be the major envelope protein of SeMNPV budded virus (BV)

  9. RELAXATION OF FUNCTIONALS INVOLVING HOMOGENEOUS FUNCTIONS AND INVARIANCE OF ENVELOPES

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    The authors compute the quasiconvex envelope of certain functions defined on the space Mmn of real m× n matrices via a homogeneous function on Mmn. They also deduce invariance properties for various convex envelopes from corresponding invariance properties satisfied by a function. Some applications related in particular to nonlinear elasticity are given.

  10. Antiviral Inhibition of Enveloped Virus Release by Tetherin/BST-2: Action and Counteraction

    OpenAIRE

    Stuart J D Neil; Anna Le Tortorec; Suzanne Willey

    2011-01-01

    Tetherin (BST2/CD317) has been recently recognized as a potent interferon-induced antiviral molecule that inhibits the release of diverse mammalian enveloped virus particles from infected cells. By targeting an immutable structure common to all these viruses, the virion membrane, evasion of this antiviral mechanism has necessitated the development of specific countermeasures that directly inhibit tetherin activity. Here we review our current understanding of the molecular basis of tetherin’s ...

  11. Envelope enhancement increases cortical sensitivity to interaural envelope delays with acoustic and electric hearing.

    Directory of Open Access Journals (Sweden)

    Douglas E H Hartley

    Full Text Available Evidence from human psychophysical and animal electrophysiological studies suggests that sensitivity to interaural time delay (ITD in the modulating envelope of a high-frequency carrier can be enhanced using half-wave rectified stimuli. Recent evidence has shown potential benefits of equivalent electrical stimuli to deaf individuals with bilateral cochlear implants (CIs. In the current study we assessed the effects of envelope shape on ITD sensitivity in the primary auditory cortex of normal-hearing ferrets, and profoundly-deaf animals with bilateral CIs. In normal-hearing animals, cortical sensitivity to ITDs (±1 ms in 0.1-ms steps was assessed in response to dichotically-presented i sinusoidal amplitude-modulated (SAM and ii half-wave rectified (HWR tones (100-ms duration; 70 dB SPL presented at the best-frequency of the unit over a range of modulation frequencies. In separate experiments, adult ferrets were deafened with neomycin administration and bilaterally-implanted with intra-cochlear electrode arrays. Electrically-evoked auditory brainstem responses (EABRs were recorded in response to bipolar electrical stimulation of the apical pair of electrodes with singe biphasic current pulses (40 µs per phase over a range of current levels to measure hearing thresholds. Subsequently, we recorded cortical sensitivity to ITDs (±800 µs in 80-µs steps within the envelope of SAM and HWR biphasic-pulse trains (40 µs per phase; 6000 pulses per second, 100-ms duration over a range of modulation frequencies. In normal-hearing animals, nearly a third of cortical neurons were sensitive to envelope-ITDs in response to SAM tones. In deaf animals with bilateral CI, the proportion of ITD-sensitive cortical neurons was approximately a fifth in response to SAM pulse trains. In normal-hearing and deaf animals with bilateral CI the proportion of ITD sensitive units and neural sensitivity to ITDs increased in response to HWR, compared with SAM stimuli

  12. Remodeling of the Nuclear Envelope and Lamina during Bovine Preimplantation Development and Its Functional Implications.

    Directory of Open Access Journals (Sweden)

    Jens Popken

    Full Text Available The present study demonstrates a major remodeling of the nuclear envelope and its underlying lamina during bovine preimplantation development. Up to the onset of major embryonic genome activation (MGA at the 8-cell stage nuclei showed a non-uniform distribution of nuclear pore complexes (NPCs. NPCs were exclusively present at sites where DNA contacted the nuclear lamina. Extended regions of the lamina, which were not contacted by DNA, lacked NPCs. In post-MGA nuclei the whole lamina was contacted rather uniformly by DNA. Accordingly, NPCs became uniformly distributed throughout the entire nuclear envelope. These findings shed new light on the conditions which control the integration of NPCs into the nuclear envelope. The switch from maternal to embryonic production of mRNAs was accompanied by multiple invaginations covered with NPCs, which may serve the increased demands of mRNA export and protein import. Other invaginations, as well as interior nuclear segments and vesicles without contact to the nuclear envelope, were exclusively positive for lamin B. Since the abundance of these invaginations and vesicles increased in concert with a massive nuclear volume reduction, we suggest that they reflect a mechanism for fitting the nuclear envelope and its lamina to a shrinking nuclear size during bovine preimplantation development. In addition, a deposit of extranuclear clusters of NUP153 (a marker for NPCs without associated lamin B was frequently observed from the zygote stage up to MGA. Corresponding RNA-Seq data revealed deposits of spliced, maternally provided NUP153 mRNA and little unspliced, newly synthesized RNA prior to MGA, which increased strongly at the initiation of embryonic expression of NUP153 at MGA.

  13. Implication of Human Endogenous Retrovirus Envelope Proteins in Placental Functions

    Directory of Open Access Journals (Sweden)

    Adjimon Gatien Lokossou

    2014-11-01

    Full Text Available Human endogenous retroviruses (ERVs represent 8% of the total human genome. Although the majority of these ancient proviral sequences have only retained non-coding long terminal repeats (LTRs, a number of “endogenized” retroviral genes encode functional proteins. Previous studies have underlined the implication of these ERV-derived proteins in the development and the function of the placenta. In this review, we summarize recent findings showing that two ERV genes, termed Syncytin-1 and Syncytin-2, which encode former envelope (Env proteins, trigger fusion events between villous cytotrophoblasts and the peripheral multinucleated syncytiotrophoblast layer. Such fusion events maintain the stability of this latter cell structure, which plays an important role in fetal development by the active secretion of various soluble factors, gas exchange and regulation of fetomaternal immunotolerance. We also highlight new studies showing that these ERV proteins, in addition to their localization at the cell surface of cytotrophoblasts, are also incorporated on the surface of various extracellular microvesicles, including exosomes. Such exosome-associated proteins could be involved in the various functions attributed to these vesicles and could provide a form of tropism. Additionally, through their immunosuppressive domains, these ERV proteins could also contribute to fetomaternal immunotolerance in a local and more distal manner. These various aspects of the implication of Syncytin-1 and -2 in placental function are also addressed in the context of the placenta-related disorder, preeclampsia.

  14. Nucleocytoplasmic transport of nucleocapsid proteins of enveloped RNA viruses

    Directory of Open Access Journals (Sweden)

    Wahyu eWulan

    2015-06-01

    Full Text Available Most viruses with non-segmented single stranded RNA genomes complete their life cycle in the cytoplasm of infected cells. However, despite undergoing replication in the cytoplasm, the structural proteins of some of these RNA viruses localize to the nucleus at specific times in the virus life cycle, primarily early in infection. Limited evidence suggests that this enhances successful viral replication by interfering with or inhibiting the host antiviral response. Nucleocapsid proteins of RNA viruses have a well-established, essential cytoplasmic role in virus replication and assembly. Intriguingly, nucleocapsid proteins of some RNA viruses also localize to the nucleus/nucleolus of infected cells. Their nuclear function is less well understood although significant advances have been made in recent years. This review will focus on the nucleocapsid protein of cytoplasmic enveloped RNA viruses, including their localization to the nucleus/nucleolus and function therein. A greater understanding of the nuclear localization of nucleocapsid proteins has the potential to enhance therapeutic strategies as it can be a target for the development of live-attenuated vaccines or antiviral drugs.

  15. Laboratory tests of short intense envelope solitons

    Science.gov (United States)

    Slunyaev, A.; Clauss, G. F.; Klein, M.; Onorato, M.

    2012-04-01

    Stability of short intense nonlinear wave groups propagating over deep water is tested in laboratory runs which are performed in the facility of the Technical University of Berlin. The strongly nonlinear simulation of quasi-steady nonlinear wave groups within the framework of the Euler equations is used to generate the surface elevation time series at a border of the water tank. Besides, the exact analytic solution of the nonlinear Schrodinger equation is used for this purpose. The time series is then transformed to a wave maker signal with use of a designed transfer algorithm. Wave group propagation along the tank was recorded by 4 distant gauges and by an array of 6 densely situated gauges. This setup allows to consider the wave evolution from 10 to 85 m from the wave maker, and to obtain the wave envelope shape directly from the instrumental data. In the experiments wave groups were characterized by the steepness values up to kAcr A.I. Dyachenko, A.O. Prokofiev, Eur. J. Mech. B / Fluids 25, 677 (2006). [2] A.I. Dyachenko, V.E. Zakharov, JETP Lett. 88, 307 (2008). [3] A.V. Slunyaev, JETP 109, 676 (2009).

  16. ANALYSES AND INFLUENCES OF GLAZED BUILDING ENVELOPES

    Directory of Open Access Journals (Sweden)

    Sabina Jordan

    2011-01-01

    Full Text Available The article presents the results of an analytical study of the functioning of glazing at two different yet interacting levels: at the level of the building as a whole, and at that of glazing as a building element. At the building level, analyses were performed on a sample of high-rise business buildings in Slovenia, where the glazing"s share of the building envelope was calculated, and estimates of the proportion of shade provided by external blinds were made. It is shown that, especially in the case of modern buildings with large proportions of glazing and buildings with no shading devices, careful glazing design is needed, together with a sound knowledge of energy performance. In the second part of the article, the energy balance values relating to selected types of glazing are presented, including solar control glazing. The paper demonstrates the need for a holistic energy approach to glazing problems, as well as how different types of glazing can be methodically compared, thus improving the design of sustainability-orientated buildings.

  17. The progenitors of stripped-envelope supernovae

    Science.gov (United States)

    Elias-Rosa, N.

    2013-05-01

    The type Ib/c SNe are those explosions which come from massive star populations, but lack hydrogen and helium. These have been proposed to originate in the explosions of massive Wolf-Rayet stars, and we should easily be able to detect the very luminous, young progenitors if they exist. However, there has not been any detection of progenitors so far. I present the study of two extinguished Type Ic SNe 2003jg and 2004cc. In both cases there is no clear evidence of a direct detection of their progenitors in deep pre-explosion images. Upper limits derived by inserting artificial stars of known brightness at random positions around the progenitor positions (M_v>-8.8 and M_v>-9 magnitudes for the progenitors of SN 2003jg and SN 2004cc, respectively) are brighter than those expected for a massive WC (Wolf-Rayet, carbon-rich) or WO (Wolf-Rayet, oxygen-rich) (e.g., approximately between -3 and -6 in the LMC). Therefore, this is perhaps further evidence that the most massive stars may give rise to black-holes forming SNe, or it is an undetected, compact massive star hidden by a thick dust lane. However the extinction toward these SNe is currently one of the largest known. Even if these results do not directly reveal the nature of the type Ic SN progenitors, they can help to characterize the dusty environment which surrounded the progenitor of the stripped-envelope CC-SNe.

  18. Pre-paid envelopes commemorating the 2013 Open Days

    CERN Multimedia

    2013-01-01

    The post office on CERN's Prévessin site is still selling pre-paid envelopes commemorating the 2013 Open Days. Hurry while stocks last!   The special envelopes, which are valid in France for non-priority letters weighing up to 20 grams, are ideal for your Christmas and New Year correspondence. A set of ten envelopes, each featuring a different image, costs € 8.70 or 10 CHF. The post office is located in Building 866 on the Prévessin site and is open Mondays to Thursdays from 9.30 a.m. to 12.30 p.m.

  19. DATA ENVELOPMENT ANALYSIS OF BANKING SECTOR IN BANGLADESH

    Directory of Open Access Journals (Sweden)

    Md. Rashedul Hoque

    2012-05-01

    Full Text Available Banking sector of Bangladesh is flourishing and contributing to its economy. In this aspect measuring efficiency is important. Data Envelopment Analysis technique is used for this purpose. The data are collected from the annual reports of twenty four different banks in Bangladesh. Data Envelopment Analysis is mainly of two types - constant returns to scale and variable returns to scale. Since this study attempts to maximize output, so the output oriented Data Envelopment Analysis is used. The most efficient bank is one that obtains the highest efficiency score.

  20. Revisiting the envelope approximation: gravitational waves from bubble collisions

    CERN Document Server

    Weir, David J

    2016-01-01

    We study the envelope approximation and its applicability to first-order phase transitions in the early universe. We demonstrate that the power laws seen in previous studies exist independent of the nucleation rate. We also compare the envelope approximation prediction to results from large-scale phase transition simulations. For phase transitions where the contribution to gravitational waves from scalar fields dominates over that from the coupled plasma of light particles, the envelope approximation is in agreement, giving a power spectrum of the same form and order of magnitude. In all other cases the form and amplitude of the gravitational wave power spectrum is markedly different and new techniques are required.

  1. Revisiting the envelope approximation: Gravitational waves from bubble collisions

    Science.gov (United States)

    Weir, David J.

    2016-06-01

    We study the envelope approximation and its applicability to first-order phase transitions in the early Universe. We demonstrate that the power laws seen in previous studies exist independently of the nucleation rate. We also compare the envelope approximation prediction to results from large-scale phase transition simulations. For phase transitions where the contribution to gravitational waves from scalar fields dominates over that from the coupled plasma of light particles, the envelope approximation is in agreement, giving a power spectrum of the same form and order of magnitude. In all other cases the form and amplitude of the gravitational wave power spectrum is markedly different and new techniques are required.

  2. Chemical inactivation of recombinant vaccinia viruses and the effects on antigenicity and immunogenicity of recombinant simian immunodeficiency virus envelope glycoproteins.

    NARCIS (Netherlands)

    E.G.J. Hulskotte (Ellen); M.E.M. Dings (Marlinda); S.G. Norley (Stephen); A.D.M.E. Osterhaus (Albert)

    1997-01-01

    textabstractThe efficiency of paraformaldehyde (PFA) and binary ethylenimine (BEI) in inactivating recombinant vaccinia virus (rVV), present in baby hamster kidney cells expressing simian immunodeficiency virus envelope glycoproteins (SIV-Env), was measured in a series of inactivation studies. Both

  3. Sorting nexin 6 enhances lamin a synthesis and incorporation into the nuclear envelope.

    Directory of Open Access Journals (Sweden)

    Jose M González-Granado

    Full Text Available Nuclear lamins are important structural and functional proteins in mammalian cells, but little is known about the mechanisms and cofactors that regulate their traffic into the nucleus. Here, we demonstrate that trafficking of lamin A, but not lamin B1, and its assembly into the nuclear envelope are regulated by sorting nexin 6 (SNX6, a major component of the retromer that targets proteins and other molecules to specific subcellular locations. SNX6 interacts with lamin A in vitro and in vivo and links it to the outer surface of the endoplasmic reticulum in human and mouse cells. SNX6 transports its lamin A cargo to the nuclear envelope in a process that takes several hours. Lamin A protein levels in the nucleus augment or decrease, respectively, upon gain or loss of SNX6 function. We further show that SNX6-dependent lamin A nuclear import occurs across the nuclear pore complex via a RAN-GTP-dependent mechanism. These results identify SNX6 as a key regulator of lamin A synthesis and incorporation into the nuclear envelope.

  4. Construction of Nuclear Envelope Shape by a High-Genus Vesicle with Pore-Size Constraint.

    Science.gov (United States)

    Noguchi, Hiroshi

    2016-08-23

    Nuclear pores have an approximately uniform distribution in the nuclear envelope of most living cells. Hence, the morphology of the nuclear envelope is a spherical stomatocyte with a high genus. We have investigated the morphology of high-genus vesicles under pore-size constraint using dynamically triangulated membrane simulations. Bending-energy minimization without volume or other constraints produces a circular-cage stomatocyte, where the pores are aligned in a circular line on an oblate bud. As the pore radius is reduced, the circular-pore alignment is more stabilized than a random pore distribution on a spherical bud. However, we have clarified the conditions for the formation of a spherical stomatocyte: a small perinuclear volume, osmotic pressure within nucleoplasm, and repulsion between the pores. When area-difference elasticity is taken into account, the formation of cylindrical or budded tubules from the stomatocyte and discoidal stomatocyte is found. PMID:27558725

  5. Reduction of a 4q35-encoded nuclear envelope protein in muscle differentiation

    Energy Technology Data Exchange (ETDEWEB)

    Ostlund, Cecilia [Department of Medicine, College of Physicians and Surgeons, Columbia University, New York, NY 10032 (United States); Department of Pathology and Cell Biology, College of Physicians and Surgeons, Columbia University, New York, NY 10032 (United States); Guan, Tinglu [Department of Cell Biology, Scripps Research Institute, La Jolla, CA 92037 (United States); Figlewicz, Denise A. [Department of Neurology, University of Michigan, Ann Arbor, MI 48109 (United States); Hays, Arthur P. [Department of Pathology and Cell Biology, College of Physicians and Surgeons, Columbia University, New York, NY 10032 (United States); Worman, Howard J. [Department of Medicine, College of Physicians and Surgeons, Columbia University, New York, NY 10032 (United States); Department of Pathology and Cell Biology, College of Physicians and Surgeons, Columbia University, New York, NY 10032 (United States); Gerace, Larry [Department of Cell Biology, Scripps Research Institute, La Jolla, CA 92037 (United States); Schirmer, Eric C., E-mail: e.schirmer@ed.ac.uk [Department of Cell Biology, Scripps Research Institute, La Jolla, CA 92037 (United States); Wellcome Trust Centre for Cell Biology, University of Edinburgh, Edinburgh EH9 3JR (United Kingdom)

    2009-11-13

    Muscular dystrophy and peripheral neuropathy have been linked to mutations in genes encoding nuclear envelope proteins; however, the molecular mechanisms underlying these disorders remain unresolved. Nuclear envelope protein p19A is a protein of unknown function encoded by a gene at chromosome 4q35. p19A levels are significantly reduced in human muscle as cells differentiate from myoblasts to myotubes; however, its levels are not similarly reduced in all differentiation systems tested. Because 4q35 has been linked to facioscapulohumeral muscular dystrophy (FSHD) and some adjacent genes are reportedly misregulated in the disorder, levels of p19A were analyzed in muscle samples from patients with FSHD. Although p19A was increased in most cases, an absolute correlation was not observed. Nonetheless, p19A downregulation in normal muscle differentiation suggests that in the cases where its gene is inappropriately re-activated it could affect muscle differentiation and contribute to disease pathology.

  6. Construction of Nuclear Envelope Shape by a High-Genus Vesicle with Pore-Size Constraint

    Science.gov (United States)

    Noguchi, Hiroshi

    2016-08-01

    Nuclear pores have an approximately uniform distribution in the nuclear envelope of most living cells. Hence, the morphology of the nuclear envelope is a spherical stomatocyte with a high genus. We have investigated the morphology of high-genus vesicles under pore-size constraint using dynamically triangulated membrane simulations. Bending-energy minimization without volume or other constraints produces a circular-cage stomatocyte, where the pores are aligned in a circular line on an oblate bud. As the pore radius is reduced, the circular-pore alignment is more stabilized than a random pore distribution on a spherical bud. However, we have clarified the conditions for the formation of a spherical stomatocyte: a small perinuclear volume, osmotic pressure within nucleoplasm, and repulsion between the pores. When area-difference elasticity is taken into account, the formation of cylindrical or budded tubules from the stomatocyte and discoidal stomatocyte is found.

  7. Membrane topology analysis of HIV-1 envelope glycoprotein gp41

    Directory of Open Access Journals (Sweden)

    Xiao Dan

    2010-11-01

    Full Text Available Abstract Background The gp41 subunit of the HIV-1 envelope glycoprotein (Env has been widely regarded as a type I transmembrane protein with a single membrane-spanning domain (MSD. An alternative topology model suggested multiple MSDs. The major discrepancy between the two models is that the cytoplasmic Kennedy sequence in the single MSD model is assigned as the extracellular loop accessible to neutralizing antibodies in the other model. We examined the membrane topology of the gp41 subunit in both prokaryotic and mammalian systems. We attached topological markers to the C-termini of serially truncated gp41. In the prokaryotic system, we utilized a green fluorescent protein (GFP that is only active in the cytoplasm. The tag protein (HaloTag and a membrane-impermeable ligand specific to HaloTag was used in the mammalian system. Results In the absence of membrane fusion, both the prokaryotic and mammalian systems (293FT cells supported the single MSD model. In the presence of membrane fusion in mammalian cells (293CD4 cells, the data obtained seem to support the multiple MSD model. However, the region predicted to be a potential MSD is the highly hydrophilic Kennedy sequence and is least likely to become a MSD based on several algorithms. Further analysis revealed the induction of membrane permeability during membrane fusion, allowing the membrane-impermeable ligand and antibodies to cross the membrane. Therefore, we cannot completely rule out the possible artifacts. Addition of membrane fusion inhibitors or alterations of the MSD sequence decreased the induction of membrane permeability. Conclusions It is likely that a single MSD model for HIV-1 gp41 holds true even in the presence of membrane fusion. The degree of the augmentation of membrane permeability we observed was dependent on the membrane fusion and sequence of the MSD.

  8. Opacities in the massive stellar envelopes

    Science.gov (United States)

    Le Pennec, Maëlle; TURCK-CHIEZE, Sylvaine; SALMON, Sébastien; CONSORTIUM, OPAC

    2015-08-01

    Helio and asteroseismology (SoHo, CoRoT, KEPLER...) have produced observed acoustic oscillations of thousands of stars. The characteristics of these oscillations are deeply linked to the transport of radiation inside the stars. However, the comparisons of seismic data of Sun and stars with model predictions have led to significant discrepancies, which could be due to a bad knowledge of production and transport of energy.We will focus here on the case of β-Cephei.β-Cephei are pulsating stars, progenitor of supernovae and thus deeply linked to our understanding of stellar medium enrichment. Their study has shown some difficulty to predict the observed oscillation modes, which are directly linked to a bump of the opacity of the elements of the iron group (Cr, Fe, Ni) at log T=5.25 through their pulsating mechanism called the κ-mechanism. We will show that the different parameters of the stars (mass, age, metallicity) have a great influence on the amplitude of the bump, and then on the structure of the considered star.The mastery of the κ-mechanism that produces the pulsation of these stars supposes a fine determination of the peak opacity of the iron group in their envelope. We will present the final results of an experiment conducted at LULI 2000 in 2011 on Cr, Fe and Ni and compare them to OP and ATOMIC, SCO-RCG codes. We will show how to improve the opacity in the range of temperature around log T= 5.3.

  9. Low Permeation Envelope Material Development for Titan Aerobot Project

    Data.gov (United States)

    National Aeronautics and Space Administration — Aerobot vehicles for missions on Titan require envelope materials that are strong, light and durable. In particular they must be able to withstand flexing at liquid...

  10. Intelligent building envelopes. Architectural concept and applications for daylighting quality

    Energy Technology Data Exchange (ETDEWEB)

    Wyckmans, Annemie

    2005-11-15

    How does an intelligent building envelope manage the variable and sometimes conflictive occupant requirements that arise in a day lit indoor environment. This is the research question that provides the basis for this Ph.D. work. As it touches upon several fields of application, the research question is untangled into four steps, each of which corresponds to a chapter of the thesis. 1) What characterises intelligent behaviour for a building envelope. 2) What characterises indoor day lighting quality. 3) Which functions can an intelligent building envelope be expected to perform in the context of day lighting quality. 4) How are the materials, components and composition of an intelligent building envelope designed to influence this performance. The emphasis is on design, environmental aspects, energy conservation, functional analysis and physical applications.

  11. Early Site Permit Demonstration Program: Plant parameters envelope report

    International Nuclear Information System (INIS)

    The Early Site Permit (ESP) Demonstration Program is the nuclear industry's initiative for piloting the early resolution of siting-related issues before the detailed design proceedings of the combined operating license review. The ESP Demonstration Program consists of three phases. The plant parameters envelopes task is part of Phase 1, which addresses the generic review of applicable federal regulations and develops criteria for safety and environmental assessment of potential sites. The plant parameters envelopes identify parameters that characterize the interface between an ALWR design and a potential site, and quantify the interface through values selected from the Utility Requirements Documents, vendor design information, or engineering assessments. When augmented with site-specific information, the plant parameters envelopes provide sufficient information to allow ESPs to be granted based on individual ALWR design information or enveloping design information for the evolutionary, passive, or generic ALWR plants. This document is expected to become a living document when used by future applicants

  12. Envelope order tracking for fault detection in rolling element bearings

    Science.gov (United States)

    Guo, Yu; Liu, Ting-Wei; Na, Jing; Fung, Rong-Fong

    2012-12-01

    An envelope order tracking analysis scheme is proposed in the paper for the fault detection of rolling element bearing (REB) under varying-speed running condition. The developed method takes the advantages of order tracking, envelope analysis and spectral kurtosis. The fast kurtogram algorithm is utilized to obtain both optimal center frequency and bandwidth of the band-pass filter based on the maximum spectral kurtosis. The envelope containing vibration features of the incipient REB fault can be extracted adaptively. The envelope is re-sampled by the even-angle sampling scheme, and thus the non-stationary signal in the time domain is represented as a quasi-stationary signal in the angular domain. As a result, the frequency-smear problem can be eliminated in order spectrum and the fault diagnosis of REB in the varying-speed running condition of the rotating machinery is achieved. Experiments are conducted to verify the validity of the proposed method.

  13. Low Permeation Envelope Material Development for Titan Aerobot Project

    Data.gov (United States)

    National Aeronautics and Space Administration — Aerobot vehicles for missions on Titan require envelope materials that are strong, light and durable. Unlike terrestrial balloon materials, these must be able to...

  14. Polarimetry and the Envelopes of Magellanic B[e] Supergiants

    CERN Document Server

    Magalhães, A M; Melgarejo, R; Pereyra, A

    2006-01-01

    We discuss the nature of the circumstellar envelopes around the B[e] supergiants (B[e]SG) in the Magellanic Clouds (MC). Contrary to those in the Galaxy, the MC B[e]SG have a well defined luminosity and can be considered members of a well defined class. We discuss spectroscopy and optical broadband polarimetry and spectropolarimetry data. These data show for the first time detailed changes in the polarization across several spectral features. We show that the envelopes of the B[e]SG are generally variable. Broadband polarimetry data show that the envelopes are definitely non-spherically symmetric and large non-axisymmetric ejections may occur. In addition to that, spectropolarimetry is coming of age as a tool to study the B[e]SG envelope structure.

  15. Beam envelope calculations in general linear coupled lattices

    Energy Technology Data Exchange (ETDEWEB)

    Chung, Moses, E-mail: mchung@unist.ac.kr [Department of Physics, Ulsan National Institute of Science and Technology, Ulsan 689-798 (Korea, Republic of); Qin, Hong [Plasma Physics Laboratory, Princeton University, Princeton, New Jersey 08543 (United States); Department of Modern Physics, University of Science and Technology of China, Hefei, Anhui 230026 (China); Groening, Lars; Xiao, Chen [GSI Helmholtzzentrum für Schwerionenforschung GmbH, Planckstrasse 1, D-64291 Darmstadt (Germany); Davidson, Ronald C. [Plasma Physics Laboratory, Princeton University, Princeton, New Jersey 08543 (United States)

    2015-01-15

    The envelope equations and Twiss parameters (β and α) provide important bases for uncoupled linear beam dynamics. For sophisticated beam manipulations, however, coupling elements between two transverse planes are intentionally introduced. The recently developed generalized Courant-Snyder theory offers an effective way of describing the linear beam dynamics in such coupled systems with a remarkably similar mathematical structure to the original Courant-Snyder theory. In this work, we present numerical solutions to the symmetrized matrix envelope equation for β which removes the gauge freedom in the matrix envelope equation for w. Furthermore, we construct the transfer and beam matrices in terms of the generalized Twiss parameters, which enables calculation of the beam envelopes in arbitrary linear coupled systems.

  16. Transport of Ions Across the Inner Envelope Membrane of Chloroplasts

    Energy Technology Data Exchange (ETDEWEB)

    McCarty, R. E.

    2004-06-02

    The technical report outlines the results of nine years of research on how ions cross the inner envelope membrane of chloroplasts. The ions include protons, nitrite, calcium and ferrous iron. Bicarbonate transport was also studied.

  17. Photon Bubbles in the Circumstellar Envelopes of Young Massive Stars

    CERN Document Server

    Turner, N J; Yorke, H W

    2007-01-01

    We show that the optically-thick dusty envelopes surrounding young high-mass stars are subject to the photon bubble instability. The infrared radiation passing through the envelope amplifies magnetosonic disturbances, with growth rates in our local numerical radiation MHD calculations that are consistent with a linear analysis. Modes with wavelengths comparable to the gas pressure scale height grow by more than two orders of magnitude in a thousand years, reaching non-linear amplitudes within the envelope lifetime. If the magnetic pressure in the envelope exceeds the gas pressure, the instability develops into trains of propagating shocks. Radiation escapes readily through the low-density material between the shocks, enabling accretion to continue despite the Eddington limit imposed by the dust opacity. The supersonic motions arising from the photon bubble instability can help explain the large velocity dispersions of hot molecular cores, while conditions in the shocked gas are suitable for maser emission. We...

  18. CISBAT 2003 proceedings. BuildingEnvelopes.org. Innovation in building envelopes and environmental systems

    Energy Technology Data Exchange (ETDEWEB)

    Scartezzini, J.-L.

    2003-07-01

    Hosted by the Swiss Federal Institute of Technology (EPFL) in Lausanne and jointly organised by EPFL and the Harvard University, Cambridge, MA, USA, the international conference 'Innovation in building envelopes and environmental systems' enjoyed the attendance of 140 participants from 14 countries all around the world. The conference proceedings include the 63 presentations grouped in 9 sections. The 3 keynote speakers addressed the following topics: Sustainable buildings, USA research; Nanostructured materials for solar energy conversion; From smart buildings to ambient intelligence. The 9 groups of topics were: Building envelopes design and renovation; Solar collectors and systems; Indoor environment quality and health; Daylighting and visual ergonomy; Advanced building control systems; New construction materials; Environmental impacts of construction; Cities, infrastructures and sustainable development; Software. Organised each second year for now 20 years, the international conference CISBAT is amongst the leading ones in its field. The 2003 edition closed with a video conference from the USA, entitled 'Cradle to cradle - A design revolution', presented by the architect W. Mc Donough, Winner of 1996 Presidential Prize for Sustainable Development.

  19. Torsin Mediates Primary Envelopment of Large Ribonucleoprotein Granules at the Nuclear Envelope

    Directory of Open Access Journals (Sweden)

    Vahbiz Jokhi

    2013-04-01

    Full Text Available A previously unrecognized mechanism through which large ribonucleoprotein (megaRNP granules exit the nucleus is by budding through the nuclear envelope (NE. This mechanism is akin to the nuclear egress of herpes-type viruses and is essential for proper synapse development. However, the molecular machinery required to remodel the NE during this process is unknown. Here, we identify Torsin, an AAA-ATPase that in humans is linked to dystonia, as a major mediator of primary megaRNP envelopment during NE budding. In torsin mutants, megaRNPs accumulate within the perinuclear space, and the messenger RNAs contained within fail to reach synaptic sites, preventing normal synaptic protein synthesis and thus proper synaptic bouton development. These studies begin to establish the cellular machinery underlying the exit of megaRNPs via budding, offer an explanation for the “nuclear blebbing” phenotype found in dystonia models, and provide an important link between Torsin and the synaptic phenotypes observed in dystonia.

  20. Investigating the periodicity of transient-evoked otoacoustic emission envelopes

    DEFF Research Database (Denmark)

    Verhulst, Sarah

    2011-01-01

    This study investigates the cochlear origin of the multiple temporal lobes that are often observed in the transient-evoked otoacoustic emission (TEOAE) envelope. This "waxing and waning" of the OAE amplitude can be observed in tone-burst (TB) OAEs and sometimes also in click-evoked (CE) OAEs. TBOAE...... and the middle-ear boundary may contribute to the TBOAE envelope periodicity, but were not the main modulation component in waxing and waning of the investigated TBOAEs....

  1. Structure of the Jovian envelope from Pioneer 10 gravity data

    Science.gov (United States)

    Anderson, J. D.; Hubbard, W. B.; Slattery, W. L.

    1974-01-01

    Measurement of Jupiter's zonal harmonics J2 and J4 by the celestial mechanics experiment on Pioneer 10 may be used to obtain a constraint on the structure of the outer envelope of Jupiter, using an inversion technique which is insensitive to the structure of the deep interior for a plausible class of planetary models. The derived structure is consistent with an adiabatic, solar-composition envelope with a starting temperature of 250 plus or minus 40 K at 1 bar pressure.

  2. Representation Theory of Quantized Enveloping Algebras with Interpolating Real Structure

    Directory of Open Access Journals (Sweden)

    Kenny De Commer

    2013-12-01

    Full Text Available Let g be a compact simple Lie algebra. We modify the quantized enveloping ∗-algebra associated to g by a real-valued character on the positive part of the root lattice. We study the ensuing Verma module theory, and the associated quotients of these modified quantized enveloping ∗-algebras. Restricting to the locally finite part by means of a natural adjoint action, we obtain in particular examples of quantum homogeneous spaces in the operator algebraic setting.

  3. The Nonlinear Analytical Envelope Equation in quadratic nonlinear crystals

    OpenAIRE

    Bache, Morten

    2016-01-01

    We here derive the so-called Nonlinear Analytical Envelope Equation (NAEE) inspired by the work of Conforti et al. [M. Conforti, A. Marini, T. X. Tran, D. Faccio, and F. Biancalana, "Interaction between optical fields and their conjugates in nonlinear media," Opt. Express 21, 31239-31252 (2013)], whose notation we follow. We present a complete model that includes $\\chi^{(2)}$ terms [M. Conforti, F. Baronio, and C. De Angelis, "Nonlinear envelope equation for broadband optical pulses in quadra...

  4. Incorporation of cellular proteins into enveloped virus particles

    OpenAIRE

    Hammarstedt, Maria

    2006-01-01

    This thesis work aimed to investigate the assembly and budding of enveloped virus particles with focus on the fate of cellular proteins, present in or near the plasma membrane (PM) where the budding occurs. It was previously shown that compact viruses, like alphaviruses, with a covering outer protein coat, did not contain any cellular proteins in the envelope. However, cellular proteins were found in purified retroviral preparations and these proteins were thought to be spec...

  5. Adaptive building envelopes, component development as well as implementation strategies

    OpenAIRE

    Tillmann Klein; Ulrich Knaack

    2015-01-01

    The papers in this issue of JFDE discuss the potential of adaptive building envelopes, component development as well as implementation strategies. The applied practice paper demonstrates decision strategies behind the adaptive sun shading system of the Al-Bahr Towers. Additivity in building envelopes is not only a strategy to fulfil the growing demands for energy efficient buildings and comfort but has great architectural implications as well. In general it asks for more complex components as...

  6. Large scale RNAi reveals the requirement of nuclear envelope breakdown for nuclear import of human papillomaviruses.

    Directory of Open Access Journals (Sweden)

    Inci Aydin

    2014-05-01

    Full Text Available A two-step, high-throughput RNAi silencing screen was used to identify host cell factors required during human papillomavirus type 16 (HPV16 infection. Analysis of validated hits implicated a cluster of mitotic genes and revealed a previously undetermined mechanism for import of the viral DNA (vDNA into the nucleus. In interphase cells, viruses were endocytosed, routed to the perinuclear area, and uncoated, but the vDNA failed to be imported into the nucleus. Upon nuclear envelope perforation in interphase cells HPV16 infection occured. During mitosis, the vDNA and L2 associated with host cell chromatin on the metaphase plate. Hence, we propose that HPV16 requires nuclear envelope breakdown during mitosis for access of the vDNA to the nucleoplasm. The results accentuate the value of genes found by RNAi screens for investigation of viral infections. The list of cell functions required during HPV16 infection will, moreover, provide a resource for future virus-host cell interaction studies.

  7. Preserving Envelope Efficiency in Performance Based Code Compliance

    Energy Technology Data Exchange (ETDEWEB)

    Thornton, Brian A. [Thornton Energy Consulting (United States); Sullivan, Greg P. [Efficiency Solutions (United States); Rosenberg, Michael I. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Baechler, Michael C. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States)

    2015-06-20

    The City of Seattle 2012 Energy Code (Seattle 2014), one of the most progressive in the country, is under revision for its 2015 edition. Additionally, city personnel participate in the development of the next generation of the Washington State Energy Code and the International Energy Code. Seattle has pledged carbon neutrality by 2050 including buildings, transportation and other sectors. The United States Department of Energy (DOE), through Pacific Northwest National Laboratory (PNNL) provided technical assistance to Seattle in order to understand the implications of one potential direction for its code development, limiting trade-offs of long-lived building envelope components less stringent than the prescriptive code envelope requirements by using better-than-code but shorter-lived lighting and heating, ventilation, and air-conditioning (HVAC) components through the total building performance modeled energy compliance path. Weaker building envelopes can permanently limit building energy performance even as lighting and HVAC components are upgraded over time, because retrofitting the envelope is less likely and more expensive. Weaker building envelopes may also increase the required size, cost and complexity of HVAC systems and may adversely affect occupant comfort. This report presents the results of this technical assistance. The use of modeled energy code compliance to trade-off envelope components with shorter-lived building components is not unique to Seattle and the lessons and possible solutions described in this report have implications for other jurisdictions and energy codes.

  8. Thermal performance of integration of solar collectors and building envelopes

    Institute of Scientific and Technical Information of China (English)

    于国清; 龚小辉; 曹双华

    2009-01-01

    The integration of building with solar collector was studied. The theoretical model of integration of building envelopes and flat plate solar collectors was set up and the thermal performance of integration was studied in winter and summer,and compared to envelopes without solar collectors. The results show that the solar collection efficiency is raised in the integration of building envelopes and solar collectors with the air layer doors closed. This is true whether in winter or summer. The increment is higher as the inlet water temperature increases or the ambient temperature is low. In winter,the heat loss is significantly reduced through integration of the building envelopes and solar collectors with the closed air layer doors. The integration with the open air layer door is worse than that without collectors. In summer,the heat gains of the integration of envelopes and solar collectors are more obviously reduced than envelopes without collectors,the integration with the open air layer door is a little better than the closed one,but the difference is very small.

  9. Dynamics of a Supernova Envelope in a Cloudy Interstellar Medium

    CERN Document Server

    Korolev, V V; Kovalenko, I G; Shchekinov, Yu A

    2015-01-01

    The evolution of a supernova remnant in a cloudy medium as a function of the volume filling factor of the clouds is studied in a three-dimensional axially symmetrical model. The model includes the mixing of heavy elements (metals) ejected by the supernova and their contribution to radiative losses. The interaction of the supernova envelope with the cloudy phase of the interstellar medium leads to nonsimultaneous, and on average earlier, onsets of the radiative phase in different parts of the supernova envelope. Growth in the volume filling factor $f$ leads to a decrease in the time for the transition of the envelope to the radiative phase and a decrease in the envelope's mean radius, due to the increased energy losses by the envelope in the cloudy medium. When the development of hydrodynamical instabilities in the supernova envelope is efficient, the thermal energy falls as $E_t\\sim t^{-2.3}$, for the propagation of the supernova remnant through either a homogeneous or a cloudy medium. When the volume filling...

  10. Planet formation with envelope enrichment: new insights on planetary diversity

    CERN Document Server

    Venturini, Julia; Benz, Willy

    2016-01-01

    We compute, for the first time, self-consistent models of planet growth including the effect of envelope enrichment. The change of envelope metallicity is assumed to be the result of planetesimal disruption or icy pebble sublimation. We solve internal structure equations taking into account global energy conservation for the envelope to compute in-situ planetary growth. We consider different opacities and equations of state suited for a wide range of metallicities. We find that envelope enrichment speeds up the formation of gas giants. It also explains naturally the formation of low and intermediate mass objects with large fractions of H-He (~ 20 - 30 % in mass). High opacity models explain well the metallicity of the giant planets of the solar system, whereas low opacity models are suited for forming small mass objects with thick H-He envelopes and gas giants with sub-solar envelope metallicities. We find good agreement between our models and the estimated water abundance for WASP-43b. For HD 189733b, HD 209...

  11. Jumping the nuclear envelop barrier: Improving polyplex-mediated gene transfection efficiency by a selective CDK1 inhibitor RO-3306.

    Science.gov (United States)

    Zhou, Xuefei; Liu, Xiangrui; Zhao, Bingxiang; Liu, Xin; Zhu, Dingcheng; Qiu, Nasha; Zhou, Quan; Piao, Ying; Zhou, Zhuxian; Tang, Jianbin; Shen, Youqing

    2016-07-28

    Successful transfection of plasmid DNA (pDNA) requires intranuclear internalization of pDNA effectively and the nuclear envelope appears to be one of the critical intracellular barriers for polymer mediated pDNA delivery. Polyethylenimine (PEI), as the classic cationic polymer, compact the negatively charged pDNA tightly and make up stable polyplexes. The polyplexes are too large to enter the nuclear through nuclear pores and it is believed that the nuclear envelope breakdown in mitosis could facilitate the nuclear entry of polyplexes. To jump the nuclear envelope barrier, we used a selective and reversible CDK1 inhibitor RO-3306 to control the G2/M transition of the cell cycle and increased the proportion of mitotic cells which have disappeared nuclear envelope during transfection. Herein, we show that RO-3306 remarkably increases the transfection efficiency of PEI polyplexes through enhanced nuclear localization of PEI and pDNA. However, RO-3306 is less effective to the charge-reversal polymer poly[(2-acryloyl)ethyl(p-boronic acid benzyl)diethylammonium bromide] (B-PDEAEA) which responses to cellular stimuli and releases free pDNA in cytoplasm. Our findings not only offer new opportunities for improving non-viral based gene delivery but also provide theoretical support for the rational design of novel functional polymers for gene delivery. We also report current data showing that RO-3306 synergizes TRAIL gene induced apoptosis in cancer cells. PMID:27212103

  12. Functional dissection of nuclear envelope mRNA translocation system: effects of phorbol ester and a monoclonal antibody recognizing cytoskeletal structures.

    Science.gov (United States)

    Schröder, H C; Diehl-Seifert, B; Rottmann, M; Messer, R; Bryson, B A; Agutter, P S; Müller, W E

    1988-03-01

    Unidirectional transport of poly(A)-containing mRNA [poly(A)+ mRNA] through the nuclear envelope pore complex is thought to be an energy (ATP or GTP)-dependent process which involves a nuclear envelope nucleoside triphosphatase (NTPase). In the intact envelope, this enzyme is regulatable by poly(A) binding and by poly(A)-dependent phosphorylation/dephosphorylation of other components of the mRNA translocation system, which are as yet unidentified. Monoclonal antibodies (mAbs) were elicited against the poly(A) binding nuclear envelope fraction isolated from rat liver. The mAbs were screened for their modulatory effects on mRNA transport in vitro. One stable clone decreased the efflux of rapidly labeled RNA and of one specific mRNA (ovalbumin) from isolated nuclei. It increased the binding of poly(A) to the envelope and increased the maximal catalytic rate of the NTPase, but it did not alter the apparent Km of the enzyme or the extent of its stimulation by poly(A). The nuclear envelope-associated protein kinase that down-regulates the NTPase was inhibited by the antibody, while other protein kinases were not affected. Because both the NTPase and mRNA efflux were inhibited by the tumor promoter, 12-O-tetradecanoylphorbol 13-acetate, the sensitive kinase is probably protein kinase C. Protein kinase C was found to be associated with the isolated nuclear envelope. The antibody reacted with both a Mr 83,000 and a Mr 65,000 nuclear envelope polypeptide from rat liver and other tissues. By immunofluorescence microscopy in CV-1 cells, the antibody localized to the nuclear envelope and, in addition, to cytoplasmic filaments which show some superposition with the microfilament network.

  13. Distinct pathways mediate the sorting of tail-anchored proteins to the plastid outer envelope.

    Directory of Open Access Journals (Sweden)

    Preetinder K Dhanoa

    Full Text Available BACKGROUND: Tail-anchored (TA proteins are a distinct class of membrane proteins that are sorted post-translationally to various organelles and function in a number of important cellular processes, including redox reactions, vesicular trafficking and protein translocation. While the molecular targeting signals and pathways responsible for sorting TA proteins to their correct intracellular destinations in yeasts and mammals have begun to be characterized, relatively little is known about TA protein biogenesis in plant cells, especially for those sorted to the plastid outer envelope. METHODOLOGY/PRINCIPAL FINDINGS: Here we investigated the biogenesis of three plastid TA proteins, including the 33-kDa and 34-kDa GTPases of the translocon at the outer envelope of chloroplasts (Toc33 and Toc34 and a novel 9-kDa protein of unknown function that we define here as an outer envelope TA protein (OEP9. Using a combination of in vivo and in vitro assays we show that OEP9 utilizes a different sorting pathway than that used by Toc33 and Toc34. For instance, while all three TA proteins interact with the cytosolic OEP chaperone/receptor, AKR2A, the plastid targeting information within OEP9 is distinct from that within Toc33 and Toc34. Toc33 and Toc34 also appear to differ from OEP9 in that their insertion is dependent on themselves and the unique lipid composition of the plastid outer envelope. By contrast, the insertion of OEP9 into the plastid outer envelope occurs in a proteinaceous-dependent, but Toc33/34-independent manner and membrane lipids appear to serve primarily to facilitate normal thermodynamic integration of this TA protein. CONCLUSIONS/SIGNIFICANCE: Collectively, the results provide evidence in support of at least two sorting pathways for plastid TA outer envelope proteins and shed light on not only the complex diversity of pathways involved in the targeting and insertion of proteins into plastids, but also the molecular mechanisms that underlie

  14. Multicriteria approach to data envelopment analysis

    Directory of Open Access Journals (Sweden)

    Hélcio Vieira Junior

    2008-08-01

    Full Text Available With the aim of making Data Envelopment Analysis (DEA more acceptable to the managers' community, the Weights Restrictions approaches were born. They allow DEA to not dispose of any data and permit the Decision Maker (DM to have some management over the method. The purpose of this paper is to suggest a Weights Restrictions DEA model that incorporates the DM preference. In order to perform that, we employed the MACBETH methodology as a tool to find out the bounds of the weights to be used in a Weights Restrictions approach named Virtual Weights Restrictions. Our proposal achieved an outcome that has an expressive correlation with three widely used decision-aids methodologies: the ELECTRE III, the SMART and the PROMETHEE I and II. In addition, our approach was able to join the most significant outcomes of all the above three Multicriteria decision-aids methodologies in one unique outcome.Com o objetivo de fazer a Análise Envoltória de Dados (DEA mais aceitável pela comunidade gerencial, as abordagens de Restrição aos Pesos foram criadas. Estas abordagens fazem com que a DEA não descarte nenhum dado e permitem que o Decisor (DM tenha alguma gerência sobre o método. O objetivo deste artigo é sugerir um modelo de restrição aos pesos que incorpore as preferências do DM. Para realizar isto, nós empregamos a metodologia MACBETH como ferramenta para descobrir os limites dos pesos a serem utilizados na abordagem de restrição aos pesos chamada "Restrição aos Pesos Virtuais". Nossa proposta alcançou um resultado que apresenta uma correlação expressiva com três metodologias de apoio à decisão amplamente utilizadas: o ELECTRE III, o SMART e o PROMETHEE I e II. Adicionalmente, nossa abordagem foi capaz de reunir os resultados mais significativos de todas estas três metodologias de apoio à decisão em um único resultado.

  15. Envelope colour on thermal load in hot humid Hong Kong: Effect of hue, value, and chroma

    Institute of Scientific and Technical Information of China (English)

    VickyCHENG; EdwardNG

    2003-01-01

    Cooling energy consumption of a building can be significantly reduced by limiting solar heat gain through envelope, in which depends on the intensity of impinging solar radiation and on the colour of external surface. Albedo, from the thermal point of view, is the prime parameter of interest; however, it does appear to be too conceptual in practice. Architects, when considering choices of envelope colour, the actual decision is between various colours: yellow, blue, or green rather than a single numerical albedo. This study is to investigate the effect and magnitude of colour, in terms of visual qualities hue, value (lightness), and chroma (saturation), on thermal load of buildings. In the experiment, air temperatures inside test cells painted into different colours were measured, the results suggest that colour attribute: chroma has negligible effect on thermal performance of building envelope, while value has significant thermal effect. The effect of hue, as shown in this study, was insignificant, however further study might be needed as to obtain a clearer picture of its effect.

  16. Nuclear Envelope Protein SUN2 Promotes Cyclophilin-A-Dependent Steps of HIV Replication

    Directory of Open Access Journals (Sweden)

    Xavier Lahaye

    2016-04-01

    Full Text Available During the early phase of replication, HIV reverse transcribes its RNA and crosses the nuclear envelope while escaping host antiviral defenses. The host factor Cyclophilin A (CypA is essential for these steps and binds the HIV capsid; however, the mechanism underlying this effect remains elusive. Here, we identify related capsid mutants in HIV-1, HIV-2, and SIVmac that are restricted by CypA. This antiviral restriction of mutated viruses is conserved across species and prevents nuclear import of the viral cDNA. Importantly, the inner nuclear envelope protein SUN2 is required for the antiviral activity of CypA. We show that wild-type HIV exploits SUN2 in primary CD4+ T cells as an essential host factor that is required for the positive effects of CypA on reverse transcription and infection. Altogether, these results establish essential CypA-dependent functions of SUN2 in HIV infection at the nuclear envelope.

  17. HIV-1 Envelope Proteins Complete Their Folding into Six-helix Bundles Immediately after Fusion Pore Formation

    OpenAIRE

    Markosyan, Ruben M; Cohen, Fredric S.; Melikyan, Grigory B.

    2003-01-01

    Fusion proteins of many viruses, including HIV-1 envelope protein (Env), fold into six-helix bundle structures. Fusion between individual Env-expressing cells and target cells was studied by fluorescence microscopy, and a temperature jump technique, to determine whether folding of Env into a bundle is complete by the time fusion pores have formed. Lowering temperature to 4°C immediately after a pore opened halted pore growth, which quickly resumed when temperature was raised again. HIV gp41-d...

  18. Fusion function of the Semliki Forest virus spike is activated by proteolytic cleavage of the envelope glycoprotein precursor p62.

    OpenAIRE

    Lobigs, M; Garoff, H

    1990-01-01

    The precursor protein p62 of the prototype alphavirus Semliki Forest virus (SFV) undergoes during transport to the cell surface a proteolytic cleavage to form the mature envelope glycoprotein E2. To investigate the biological significance of this cleavage event, single amino acid substitutions were introduced at the cleavages site through mutagenesis of cDNA corresponding to the structural region of the SFV genome. The phenotypes of the cleavage site mutants were studied in BHK cells by using...

  19. The dengue virus type 2 envelope protein fusion peptide is essential for membrane fusion

    International Nuclear Information System (INIS)

    The flaviviral envelope (E) protein directs virus-mediated membrane fusion. To investigate membrane fusion as a requirement for virus growth, we introduced 27 unique mutations into the fusion peptide of an infectious cDNA clone of dengue 2 virus and recovered seven stable mutant viruses. The fusion efficiency of the mutants was impaired, demonstrating for the first time the requirement for specific FP AAs in optimal fusion. Mutant viruses exhibited different growth kinetics and/or genetic stabilities in different cell types and adult mosquitoes. Virus particles could be recovered following RNA transfection of cells with four lethal mutants; however, recovered viruses could not re-infect cells. These viruses could enter cells, but internalized virus appeared to be retained in endosomal compartments of infected cells, thus suggesting a fusion blockade. Mutations of the FP also resulted in reduced virus reactivity with flavivirus group-reactive antibodies, confirming earlier reports using virus-like particles.

  20. Repairing oxidized proteins in the bacterial envelope using respiratory chain electrons.

    Science.gov (United States)

    Gennaris, Alexandra; Ezraty, Benjamin; Henry, Camille; Agrebi, Rym; Vergnes, Alexandra; Oheix, Emmanuel; Bos, Julia; Leverrier, Pauline; Espinosa, Leon; Szewczyk, Joanna; Vertommen, Didier; Iranzo, Olga; Collet, Jean-François; Barras, Frédéric

    2015-12-17

    The reactive species of oxygen and chlorine damage cellular components, potentially leading to cell death. In proteins, the sulfur-containing amino acid methionine is converted to methionine sulfoxide, which can cause a loss of biological activity. To rescue proteins with methionine sulfoxide residues, living cells express methionine sulfoxide reductases (Msrs) in most subcellular compartments, including the cytosol, mitochondria and chloroplasts. Here we report the identification of an enzymatic system, MsrPQ, repairing proteins containing methionine sulfoxide in the bacterial cell envelope, a compartment particularly exposed to the reactive species of oxygen and chlorine generated by the host defence mechanisms. MsrP, a molybdo-enzyme, and MsrQ, a haem-binding membrane protein, are widely conserved throughout Gram-negative bacteria, including major human pathogens. MsrPQ synthesis is induced by hypochlorous acid, a powerful antimicrobial released by neutrophils. Consistently, MsrPQ is essential for the maintenance of envelope integrity under bleach stress, rescuing a wide series of structurally unrelated periplasmic proteins from methionine oxidation, including the primary periplasmic chaperone SurA. For this activity, MsrPQ uses electrons from the respiratory chain, which represents a novel mechanism to import reducing equivalents into the bacterial cell envelope. A remarkable feature of MsrPQ is its capacity to reduce both rectus (R-) and sinister (S-) diastereoisomers of methionine sulfoxide, making this oxidoreductase complex functionally different from previously identified Msrs. The discovery that a large class of bacteria contain a single, non-stereospecific enzymatic complex fully protecting methionine residues from oxidation should prompt a search for similar systems in eukaryotic subcellular oxidizing compartments, including the endoplasmic reticulum.

  1. Contribution of intrinsic reactivity of the HIV-1 envelope glycoproteins to CD4-independent infection and global inhibitor sensitivity.

    Directory of Open Access Journals (Sweden)

    Hillel Haim

    2011-06-01

    Full Text Available Human immunodeficiency virus (HIV-1 enters cells following sequential activation of the high-potential-energy viral envelope glycoprotein trimer by target cell CD4 and coreceptor. HIV-1 variants differ in their requirements for CD4; viruses that can infect coreceptor-expressing cells that lack CD4 have been generated in the laboratory. These CD4-independent HIV-1 variants are sensitive to neutralization by multiple antibodies that recognize different envelope glycoprotein epitopes. The mechanisms underlying CD4 independence, global sensitivity to neutralization and the association between them are still unclear. By studying HIV-1 variants that differ in requirements for CD4, we investigated the contribution of CD4 binding to virus entry. CD4 engagement exposes the coreceptor-binding site and increases the "intrinsic reactivity" of the envelope glycoproteins; intrinsic reactivity describes the propensity of the envelope glycoproteins to negotiate transitions to lower-energy states upon stimulation. Coreceptor-binding site exposure and increased intrinsic reactivity promote formation/exposure of the HR1 coiled coil on the gp41 transmembrane glycoprotein and allow virus entry upon coreceptor binding. Intrinsic reactivity also dictates the global sensitivity of HIV-1 to perturbations such as exposure to cold and the binding of antibodies and small molecules. Accordingly, CD4 independence of HIV-1 was accompanied by increased susceptibility to inactivation by these factors. We investigated the role of intrinsic reactivity in determining the sensitivity of primary HIV-1 isolates to inhibition. Relative to the more common neutralization-resistant ("Tier 2-like" viruses, globally sensitive ("Tier 1" viruses exhibited increased intrinsic reactivity, i.e., were inactivated more efficiently by cold exposure or by a given level of antibody binding to the envelope glycoprotein trimer. Virus sensitivity to neutralization was dictated both by the efficiency of

  2. A strategy for O-glycoproteomics of enveloped viruses--the O-glycoproteome of herpes simplex virus type 1.

    Directory of Open Access Journals (Sweden)

    Ieva Bagdonaite

    2015-04-01

    Full Text Available Glycosylation of viral envelope proteins is important for infectivity and interaction with host immunity, however, our current knowledge of the functions of glycosylation is largely limited to N-glycosylation because it is difficult to predict and identify site-specific O-glycosylation. Here, we present a novel proteome-wide discovery strategy for O-glycosylation sites on viral envelope proteins using herpes simplex virus type 1 (HSV-1 as a model. We identified 74 O-linked glycosylation sites on 8 out of the 12 HSV-1 envelope proteins. Two of the identified glycosites found in glycoprotein B were previously implicated in virus attachment to immune cells. We show that HSV-1 infection distorts the secretory pathway and that infected cells accumulate glycoproteins with truncated O-glycans, nonetheless retaining the ability to elongate most of the surface glycans. With the use of precise gene editing, we further demonstrate that elongated O-glycans are essential for HSV-1 in human HaCaT keratinocytes, where HSV-1 produced markedly lower viral titers in HaCaT with abrogated O-glycans compared to the isogenic counterpart with normal O-glycans. The roles of O-linked glycosylation for viral entry, formation, secretion, and immune recognition are poorly understood, and the O-glycoproteomics strategy presented here now opens for unbiased discovery on all enveloped viruses.

  3. Integrated energy design of the building envelope

    Energy Technology Data Exchange (ETDEWEB)

    Vraa Nielsen, M.

    2012-07-01

    This thesis describes the outcome of the PhD project Integrated energy design of the building envelope carried out through a combination of scientific dissemination reported through peer-reviewed journals and a wide range of affiliated projects involved in at an architectural firm. The research project analysed how the implementation of technical knowledge early in the building design process can quantify the effect of a building's facades on its energy efficiency and indoor climate and thereby facilitate a more qualified design development. The project was structured in the following way: 1) the importance of integrating knowledge in the early stages of design, and how it can be done; 2) understanding the facade's typology; and 3) the complex notion of comfort. The project touched not only on the technical capabilities and requirements governing facade design, but also the process by which it takes place. This was done by applying the methodology of Integrated Energy Design (IED) and analysing its applicability in the design of facades. A major part of the project was an actual engagement in the architectural process to test out incorporating a consciousness about energy and comfort as part of a more holistic performance evaluation. The research project illustrates the great potential in taking passive properties into account through a geometrical optimisation inherent in the development of the architectural concept. It demonstrates that integration of technical knowledge at the early stages of design not only can qualify the geometrical processing, but also facilitate the design development of the facade. Thereby a more holistic performance optimisation can be obtained through parameters such as overall facade geometry and orientation, functional organisation, room height and depth, facade layout, window geometry and transparency, design of the window aperture, etc. Through the wide range of affiliated project involved in at the architectural firm over

  4. Energy performance of the self-shading building envelope

    Energy Technology Data Exchange (ETDEWEB)

    Capeluto, I.G. [Climate and Energy Laboratory in Architecture, Faculty of Architecture and Town Planning, Technion: Israel Institute of Technology, Haifa (Israel)

    2002-07-01

    In this work, the Solar Collection Envelope (SCE) concept is used for the generation of the self-shading envelope. The computer model 'SustArc' was applied to create the nomogram of the Solar Collection Envelope. The model allows for the generation of the building shape in a way that the building facades are self-shaded during a required period determined by the designer. The presented method is limited to self-shading buildings and the use of additional shading devices should be considered by the designer to avoid very inclined walls. The model and algorithm for the generation of the Solar Collection Envelope are presented. The paper includes a detailed example of the implementation of the method, and the evaluation of the influence of the proposed building geometry on the energy performance of the building, based on a comparison with a traditional vertical facade building. The simulation results reveal that for all the orientations there is an important improvement in the energy performance of the building when designing according to the self-shading envelope. Similar results can be also obtained for vertical facades using high-performance low-emissivity windows. The combination of the building self-shading geometry and internal blinds provide the best solution, particularly for east and west orientations. (author)

  5. Energy performance of the self-shading building envelope

    Energy Technology Data Exchange (ETDEWEB)

    Capeluto, I.G. [Israel Institute of Technology, Haifa (Israel). Faculty of Architecture and Town PLanning, Climate and Energy Laboratory in Architecture

    2003-03-01

    In this work, the Solar Collection Envelope (SCE) concept is used for the generation of the self-shading envelope. The computer model SustArc was applied to create the nomogram of the Solar Collection Envelope. The model allows for the generation of the building shape in a way that the building facades are self-shaded during a required period determined by the designer. The presented method is limited to self-shading buildings and the use of additional shading devices should be considered by the designer to avoid very inclined walls. The model and algorithm for the generation of the Solar Collection Envelope are presented. The paper includes a detailed example of the implementation of the method, and the evaluation of the influence of the proposed building geometry on the energy performance of the building, based on a comparison with a traditional vertical facade building. The simulation results reveal that for all the orientations there is an important improvement in the energy performance of the building when designing according to the self-shading envelope. Similar results can be also obtained for vertical facades using high-performance low-emissivity windows. The combination of the building self-shading geometry and internal blinds provide the best solution, particularly for east and west orientations. (author)

  6. Building envelope innovation: smart facades for non residential buildings

    Directory of Open Access Journals (Sweden)

    Marco Sala

    2011-11-01

    Full Text Available The research analyzes the evolution of smart façade systems in the area of design and industrial production, in order to investigate the technological, functional and qualitative standards of dynamic façade and evaluate the energy performance of the building envelope as a dynamic system that interacts between indoor and outdoor environment. The study focused on dynamic envelopes for office building analyzing the evolution of façade systems in terms of: building construction, innovative systems, smart materials, dynamic system. Aiming to improve building energy performances. The research, developed during the PhD thesis “Smart Envelope - dynamic and innovative technologies for energy saving” and the research “Abitare Mediterraneo”, aims to identify and define the energy performances of smart envelopes trough the analysis of the state of art, related to dynamic building envelope of double skin façade, and the development of a new dynamic façade system.

  7. Solar envelope concepts: moderate density building applications. Final report

    Energy Technology Data Exchange (ETDEWEB)

    Knowles, R.L.; Berry, R.D.

    1980-04-01

    Solar energy utilization in urban areas requires public guarantees that all property owners have direct access to the sun. The study examines the implications of this premise in relation to the need for cities to also encourage or accommodate rebuilding and future development. The public policy mechanism for guaranteeing solar access is conceptualized as a solar zoning envelope that allows the largest possible building bulk on a land parcel without shadowing neighboring properties during specified times. Step-by-step methods for generating solar envelopes are described with extensive drawings, showing a variety of urban platting and lot configurations. Development and design possibilities are examined on a selected set of Los Angeles sites with typically diverse urban characteristics. Envelope attributes suitable for encouraging moderate-density commercial and residential building are examined in the context of two hypothetical but realistic development programs: one for speculative office buildings and one for condominium housing. Numerous illustrations of envelope forms and prototypical building designs are provided. The results of development simulation studies on all test sites are tabulated to show building bulk, density, land-coverage and open space characteristics obtainable under the hypothesized envelopes.

  8. Responsive envelope tessellation and stochastic rotation of 4-fold penttiles

    Directory of Open Access Journals (Sweden)

    Sambit Datta

    2014-06-01

    Full Text Available This paper reports on the design and control of a responsive envelope based on the rotation of tessellated components. The study investigates responsive and dynamic approaches for building facades and envelopes to regulate solar shading, light control, views and thermal gain within the building. It is well known that near real-time visual output from computational simulation can significantly impact the prediction of dynamic building-environment interactions and lead to the development of smart, adaptable, net zero energy buildings. To address these motivations, this paper reports the development of an experimental simulation of a responsive envelope based on using a 4-fold penttile scheme. The simulation is developed using a novel pentagonal approach involving component (tile design, tessellation and control methods. The paper further elaborates on the geometry and control aspects of the facade subdivision and presents the results of applying this tessellation geometry to a building envelope shading study based on facade components with rotation. Finally, it tests the “responsiveness” to multiple performance metrics by applying a non-deterministic exploration method for the stochastic rotation of individual panels. The sophisticated evaluation of alternative envelope configurations for a set of performance criteria require a tighter computational coupling between modelling and control of dynamic geometry.

  9. The South Carolina bridge-scour envelope curves

    Science.gov (United States)

    Benedict, Stephen T.; Feaster, Toby D.; Caldwell, Andral

    2016-09-30

    The U.S. Geological Survey, in cooperation with the South Carolina Department of Transportation, conducted a series of three field investigations to evaluate historical, riverine bridge scour in the Piedmont and Coastal Plain regions of South Carolina. These investigations included data collected at 231 riverine bridges, which lead to the development of bridge-scour envelope curves for clear-water and live-bed components of scour. The application and limitations of the South Carolina bridge-scour envelope curves were documented in four reports, each report addressing selected components of bridge scour. The current investigation (2016) synthesizes the findings of these previous reports into a guidance manual providing an integrated procedure for applying the envelope curves. Additionally, the investigation provides limited verification for selected bridge-scour envelope curves by comparing them to field data collected outside of South Carolina from previously published sources. Although the bridge-scour envelope curves have limitations, they are useful supplementary tools for assessing the potential for scour at riverine bridges in South Carolina.

  10. AN EFFICIENT SIMULATION OF MULTIPLE CORRELATED RAYLEIGH FADING ENVELOPES

    Institute of Scientific and Technical Information of China (English)

    Zhou Ke; Cao Shike; Song Rongfang

    2008-01-01

    In order to better assess the performance of wireless communication systems,it is desirable to produce multiple Rayleigh fading envelopes with specified correlations. In this paper,we analyze theoretically a procedure which generates correlated Gaussian random variables from independent Gaussian random variables and give a physical explanation for the limitation of this procedure. Then,based on some uncorrelated Rayleigh fading envelopes,a simple but efficient procedure for generating an arbitrary number of cross-correlated Rayleigh fading envelopes is proposed. Simulation results and computational complexity analysis are presented,which show that the proposed method has some advantages,such as high accuracy,low computational complexity and easy implementation,over the conventional simulation method.

  11. Experimental evaluation of envelope tracking techniques for voltage disturbances

    Energy Technology Data Exchange (ETDEWEB)

    Marei, Mostafa I. [Electrical Power and Machines Dept., Faculty of Engineering, Ain Shams University, 1 El-Sarayat St., Abbasia, 11517 Cairo (Egypt); El-Saadany, Ehab F.; Salama, Magdy M.A. [Electrical and Computer Engineering Dept., University of Waterloo, 200 University Avenue West, Waterloo, ON (Canada)

    2010-03-15

    In this paper a digital signal processor (DSP) based real time voltage envelope tracking system is developed and examined. The ADAptive LINEar neuron (ADALINE) and the Recursive Least Square (RLS) algorithms are adopted for envelope tracking. The proposed ADALINE and RLS algorithms give accurate results even under rapid dynamic changes. The paper investigates the effects of different parameters on the performance of the ADALINE algorithm and that of the RLS algorithm. The experimental system is cantered around a Texas Instrument 16 bit fixed-point arithmetic (TMS320LF2407A) evaluation board. Both the ADALINE and the RLS tracking algorithms are developed using the DSP-assembly language. A simple voltage flicker generator is implemented to produce various voltage disturbances. Extensive tests of the proposed envelope tracking algorithms are conducted to evaluate their dynamic performance. (author)

  12. An adaptive envelope spectrum technique for bearing fault detection

    International Nuclear Information System (INIS)

    In this work, an adaptive envelope spectrum (AES) technique is proposed for bearing fault detection, especially for analyzing signals with transient events. The proposed AES technique first modulates the signal using the empirical mode decomposition to formulate the representative intrinsic mode functions (IMF), and then a novel IMF reconstruction method is proposed based on a correlation analysis of the envelope spectra. The reconstructed signal is post-processed by using an adaptive filter to enhance impulsive signatures, where the filter length is optimized by the proposed sparsity analysis technique. Bearing health conditions are diagnosed by examining bearing characteristic frequency information on the envelope power spectrum. The effectiveness of the proposed fault detection technique is verified by a series of experimental tests corresponding to different bearing conditions. (paper)

  13. The Binding Energy Parameter for Common Envelope Evolution

    CERN Document Server

    Wang, Cheng; Li, Xiang-Dong

    2016-01-01

    The binding energy parameter $\\lambda$ plays a vital role in common envelope evolution. Though it is well known that $\\lambda$ takes different values for stars with different masses and varies during stellar evolution, it has been erroneously adopted as a constant in most of the population synthesis calculations. We have systematically calculated the values of $\\lambda$ for stars of masses $1-60\\,M_{\\odot}$ by use of an updated stellar evolution code, taking into account contribution from both gravitational energy and internal energy to the binding energy of the envelope. We adopt the criterion for the core-envelope boundary advocated by \\citet{Ivanova2011}. A new kind of $\\lambda$ with the enthalpy prescription is also investigated. We present fitting formulae for the calculated values of various kinds of $\\lambda$, which can be used in future population synthesis studies.

  14. Efficiency of Planetesimal Ablation in Giant Planetary Envelopes

    CERN Document Server

    Pinhas, Arazi; Clarke, Cathie

    2016-01-01

    Observations of exoplanetary spectra are leading to unprecedented constraints on their atmospheric elemental abundances, particularly O/H, C/H, and C/O ratios. Recent studies suggest that elemental ratios could provide important constraints on formation and migration mechanisms of giant exoplanets. A fundamental assumption in such studies is that the chemical composition of the planetary envelope represents the sum-total of compositions of the accreted gas and solids during the formation history of the planet. We investigate the efficiency with which accreted planetesimals ablate in a giant planetary envelope thereby contributing to its composition rather than sinking to the core. From considerations of aerodynamic drag causing `frictional ablation' and the envelope temperature structure causing `thermal ablation', we compute mass ablations for impacting planetesimals of radii 30 m to 1 km for different compositions (ice to iron) and a wide range of velocities and impact angles, assuming spherical symmetry. I...

  15. Intermediate luminosity optical transients during the grazing envelope evolution (GEE)

    Science.gov (United States)

    Soker, Noam

    2016-08-01

    By comparing photon diffusion time with gas outflow time, I argue that a large fraction of the energy carried by the jets during the grazing envelope evolution (GEE) might end in radiation, hence leading to an intermediate luminosity optical transient (ILOT). In the GEE a companion orbiting near the outskirts of the larger primary star accretes mass through an accretion disk, and launches jets that efficiently remove the envelope gas from the vicinity of the secondary star. In cases of high mass accretion rates onto the stellar companion the energy carried by the jets surpass the recombination energy from the ejected mass, and when the primary star is a giant this energy surpasses also the gravitational binding energy of the binary system. Some future ILOTs of giant stars might be better explained by the GEE than by merger and common envelope evolution without jets.

  16. Envelope induced ionization dynamics beyond the dipole approximation

    CERN Document Server

    Simonsen, Aleksander Skjerlie; Førre, Morten; Lindroth, Eva; Selstø, Sølve

    2015-01-01

    When atoms and molecules are ionized by laser pulses of finite duration and increasingly high intensities, the validity of the much used dipole approximation, in which the spatial dependence and magnetic component of the external field are neglected, eventually breaks down. We report that when going beyond the dipole approximation for the description of atoms exposed to ultraviolet light, the spatial dependence of the pulse shape, the envelope, provides the dominant correction, while the spatial dependence of the carrier may safely be neglected in the general case. We present a first order beyond-dipole correction to the Hamiltonian which accounts exclusively for effects stemming from the carrier-envelope of the pulse. This much simpler form of the correction is further discussed in connection with various descriptions of the light-matter interaction. We demonstrate by ab initio calculations that this approximation, which we will refer to as the envelope approximation, reproduces the full interaction beyond t...

  17. The envelope Hamiltonian for electron interaction with ultrashort pulses

    CERN Document Server

    Toyota, Koudai; Rost, Jan M

    2014-01-01

    For ultrashort VUV pulses with a pulse length comparable to the orbital time of the bound electrons they couple to we propose a simplified envelope Hamiltonian. It is based on the Kramers-Henneberger representation in connection with a Floquet expansion of the strong-field dynamics but keeps the time dependence of the pulse envelope explicit. Thereby, the envelope Hamiltonian captures the essence of the physics, -- light-induced shifts of bound states, single-photon absorption, and non-adiabatic electronic transitions. It delivers quantitatively accurate ionization dynamics and allows for physical insight into the processes occurring. Its minimal requirements for construction in terms of laser parameters make it ideally suited for a large class of atomic and molecular problems.

  18. The binding energy parameter for common envelope evolution

    Science.gov (United States)

    Wang, Chen; Jia, Kun; Li, Xiang-Dong

    2016-08-01

    The binding energy parameter λ plays a vital role in common envelope evolution. Though it is well known that λ takes different values for stars with different masses and varies during stellar evolution, it has been erroneously adopted as a constant in most population synthesis calculations. We have systematically calculated the values of λ for stars of masses 1 – 60 M ⊙ by use of an updated stellar evolution code, taking into account the contribution from both gravitational energy and internal energy to the binding energy of the envelope. We adopt the criterion for the core-envelope boundary advocated by Ivanova. A new kind of λ with an enthalpy prescription is also investigated. We present fitting formulae for the calculated values of various kinds of λ, which can be used in future population synthesis studies.

  19. Intermediate luminosity optical transients during the grazing envelope evolution (GEE)

    CERN Document Server

    Soker, Noam

    2016-01-01

    By comparing photon diffusion time with gas outflow time, I argue that a large fraction of the energy carried by the jets during the grazing envelope evolution (GEE) might end in radiation, hence leading to an intermediate luminosity optical transient (ILOT). In the GEE a companion orbiting near the outskirts of the larger primary star accretes mass through an accretion disk, and launches jets that efficiently remove the envelope gas in the vicinity of the secondary star. In cases of high mass accretion rates onto the stellar companion the energy carried by the jets surpass the recombination energy from the ejected mass, and when the primary star is a giant this energy surpasses also the gravitational energy of the binary system. Some future ILOTs of giant stars might be better explained by the GEE than by merger and common envelope evolution without jets.

  20. Planetary Gearbox Fault Diagnosis Using Envelope Manifold Demodulation

    Directory of Open Access Journals (Sweden)

    Weigang Wen

    2016-01-01

    Full Text Available The important issue in planetary gear fault diagnosis is to extract the dependable fault characteristics from the noisy vibration signal of planetary gearbox. To address this critical problem, an envelope manifold demodulation method is proposed for planetary gear fault detection in the paper. This method combines complex wavelet, manifold learning, and frequency spectrogram to implement planetary gear fault characteristic extraction. The vibration signal of planetary gear is demodulated by wavelet enveloping. The envelope energy is adopted as an indicator to select meshing frequency band. Manifold learning is utilized to reduce the effect of noise within meshing frequency band. The fault characteristic frequency of the planetary gear is shown by spectrogram. The planetary gearbox model and test rig are established and experiments with planet gear faults are conducted for verification. All results of experiment analysis demonstrate its effectiveness and reliability.

  1. Topological ∗-algebras with *-enveloping Algebras II

    Indian Academy of Sciences (India)

    S J Bhatt

    2001-02-01

    Universal *-algebras *() exist for certain topological ∗-algebras called algebras with a *-enveloping algebra. A Frechet ∗-algebra has a *-enveloping algebra if and only if every operator representation of maps into bounded operators. This is proved by showing that every unbounded operator representation , continuous in the uniform topology, of a topological ∗-algebra , which is an inverse limit of Banach ∗-algebras, is a direct sum of bounded operator representations, thereby factoring through the enveloping pro-* algebra () of . Given a *-dynamical system (, , ), any topological ∗-algebra containing (, ) as a dense ∗-subalgebra and contained in the crossed product *-algebra *(, , ) satisfies ()=*(, , ). If $G = \\mathbb{R}$, if is an -invariant dense Frechet ∗-subalgebra of such that () = , and if the action on is -tempered, smooth and by continuous ∗-automorphisms: then the smooth Schwartz crossed product $S(\\mathbb{R}, B, )$ satisfies $E(S(\\mathbb{R}, B, )) = C^*(\\mathbb{R}, A, )$. When is a Lie group, the ∞-elements ∞(), the analytic elements () as well as the entire analytic elements () carry natural topologies making them algebras with a *-enveloping algebra. Given a non-unital *-algebra , an inductive system of ideals is constructed satisfying $A = C^*-\\mathrm{ind} \\lim I_$; and the locally convex inductive limit $\\mathrm{ind}\\lim I_$ is an -convex algebra with the *-enveloping algebra and containing the Pedersen ideal of . Given generators with weakly Banach admissible relations , we construct universal topological ∗-algebra (, ) and show that it has a *-enveloping algebra if and only if (, ) is *-admissible.

  2. Efficiency of Planetesimal Ablation in Giant Planetary Envelopes

    Science.gov (United States)

    Pinhas, Arazi; Madhusudhan, Nikku; Clarke, Cathie

    2016-09-01

    Observations of exoplanetary spectra are leading to unprecedented constraints on their atmospheric elemental abundances, particularly O/H, C/H, and C/O ratios. Recent studies suggest that elemental ratios could provide important constraints on formation and migration mechanisms of giant exoplanets. A fundamental assumption in such studies is that the chemical composition of the planetary envelope represents the sum-total of compositions of the accreted gas and solids during the formation history of the planet. We investigate the efficiency with which accreted planetesimals ablate in a giant planetary envelope thereby contributing to its composition rather than sinking to the core. From considerations of aerodynamic drag causing `frictional ablation' and the envelope temperature structure causing `thermal ablation', we compute mass ablations for impacting planetesimals of radii 30 m to 1 km for different compositions (ice to iron) and a wide range of velocities and impact angles, assuming spherical symmetry. Icy impactors are fully ablated in the outer envelope for a wide range of parameters. Even for Fe impactors substantial ablation occurs in the envelope for a wide range of sizes and velocities. For example, iron impactors of sizes below ˜0.5 km and velocities above ˜30 km/s are found to ablate by ˜ 60-80% within the outer envelope at pressures below 103 bar due to frictional ablation alone. For deeper pressures (˜107 bar), substantial ablation happens over a wider range of parameters. Therefore, our exploratory study suggests that atmospheric abundances of volatile elements in giant planets reflect their accretion history during formation.

  3. The envelopes of amphibian oocytes: physiological modifications in Bufo arenarum

    Directory of Open Access Journals (Sweden)

    Sánchez Mercedes

    2003-02-01

    Full Text Available Abstract A characterization of the Amphibian Bufo arenarum oocyte envelope is presented. It was made in different functional conditions of the oocyte: 1 when it has been released into the coelomic cavity during ovulation (surrounded by the coelomic envelope, (CE, 2 after it has passed through the oviduct and is deposed (surrounded by the viteline envelope, (VE, and 3 after oocyte activation (surrounded by the fertilization envelope, (FE. The characterization was made by SDS-PAGE followed by staining for protein and glycoproteins. Labeled lectins were used to identify glycosidic residues both in separated components on nitrocellulose membranes or in intact oocytes and embryos. Proteolytic properties of the content of the cortical granules were also analyzed. After SDS-PAGE of CE and VE, a different protein pattern was observed. This is probably due to the activity of a protease present in the pars recta of the oviduct. Comparison of the SDS-PAGE pattern of VE and FE showed a different mobility for one of the glycoproteins, gp75. VE and FE proved to have different sugar residues in their oligosaccharide chains. Mannose residues are only present in gp120 of the three envelopes. N-acetyl-galactosamine residues are present in all of the components, except for gp69 in the FE. Galactose residues are present mainly in gp120 of FE. Lectin-binding assays indicate the presence of glucosamine, galactose and N-acetyl galactosamine residues and the absence (or non-availability of N-acetyl-glucosamine or fucose residues on the envelopes surface. The cortical granule product (CGP shows proteolytic activity on gp75 of the VE.

  4. Antiviral Inhibition of Enveloped Virus Release by Tetherin/BST-2: Action and Counteraction

    Directory of Open Access Journals (Sweden)

    Stuart J. D. Neil

    2011-05-01

    Full Text Available Tetherin (BST2/CD317 has been recently recognized as a potent interferon-induced antiviral molecule that inhibits the release of diverse mammalian enveloped virus particles from infected cells. By targeting an immutable structure common to all these viruses, the virion membrane, evasion of this antiviral mechanism has necessitated the development of specific countermeasures that directly inhibit tetherin activity. Here we review our current understanding of the molecular basis of tetherin’s mode of action, the viral countermeasures that antagonize it, and how virus/tetherin interactions may affect viral transmission and pathogenicity.

  5. Production and Characterization of Monoclonal Antibodies of Shrimp White Spot Syndrome Virus Envelope Protein VP28

    Institute of Scientific and Technical Information of China (English)

    Wan-gang GU; Jun-fa YUAN; Ge-lin XU; Li-juan LI; Ni LIU; Cong ZHANG; Jian-hong ZHANG; Zheng-li SHI

    2007-01-01

    BALB/c mice were immunized with purified White spot syndrome virus (WSSV).Six monoclonal antibody cell lines were selected by ELISA with VP28 protein expressed in E.coll in vitro neutralization experiments showed that 4 of them could inhibit the virus infection in crayfish.Westernblot suggested that all these monoclonal antibodies were against the conformational structure of VP28.The monoclonal antibody 7B4 was labeled with colloidal gold particles and used to locate the VP28 on virus envelope by immunogold labeling.These monoclonal antibodies could be used to develop immunological diagnosis methods for WSSV infection.

  6. Structural proteins of ribonucleic acid tumor viruses. Purification of envelope, core, and internal components.

    Science.gov (United States)

    Strand, M; August, J T

    1976-01-25

    Murine type C virus structural proteins, the envelope glycopeptides, 30,000 dalton major core protein, and 15,000 dalton internal protein have each been purified to near homogeneity and in high yield from the smae batch of virus by use of phosphocellulose column chromatography and gel filtration procedures. Evidence that these proteins are specified by the viral genome was obtained by competition radioimmunoassay analysis, comparing these polypeptides from Rauscher virus cultivated in a variety of mammalian cell lines; all of the reactive antigenic determinants of these proteins appeared to be virus-specific.

  7. Boosting of HIV-1 neutralizing antibody responses by a distally related retroviral envelope protein

    DEFF Research Database (Denmark)

    Uchtenhagen, Hannes; Schiffner, Torben; Bowles, Emma;

    2014-01-01

    Our knowledge of the binding sites for neutralizing Abs (NAb) that recognize a broad range of HIV-1 strains (bNAb) has substantially increased in recent years. However, gaps remain in our understanding of how to focus B cell responses to vulnerable conserved sites within the HIV-1 envelope...... glycoprotein (Env). In this article, we report an immunization strategy composed of a trivalent HIV-1 (clade B envs) DNA prime, followed by a SIVmac239 gp140 Env protein boost that aimed to focus the immune response to structurally conserved parts of the HIV-1 and simian immunodeficiency virus (SIV) Envs...

  8. Calculation of CWKB envelope in boson and fermion productions

    Indian Academy of Sciences (India)

    S Biswas; I Chowdhury

    2007-01-01

    We present the calculation of envelope of boson and of both low- and high- mass fermion production at the end of inflation when the coherently oscillating inflatons decay into bosons and fermions. We consider three different models of inflation and use CWKB technique to calculate the envelope to understand the structure of resonance band formation. We observe that though low-mass fermion production is not effective in pre-heating because of Pauli blocking, it is quite probable for high-mass fermion to take part in pre-heating.

  9. Method of accurate grinding for single enveloping TI worm

    Institute of Scientific and Technical Information of China (English)

    SUN Yuehai; ZHENG Huijiang; BI Qingzhen; WANG Shuren

    2005-01-01

    TI worm drive consists of involute helical gear and its enveloping Hourglass worm. Accurate grinding for TI worm is the key manufacture technology for TI worm gearing being popularized and applied. According to the theory of gear mesh, the equations of tooth surface of worm drive are gained, and the equation of the axial section profile of grinding wheel that can accurately grind TI worm is extracted. Simultaneously,the relation of position and motion between TI worm and grinding wheel are expounded.The method for precisely grinding single enveloping TI worm is obtained.

  10. Formation of Jupiter's Core and Early Stages of Envelope Accretion

    Science.gov (United States)

    D'Angelo, G.; Weidenschilling, S.; Lissauer, J. J.; Bodenheimer, P.; Hubickyj, O.

    2012-12-01

    We are performing calculations of the formation of Jupiter via core nucleated accretion and gas capture. The core starts as a seed body of a few hundred kilometers in radius and orbits within a swarm of planetesimals whose initial size distribution ranges from ~10 m to ~100 km. The planetesimals are immersed in a gaseous disk, representative of an early solar nebula. The evolution of the swarm of planetesimals accounts for collisions and gravitational stirring due to mutual interactions among bodies, and for migration and velocity damping due to interactions with the nebula gas. Collisions among planetesimals lead to growth and/or fragmentation, altering the size distribution of the swarm over time. Collisions of planetesimals with the seed body lead to its growth, resulting in the formation of a planetary core. Gas capture by the core leads to the accumulation of a tenuous atmosphere, which later becomes a massive envelope, increasing the size-dependent effective cross-section of the planet for planetesimals' accretion. Planetesimals that travel through the core's envelope release energy, affecting the thermal budget of the envelope, and deliver mass, affecting the opacity of the envelope. The calculation of dust opacity, which is especially important for envelope contraction, is performed self-consistently, accounting for coagulation and sedimentation of dust and small particles that are released in the envelope as passing planetesimals are ablated. We find that, in a disk of planetesimals with a surface density of about 10 g/cm2 at 5.2 AU, a one Earth mass core accumulates in less than 1e5 years, and that it takes over 1.5e6 years to accumulate a core of 3 Earth masses, when the core's geometrical cross-section is used for the accretion of planetesimals. Gas drag in the core's envelope increases the ability of the planet to accrete planetesimals. Smaller planetesimals are affected to a greater extent than are larger planetesimals. We find that the effective

  11. Recombinant lipidated dengue-3 envelope protein domain III stimulates broad immune responses in mice.

    Science.gov (United States)

    Chiang, Chen-Yi; Liu, Shih-Jen; Hsieh, Chun-Hsiang; Chen, Mei-Yu; Tsai, Jy-Ping; Liu, Hsueh-Hung; Chen, I-Hua; Chong, Pele; Leng, Chih-Hsiang; Chen, Hsin-Wei

    2016-02-17

    The linkage of an immunogen with a toll-like receptor ligand has great potential to induce highly potent immune responses with the initial features of antigen-presenting cell activation. In the current study, we expressed recombinant dengue-3 envelope protein domain III (D3ED III) in lipidated form using an Escherichia coli-based system. The recombinant lipidated dengue-3 envelope protein domain III (LD3ED III) augments the expression levels of IL-12 family cytokines. LD3ED III-immunized mice enhance wide ranges of T cell responses as indicated by IFN-γ, IL-17, IL-21 production. Additionally, LD3ED III-immunized mice increase the frequencies of anti-D3ED III antibody producing cells. The boosted antibody titers cover various IgG isotypes, including IgG1, IgG2a, IgG2b, and IgG3. Importantly, LD3ED III-immunized mice induce neutralizing antibody capacity associated with a reduction of viremia levels after challenges. In contrast, mice that are immunized with D3ED III formulated with aluminum phosphate (D3ED III/Alum) only enhance Th2 responses and boost IgG1 antibody titers. Neither neutralizing antibody responses nor the inhibition of viremia levels after challenge is observed in mice that are immunized with D3ED III/Alum. These results suggest that LD3ED III can induce broad profiles of cellular and humoral immune responses.

  12. The nuclear envelope and cancer: a diagnostic perspective and historical overview.

    Science.gov (United States)

    de Las Heras, Jose I; Schirmer, Eric C

    2014-01-01

    Cancer has been diagnosed for millennia, but its cellular nature only began to be understood in the mid-nineteenth century when advances in microscopy allowed detailed specimen observations. It was soon noted that cancer cells often possessed nuclei that were altered in size and/or shape. This became an important criterion for cancer diagnosis that continues to be used today. The mechanisms linking nuclear abnormalities and cancer only started to be understood in the second half of the twentieth century, with the discovery of nuclear lamina composition differences in cancer cells compared to normal cells. The nuclear envelope, rather than providing a mere physical barrier between the genetic material in the nucleus and the cytoplasm, is a very important functional hub for many cellular processes. In this review we give an overview of the links between cancer biology and nuclear envelope, from the early days of microscopy until the present day's understanding of some of the molecular mechanisms behind those links. PMID:24563341

  13. Secreted expression of dengue virus type 2 envelope glycoprotein in Eukaryotic cells%登革2型病毒ZS01/01株E蛋白在真核细胞中的分泌表达研究

    Institute of Scientific and Technical Information of China (English)

    张硕; 李建东; 梁米芳; 李德新; 顾雯; 李川; 苗芳; 陆鹏; 曲靖; 韦艳; 张全福; 刘琴芝

    2011-01-01

    Objective To secreted express envelope glycoprotein (E) of dengue virus type 2 extracellularly. Methods The entire prM/E gene was amplified by RT-PCR. An optimized signal sequence gene from Japanese encephalits virus (JEV, SA14-14-2 strain) was introduced using fusion PCR. The impact of E protein transmembrane and cytoplasmatic domains was compared by amplifying prM and E with full length of E gene, with 20% truncation of the E gene at 3' terminus and one chimeric gene, which was generated by replacing the 3' terminal 20% region of E gene with the corresponding sequence of JEV ( SA14-14-2 strain). The PCR segments were inserted into the NheI and Notl sites of pcDNA5/FRT vector or into the Nhel and Xhol sites of pAcUW51-M. Then they were transfected into 293T cells or St9 cells respectively. The expression and secretion of E protein were detected by immunofluorescence assay ( IFA ) and Western Blot. Results After transected into 293T cells or St9 cells, all constructs expressed E protein intracellularly indentified by IFA while only two plasmids could secret detectable E protein into tissue culture using Western Blot analysis. Conclusion Signal peptide as well as the transmemhrane and cytoplasmatic domains is crucial for the secretion of dengue E protein.%目的 对登革2型病毒(DENV-2)ZS01/01株E蛋白在哺乳动物细胞及昆虫细胞中的分泌表达进行研究.方法 RT-PCR扩增DENV-2 prM/E基因,通过融合PCR在prM基因前添加来自乙型脑炎病毒的信号肽序列,并将E基因羧基末端20%区域缺失或替换为乙型脑炎病毒SA14-14-2株E基因相应序列,将上述基因元件分别克隆入哺乳动物细胞表达载体pcDNA5/FRT及昆虫细胞表达载体pAcUW51-M中,将重组质粒转染293T细胞或S19细胞,利用间接免疫荧光(Immunofluoreseence assay,IFA)及Western Blot检测E蛋白的表达与分泌.结果 各重组质粒分别转染293T细胞或Sf9细胞后,E蛋白在细胞内均有效表达,而仅有携带乙脑信号肽

  14. Structure based design towards the identification of novel binding sites and inhibitors for the chikungunya virus envelope proteins.

    Science.gov (United States)

    Rashad, Adel A; Keller, Paul A

    2013-07-01

    Chikungunya virus is an emerging arbovirus that is widespread in tropical regions and is spreading quickly to temperate climates with recent epidemics in Africa, Asia, Europe and the Americas. It is having an increasingly major impact on humans with potentially life-threatening and debilitating arthritis. Thus far, neither vaccines nor medications are available to treat or control the virus and therefore, the development of medicinal chemistry is a vital and immediate issue that needs to be addressed. The viral envelope proteins play a major role during infection through mediation of binding and fusion with the infected cell surfaces. The possible binding target sites of the chikungunya virus envelope proteins have not previously been investigated; we describe here for the first time the identification of novel sites for potential binding on the chikungunya glycoprotein complexes and the identification of possible antagonists for these sites through virtual screening using two successive docking scores; FRED docking for fast precise screening, with the top hits then subjected to a ranking scoring using the AUTODOCK algorithm. Both the immature and the mature forms of the chikungunya envelope proteins were included in the study to increase the probability of finding positive and reliable hits. Some small molecules have been identified as good in silico chikungunya virus envelope proteins inhibitors and these could be good templates for drug design targeting this virus.

  15. Nuclear envelope proteins and chromatin arrangement: a pathogenic mechanism for laminopathies

    Directory of Open Access Journals (Sweden)

    NM Maraldi

    2009-06-01

    Full Text Available The involvement of the nuclear envelope in the modulation of chromatin organization is strongly suggested by the increasing number of human diseases due to mutations of nuclear envelope proteins. A common feature of these diseases, named laminopathies, is the occurrence of major chromatin defects. Laminopathies share in some instances their clinical features, but each of them is characterized by a phenotype that involves one or multiple tissues.We previously reported that cells from laminopathic patients show an altered nuclear profile, and loss or detachment of heterochromatin from the nuclear envelope. Recent evidence indicates that processing of the lamin A precursor is altered in laminopathies featuring pre-mature aging and/or lipodystrophy phenotype. In these cases, pre-lamin A is accumulated in the nucleus and heterochromatin is severely disorganized. Moreover, altered distribution and solubility properties of heterochromatin-associated proteins such as HP1 are observed. These findings indicate that defects of chromatin remodeling are involved in the cascade of epigenetic events leading to the laminopathic phenotypes. Here we report evidence indicating that pre-lamin A is mis-localized in the nuclei of Emery-Dreifuss muscular dystrophy fibroblasts, either bearing lamin A/C or emerin mutations. Abnornal pre-lamin A-containing structures are formed following treatment with a farnesyl-transferase inhibitor, a drug that causes accumulation of non-farnesylated pre-lamin A. Pre-lamin A-labeled structures co-localize with heterochromatin clumps. These data indicate that in almost all laminopathies the expression of the mutant lamin A precursor disrupts the organization of heterochromatin domains so that affected cells are unable to maintain the silenced chromatin state capable to allow/preserve terminal differentiation. Our results further show that the absence of emerin expression alters the distribution of pre-lamin A and of heterochromatin

  16. Envelope-Law and Geometric-Mean STAP Detection

    NARCIS (Netherlands)

    Anitori, L.; Srinivasan, R.; Rangaswamy, M.

    2010-01-01

    Two detectors for space-time adaptive processing (STAP) are proposed here. These are variants that use envelope-law and geometric-mean (GM) (or logarithmic) processing, both being well-known concepts from conventional constant false alarm rate (CFAR) square-law radar detection [212]. The variants ar

  17. Neural coding of sound envelope in reverberant environments.

    Science.gov (United States)

    Slama, Michaël C C; Delgutte, Bertrand

    2015-03-11

    Speech reception depends critically on temporal modulations in the amplitude envelope of the speech signal. Reverberation encountered in everyday environments can substantially attenuate these modulations. To assess the effect of reverberation on the neural coding of amplitude envelope, we recorded from single units in the inferior colliculus (IC) of unanesthetized rabbit using sinusoidally amplitude modulated (AM) broadband noise stimuli presented in simulated anechoic and reverberant environments. Although reverberation degraded both rate and temporal coding of AM in IC neurons, in most neurons, the degradation in temporal coding was smaller than the AM attenuation in the stimulus. This compensation could largely be accounted for by the compressive shape of the modulation input-output function (MIOF), which describes the nonlinear transformation of modulation depth from acoustic stimuli into neural responses. Additionally, in a subset of neurons, the temporal coding of AM was better for reverberant stimuli than for anechoic stimuli having the same modulation depth at the ear. Using hybrid anechoic stimuli that selectively possess certain properties of reverberant sounds, we show that this reverberant advantage is not caused by envelope distortion, static interaural decorrelation, or spectral coloration. Overall, our results suggest that the auditory system may possess dual mechanisms that make the coding of amplitude envelope relatively robust in reverberation: one general mechanism operating for all stimuli with small modulation depths, and another mechanism dependent on very specific properties of reverberant stimuli, possibly the periodic fluctuations in interaural correlation at the modulation frequency.

  18. Variational-Wavelet Approach to RMS Envelope Equations

    CERN Document Server

    Fedorova, A N; Fedorova, Antonina N.; Zeitlin, Michael G.

    2000-01-01

    We present applications of variational-wavelet approach to nonlinear (rational) rms envelope equations. We have the solution as a multiresolution (multiscales) expansion in the base of compactly supported wavelet basis. We give extension of our results to the cases of periodic beam motion and arbitrary variable coefficients. Also we consider more flexible variational method which is based on biorthogonal wavelet approach.

  19. Design, Testing, and Realisation of a Medium Size Aerostat Envelope

    Directory of Open Access Journals (Sweden)

    A. Kumar

    2016-03-01

    Full Text Available The design, testing and realisation aspects during the development of a medium size aerostat envelope in the present work. The payload capacity of this aerostat is 300 kg at 1 km above mean sea level. The aerostat envelope is the aerodynamically shaped fabric enclosure part of the aerostat which generally uses helium for lifting useful payloads to a specified height. The envelope volume estimation technique is discussed which provides the basis for sizing. The design, material selection, testing and realisation aspects of this aerostat envelope are also discussed. The empirical formulas and finite element analysis are used to estimate the aerodynamic, structural and other design related parameters of the aerostat. Equilibrium studies are then explained for balancing forces and moments in static conditions. The tether profile estimation technique is discussed to estimate blow by distance and tether length. A comparison of estimated and measured performance parameters during trials has also been discussed.Defence Science Journal, Vol. 66, No. 2, March 2016, pp.93-99, DOI: http://dx.doi.org/10.14429/dsj.66.9291

  20. Instabilities in the Envelopes and Winds of Very Massive Stars

    CERN Document Server

    Owocki, Stanley P

    2014-01-01

    The high luminosity of Very Massive Stars (VMS) means that radiative forces play an important, dynamical role both in the structure and stability of their stellar envelope, and in driving strong stellar-wind mass loss. Focusing on the interplay of radiative flux and opacity, with emphasis on key distinctions between continuum vs. line opacity, this chapter reviews instabilities in the envelopes and winds of VMS. Specifically, we discuss how: 1) the iron opacity bump can induce an extensive inflation of the stellar envelope; 2) the density dependence of mean opacity leads to strange mode instabilities in the outer envelope; 3) desaturation of line-opacity by acceleration of near-surface layers initiates and sustains a line-driven stellar wind outflow; 4) an associated line-deshadowing instability leads to extensive small-scale structure in the outer regions of such line-driven winds; 5) a star with super-Eddington luminosity can develop extensive atmospheric structure from photon bubble instabilities, or from ...

  1. Republic of Armenia Public Expenditure Review : Expanding the Fiscal Envelope

    OpenAIRE

    World Bank Group

    2014-01-01

    Armenia's small revenue and spending envelopes limit the government's ability to influence the economy, even while its influence through laws, rules, and regulations is significant. The government has an important role to play to reduce poverty and boost shared prosperity, and needs fiscal space. This public expenditure review (PER) analyzes and provides recommendations for the different d...

  2. Enveloped virus-like particles as vaccines against pathogenic arboviruses

    NARCIS (Netherlands)

    Pijlman, G.P.

    2015-01-01

    Arthropod-borne arboviruses form a continuous threat to human and animal health, but few arboviral vaccines are currently available. Advances in expression technology for complex, enveloped virus-like particles (eVLPs) create new opportunities to develop potent vaccines against pathogenic arboviruse

  3. Traffic to the inner membrane of the nuclear envelope

    NARCIS (Netherlands)

    Laba, Justyna K.; Steen, Anton; Veenhoff, Liesbeth M.

    2014-01-01

    Past research has yielded valuable insight into the mechanisms that regulate the nuclear transport of soluble molecules like transcription factors and mRNA. Much less is known about the mechanisms responsible for the transportation of membrane proteins to the inner membrane of the nuclear envelope.

  4. AM Envelope: The Potential of Additive Manufacturing for facade constructions

    NARCIS (Netherlands)

    Strauss, H.

    2013-01-01

    The continuous development of the building envelope over the past hundred years can be exemplified by a few ground-breaking inventions. Firstly, the separation of primary and secondary structure during the beginning of the 20th century; by implementing a curtain wall façade to physically separate th

  5. Masking Release for Sweeping Masker Components with Correlated Envelopes

    DEFF Research Database (Denmark)

    Verhey, Jesko l.; Klein-Hennig, Hendrike; Epp, Bastian

    2013-01-01

    To separate sounds from different sound sources, common properties of natural sounds are used by the auditory system, such as coherent temporal envelope fluctuations and correlated changes of frequency in different frequency regions. The present study investigates how the auditory systemprocesses...

  6. Performance profiles of exterior fire protective building envelopes

    Directory of Open Access Journals (Sweden)

    Jarnskjold Tobias

    2016-01-01

    Full Text Available The fire protective envelope of any building consists of multiple elements with widely differing properties relating to a fire, such as glass, roof tiles and sheathings, wood cladding, gaps and openings. Where resistance to an exterior fire is required, all elements should be verified to provide a comparable risk of burn-through. Elements are rated by either the material response to fire or fire resistance. In Europe, cladding sheets and wall membranes can be rated by K classes, which effectively include a measure of the time to burn through. A determination of burn-through time of each element of a specific building envelope should be obtained. A design tool to verify the performance of a building's fire protective envelope has been developed. In this paper, a general description of passive elements of the envelope, which should be included in a risk assessment tool such as an index method, is presented. An illustrative approach to visualise the profiles for areas densely spaced structures where an exterior fire may trigger building-to-building fire spread is also included. The research is based on the hypothesis that a relatively subtle and pointed upgrading of an exterior building envelope will severely reduce the speed of building-to-building fire spread, thus allowing firefighting efforts to get on top of the situation. For a burning structure to expose other buildings to fire, the fire has to settle, which leads to a burn-through to the inside. Once inside, an enclosure fire needs to develop and burn through the roof or break one or more large window panes. It is estimated that a 5–10 min delay for a structure to expose other structures to fire can be sufficient to avoid loss of multiple structures. A 10–50 min burn-through time allows for an extended intervention by the fire brigade, which is significant in rural areas. A fire protective envelope may prevent an exterior fire from penetrating the protective envelope at all and the

  7. Studies on photoinactivation by various phthalocyanines of a free or replicating non-enveloped virus.

    Science.gov (United States)

    Gaspard, S; Tempête, C; Werner, G H

    1995-12-01

    The non-enveloped picornaviruses, which are particularly resistant to physicochemical inactivation, include the aetiological agents of poliomyelitis, hepatitis A and E and infectious common cold (rhinovirus). In this work we used human rhinovirus type 5 (RV-5) cultivated in VERO cells to study the photoinactivating effects of several phthalocyanines and naphthobenzoporphyrazines. Free RV-5 was photoinactivated by aluminium trisulphonated naphthobenzoporphyrazine at 5 x 10(-8) M concentration. This photosensitizer was also active on replicating virus when the infected VERO cells were treated with 5 x 10(-6) M concentration followed by a very short illumination period. On the other hand, the ZnPc(3-MeO-Py)4 phthalocyanine, which possesses four positive charges, does not photoinactivate free rhinovirus, but this molecule protects VERO cells against RV-5 infection when added to the cultures before virus inoculation, in the presence or absence of subsequent illumination, and may therefore be considered as an antiviral agent in itself. PMID:8583283

  8. The psychic envelopes in psychoanalytic theories of infancy.

    Directory of Open Access Journals (Sweden)

    Denis eMellier

    2014-07-01

    Full Text Available This paper aims to review the topic of psychic envelopes and to sketch the main outlines of this concept in infancy. We first explore the origins of the concept in Freud's 'protective shield' and then its development in adult psychoanalysis before going on to see how this fits in infancy with post-Bionian psychoanalysis and development. Four central notions guide this review:1 Freud's protective shield describes a barrier to protect the psychic apparatus against potentially overflowing trauma. It is a core notion which highlights a serious clinical challenge for patients for whom the shield is damaged or faulty: the risk of confusion of borders between the internal/external world, conscious/unconscious, mind/body, or self-conservation/sexuality.2 Anzieu's Skin-Ego is defined by the different senses of the body. The different layers of experienced sensation, of this body-ego, go on to form the psychic envelope. This theory contributes to our understanding of how early trauma, due to the failures of maternal care, can continue to have an impact in adult life. 3 Bick's psychic skin establishes the concept in relation to infancy. The mother’s containing functions allow a first psychic skin to develop, which then defines an infant’s psychic space and affords the infant a degree of self-containment. Houzel then conceptualized this process as a stabilization of drive forces.4 Stern's narrative envelope derives from the intersection between psychoanalysis and neuroscience. It gives us another way to conceptualise the development of pre-verbal communication. It may also pave the way for a finer distinction of different types of envelopes.Ultimately, in this review we find that psychic envelopes in infancy can be viewed from four different perspectives (economic, topographical, dynamic and genetic and recommend further investigation.

  9. Genetic analysis of human immunodeficiency virus type 1 envelope V3 region isolates from mothers and infants after perinatal transmission.

    OpenAIRE

    Ahmad, N.; Baroudy, B M; Baker, R. C.; Chappey, C

    1995-01-01

    The human immunodeficiency virus type 1 (HIV-1) sequences from variable region 3 (V3) of the envelope gene were analyzed from seven infected mother-infant pairs following perinatal transmission. The V3 region sequences directly derived from the DNA of the uncultured peripheral blood mononuclear cells from infected mothers displayed a heterogeneous population. In contrast, the infants' sequences were less diverse than those of their mothers. In addition, the sequences from the younger infants'...

  10. Studies in the development of Japanese encephalitis vaccine: expression of virus envelope glycoprotein V3 (E) gene in yeast

    OpenAIRE

    Fujita, H; Sumiyoshi, H.; Mori, C.; Manabe, S.; Takagi, M.; Yoshida, I.; Morita, K.; Fuke, I.; FUKAI, K.; Igarashi, A.

    1987-01-01

    A safe, effective and economical vaccine is required for the prevention of Japanese encephalitis (JE), a disease with high mortality and grave sequelae, which is prevalent in Japan and other countries in east, south-east and southern Asia. As the initial step to produce a second-generation vaccine, recombinant DNA technology was utilized to express the JE virus envelope glycoprotein V3 (E) gene in yeast cells.

  11. A sensitive HIV-1 envelope induced fusion assay identifies fusion enhancement of thrombin

    Energy Technology Data Exchange (ETDEWEB)

    Cheng, De-Chun; Zhong, Guo-Cai; Su, Ju-Xiang [Department of Microbiology, Harbin Medical University, 194 Xuefu Road, Harbin, Heilongjiang 150081 (China); Liu, Yan-Hong [Second Affiliated Hospital of Harbin Medical University, 246 Xuefu Road, Harbin, Heilongjiang 150081 (China); Li, Yan; Wang, Jia-Ye [Department of Microbiology, Harbin Medical University, 194 Xuefu Road, Harbin, Heilongjiang 150081 (China); Hattori, Toshio [Department of Emerging Infectious Diseases, Division of Internal Medicine, Graduate School of Medicine, Tohoku University, Sendai 9808574 (Japan); Ling, Hong, E-mail: lingh@ems.hrbmu.edu.cn [Department of Microbiology, Harbin Medical University, 194 Xuefu Road, Harbin, Heilongjiang 150081 (China); Department of Parasitology, Harbin Medical University, 194 Xuefu Road, Harbin, Heilongjiang 150081 (China); Key Lab of Heilongjiang Province for Infection and Immunity, Key Lab of Heilongjiang Province Education Bureau for Etiology, Harbin, Heilongjiang 150081 (China); Zhang, Feng-Min, E-mail: fengminzhang@yahoo.com.cn [Department of Microbiology, Harbin Medical University, 194 Xuefu Road, Harbin, Heilongjiang 150081 (China); Key Lab of Heilongjiang Province for Infection and Immunity, Key Lab of Heilongjiang Province Education Bureau for Etiology, Harbin, Heilongjiang 150081 (China)

    2010-01-22

    To evaluate the interaction between HIV-1 envelope glycoprotein (Env) and target cell receptors, various cell-cell-fusion assays have been developed. In the present study, we established a novel fusion system. In this system, the expression of the sensitive reporter gene, firefly luciferase (FL) gene, in the target cells was used to evaluate cell fusion event. Simultaneously, constitutively expressed Renilla luciferase (RL) gene was used to monitor effector cell number and viability. FL gave a wider dynamic range than other known reporters and the introduction of RL made the assay accurate and reproducible. This system is especially beneficial for investigation of potential entry-influencing agents, for its power of ruling out the false inhibition or enhancement caused by the artificial cell-number variation. As a case study, we applied this fusion system to observe the effect of a serine protease, thrombin, on HIV Env-mediated cell-cell fusion and have found the fusion enhancement activity of thrombin over two R5-tropic HIV strains.

  12. Calcium signals can freely cross the nuclear envelope in hippocampal neurons: somatic calcium increases generate nuclear calcium transients

    Directory of Open Access Journals (Sweden)

    Bading Hilmar

    2007-07-01

    Full Text Available Abstract Background In hippocampal neurons, nuclear calcium signaling is important for learning- and neuronal survival-associated gene expression. However, it is unknown whether calcium signals generated by neuronal activity at the cell membrane and propagated to the soma can unrestrictedly cross the nuclear envelope to invade the nucleus. The nuclear envelope, which allows ion transit via the nuclear pore complex, may represent a barrier for calcium and has been suggested to insulate the nucleus from activity-induced cytoplasmic calcium transients in some cell types. Results Using laser-assisted uncaging of caged calcium compounds in defined sub-cellular domains, we show here that the nuclear compartment border does not represent a barrier for calcium signals in hippocampal neurons. Although passive diffusion of molecules between the cytosol and the nucleoplasm may be modulated through changes in conformational state of the nuclear pore complex, we found no evidence for a gating mechanism for calcium movement across the nuclear border. Conclusion Thus, the nuclear envelope does not spatially restrict calcium transients to the somatic cytosol but allows calcium signals to freely enter the cell nucleus to trigger genomic events.

  13. 40 CFR 426.120 - Applicability; description of the incandescent lamp envelope manufacturing subcategory.

    Science.gov (United States)

    2010-07-01

    ... incandescent lamp envelope manufacturing subcategory. 426.120 Section 426.120 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) EFFLUENT GUIDELINES AND STANDARDS GLASS MANUFACTURING POINT SOURCE CATEGORY Incandescent Lamp Envelope Manufacturing Subcategory § 426.120 Applicability; description of...

  14. AM Envelope. The potential of Additive Manufacturing for facade constructions

    Directory of Open Access Journals (Sweden)

    Holger Strauss

    2013-02-01

    Full Text Available This dissertation shows the potential of Additive Manufacturing (AM for the development of building envelopes: AM will change the way of designing facades, how we engineer and produce them. To achieve today’s demands from those future envelopes, we have to find new solutions.New technologies offer one possible way to do so. They open new approaches in designing, producing and processing building construction and facades. Finding the one capable of having big impact is difficult – Additive Manufacturing is one possible answer.The term ‘AM Envelope’ (Additive Manufacturing Envelope describes the transfer of this technology to the building envelope. Additive Fabrication is a building block that aids in developing the building envelope from a mere space enclosure to a dynamic building envelope.First beginnings of AM facade construction show up when dealing with relevant aspects like material consumption, mounting or part’s performance.From those starting points several parts of an existing post-and-beam façade system were optimized, aiming toward the implementation of AM into the production chain. Enhancements on all different levels of production were achieved: storing, producing, mounting and performance.AM offers the opportunity to manufacture facades ‘just in time’. It is no longer necessary to store or produce large numbers of parts in advance. Initial investment for tooling can be avoided, as design improvements can be realized within the dataset of the AM part. AM is based on ‘tool-less’ production, all parts can be further developed with every new generation.Producing tool-less also allows for new shapes and functional parts in small batch sizes – down to batch size one. The parts performance can be re-interpreted based on the demands within the system, not based on the limitations of conventional manufacturing. AM offers new ways of materializing the physical part around its function. It leads toward customized and

  15. Identification of the Receptor Binding Domain of the Mouse Mammary Tumor Virus Envelope Protein

    Science.gov (United States)

    Zhang, Yuanming; Rassa, John C.; deObaldia, Maria Elena; Albritton, Lorraine M.; Ross, Susan R.

    2003-01-01

    Mouse mammary tumor virus (MMTV) is a betaretrovirus that infects rodent cells and uses mouse transferrin receptor 1 for cell entry. To characterize the interaction of MMTV with its receptor, we aligned the MMTV envelope surface (SU) protein with that of Friend murine leukemia virus (F-MLV) and identified a putative receptor-binding domain (RBD) that included a receptor binding sequence (RBS) of five amino acids and a heparin-binding domain (HBD). Mutation of the HBD reduced virus infectivity, and soluble heparan sulfate blocked infection of cells by wild-type pseudovirus. Interestingly, some but not all MMTV-like elements found in primary and cultured human breast cancer cell lines, termed h-MTVs, had sequence alterations in the putative RBS. Single substitution of one of the amino acids found in an h-MTV RBS variant in the RBD of MMTV, Phe40 to Ser, did not alter species tropism but abolished both virus binding to cells and infectivity. Neutralizing anti-SU monoclonal antibodies also recognized a glutathione S-transferase fusion protein that contained the five-amino-acid RBS region from MMTV. The critical Phe40 residue is located on a surface of the MMTV RBD model that is distant from and may be structurally more rigid than the region of F-MLV RBD that contains its critical binding site residues. This suggests that, in contrast to other murine retroviruses, binding to its receptor may result in few or no changes in MMTV envelope protein conformation. PMID:12970432

  16. Habitat classification modeling with incomplete data: pushing the habitat envelope.

    Science.gov (United States)

    Zarnetske, Phoebe L; Edwards, Thomas C; Moisen, Gretchen G

    2007-09-01

    Habitat classification models (HCMs) are invaluable tools for species conservation, land-use planning, reserve design, and metapopulation assessments, particularly at broad spatial scales. However, species occurrence data are often lacking and typically limited to presence points at broad scales. This lack of absence data precludes the use of many statistical techniques for HCMs. One option is to generate pseudo-absence points so that the many available statistical modeling tools can bb used. Traditional techniques generate pseudo-absence points at random across broadly defined species ranges, often failing to include biological knowledge concerning the species-habitat relationship. We incorporated biological knowledge of the species-habitat relationship into pseudo-absence points by creating habitat envelopes that constrain the region from which points were randomly selected. We define a habitat envelope as an ecological representation of a species, or species feature's (e.g., nest) observed distribution (i.e., realized niche) based on a single attribute, or the spatial intersection of multiple attributes. We created HCMs for Northern Goshawk (Accipiter gentilis atricapillus) nest habitat during the breeding season across Utah forests with extant nest presence points and ecologically based pseudo-absence points using logistic regression. Predictor variables were derived from 30-m USDA Landfire and 250-m Forest Inventory and Analysis (FIA) map products. These habitat-envelope-based models were then compared to null envelope models which use traditional practices for generating pseudo-absences. Models were assessed for fit and predictive capability using metrics such as kappa, threshold-independent receiver operating characteristic (ROC) plots, adjusted deviance (D(adj)2), and cross-validation, and were also assessed for ecological relevance. For all cases, habitat envelope-based models outperformed null envelope models and were more ecologically relevant

  17. Function, oligomerization and N-linked glycosylation of the Helicoverpa armigera single nucleopolyhedrovirus envelope fusion protein

    NARCIS (Netherlands)

    Long, G.; Westenberg, M.; Wang, H.; Vlak, J.M.; Hu, Z.

    2006-01-01

    In the family Baculoviridae, two distinct envelope fusion proteins are identified in budded virions (BVs). GP64 is the major envelope fusion protein of group I nucleopolyhedrovirus (NPV) BVs. An unrelated type of envelope fusion protein, named F, is encoded by group II NPVs. The genome of Helicoverp

  18. The Use of Polyacrylamide Hydrogels to Study the Effects of Matrix Stiffness on Nuclear Envelope Properties.

    Science.gov (United States)

    Minaisah, Rose-Marie; Cox, Susan; Warren, Derek T

    2016-01-01

    Matrix-derived mechanical cues influence cell proliferation, motility, and differentiation. Recent findings clearly demonstrate that the nuclear envelope (NE) adapts and remodels in response to mechanical signals, including matrix stiffness, yet a plethora of studies have been performed on tissue culture plastic or glass that have a similar stiffness to cortical bone. Using methods that allow modulation of matrix stiffness will provide further insight into the role of the NE in physiological conditions and the impact of changes in stiffness observed during ageing and disease on cellular function. In this chapter, we describe the polyacrylamide hydrogel system, which allows fabrication of hydrogels with variable stiffness to better mimic the environment experienced by cells in most tissues of the body.

  19. Till disassembly do us part: a happy marriage of nuclear envelope and chromatin.

    Science.gov (United States)

    Tsuchiya, Yuichi

    2008-02-01

    A characteristic feature of eukaryotic cells is the presence of nuclear envelope (NE) which separates genomic DNA from cytoplasm. NE is composed of inner nuclear membrane (INM), which interacts with chromatin, and outer nuclear membrane, which is connected to endoplasmic reticulum. Nuclear pore complexes are inserted into NE to form transport channels between nucleus and cytoplasm. In metazoan cells, an intermediate filament-based meshwork called as nuclear lamina exists between INM and chromatin. Sophisticated collaboration of these molecular machineries is necessary for the structure and functions of NE. Recent research advances have revealed that NE dynamically communicates with chromatin and cytoskeleton to control multiple nuclear functions. In this mini review, I briefly summarize the basic concepts and current topics of functional relationships between NE and chromatin.

  20. Human broadly neutralizing antibodies to the envelope glycoprotein complex of hepatitis C virus

    DEFF Research Database (Denmark)

    Giang, Erick; Dorner, Marcus; Prentoe, Jannick C;

    2012-01-01

    Hepatitis C virus (HCV) infects ∼2% of the world's population. It is estimated that there are more than 500,000 new infections annually in Egypt, the country with the highest HCV prevalence. An effective vaccine would help control this expanding global health burden. HCV is highly variable......, and an effective vaccine should target conserved T- and B-cell epitopes of the virus. Conserved B-cell epitopes overlapping the CD81 receptor-binding site (CD81bs) on the E2 viral envelope glycoprotein have been reported previously and provide promising vaccine targets. In this study, we isolated 73 human m......bs on the E1E2 complex, has an exceptionally broad neutralizing activity toward diverse HCV genotypes and protects against heterologous HCV challenge in a small animal model. The mAb panel will be useful for the design and development of vaccine candidates to elicit broadly neutralizing antibodies...

  1. Characterization of virulence-associated determinants in the envelope glycoprotein of Pichinde virus.

    Science.gov (United States)

    Kumar, Naveen; Wang, Jialong; Lan, Shuiyun; Danzy, Shamika; McLay Schelde, Lisa; Seladi-Schulman, Jill; Ly, Hinh; Liang, Yuying

    2012-11-10

    We use a small animal model, based on guinea pigs infected with a non-pathogenic Pichinde virus (PICV), to understand the virulence mechanisms of arenavirus infections in the hosts. PICV P2 strain causes a mild febrile reaction in guinea pigs, while P18 causes severe disease with clinical and pathological features reminiscent of Lassa hemorrhagic fever in humans. The envelope glycoproteins (GPC) of P2 and P18 viruses differ at positions 119, 140, and 164, all localized to the receptor-binding G1 subunit. We found that lentiviral pseudotyped virions (VLPs) bearing P18 GPC show more efficient cell entry than those with P2 GPC, and that the E140 residue plays a critical role in this process. Infection of guinea pigs with the recombinant viruses containing the E140K change demonstrated that E140 of GPC is a necessary virulence determinant of P18 infections, possibly by enhancing the ability of virus to enter target cells.

  2. Metallicity dependence of turbulent pressure and macroturbulence in stellar envelopes

    CERN Document Server

    Grassitelli, Luca; Langer, Norbert; Simon-Diaz, Sergio; Castro, Norberto; Sanyal, Debashis

    2016-01-01

    Macroturbulence, introduced as a fudge to reproduce the width and shape of stellar absorption lines, reflects gas motions in stellar atmospheres. While in cool stars, it is thought to be caused by convection zones immediately beneath the stellar surface, the origin of macroturbulence in hot stars is still under discussion. Recent works established a correlation between the turbulent-to-total pressure ratio inside the envelope of stellar models and the macroturbulent velocities observed in corresponding Galactic stars. To probe this connection further, we evaluated the turbulent pressure that arises in the envelope convective zones of stellar models in the mass range 1-125 Msun based on the mixing-length theory and computed for metallicities of the Large and Small Magellanic Cloud. We find that the turbulent pressure contributions in models with these metallicities located in the hot high-luminosity part of the Hertzsprung-Russel (HR) diagram is lower than in similar models with solar metallicity, whereas the ...

  3. Influence of Building Envelope Thermal Mass on Heating Design Temperature

    Science.gov (United States)

    Gaujena, B.; Borodinecs, A.; Zemitis, J.; Prozuments, A.

    2015-11-01

    The stability of indoor air parameters is a very important factor, essential for such institutions as museums, schools and hospitals. Nowadays the use of renewable energy for space heating became one of the top priorities in modern building design. The active and passive solar energy as well as heat pumps are widely used nowadays. However, such technologies have a limitation in cold climates and often are not able to cover maximal heating loads. This paper is devoted to analysis of influence of building envelope's properties and outdoor air parameters on indoor air thermodynamic parameters stability in winter time. It presents analysis of thermal mass impact on building energy performance and indoor air parameter stability in cold climate. The results show that the thermal mass of building envelope is able to cover extreme winter temperatures as well as in case of emergency heat supply break.

  4. Structural basis for membrane anchoring of HIV-1 envelope spike.

    Science.gov (United States)

    Dev, Jyoti; Park, Donghyun; Fu, Qingshan; Chen, Jia; Ha, Heather Jiwon; Ghantous, Fadi; Herrmann, Tobias; Chang, Weiting; Liu, Zhijun; Frey, Gary; Seaman, Michael S; Chen, Bing; Chou, James J

    2016-07-01

    HIV-1 envelope spike (Env) is a type I membrane protein that mediates viral entry. We used nuclear magnetic resonance to determine an atomic structure of the transmembrane (TM) domain of HIV-1 Env reconstituted in bicelles that mimic a lipid bilayer. The TM forms a well-ordered trimer that protects a conserved membrane-embedded arginine. An amino-terminal coiled-coil and a carboxyl-terminal hydrophilic core stabilize the trimer. Individual mutations of conserved residues did not disrupt the TM trimer and minimally affected membrane fusion and infectivity. Major changes in the hydrophilic core, however, altered the antibody sensitivity of Env. These results show how a TM domain anchors, stabilizes, and modulates a viral envelope spike and suggest that its influence on Env conformation is an important consideration for HIV-1 immunogen design. PMID:27338706

  5. Carrier-envelope Phase Drift Detection of Picosecond Pulses

    Directory of Open Access Journals (Sweden)

    Cormier E.

    2013-03-01

    Full Text Available A bandwidth-independent, linear and scalable method for carrier-envelope phase drift measurement demonstrated. Our experiments reveal that carrier-envelope phase drift of a picosecond pulse train can be directly obtained from the spectrally resolved interference pattern of a length-stabilized multiple-beam interferometer. The retrieved phase from the pattern correlates well with the strongly CEP-sensitive coupling signal between the frequency combs of the picosecond oscillator and an ultra-high finesse Fabry-Perot interferometer. Our results can lead to the generation of a robust CEP-stabilized seed pulse train for high resolution comb spectroscopy as well as to compact Compton X-ray and gamma-ray sources

  6. Identification of the Long-Sought Common-Envelope Events

    CERN Document Server

    Ivanova, N; Nandez, J L Avendano; Lombardi, J C; 10.1126/science.1225540

    2013-01-01

    Common-envelope events (CEEs), during which two stars temporarily orbit within a shared envelope, are believed to be vital for the formation of a wide range of close binaries. For decades, the only evidence that CEEs actually occur has been indirect, based on the existence of systems that could not be otherwise explained. Here we propose a direct observational signature of CEE arising from a physical model where emission from matter ejected in a CEE is controlled by a recombination front as the matter cools. The natural range of timescales and energies from this model, as well the expected colors, light-curve shapes, ejection velocities and event rate, match those of a recently-recognized class of red transient outbursts.

  7. Determining the approach speed envelope of carrier aircraft

    Institute of Scientific and Technical Information of China (English)

    Geng Jianzhong; Yao Hailin; Duan Zhuoyi

    2013-01-01

    Many factors,such as deck motion and air wave,influence the determination of the approach speed which has an important effect on landing safety. Until recently,there are no design criteria about approach speed of carrier aircraft in the current standards and available publications. Therefore,the requirements of stall margin, longitudinal acceleration ability,altitude correction and field-of-view on approach speed were researched. Based on the flight dynamics model,the flight simulations were conducted to study the effect of the response time of en-gine,wave off requirements,elevator efficiency and deflection rate on the approach speed. The results presented that the approach longitudinal acceleration and altitude correction ability had crucial influence on the approach speed envelope of the aircraft. The limitations of the control requirements,field-of-view requirements and gear were also given through the simulation and analysis. Based on the above results,the approach speed envelope were determined.

  8. Serial femtosecond X-ray diffraction of enveloped virus microcrystals

    Directory of Open Access Journals (Sweden)

    Robert M. Lawrence

    2015-07-01

    Full Text Available Serial femtosecond crystallography (SFX using X-ray free-electron lasers has produced high-resolution, room temperature, time-resolved protein structures. We report preliminary SFX of Sindbis virus, an enveloped icosahedral RNA virus with ∼700 Å diameter. Microcrystals delivered in viscous agarose medium diffracted to ∼40 Å resolution. Small-angle diffuse X-ray scattering overlaid Bragg peaks and analysis suggests this results from molecular transforms of individual particles. Viral proteins undergo structural changes during entry and infection, which could, in principle, be studied with SFX. This is an important step toward determining room temperature structures from virus microcrystals that may enable time-resolved studies of enveloped viruses.

  9. Innovative Danish Building Envelope Components for Passive Houses

    DEFF Research Database (Denmark)

    Tommerup, Henrik M.; Svendsen, Svend

    2006-01-01

    . The perhaps most important basic passive house concept requirement in a relatively cold Danish climate is envelope constructions with superior thermal insulation without thermal bridges. Some Danish producers of building components have during the last couple of years, developed new highly insulated...... and in some cases very innovative envelope constructions. In this paper, two of the most interesting components are described; a prefabricated light-weight exterior wall element with a load-bearing plywood and steel frame and a foundation / slab on ground solution based on concrete and EPS insulation......The Passive House concept has not as yet become generally accepted in Denmark. But there is a growing awareness of the concept as a solution to achieve high thermal comfort conditions and a low energy demand on low construction costs. This growing awareness is partly due to the introduction of new...

  10. Substrate Integrated Slot Array Antenna with Required Radiation Pattern Envelope

    Directory of Open Access Journals (Sweden)

    M. M. Zhou

    2016-01-01

    Full Text Available A substrate integrated slot array antenna with a prescribed radiation pattern is investigated in this paper. To meet the requirement of a certain standard radiation pattern envelope, the array configuration and the element excitation coefficient should be considered together. An efficient and systematic method is proposed to determine the element number and element weights in a planar array. After that, the geometrical dimension of the substrate integrated slot array can be synthesized. As an example, a K-band 16 × 22 slot array antenna based on the substrate integrated waveguide (SIW technology is designed, fabricated, and measured. Its radiation pattern can meet the class 3 antenna radiation pattern envelope of the European Telecommunications Standards Institute (ETSI standard pattern. Experimental results are in good agreement with simulated ones.

  11. Maximum Torque and Momentum Envelopes for Reaction Wheel Arrays

    Science.gov (United States)

    Markley, F. Landis; Reynolds, Reid G.; Liu, Frank X.; Lebsock, Kenneth L.

    2009-01-01

    Spacecraft reaction wheel maneuvers are limited by the maximum torque and/or angular momentum that the wheels can provide. For an n-wheel configuration, the torque or momentum envelope can be obtained by projecting the n-dimensional hypercube, representing the domain boundary of individual wheel torques or momenta, into three dimensional space via the 3xn matrix of wheel axes. In this paper, the properties of the projected hypercube are discussed, and algorithms are proposed for determining this maximal torque or momentum envelope for general wheel configurations. Practical strategies for distributing a prescribed torque or momentum among the n wheels are presented, with special emphasis on configurations of four, five, and six wheels.

  12. Case Study of Envelope Sealing in Existing Multiunit Structures

    Energy Technology Data Exchange (ETDEWEB)

    Dentz, Jordan [ARIES Collaborative, New York, NY (United States); Conlin, Francis [ARIES Collaborative, New York, NY (United States); Podorson, David [ARIES Collaborative, New York, NY (United States)

    2012-10-01

    This report describes envelope air sealing that was included in the retrofit of a 244 unit low-rise multifamily housing complex in Durham, N.C. On average, total leakage was reduced by nearly half, from 19.7 ACH50 to 9.4 ACH50. Important air leakage locations identified included plumbing and electrical penetrations, dropped ceilings/soffits, windows, ducts and wall-to-floor intersections. Specifications and a pictorial guide were developed for contractors performing the work.

  13. Expert Meeting Report: Advanced Envelope Research for Factory Built Housing

    Energy Technology Data Exchange (ETDEWEB)

    Levy, E.; Mullens, M.; Tompos, E.; Kessler, B.; Rath, P.

    2012-04-01

    This report provides information about the Building America expert meeting on advanced envelope research for factory built housing, hosted by the ARIES Collaborative on October 11, 2011, in Phoenix, Arizona. The goals of this meeting were to provide a comprehensive solution to the use of three previously selected advanced alternatives for factory-built wall construction, assess each option focusing on major issues relating to viability and commercial potential, and determine additional steps are required to reach this potential.

  14. Stripped-envelope supernova rates and host-galaxy properties

    CERN Document Server

    Graur, Or; Modjaz, Maryam; Maoz, Dan; Shivvers, Isaac; Filippenko, Alexei V; Li, Weidong

    2015-01-01

    The progenitors of stripped-envelope supernovae (SNe Ibc) remain to be conclsuively identified, but correlations between SN rates and host-galaxy properties can constrain progenitor models. Here, we present one result from a re-analysis of the rates from the Lick Observatory Supernova Search. Galaxies with stellar masses less than $\\sim 10^{10}~{\\rm M_\\odot}$ are less efficient at producing SNe Ibc than more massive galaxies. Any progenitor scenario must seek to explain this new observation.

  15. Estimating returns to scale in imprecise data envelopment analysis

    DEFF Research Database (Denmark)

    Hatami-Marbini, Adel; Beigi, Zahra Ghelej; Hougaard, Jens Leth;

    The economic concept of Returns-to-Scale (RTS) has been intensively studied in the context of Data Envelopment Analysis (DEA). The conventional DEA models that are used for RTS classification require well-defined and accurate data whereas in reality data are often imprecise, vague, uncertain or i...... and increasing RTS using sensitivity analysis. Finally, we present the stability region of an observation while preserving its current RTS classification using the optimal values of a set of proposed DEA-based models....

  16. Chinese Companies Distress Prediction: An Application of Data Envelopment Analysis

    OpenAIRE

    Li, Zhiyong; Crook, Jonathan; Andreeva, Galina

    2013-01-01

    Bankruptcy prediction is a key part in corporate credit risk management. Traditional bankruptcy prediction models employ financial ratios or market prices to predict bankruptcy or financial distress prior to its occurrence. We investigate the predictive accuracy of corporate efficiency measures along with standard financial ratios in predicting corporate distress in Chinese companies. Data Envelopment Analysis (DEA) is used to measure corporate efficiency. In contrast to previous applications...

  17. Measuring economic journals’ citation efficiency: A data envelopment analysis approach

    OpenAIRE

    Halkos, George; Tzeremes, Nickolaos

    2011-01-01

    This paper by using Data Envelopment Analysis (DEA) and statistical inference evaluates the citation performance of 229 economic journals. The paper categorizes the journals into four main categories (A to D) based on their efficiency levels. The results are then compared to the 27 “core economic journals” as introduced by Dimond (1989). The results reveal that after more than twenty years Diamonds’ list of “core economic journals” is still valid. Finally, for the first time the paper uses da...

  18. Modeling water emission from low-mass protostellar envelopes

    OpenAIRE

    van Kempen, T. A.; Doty, S. D.; van Dishoeck, E. F.; Hogerheijde, M.R.; Joergensen, J. K.

    2008-01-01

    Within low-mass star formation, water vapor plays a key role in the chemistry and energy balance of the circumstellar material. The Herschel Space Observatory will open up the possibility to observe water lines originating from a wide range of excitation energies.Our aim is to simulate the emission of rotational water lines from envelopes characteristic of embedded low-mass protostars. A large number of parameters that influence the water line emission are explored: luminosity, density,densit...

  19. An Envelope-Based Paradigm for Seismic Early Warning

    Science.gov (United States)

    Cua, G. B.; Heaton, T. H.

    2003-12-01

    We present a waveform envelope-based paradigm for seismic early warning. As suggested by theoretical scaling relations and as observed from data, acceleration saturates with increasing magnitude at a faster rate than does velocity or displacement. Thus, ratios of velocity or displacement to acceleration should be indicative of the magnitude of an earthquake. We introduce an evenlope-based parameterization of ground motion, where the observed ground motion envelope is decomposed into independent P-wave, S-wave, and ambient noise envelopes. The body wave envelopes, in turn, are parameterized by a rise time, an amplitude, a duration, and two decay parameters. We apply this parameterization to a database of over 30,000 records of horizontal and vertical acceleration, velocity, and displacement recorded on digital Southern California Seismic Network stations within 200 km of 80 regional events ranging in magnitude from M2.0 to M7.3. We derive attenuation relationships that account for magnitude-dependent saturation for vertical and horizontal acceleration, velocity, and displacement for P- and S-wave amplitudes, obtain station corrections relative to the mean hard rock response, and use these relationships to examine trends with magnitude and distance of ratios of different components of ground motion. An important consequence of our parameterization is the insight it provides into P-wave characteristics. We find that various ratios of P-wave velocity and displacement to acceleration are indicative of magnitude, and may have potential as another quick method to estimate magnitude for seismic early warning.

  20. Ion acoustic envelope solitons in explosive ionospheric experiments

    Science.gov (United States)

    Kovaleva, I. Kh.

    2008-01-01

    The conditions are studied under which stable ion acoustic envelope solitons propagating perpendicular to the magnetic field lines can exist in the ionospheric plasma. The amplitudes, frequencies, and lengths of the waves are determined. The results obtained are compared with the experimental data. It is suggested that such solitons play an important role in both the formation of an ionization front and its motion across the magnetic field and also give rise to a fluctuation precursor in explosive ionospheric experiments.

  1. Intracellular self-assembly based multi-labeling of key viral components: Envelope, capsid and nucleic acids.

    Science.gov (United States)

    Wen, Li; Lin, Yi; Zhang, Zhi-Ling; Lu, Wen; Lv, Cheng; Chen, Zhi-Liang; Wang, Han-Zhong; Pang, Dai-Wen

    2016-08-01

    Envelope, capsid and nucleic acids are key viral components that are all involved in crucial events during virus infection. Thus simultaneous labeling of these key components is an indispensable prerequisite for monitoring comprehensive virus infection process and dissecting virus infection mechanism. Baculovirus was genetically tagged with biotin on its envelope protein GP64 and enhanced green fluorescent protein (EGFP) on its capsid protein VP39. Spodoptera frugiperda 9 (Sf9) cells were infected by the recombinant baculovirus and subsequently fed with streptavidin-conjugated quantum dots (SA-QDs) and cell-permeable nucleic acids dye SYTO 82. Just by genetic engineering and virus propagation, multi-labeling of envelope, capsid and nucleic acids was spontaneously accomplished during virus inherent self-assembly process, significantly simplifying the labeling process while maintaining virus infectivity. Intracellular dissociation and transportation of all the key viral components, which was barely reported previously, was real-time monitored based on the multi-labeling approach, offering opportunities for deeply understanding virus infection and developing anti-virus treatment. PMID:27209260

  2. Mechanistic understanding of gene delivery mediated by highly efficient multicomponent envelope-type nanoparticle systems.

    Science.gov (United States)

    Pozzi, D; Marchini, C; Cardarelli, F; Rossetta, A; Colapicchioni, V; Amici, A; Montani, M; Motta, S; Brocca, P; Cantù, L; Caracciolo, G

    2013-12-01

    We packaged condensed DNA/protamine particles in multicomponent envelope-type nanoparticle systems (MENS) combining different molar fractions of the cationic lipids 1,2-dioleoyl-3-trimethylammonium-propane (DOTAP) and 3β-[N-(N,N-dimethylaminoethane)-carbamoyl] cholesterol (DC-Chol) and the zwitterionic lipids dioleoylphosphocholine (DOPC) and dioleoylphosphatidylethanolamine (DOPE). Dynamic light scattering (DLS) and microelectrophoresis allowed us to identify the cationic lipid/DNA charge ratio at which MENS are small sized and positively charged, while synchrotron small-angle X-ray scattering (SAXS) and atomic force microscopy (AFM) revealed that MENS are well-shaped DNA/protamine particles covered by a lipid monobilayer. Transfection efficiency (TE) experiments indicate that a nanoparticle formulation, termed MENS-3, was not cytotoxic and highly efficient to transfect Chinese hamster ovary (CHO) cells. To rationalize TE, we performed a quantitative investigation of cell uptake, intracellular trafficking, endosomal escape, and final fate by laser scanning confocal microscopy (LSCM). We found that fluid-phase macropinocytosis is the only endocytosis pathway used by MENS-3. Once taken up by the cell, complexes that are actively transported by microtubules frequently fuse with lysosomes, while purely diffusing systems do not. Indeed, spatiotemporal image correlation spectroscopy (STICS) clarified that MENS-3 mostly exploit diffusion to move in the cytosol of CHO cells, thus explaining the high TE levels observed. Also, MENS-3 exhibited a marked endosomal rupture ability resulting in extraordinary DNA release. The lipid-dependent and structure-dependent TE boost suggests that efficient transfection requires both the membrane-fusogenic activity of the nanocarrier envelope and the employment of lipid species with intrinsic endosomal rupture ability. PMID:24188138

  3. Metallicity dependence of turbulent pressure and macroturbulence in stellar envelopes

    Science.gov (United States)

    Grassitelli, L.; Fossati, L.; Langer, N.; Simón-Díaz, S.; Castro, N.; Sanyal, D.

    2016-08-01

    Macroturbulence, introduced as a fudge to reproduce the width and shape of stellar absorption lines, reflects gas motions in stellar atmospheres. While in cool stars, it is thought to be caused by convection zones immediately beneath the stellar surface, the origin of macroturbulence in hot stars is still under discussion. Recent works established a correlation between the turbulent-to-total pressure ratio inside the envelope of stellar models and the macroturbulent velocities observed in corresponding Galactic stars. To probe this connection further, we evaluated the turbulent pressure that arises in the envelope convective zones of stellar models in the mass range 1-125 M⊙ based on the mixing-length theory and computed for metallicities of the Large and Small Magellanic Cloud. We find that the turbulent pressure contributions in models with these metallicities located in the hot high-luminosity part of the Hertzsprung-Russel (HR) diagram is lower than in similar models with solar metallicity, whereas the turbulent pressure in low-metallicity models populating the cool part of the HR-diagram is not reduced. Based on our models, we find that the currently available observations of hot massive stars in the Magellanic Clouds appear to support a connection between macroturbulence and the turbulent pressure in stellar envelopes. Multidimensional simulations of sub-surface convection zones and a larger number of high-quality observations are necessary to test this idea more rigorously.

  4. Inactivation of enveloped virus by laser-driven protein aggregation

    Science.gov (United States)

    Tsen, Shaw-Wei D.; Chapa, Travis; Beatty, Wandy; Tsen, Kong-Thon; Yu, Dong; Achilefu, Samuel

    2012-12-01

    Ultrafast lasers in the visible and near-infrared range have emerged as a potential new method for pathogen reduction of blood products and pharmaceuticals. However, the mechanism of enveloped virus inactivation by this method is unknown. We report the inactivation as well as the molecular and structural effects caused by visible (425 nm) femtosecond laser irradiation on murine cytomegalovirus (MCMV), an enveloped, double-stranded DNA virus. Our results show that laser irradiation (1) caused a 5-log reduction in MCMV titer, (2) did not cause significant changes to the global structure of MCMV virions including membrane and capsid, as assessed by electron microscopy, (3) produced no evidence of double-strand breaks or crosslinking in MCMV genomic DNA, and (4) caused selective aggregation of viral capsid and tegument proteins. We propose a model in which ultrafast laser irradiation induces partial unfolding of viral proteins by disrupting hydrogen bonds and/or hydrophobic interactions, leading to aggregation of closely associated viral proteins and inactivation of the virus. These results provide new insight into the inactivation of enveloped viruses by visible femtosecond lasers at the molecular level, and help pave the way for the development of a new ultrafast laser technology for pathogen reduction.

  5. The epigenetics of nuclear envelope organization and disease

    Energy Technology Data Exchange (ETDEWEB)

    Schirmer, Eric C. [Wellcome Trust Centre for Cell Biology, University of Edinburgh, Kings Buildings, Michael Swann Building, Room 5.22, Edinburgh EH9 3JR (United Kingdom)], E-mail: e.schirmer@ed.ac.uk

    2008-12-01

    Mammalian chromosomes and some specific genes have non-random positions within the nucleus that are tissue-specific and heritable. Work in many organisms has shown that genes at the nuclear periphery tend to be inactive and altering their partitioning to the interior results in their activation. Proteins of the nuclear envelope can recruit chromatin with specific epigenetic marks and can also recruit silencing factors that add new epigenetic modifications to chromatin sequestered at the periphery. Together these findings indicate that the nuclear envelope is a significant epigenetic regulator. The importance of this function is emphasized by observations of aberrant distribution of peripheral heterochromatin in several human diseases linked to mutations in NE proteins. These debilitating inherited diseases range from muscular dystrophies to the premature aging progeroid syndromes and the heterochromatin changes are just one early clue for understanding the molecular details of how they work. The architecture of the nuclear envelope provides a unique environment for epigenetic regulation and as such a great deal of research will be required before we can ascertain the full range of its contributions to epigenetics.

  6. Magnetic Field Amplification During the Common Envelope Phase

    CERN Document Server

    Ohlmann, Sebastian T; Pakmor, Ruediger; Springel, Volker; Mueller, Ewald

    2016-01-01

    During the common envelope (CE) phase, a giant star in a binary system overflows its Roche lobe and unstable mass transfer leads to a spiral-in of the companion, resulting in a close binary system or in a merger of the stellar cores. Dynamo processes during the CE phase have been proposed as a mechanism to generate magnetic fields that are important for forming magnetic white dwarfs (MWDs) and for shaping planetary nebulae. Here, we present the first magnetohydrodynamics simulations of the dynamical spiral-in during a CE phase. We find that magnetic fields are strongly amplified in the accretion stream around the $1M_\\odot$ companion as it spirals into the envelope of a $2M_\\odot$ RG. This leads to field strengths of 10 to 100 kG throughout the envelope after 120 d. The magnetic field amplification is consistent with being driven by the magnetorotational instability. The field strengths reached in our simulation make the magnetic field interesting for diagnostic purposes, but they are dynamically irrelevant. ...

  7. The Nonlinear Analytical Envelope Equation in quadratic nonlinear crystals

    CERN Document Server

    Bache, Morten

    2016-01-01

    We here derive the so-called Nonlinear Analytical Envelope Equation (NAEE) inspired by the work of Conforti et al. [M. Conforti, A. Marini, T. X. Tran, D. Faccio, and F. Biancalana, "Interaction between optical fields and their conjugates in nonlinear media," Opt. Express 21, 31239-31252 (2013)], whose notation we follow. We present a complete model that includes $\\chi^{(2)}$ terms [M. Conforti, F. Baronio, and C. De Angelis, "Nonlinear envelope equation for broadband optical pulses in quadratic media," Phys. Rev. A 81, 053841 (2010)], $\\chi^{(3)}$ terms, and then extend the model to delayed Raman effects in the $\\chi^{(3)}$ term. We therefore get a complete model for ultrafast pulse propagation in quadratic nonlinear crystals similar to the Nonlinear Wave Equation in Frequency domain [H. Guo, X. Zeng, B. Zhou, and M. Bache, "Nonlinear wave equation in frequency domain: accurate modeling of ultrafast interaction in anisotropic nonlinear media," J. Opt. Soc. Am. B 30, 494-504 (2013)], but where the envelope is...

  8. Planet formation from the ejecta of common envelopes

    CERN Document Server

    Schleicher, Dominik R G

    2013-01-01

    The close binary system NN Serpentis must have gone through a common envelope phase before the formation of its white dwarf. During this phase, a substantial amount of mass was lost from the envelope. The recently detected orbits of circumbinary planets were suggested to be inconsistent with planet formation before the mass loss. We explore whether new planets may have formed from the ejecta of the common envelope, and derive the expected planetary mass as a function of radius. We employ the model of \\citet{Kashi11} to estimate the amount of mass that is retained during the ejection event, and infer the properties of the resulting disk from the conservation of mass and angular momentum. The resulting planetary masses are estimated from models with and without radiative feedback. We show that the observed planetary masses can be reproduced for appropriate model parameters. Photoheating can stabilize the disks in the interior, potentially explaining the observed planetary orbits on scales of a few AU. We compar...

  9. Diagnostic of the unstable envelopes of Wolf-Rayet stars

    CERN Document Server

    Grassitelli, Luca; Sanyal, Debashis; Langer, Norbert; Louis, Nicole St; Bestenlehner, Joachim; Fossati, Luca

    2016-01-01

    The envelopes of stars near the Eddington limit are prone to various instabilities. A high Eddington factor in connection with the Fe opacity peak leads to convective instability, and a corresponding envelope inflation may induce pulsational instability. Here, we investigate the occurrence and consequences of both instabilities in models of Wolf-Rayet stars. We determine the convective velocities in the sub-surface convective zones to estimate the amplitude of the turbulent velocity at the base of the wind that potentially leads to the formation of small-scale wind structures, as observed in several WR stars. We also investigate the effect of mass loss on the pulsations of our models. We approximated solar metallicity WR stars by models of mass-losing helium stars, and we characterized the properties of convection in the envelope adopting the standard MLT. Our results show the occurrence of sub-surface convective regions in all studied models. Small surface velocity amplitudes are predicted for models with ma...

  10. Solar active envelope module with an adjustable transmittance/absorptance

    Directory of Open Access Journals (Sweden)

    C. Villasante Villasante

    2015-06-01

    Full Text Available A solar active envelope module with a high flexibility degree is proposed in this paper. The transparent module controls the day-lighting of the room, improving the indoor environment, while absorbing the superfluous solar energy inside. That energy is used to increase the efficiency of heating, ventilation, and the air-conditioning (HVAC system of the building. This is carried out through a fine control of the absorptance of the envelope module. The active envelope module consists of three glazed chambers with advanced coatings and frames to assure a minimum thermal transmittance while allowing transparency. A fluid containing heat-absorbing nanoparticles flows inside the central chamber and is heated up due to the impinging solar energy. Unlike other systems proposed in the past, which included transparency control systems based on complex filters and chemical processes, the absorption of the module is controlled by the variation of the thickness of the central chamber with a mechanical device. That is, varying the thickness of the central chamber, it allows controlling the absorptance of the whole system and, as a result, indoor day-lighting and thermal loads. Therefore, a new system is proposed that enables to:  

  11. Subdwarf B stars from the common envelope ejection channel

    CERN Document Server

    Xiong, H; Podsiadlowski, P; Han, Z

    2016-01-01

    From the canonical binary scenario, the majority of sdBs are produced from low-mass stars with degenerate cores where helium is ignited in a way of flashes. Due to numerical difficulties, the models of produced sdBs are generally constructed from more massive stars with non-degenerate cores, leaving several uncertainties on the exact characteristics of sdB stars. Employing MESA, we systematically studied the characteristics of sdBs produced from the common envelope (CE) ejection channel, and found that the sdB stars produced from the CE ejection channel appear to form two distinct groups on the effective temperature-gravity diagram. One group (the flash-mixing model) almost has no H-rich envelope and crows at the hottest temperature end of the extremely horizontal branch (EHB), while the other group has significant H-rich envelope and spreads over the whole canonical EHB region. The key factor for the dichotomy of the sdB properties is the development of convection during the first helium flash, which is dete...

  12. Biomimetic Architecture in Building Envelope Maintenance (A Literature

    Directory of Open Access Journals (Sweden)

    Agus Salim N.A.

    2014-01-01

    Full Text Available The study of biomimetic architecture on building envelope is the main structure of this research. The concept is believed more sustainable and efficient for energy saving, operating cost consumption, waste recycle and design renewal in the future. The inspiration from the nature developed the intention on this study to explore on what and how this concept to overcome the problems through design. Biomimicry does catch the attention of human to study more on the system and function of its nature course. The designers are not exception influenced by this concept when the form, shape, texture and colour inspired them in their design. The domination of building form will affect the building envelope as the skin of the structure. A clear impact on building failure is begun with building envelope appearance without a proper maintenance. The faults in building design place a heavy burden on the building for the rest of its operational life and there is no compensation for it. In such situations, the responsibility falls on the shoulders of the designer.

  13. Magnetic field amplification during the common envelope phase

    Science.gov (United States)

    Ohlmann, Sebastian T.; Röpke, Friedrich K.; Pakmor, Rüdiger; Springel, Volker; Müller, Ewald

    2016-10-01

    During the common envelope (CE) phase, a giant star in a binary system overflows its Roche lobe and unstable mass transfer leads to a spiral-in of the companion, resulting in a close binary system or in a merger of the stellar cores. Dynamo processes during the CE phase have been proposed as a mechanism to generate magnetic fields that are important for forming magnetic white dwarfs (MWDs) and for shaping planetary nebulae. Here, we present the first magnetohydrodynamics simulations of the dynamical spiral-in during a CE phase. We find that magnetic fields are strongly amplified in the accretion stream around the 1 M⊙ companion as it spirals into the envelope of a 2 M⊙ RG. This leads to field strengths of 10-100 kG throughout the envelope after 120 d. The magnetic field amplification is consistent with being driven by the magnetorotational instability. The field strengths reached in our simulation make the magnetic field interesting for diagnostic purposes, but they are dynamically irrelevant. They are also too small to explain the formation of the highest fields found in MWDs, but may be relevant for luminous red novae, and detecting magnetic fields in these events would support the scenario as proposed here.

  14. An alternative conformation of the gp41 heptad repeat 1 region coiled coil exists in the human immunodeficiency virus (HIV-1) envelope glycoprotein precursor

    International Nuclear Information System (INIS)

    The human immunodeficiency virus (HIV-1) transmembrane envelope glycoprotein, gp41, which mediates virus-cell fusion, exists in at least three different conformations within the trimeric envelope glycoprotein complex. The structures of the prefusogenic and intermediate states are unknown; structures representing the postfusion state have been solved. In the postfusion conformation, three helical heptad repeat 2 (HR2) regions pack in an antiparallel fashion into the hydrophobic grooves on the surface of a triple-helical coiled coil formed by the heptad repeat 1 (HR1) regions. We studied the prefusogenic conformation of gp41 by mutagenic alteration of membrane-anchored and soluble forms of the HIV-1 envelope glycoproteins. Our results indicate that, in the HIV-1 envelope glycoprotein precursor, the gp41 HR1 region is in a conformation distinct from that of a trimeric coiled coil. Thus, the central gp41 coiled coil is formed during the transition of the HIV-1 envelope glycoproteins from the precursor state to the receptor-bound intermediate

  15. Flight envelope protection of aircraft using adaptive neural network and online linearisation

    Science.gov (United States)

    Shin, Hohyun; Kim, Youdan

    2016-03-01

    Flight envelope protection algorithm is proposed to improve the safety of an aircraft. Flight envelope protection systems find the control inputs to prevent an aircraft from exceeding structure/aerodynamic limits and maximum control surface deflections. The future values of state variables are predicted using the current states and control inputs based on linearised aircraft model. To apply the envelope protection algorithm for the wide envelope of the aircraft, online linearisation is adopted. Finally, the flight envelope protection system is designed using adaptive neural network and least-squares method. Numerical simulations are conducted to verify the performance of the proposed scheme.

  16. Review on thermal performance of phase change energy storage building envelope

    Institute of Scientific and Technical Information of China (English)

    WANG Xin; ZHANG YinPing; XlAO Wei; ZENG RuoLang; ZHANG QunLi; DI HongFa

    2009-01-01

    Improving the thermal performance of building envelope is an important way to save building energy consumption. The phase change energy storage building envelope is helpful to effective use of renewable energy, reducing building operational energy consumption, increasing building thermal comfort, and reducing environment pollution and greenhouse gas emission. This paper presents the concept of ideal energy-saving building envelope, which is used to guide the building envelope material selection and thermal performance design. This paper reviews some available researches on phase change building material and phase change energy storage building envelope. At last, this paper presents some current problems needed further research.

  17. Functional dissection of the Moloney murine leukemia virus envelope protein gp70.

    Science.gov (United States)

    Bae, Y; Kingsman, S M; Kingsman, A J

    1997-03-01

    The envelope protein of Moloney murine leukemia virus (Mo-MLV) is a complex glycoprotein that mediates receptor binding and entry via fusion with cell membranes. By using a series of substitution mutations and truncations in the Mo-MLV external envelope surface protein gp70, we have identified regions important for these processes. Firstly, truncations of gp70 revealed that the minimal continuous receptor-binding region is amino acids 9 to 230, in broad agreement with other studies. Secondly, within this region there are two key basic amino acids, Arg-83 and Arg-95, that are essential for receptor binding and may interact with a negatively charged residue(s) or with the pi electrons of the aromatic ring on a hydrophobic residue(s) in the basic amino acid transporter protein that is the Mo-MLV ecotropic receptor. Finally, we showed that outside the minimal receptor-binding region at amino acids 2 to 8, there is a region that is essential for postbinding fusion events. PMID:9032341

  18. Virtual Nuclear Envelope Breakdown and Its Regulators in Fission Yeast Meiosis.

    Science.gov (United States)

    Asakawa, Haruhiko; Yang, Hui-Ju; Hiraoka, Yasushi; Haraguchi, Tokuko

    2016-01-01

    Ran, a small GTPase, is required for the spindle formation and nuclear envelope (NE) formation. After NE breakdown (NEBD) during mitosis in metazoan cells, the Ran-GTP gradient across the NE is lost and Ran-GTP becomes concentrated around chromatin, thus affecting the stability of microtubules and promoting the assembly of spindle microtubules and segregation of chromosomes. Mitosis in which chromosomes are segregated subsequent to NEBD is called "open mitosis." In contrast, many fungi undergo a process termed "closed mitosis" in which chromosome segregation and spindle formation occur without NEBD. Although the fission yeast Schizosaccharomyces pombe undergoes a closed mitosis, it exhibits a short period during meiosis (anaphase of the second meiosis; called "anaphase II") when nuclear and cytoplasmic proteins are mixed in the presence of intact NE and nuclear pore complexes (NPC). This "virtual" nuclear envelope breakdown (vNEBD) involves changes in the localization of RanGAP1, an activator of Ran-GTP hydrolysis. Recently, Nup132, a component of the structural core Nup107-160 subcomplex of the NPC, has been shown to be involved in the maintenance of the nuclear cytoplasmic barrier in yeast meiosis. In this review, we highlight the possible roles of RanGAP1 and Nup132 in vNEBD and discuss the biological significance of vNEBD in S. pombe meiosis. PMID:26870731

  19. Potential of carbohydrate-binding agents as therapeutics against enveloped viruses.

    Science.gov (United States)

    François, K O; Balzarini, J

    2012-03-01

    Twenty-seven years after the discovery of HIV as the cause of AIDS more than 25 drugs directed against four different viral targets (i.e. reverse transcriptase, protease, integrase, envelope gp41) and one cellular target (i.e. CCR5 co-receptor) are available for treatment. However, the search for an efficient vaccine is still ongoing. One of the main problems is the presence of a continuously evolving dense carbohydrate shield, consisting of N-linked glycans that surrounds the virion and protects it against efficient recognition and persistent neutralization by the immune system. However, several lectins from the innate immune system specifically bind to these glycans in an attempt to process the virus antigens to provoke an immune response. Across a wide variety of different species in nature lectins can be found that can interact with the glycosylated envelope of HIV-1 and can block the infection of susceptible cells by the virus. In this review, we will give an overview of the lectins from non-mammalian origin that are endowed with antiviral properties and discuss the complex interactions between lectins of the innate immune system and HIV-1. Also, attention will be given to different carbohydrate-related modalities that can be exploited for antiviral chemotherapy.

  20. Structural models of the membrane anchors of envelope glycoproteins E1 and E2 from pestiviruses

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Jimin, E-mail: jimin.wang@yale.edu; Li, Yue; Modis, Yorgo, E-mail: yorgo.modis@yale.edu

    2014-04-15

    The membrane anchors of viral envelope proteins play essential roles in cell entry. Recent crystal structures of the ectodomain of envelope protein E2 from a pestivirus suggest that E2 belongs to a novel structural class of membrane fusion machinery. Based on geometric constraints from the E2 structures, we generated atomic models of the E1 and E2 membrane anchors using computational approaches. The E1 anchor contains two amphipathic perimembrane helices and one transmembrane helix; the E2 anchor contains a short helical hairpin stabilized in the membrane by an arginine residue, similar to flaviviruses. A pair of histidine residues in the E2 ectodomain may participate in pH sensing. The proposed atomic models point to Cys987 in E2 as the site of disulfide bond linkage with E1 to form E1–E2 heterodimers. The membrane anchor models provide structural constraints for the disulfide bonding pattern and overall backbone conformation of the E1 ectodomain. - Highlights: • Structures of pestivirus E2 proteins impose constraints on E1, E2 membrane anchors. • Atomic models of the E1 and E2 membrane anchors were generated in silico. • A “snorkeling” arginine completes the short helical hairpin in the E2 membrane anchor. • Roles in pH sensing and E1–E2 disulfide bond formation are proposed for E1 residues. • Implications for E1 ectodomain structure and disulfide bonding pattern are discussed.

  1. Adaptive building envelopes, component development as well as implementation strategies

    Directory of Open Access Journals (Sweden)

    Tillmann Klein

    2015-11-01

    Full Text Available The papers in this issue of JFDE discuss the potential of adaptive building envelopes, component development as well as implementation strategies. The applied practice paper demonstrates decision strategies behind the adaptive sun shading system of the Al-Bahr Towers. Additivity in building envelopes is not only a strategy to fulfil the growing demands for energy efficient buildings and comfort but has great architectural implications as well. In general it asks for more complex components as well as control strategies. But complexity also means costs and risks, and we need to discuss the means and effects. This discussion in particular is very interesting because here science and practice meet. The Journal of Facade Design and Engineering JFDE will actively follow and stimulate by providing high quality contributions. Four of the paper contributions have their origins in the Conference ‘Facades 2014’, held in November 2014 in Lucerne. The contributions have been carefully selected and have been subjected to the regular double blind review process of the journal. We want to thank Prof. Dr. Andres Luible for the help in making this issue happen. We are proud that JFDE is the scientific partner for a number of conferences such as ‘The Future Envelope’ Conference on Building Envelopes held yearly in Delft (NL or Bath (UK, the ICAE International Congress on Architectural Envelopes in San Sebastian (ES and the above mentioned conference ‘Facades’ in Lucerne (CH and Detmold (D. Our latest partner is the ICBEST 2017 - International Conference on Building Envelope Systems and Technologies in Istanbul. The growing number of partners indicates the relevance of JFDE for our growing discipline and will assure the continuity of the journal. Facade Design and Engineering is a peer reviewed, open access journal, funded by The Netherlands Organisation for Scientific Research NWO (www.nwo.nl. We see ‘open access’ as the future publishing model

  2. Rapid Process to Generate Beam Envelopes for Optical System Analysis

    Science.gov (United States)

    Howard, Joseph; Seals, Lenward

    2012-01-01

    The task of evaluating obstructions in the optical throughput of an optical system requires the use of two disciplines, and hence, two models: optical models for the details of optical propagation, and mechanical models for determining the actual structure that exists in the optical system. Previous analysis methods for creating beam envelopes (or cones of light) for use in this obstruction analysis were found to be cumbersome to calculate and take significant time and resources to complete. A new process was developed that takes less time to complete beam envelope analysis, is more accurate and less dependent upon manual node tracking to create the beam envelopes, and eases the burden on the mechanical CAD (computer-aided design) designers to form the beam solids. This algorithm allows rapid generation of beam envelopes for optical system obstruction analysis. Ray trace information is taken from optical design software and used to generate CAD objects that represent the boundary of the beam envelopes for detailed analysis in mechanical CAD software. Matlab is used to call ray trace data from the optical model for all fields and entrance pupil points of interest. These are chosen to be the edge of each space, so that these rays produce the bounding volume for the beam. The x and y global coordinate data is collected on the surface planes of interest, typically an image of the field and entrance pupil internal of the optical system. This x and y coordinate data is then evaluated using a convex hull algorithm, which removes any internal points, which are unnecessary to produce the bounding volume of interest. At this point, tolerances can be applied to expand the size of either the field or aperture, depending on the allocations. Once this minimum set of coordinates on the pupil and field is obtained, a new set of rays is generated between the field plane and aperture plane (or vice-versa). These rays are then evaluated at planes between the aperture and field, at a

  3. Ribonucleic acid stimulation of mammalian liver nuclear-envelope nucleoside triphosphatase. A possible enzymic marker for the nuclear envelope.

    Science.gov (United States)

    Agutter, P S; Harris, J R; Stevenson, I

    1977-03-15

    1. The specific activity of rat and pig liver nuclear-envelope nucleoside triphosphatase (EC 3.6.1.3) decreases when the system is depleted of RNA. The activity can be restored by adding high concentrations of yeast RNA to the assay medium. 2. Exogenous RNA also increases the activity of the enzyme in control envelopes (not RNA-depleted). The effect appears to be largely specific for poly(A) and poly(G); it is not stimulated by rRNA or tRNA preparations, ribonuclease-hydrolysed RNA, AMP, or double- or single-stranded DNA. 3. Inhibitors of the enzyme, in concentrations at which half-maximal inhibition of the enzyme is achieved, do not affect the percentage stimulation of the enzyme by yeast RNA. 4. The simulation is abolished by the inclusion of 150 mM-KCl or -NaCl in the assay medium, but not by increasing the assay pH to 8.5. 5. The results are discussed in the light of the possible role of the nucleoside triphosphatase in vivo in nucleo-cytoplasmic ribonucleoprotein translocation. 6. It is proposed that poly(G)-stimulated Mg2+-activated adenosine triphosphatase activity should be adopted as an enzymic marker for the nuclear envelope.

  4. The budding yeast nuclear envelope adjacent to the nucleolus serves as a membrane sink during mitotic delay.

    Science.gov (United States)

    Witkin, Keren L; Chong, Yolanda; Shao, Sichen; Webster, Micah T; Lahiri, Sujoy; Walters, Alison D; Lee, Brandon; Koh, Judice L Y; Prinz, William A; Andrews, Brenda J; Cohen-Fix, Orna

    2012-06-19

    The mechanisms that dictate nuclear shape are largely unknown. Here we screened the budding yeast deletion collection for mutants with abnormal nuclear shape. A common phenotype was the appearance of a nuclear extension, particularly in mutants in DNA repair and chromosome segregation genes. Our data suggest that these mutations led to the abnormal nuclear morphology indirectly, by causing a checkpoint-induced cell-cycle delay. Indeed, delaying cells in mitosis by other means also led to the appearance of nuclear extensions, whereas inactivating the DNA damage checkpoint pathway in a DNA repair mutant reduced the fraction of cells with nuclear extensions. Formation of a nuclear extension was specific to a mitotic delay, because cells arrested in S or G2 had round nuclei. Moreover, the nuclear extension always coincided with the nucleolus, while the morphology of the DNA mass remained largely unchanged. Finally, we found that phospholipid synthesis continued unperturbed when cells delayed in mitosis, and inhibiting phospholipid synthesis abolished the formation of nuclear extensions. Our data suggest a mechanism that promotes nuclear envelope expansion during mitosis. When mitotic progression is delayed, cells sequester the added membrane to the nuclear envelope associated with the nucleolus, possibly to avoid disruption of intranuclear organization.

  5. Loss of A-type lamin expression compromises nuclear envelope integrity in breast cancer

    Institute of Scientific and Technical Information of China (English)

    Callinice D. Capo-chichi; Kathy Q. Car; Jennifer Smedberg; Parvin Ganjei-Azar; Andrew K. Godwin; Xiang-Xi Xu

    2011-01-01

    Through advances in technology, the genetic basis of cancer has been investigated at the genomic level, and many fundamental questions have begun to be addressed. Among several key unresolved questions in cancer biology, the molecular basis for the link between nuclear deformation and malignancy has not been determined. Another hallmark of human cancer is aneuploidy; however, the causes and consequences of aneuploidy are unanswered and are hotly contested topics. We found that nuclear lamina proteins lamin A/C are absent in a significant fraction (38%) of human breast cancer tissues. Even in lamin A/C-positive breast cancer, lamin A/C expression is heterogeneous or aberrant (such as nonnuclear distribution) in the population of tumor cells, as determined by immunohistology and immunofluorescence microscopy. In most breast cancer cell lines, a significant fraction of the lamin A/Cnegative population was observed. To determine the consequences of the loss of lamin A/C, we suppressed their expression by shRNA in non-cancerous primary breast epithelial cells. Down-regulation of lamin A/C in breast epithelial cells led to morphological deformation, resembling that of cancer cells, as observed by immunofluorescence microscopy. The lamin A/C-suppressed breast epithelial cells developed aneuploidy as determined by both flow cytometry and fluorescence in situ hybridization. We conclude that the loss of nuclear envelope structural proteins lamin A/C in breast cancer underlies the two hallmarks of cancer aberrations in nuclear morphology and aneuploidy.

  6. Application of HVJ envelope system to boron neutron capture therapy (BNCT)

    International Nuclear Information System (INIS)

    Boron Neutron Capture Therapy (BNCT) has been used clinically for the treatment of malignant tumors. Two drugs, p-boronophenylalanine (BPA) and sulfhydral borane (BSH), have been used as boron delivery agents. These drugs seem to be taken up preferentially in solid tumors, but it is uncertain whether therapeutic quantities of boron atoms are taken up by micro-invasive or distant tumor cells. High accumulation and high selective delivery of boron into tumor tissues are the most important requirements to achieve efficient BNCT for malignant tumor. The HVJ envelope (HVJ-E) vector system is a novel fusion-mediated gene delivery system based on inactivated hemagglutinating virus of Japan (HVJ; Sendai virus). Although we developed this vector system for gene transfer, it can also deliver proteins, synthetic oligonucleotides, and drugs. HVJ-liposome, which is liposome fused with HVJ-E, has higher boron trapping efficiency than HVJ-E alone. We report the boron delivery into cultured cells with HVJ-liposome systems. The cellular 10B concentration after 60 min incubation with HVJ-E containing BSH was 24.9 μg/g cell pellet for BHK-21 cells (baby hamster kidney cells) and 19.4 μg/g cell pellet for SCC VII cells (murine squamous cell carcinoma). These concentrations are higher than that of 60 min incubated cells with BSH containing (100μg 10B/ml) medium. These results indicate the HVJ-E fused with tumor cell membrane and rapidly delivered boron agents, and that the HVJ-E-mediated delivery system could be applicable to BNCT. Plans are underway to begin neutron radiation experiments in vivo and in vitro. (author)

  7. Dynamic network data envelopment analysis for university hospitals evaluation

    Directory of Open Access Journals (Sweden)

    Maria Stella de Castro Lobo

    2016-01-01

    Full Text Available ABSTRACT OBJECTIVE To develop an assessment tool to evaluate the efficiency of federal university general hospitals. METHODS Data envelopment analysis, a linear programming technique, creates a best practice frontier by comparing observed production given the amount of resources used. The model is output-oriented and considers variable returns to scale. Network data envelopment analysis considers link variables belonging to more than one dimension (in the model, medical residents, adjusted admissions, and research projects. Dynamic network data envelopment analysis uses carry-over variables (in the model, financing budget to analyze frontier shift in subsequent years. Data were gathered from the information system of the Brazilian Ministry of Education (MEC, 2010-2013. RESULTS The mean scores for health care, teaching and research over the period were 58.0%, 86.0%, and 61.0%, respectively. In 2012, the best performance year, for all units to reach the frontier it would be necessary to have a mean increase of 65.0% in outpatient visits; 34.0% in admissions; 12.0% in undergraduate students; 13.0% in multi-professional residents; 48.0% in graduate students; 7.0% in research projects; besides a decrease of 9.0% in medical residents. In the same year, an increase of 0.9% in financing budget would be necessary to improve the care output frontier. In the dynamic evaluation, there was progress in teaching efficiency, oscillation in medical care and no variation in research. CONCLUSIONS The proposed model generates public health planning and programming parameters by estimating efficiency scores and making projections to reach the best practice frontier.

  8. Cepheids at high angular resolution: circumstellar envelope and pulsation

    Science.gov (United States)

    Gallenne, Alexandre

    2011-12-01

    In 2005, interferometric observations with VLTI/VINCI and CHARA/FLUOR revealed the existence of a circumstellar envelope (CSE) around some Cepheids. This surrounding material is particularly interesting for two reasons: it could have an impact on the distance estimates and could be linked to a past or on-going mass loss. The use of Baade-Wesselink methods for independent distance determinations could be significantly biased by the presence of these envelopes. Although their observations are difficult because of the high contrast between the photosphere of the star and the CSE, several observation techniques have the potential to improve our knowledge about their physical properties. In this thesis, I discuss in particular high angular resolution techniques that I applied to the study of several bright Galactic Cepheids. First, I used adaptive optic observations with NACO of the Cepheid RS Puppis, in order to deduce the flux ratio between the CSE and the photosphere of the star. In addition, I could carry out a statistical study of the speckle noise and inspect a possible asymmetry. Secondly, I analysed VISIR data to study the spectral energy distribution of a sample of Cepheids. These diffraction-limited images enabled me to carry out an accurate photometry in the N band and to detect an IR excess linked to the presence of a circumstellar component. On the other hand, applying a Fourier analysis I showed that some components are resolved. I then explored the K' band with the recombination instrument FLUOR for some bright Cepheids. Thanks to new set of data of Y Oph, I improved the study of its circumstellar envelope, using a ring-like model for the CSE. For two other Cepheids, U Vul and S Sge, I applied the interferometric Baade-Wesselink method in order to estimate their distance.

  9. Dynamic network data envelopment analysis for university hospitals evaluation

    Science.gov (United States)

    Lobo, Maria Stella de Castro; Rodrigues, Henrique de Castro; André, Edgard Caires Gazzola; de Azeredo, Jônatas Almeida; Lins, Marcos Pereira Estellita

    2016-01-01

    ABSTRACT OBJECTIVE To develop an assessment tool to evaluate the efficiency of federal university general hospitals. METHODS Data envelopment analysis, a linear programming technique, creates a best practice frontier by comparing observed production given the amount of resources used. The model is output-oriented and considers variable returns to scale. Network data envelopment analysis considers link variables belonging to more than one dimension (in the model, medical residents, adjusted admissions, and research projects). Dynamic network data envelopment analysis uses carry-over variables (in the model, financing budget) to analyze frontier shift in subsequent years. Data were gathered from the information system of the Brazilian Ministry of Education (MEC), 2010-2013. RESULTS The mean scores for health care, teaching and research over the period were 58.0%, 86.0%, and 61.0%, respectively. In 2012, the best performance year, for all units to reach the frontier it would be necessary to have a mean increase of 65.0% in outpatient visits; 34.0% in admissions; 12.0% in undergraduate students; 13.0% in multi-professional residents; 48.0% in graduate students; 7.0% in research projects; besides a decrease of 9.0% in medical residents. In the same year, an increase of 0.9% in financing budget would be necessary to improve the care output frontier. In the dynamic evaluation, there was progress in teaching efficiency, oscillation in medical care and no variation in research. CONCLUSIONS The proposed model generates public health planning and programming parameters by estimating efficiency scores and making projections to reach the best practice frontier. PMID:27191158

  10. Comprehensive Analysis of Contributions from Protein Conformational Stability and Major Histocompatibility Complex Class II-Peptide Binding Affinity to CD4+ Epitope Immunogenicity in HIV-1 Envelope Glycoprotein

    OpenAIRE

    Li, Tingfeng; Steede, N. Kalaya; Nguyen, Hong-Nam P.; Freytag, Lucy C.; McLachlan, James B.; Mettu, Ramgopal R.; Robinson, James E.; Landry, Samuel J.

    2014-01-01

    Helper T-cell epitope dominance in human immunodeficiency virus type 1 (HIV-1) envelope glycoprotein gp120 is not adequately explained by peptide binding to major histocompatibility complex (MHC) proteins. Antigen processing potentially influences epitope dominance, but few, if any, studies have attempted to reconcile the influences of antigen processing and MHC protein binding for all helper T-cell epitopes of an antigen. Epitopes of gp120 identified in both humans and mice occur on the C-te...

  11. Light-activated amino acid transport in Halobacterium halobium envelope vesicles

    Science.gov (United States)

    Macdonald, R. E.; Lanyi, J. K.

    1977-01-01

    Vesicles prepared from Halobacterium halobium cell envelopes accumulate amino acids in response to light-induced electrical and chemical gradients. Nineteen of 20 commonly occurring amino acids have been shown to be actively accumulated by these vesicles in response to illumination or in response to an artificially created Na+ gradient. On the basis of shared common carriers the transport systems can be divided into eight classes, each responsible for the transport of one or several amino acids: arginine, lysine, histidine; asparagine, glutamine; alanine, glycine, threonine, serine; leucine, valine, isoleucine, methionine; phenylalanine, tyrosine, tryptophan; aspartate; glutamate; proline. Available evidence suggests that these carriers are symmetrical in that amino acids can be transported equally well in both directions across the vesicle membranes. A tentative working model to account for these observations is presented.

  12. Preparation of vesicular stomatitis virus pseudotype with Chikungunya virus envelope protein.

    Science.gov (United States)

    Tong, W; Yin, X-X; Lee, B-J; Li, Y-G

    2015-06-01

    Chikungunya virus (CHIKV) is a mosquito-transmitted alphavirus that causes Chikungunya fever (CHIKF) in millions of people mainly in developing countries. CHIKF is characterized by high fever, fatigue, headache, nausea, vomiting, rash, myalgia and severe arthralgia. To date, there is no specific treatment and no licensed vaccine against CHIKV infection. In this study, we developed a safe, efficient and easy neutralization assay of CHIKV based on vesicular stomatitis virus (VSV) pseudotype with CHIKV envelope protein and the green fluorescent protein (GFP) or luciferase as reporter gene, which could be used under a reduced safety level. The VSV pseudotype can be applied to the epidemic survey by measuring the expression of GFP or luciferase activity in infected cells. This system can also be used to study the mechanisms of virus entry.

  13. The Flavivirus Precursor Membrane-Envelope Protein Complex: Structure and Maturation

    Energy Technology Data Exchange (ETDEWEB)

    Li, Long; Lok, Shee-Mei; Yu, I-Mei; Zhang, Ying; Kuhn, Richard J.; Chen, Jue; Rossmann, Michael G. (Purdue)

    2008-09-17

    Many viruses go through a maturation step in the final stages of assembly before being transmitted to another host. The maturation process of flaviviruses is directed by the proteolytic cleavage of the precursor membrane protein (prM), turning inert virus into infectious particles. We have determined the 2.2 angstrom resolution crystal structure of a recombinant protein in which the dengue virus prM is linked to the envelope glycoprotein E. The structure represents the prM-E heterodimer and fits well into the cryo-electron microscopy density of immature virus at neutral pH. The pr peptide {beta}-barrel structure covers the fusion loop in E, preventing fusion with host cell membranes. The structure provides a basis for identifying the stages of its pH-directed conformational metamorphosis during maturation, ending with release of pr when budding from the host.

  14. Immunobiology of the human immunodeficiency virus envelope and its relationship to vaccine strategies.

    Science.gov (United States)

    Bolognesi, D P

    1990-02-01

    The envelope of human immunodeficiency virus (HIV) is an essential building block of the virus and it plays a major role in its life-cycle, particularly during the early stages of infection. It very likely determines, at least in part, the host range and tissue specificity of HIV, participates in pathogenic processes mediated by the virus and can itself be immunosuppressive. Because of its strategic location on the outer surface of the virion and the infected cell, it also represents an optimal (although not the only) target for immune attack and thus a prime candidate for development of vaccine and therapeutic strategies. Efforts to better understand its structural, functional and antigenic properties will thus be well worthwhile. Some of its principal features are reviewed herein and its role in vaccine strategies is discussed. PMID:2182967

  15. Assessing Canadian Bank Branch Operating Efficiency Using Data Envelopment Analysis

    Science.gov (United States)

    Yang, Zijiang

    2009-10-01

    In today's economy and society, performance analyses in the services industries attract more and more attention. This paper presents an evaluation of 240 branches of one big Canadian bank in Greater Toronto Area using Data Envelopment Analysis (DEA). Special emphasis was placed on how to present the DEA results to management so as to provide more guidance to them on what to manage and how to accomplish the changes. Finally the potential management uses of the DEA results were presented. All the findings are discussed in the context of the Canadian banking market.

  16. Orbital Period Variations in Eclipsing Post Common Envelope Binaries

    OpenAIRE

    Parsons, S. G.; Marsh, T. R.; Copperwheat, C. M.; Dhillon, V S; Littlefair, S. P.; Hickman, R. D. G.; Maxted, P. F. L.; Gänsicke, B. T.; Unda-Sanzana, E.; Colque, J. P.; Barraza, N.; Sánchez, N.; Monard, L. A. G.

    2010-01-01

    We present high speed ULTRACAM photometry of the eclipsing post common envelope binaries DE CVn, GK Vir, NN Ser, QS Vir, RR Cae, RX J2130.6+4710, SDSS 0110+1326 and SDSS 0303+0054 and use these data to measure precise mid-eclipse times in order to detect any period variations. We detect a large (~ 250 sec) departure from linearity in the eclipse times of QS Vir which Applegate's mechanism fails to reproduce by an order of magnitude. The only mechanism able to drive this period change is a thi...

  17. Field Testing of Nano-PCM Enhanced Building Envelope Components

    Energy Technology Data Exchange (ETDEWEB)

    Biswas, Kaushik [ORNL; Childs, Phillip W [ORNL; Atchley, Jerald Allen [ORNL

    2013-08-01

    The U.S. Department of Energy s (DOE) Building Technologies Program s goal of developing high-performance, energy efficient buildings will require more cost-effective, durable, energy efficient building envelopes. Forty-eight percent of the residential end-use energy consumption is spent on space heating and air conditioning. Reducing envelope-generated heating and cooling loads through application of phase change material (PCM)-enhanced envelope components can facilitate maximizing the energy efficiency of buildings. Field-testing of prototype envelope components is an important step in estimating their energy benefits. An innovative phase change material (nano-PCM) was developed with PCM encapsulated with expanded graphite (interconnected) nanosheets, which is highly conducive for enhanced thermal storage and energy distribution, and is shape-stable for convenient incorporation into lightweight building components. During 2012, two test walls with cellulose cavity insulation and prototype PCM-enhanced interior wallboards were installed in a natural exposure test (NET) facility at Charleston, SC. The first test wall was divided into four sections, which were separated by wood studs and thin layers of foam insulation. Two sections contained nano-PCM-enhanced wallboards: one was a three-layer structure, in which nano-PCM was sandwiched between two gypsum boards, and the other one had PCM dispersed homogeneously throughout graphite nanosheets-enhanced gypsum board. The second test wall also contained two sections with interior PCM wallboards; one contained nano-PCM dispersed homogeneously in gypsum and the other was gypsum board containing a commercial microencapsulated PCM (MEPCM) for comparison. Each test wall contained a section covered with gypsum board on the interior side, which served as control or a baseline for evaluation of the PCM wallboards. The walls were instrumented with arrays of thermocouples and heat flux transducers. Further, numerical modeling of

  18. A competitive-inhibiton radioimmunoassay for influenza virus envelope antigens

    International Nuclear Information System (INIS)

    A double-antibody competitive-inhibition radioimmunoassay for influenza virus envelope antigens is described. A viral antigen preparation from influenza A virus recombinant MRC11 [antigenically identical to A/Port Chalmers/1/73 (H3N2)] consisting of haemagglutinin and neuraminidase was labelled with radioiodine. Rabbit antisera were allowed to react with the labelled antigen and the resultant antigen-antibody complexes were precipitated with the appropriate antiglobulin. The competitive-inhibition radioimmunoassay very sensitively elucidated differences even among closely related influenza virus strains. Attempts have been made to eliminate neuraminidase from radioimmunoprecipitation to obtain a competitive-inhibition radioimmunoassay system for haemagglutinin alone. (author)

  19. Towards a fourth skin? sustainability and double-envelope buildings

    Energy Technology Data Exchange (ETDEWEB)

    Diprose, P.R.; Robertson, G. [Auckland Univ. (New Zealand)

    1996-05-01

    In several well publicised designs for `green` office buildings, the zone of meditation between inside and outside has been increased by the addition of a second building envelope. When interpreted as exemplars of sustainable architecture, the addition of a second wall in these buildings is questionable both biophysically and psycho-culturally. More constructive design strategies acknowledge the wider biophysical contexts of the human ecosystem, the prudent use of material and energy resources throughout a building`s life, make realistic use of climate, and promote psycho-cultural needs arising out of ecologism. (author)

  20. Immunogenicity of Escherichia coli expressed envelope 2 protein of Chikungunya virus.

    Science.gov (United States)

    Tripathi, Nagesh K; Priya, Raj; Shrivastava, Ambuj

    2014-01-01

    Chikungunya fever, a re-emerging infection, is an arthropod-borne viral disease prevalent in different parts of the world, particularly Africa and South East Asia. Chikungunya virus envelope 2 protein is involved in binding to host receptors and it contains specific epitopes that elicit virus neutralizing antibodies. A highly immunogenic, recombinant Chikungunya virus envelope 2 protein was produced by bioreactor in Escherichia coli for development of a suitable diagnostic and vaccine candidate. This protein was refolded and further purified to achieve biologically active protein. The biological function of refolded and purified recombinant envelope 2 protein of Chikungunya virus was confirmed by its ability to generate envelope 2 specific antibodies with high titers in animal models. These findings suggest that recombinant envelope 2 protein of Chikungunya virus in combination with compatible adjuvant is highly immunogenic. Thus, recombinant envelope 2 protein can be a potential diagnostic reagent and vaccine candidate against Chikungunya virus infection.

  1. Critical core mass for enriched envelopes: the role of H2O condensation

    CERN Document Server

    Venturini, J; Benz, W; Ikoma, M

    2015-01-01

    Context. Within the core accretion scenario of planetary formation, most simulations performed so far always assume the accreting envelope to have a solar composition. From the study of meteorite showers on Earth and numerical simulations, we know that planetesimals must undergo thermal ablation and disruption when crossing a protoplanetary envelope. Once the protoplanet has acquired an atmosphere, the primordial envelope gets enriched in volatiles and silicates from the planetesimals. This change of envelope composition during the formation can have a significant effect in the final atmospheric composition and on the formation timescale of giant planets. Aims. To investigate the physical implications of considering the envelope enrichment of protoplanets due to the disruption of icy planetesimals during their way to the core. Particular focus is placed on the effect on the critical core mass for envelopes where condensation of water can occur. Methods. Internal structure models are numerically solved with th...

  2. Case Study of Envelope Sealing in Existing Multiunit Structures

    Energy Technology Data Exchange (ETDEWEB)

    Dentz, J.; Conlin, F.; Podorson, D.

    2012-10-01

    Envelope air sealing was included in the retrofit of a 244 unit low-rise multifamily housing complex in Durham, N.C. Pre- and post-retrofit enclosure leakage tests were conducted on 51 units and detailed diagnostics were performed on 16. On average, total leakage was reduced by nearly half, from 19.7 ACH50 to 9.4 ACH50. Costs for air sealing were $0.31 per square foot of conditioned floor area, lower than estimates found in the National Residential Efficiency Measures Database (NREMD) and other sources, perhaps due in part to the large-scale production nature of the project. Modeling with BEopt software -- using an estimate of 85% of the envelope air leakage going to the outside (based on guarded tests performed at the site) -- calculated a space conditioning energy cost savings of 15% to 21% due to the air sealing retrofit. Important air leakage locations identified included plumbing and electrical penetrations, dropped ceilings/soffits, windows, ducts and wall-to-floor intersections. Previous repair activity had created significant leakage locations as well. Specifications and a pictorial guide were developed for contractors performing the work.

  3. Hospitals Productivity Measurement Using Data Envelopment Analysis Technique.

    Directory of Open Access Journals (Sweden)

    Amin Torabipour

    2014-11-01

    Full Text Available This study aimed to measure the hospital productivity using data envelopment analysis (DEA technique and Malmquist indices.This is a cross sectional study in which the panel data were used in a 4 year period from 2007 to 2010. The research was implemented in 12 teaching and non-teaching hospitals of Ahvaz County. Data envelopment analysis technique and the Malmquist indices with an input-orientation approach, was used to analyze the data and estimation of productivity. Data were analyzed using the SPSS.18 and DEAP.2 software.Six hospitals (50% had a value lower than 1, which represents an increase in total productivity and other hospitals were non-productive. the average of total productivity factor (TPF was 1.024 for all hospitals, which represents a decrease in efficiency by 2.4% from 2007 to 2010. The average technical, technologic, scale and managerial efficiency change was 0.989, 1.008, 1.028, and 0.996 respectively. There was not a significant difference in mean productivity changes among teaching and non-teaching hospitals (P>0.05 (except in 2009 years.Productivity rate of hospitals had an increasing trend generally. However, the total average of productivity was decreased in hospitals. Besides, between the several components of total productivity, variation of technological efficiency had the highest impact on reduce of total average of productivity.

  4. Cepheids at high angular resolution: circumstellar envelope and pulsation

    CERN Document Server

    Gallenne, Alexandre

    2011-01-01

    In 2005, interferometric observations with VLTI/VINCI and CHARA/FLUOR revealed the existence of a circumstellar envelope (CSE) around some Cepheids. This surrounding material is particularly interesting for two reasons: it could have an impact on the distance estimates and could be linked to a past or on-going mass loss. The use of Baade-Wesselink methods for independent distance determinations could be significantly biased by the presence of these envelopes. Although their observations are difficult because of the high contrast between the photosphere of the star and the CSE, several observation techniques have the potential to improve our knowledge about their physical properties. In this thesis, I discuss in particular high angular resolution techniques that I applied to the study of several bright Galactic Cepheids. First, I used adaptive optic observations with NACO of the Cepheid RS Puppis, in order to deduce the flux ratio between the CSE and the photosphere of the star. In addition, I could carry out ...

  5. Crystal Structure of the Japanese Encephalitis Virus Envelope Protein

    Energy Technology Data Exchange (ETDEWEB)

    Luca, Vincent C.; AbiMansour, Jad; Nelson, Christopher A.; Fremont, Daved H. (WU-MED)

    2012-03-13

    Japanese encephalitis virus (JEV) is the leading global cause of viral encephalitis. The JEV envelope protein (E) facilitates cellular attachment and membrane fusion and is the primary target of neutralizing antibodies. We have determined the 2.1-{angstrom} resolution crystal structure of the JEV E ectodomain refolded from bacterial inclusion bodies. The E protein possesses the three domains characteristic of flavivirus envelopes and epitope mapping of neutralizing antibodies onto the structure reveals determinants that correspond to the domain I lateral ridge, fusion loop, domain III lateral ridge, and domain I-II hinge. While monomeric in solution, JEV E assembles as an antiparallel dimer in the crystal lattice organized in a highly similar fashion as seen in cryo-electron microscopy models of mature flavivirus virions. The dimer interface, however, is remarkably small and lacks many of the domain II contacts observed in other flavivirus E homodimers. In addition, uniquely conserved histidines within the JEV serocomplex suggest that pH-mediated structural transitions may be aided by lateral interactions outside the dimer interface in the icosahedral virion. Our results suggest that variation in dimer structure and stability may significantly influence the assembly, receptor interaction, and uncoating of virions.

  6. Planet formation in post-common-envelope binaries

    CERN Document Server

    Schleicher, Dominik; Völschow, Marcel; Banerjee, Robi; Hessman, Frederic V

    2015-01-01

    To understand the evolution of planetary systems, it is important to investigate planets in highly evolved stellar systems, and to explore the implications of their observed properties with respect to potential formation scenarios. Observations suggest the presence of giant planets in post-common-envelope binaries (PCEBs). A particularly well-studied system with planetary masses of 1.7 M_J and 7.0 M_J is NN Ser. We show here that a pure first-generation scenario where the planets form before the common envelope (CE) phase and the orbits evolve due to the changes in the gravitational potential is inconsistent with the current data. We propose a second-generation scenario where the planets are formed from the material that is ejected during the CE, which may naturally explain the observed planetary masses. In addition, hybrid scenarios where the planets form before the CE and evolve due to the accretion of the ejected gas appear as a realistic possibility.

  7. Design and performance of an integrated envelope/lighting system

    Energy Technology Data Exchange (ETDEWEB)

    Lee, E.S.; Selkowitz, S.E.

    1997-04-01

    Dynamic envelope/lighting systems offer the potential to achieve a near optimum energy-efficient environment meeting occupant needs throughout the year by adapting to dynamic meteorological conditions and changing occupant preferences in real time. With the dramatic increased functionality of the microprocessor, there is an untapped potential to make dynamic envelop/lighting systems easier to use, diagnose, and monitor, and to integrate them as part of a sophisticated building-wide control system. This study addresses the complex relationship between this energy-efficiency technology and many of the non-energy issues related to its potential acceptance by the building industry, architects, owners, and users. The authors demonstrate the concept of integrated dynamic systems with a prototype motorized venetian blind operated in synchronization with electric lighting and daylighting controls via an intelligent control system. Research work conducted with simulation software and reduced-scale and full-scale field tests is summarized. Much of this work is directly relevant to other active shading and daylighting systems on the market today and to state-of-the-art window systems yet to come (i.e., electrochromics).

  8. The properties of heavy elements in giant planet envelopes

    CERN Document Server

    Soubiran, Francois

    2016-01-01

    The core accretion model for giant planet formation suggests a two layer picture for the initial structure of Jovian planets, with heavy elements in a dense core and a thick H-He envelope. Late planetesimal accretion and core erosion could potentially enrich the H-He envelope in heavy elements, which is supported by the three-fold solar metallicity that was measured in Jupiter's atmosphere by the Galileo entry probe. In order to reproduce the observed gravitational moments of Jupiter and Saturn, models for their interiors include heavy elements, $Z$, in various proportions. However, their effect on the equation of state of the hydrogen-helium mixtures has not been investigated beyond the ideal mixing approximation. In this article, we report results from \\textit{ab initio} simulations of fully interacting H-He-$Z$ mixtures in order to characterize their equation of state and to analyze possible consequences for the interior structure and evolution of giant planets. Considering C, N, O, Si, Fe, MgO and SiO$_2$...

  9. Massive circumstellar envelope around type IIn supernova SN 1995G

    CERN Document Server

    Chugai, N N

    2003-01-01

    We model the interaction of the supernova SN 1995G with a dense circumstellar (CS) gas in a thin shell approximation. A model fit of the observed bolometric light curve combined with data on the supernova expansion velocity provides an estimate of the density of the CS shell, its mass ($approx 1 M_{odot}$), and age ($approx 8$ years). It is shown that the derived CS gas density does not depend on the assumed mass of the supernova ejecta. This results from the high CS density, which ensures that the forward shock wave is essentially radiative. The derived CS density is consistent with the H$alpha$ luminosity and with the presence of the apparent effect of Thomson scattering in the red wing of this line. The mass of the CS envelope together with its expansion velocity indicates that the CS envelope was ejected as a result of violent energy release ($sim 6times10^{48}$ erg) eight years before the supernova outburst.

  10. The growth and hydrodynamic collapse of a protoplanet envelope

    CERN Document Server

    Ayliffe, Ben A

    2012-01-01

    We have conducted three-dimensional self-gravitating radiation hydrodynamical models of gas accretion onto high mass cores (15-33 Earth masses) over hundreds of orbits. Of these models, one case accretes more than a third of a Jupiter mass of gas, before eventually undergoing a hydrodynamic collapse. This collapse causes the density near the core to increase by more than an order of magnitude, and the outer envelope to evolve into a circumplanetary disc. A small reduction in the mass within the Hill radius (R_H) accompanies this collapse as a shock propagates outwards. This collapse leads to a new hydrostatic equilibrium for the protoplanetary envelope, at which point 97 per cent of the mass contained within the Hill radius is within the inner 0.03 R_H which had previously contained less than 40 per cent. Following this collapse the protoplanet resumes accretion at its prior rate. The net flow of mass towards this dense protoplanet is predominantly from high latitudes, whilst at the outer edge of the circumpl...

  11. The Properties of Heavy Elements in Giant Planet Envelopes

    Science.gov (United States)

    Soubiran, François; Militzer, Burkhard

    2016-09-01

    The core-accretion model for giant planet formation suggests a two-layer picture for the initial structure of Jovian planets, with heavy elements in a dense core and a thick H-He envelope. Late planetesimal accretion and core erosion could potentially enrich the H-He envelope in heavy elements, which is supported by the threefold solar metallicity that was measured in Jupiter’s atmosphere by the Galileo entry probe. In order to reproduce the observed gravitational moments of Jupiter and Saturn, models for their interiors include heavy elements, Z, in various proportions. However, their effect on the equation of state of the hydrogen-helium mixtures has not been investigated beyond the ideal mixing approximation. In this article, we report results from ab initio simulations of fully interacting H-He-Z mixtures in order to characterize their equation of state and to analyze possible consequences for the interior structure and evolution of giant planets. Considering C, N, O, Si, Fe, MgO, and SiO2, we show that the behavior of heavy elements in H-He mixtures may still be represented by an ideal mixture if the effective volumes and internal energies are chosen appropriately. In the case of oxygen, we also compute the effect on the entropy. We find the resulting changes in the temperature-pressure profile to be small. A homogeneous distribution of 2% oxygen by mass changes the temperature in Jupiter’s interior by only 80 K.

  12. Rational design of vaccines against enveloped RNA viruses.

    Science.gov (United States)

    Stephenson, J R

    1985-03-01

    The enveloped RNA viruses are responsible for many important infectious diseases both in the UK and worldwide. The most familiar of these would probably be influenza, measles, mumps, rubella, rabies, dengue and yellow fever. Conventional vaccines against all of the most widespread diseases have been available for several years, although with widely varying degrees of safety and efficacy. Although vaccines against diseases such as measles, rubella, and yellow fever have been fairly successful, all vaccines against diseases caused by this group of viruses still have several drawbacks and are in need of improvement for a variety of reasons. During the past decade our knowledge in several diverse areas of the biological sciences has expanded to the extent that it can now be combined and serious attempts made to design and engineer biological molecules with immunogenic potential. First, significant advances have been made in elucidating the mechanisms operating in the immune defence network and in determining the structure of both immunogenic molecules and the components of the immune system with which they interact. Second, the development of recombinant DNA technology has enabled biological molecules to be synthesized under conditions not restricted by the characteristics of their parent organism. Such molecules can then be altered in such a way as to improve their efficiency and their level of production. It is the purpose of this paper to outline the problems associated with the production of vaccines against enveloped RNA viruses and to discuss how recent advances in knowledge and techniques can help to overcome these problems. PMID:2408398

  13. Structures of Equatorial Envelope Rossby Wave Under a Generalized External Forcing

    Institute of Scientific and Technical Information of China (English)

    FU Zun-Tao; LIU Shi-Da; LIU Shi-Kuo

    2004-01-01

    The cubic nonlinear Schrodinger (NLS for short) equation with a generalized external heating source is derived for large amplitude equatorial envelope Rossby wave in a shear flow. And then various periodic structures for these equatorial envelope Rossby waves are obtained with the help of a new transformation, Jacobi elliptic functions,and elliptic equation. It is shown that different types of resonant phase-locked diabatic heating play different roles in structures of equatorial envelope Rossby wave.

  14. Functional contribution of cysteine residues to the human immunodeficiency virus type 1 envelope.

    OpenAIRE

    Tschachler, E; Buchow, H; Gallo, R C; Reitz, M S

    1990-01-01

    Although the envelope gene of human immunodeficiency virus type 1 shows considerable strain variability, cysteine residues of the envelope protein are strongly conserved, suggesting that they are important to the envelope structure. We constructed and analyzed mutants of a biologically active molecular clone of human immunodeficiency virus type 1 in which different cysteines were replaced by other amino acids in order to determine their functional importance. Substitution of cysteines 296 and...

  15. The influence of amplitude envelope information on resolving lexically ambiguous spoken words.

    Science.gov (United States)

    Szostak, Christine M; Pitt, Mark A

    2014-10-01

    Prior studies exploring the contribution of amplitude envelope information to spoken word recognition are mixed with regard to the question of whether amplitude envelope alone, without spectral detail, can aid isolated word recognition. Three experiments show that the amplitude envelope will aid word identification only if two conditions are met: (1) It is not the only information available to the listener and (2) lexical ambiguity is not present. Implications for lexical processing are discussed. PMID:25324106

  16. A Doherty Amplifier with Envelope Tracking Technique and DSP for High Efficiency

    Directory of Open Access Journals (Sweden)

    Ambar Saxena

    2012-01-01

    Full Text Available A Doherty amplifier employing input signal envelope tracking technique. In the amplifier, gate bias of peaking amplifier is controlled according to the magnitude of the envelope. The performance of the microwave Doherty amplifier has been compared with class AB amplifier. DSP is used to dynamically adjust the gate bias of the auxiliary (peaking amplifier at the rate of the signal envelope to obtain gain flatness. DSP is used as a digital predistortor to improve the overall linearity and efficiency.

  17. Formation of the postmitotic nuclear envelope from extended ER cisternae precedes nuclear pore assembly

    OpenAIRE

    Ladinsky, Mark S.; Lu, Lei; Kirchhausen, Tomas Leopold

    2011-01-01

    During mitosis, the nuclear envelope merges with the endoplasmic reticulum (ER), and nuclear pore complexes are disassembled. In a current model for reassembly after mitosis, the nuclear envelope forms by a reshaping of ER tubules. For the assembly of pores, two major models have been proposed. In the insertion model, nuclear pore complexes are embedded in the nuclear envelope after their formation. In the prepore model, nucleoporins assemble on the chromatin as an intermediate nuclear pore c...

  18. The Malleable Nature of the Budding Yeast Nuclear Envelope: Flares, Fusion, and Fenestrations.

    Science.gov (United States)

    Meseroll, Rebecca A; Cohen-Fix, Orna

    2016-11-01

    In eukaryotes, the nuclear envelope (NE) physically separates nuclear components and activities from rest of the cell. The NE also provides rigidity to the nucleus and contributes to chromosome organization. At the same time, the NE is highly dynamic; it must change shape and rearrange its components during development and throughout the cell cycle, and its morphology can be altered in response to mutation and disease. Here we focus on the NE of budding yeast, Saccharomyces cerevisiae, which has several unique features: it remains intact throughout the cell cycle, expands symmetrically during interphase, elongates during mitosis and, expands asymmetrically during mitotic delay. Moreover, its NE is safely breached during mating and when large structures, such as nuclear pore complexes and the spindle pole body, are embedded into its double membrane. The budding yeast NE lacks lamins and yet the nucleus is capable of maintaining a spherical shape throughout interphase. Despite these eccentricities, studies of the budding yeast NE have uncovered interesting, and likely conserved, processes that contribute to NE dynamics. In particular, we discuss the processes that drive and enable NE expansion and the dramatic changes in the NE that lead to extensions and fenestrations. J. Cell. Physiol. 231: 2353-2360, 2016. Published 2016. This article is a U.S. Government work and is in the public domain in the USA. PMID:26909870

  19. Envelope structure of Synechococcus sp. WH8113, a nonflagellated swimming cyanobacterium

    Directory of Open Access Journals (Sweden)

    Reese Thomas S

    2001-04-01

    Full Text Available Abstract Background Many bacteria swim by rotating helical flagellar filaments [1]. Waterbury et al. [15] discovered an exception, strains of the cyanobacterium Synechococcus that swim without flagella or visible changes in shape. Other species of cyanobacteria glide on surfaces [2,7]. The hypothesis that Synechococcus might swim using traveling surface waves [6,13] prompted this investigation. Results Using quick-freeze electron microscopy, we have identified a crystalline surface layer that encloses the outer membrane of the motile strain Synechococcus sp. WH8113, the components of which are arranged in a rhomboid lattice. Spicules emerge in profusion from the layer and extend up to 150 nm into the surrounding fluid. These spicules also send extensions inwards to the inner cell membrane where motility is powered by an ion-motive force [17]. Conclusion The envelope structure of Synechococcus sp. WH8113 provides new constraints on its motile mechanism. The spicules are well positioned to transduce energy at the cell membrane into mechanical work at the cell surface. One model is that an unidentified motor embedded in the cell membrane utilizes the spicules as oars to generate a traveling wave external to the surface layer in the manner of ciliated eukaryotes.

  20. Characteristics of S-wave Envelope Broadening in the Changbaishan Tianchi Volcano

    Institute of Scientific and Technical Information of China (English)

    Fan Xiaoping; Li Qinghe; He Haibing; Yang Congjie; Jin Shumei

    2010-01-01

    High-frequency S-wave seismogram envelopes of microearthquakes broaden with increasing travel distance,a phenomenon known as S-wave envelope broadening.Multiple forward scattering and diffraction for the random inhomogeneities along the seismic ray path are the main causes of S-wave envelope broadening,so the phenomenon of S-wave envelope broadening is used to study the inhomogeneity of the medium.The peak delay time of an S-wave,which is defined as the time lag from the direct S-wave onset to the maximum amplitude arrival of its envelope.is accepted to quantify S-wave envelope broadening.204 small earthquake records in Changbaishan Tianchi volcano were analyzed by the S-wave envelope broadening algorithm.The results show that S-wave envelope broadening in the Changbaishan Tianchi volcano is obvious,and that the peak delay time of S-wave has a positive correlation with the hypocenter distance and frequency of the Swave.The relationships between the S-wave peak delay time and the hypocenter distance for different frequency bands were obtained using the statistics method.The results are beneficial to the understanding of the S-wave envelope broadening phenomena and the quantitative research on the inhomogeneities of the crust medium in the Changbaishan Tianchi volcano region.

  1. In situ monitoring of internal surface temperature of the historic building envelope

    Science.gov (United States)

    Labovská, Veronika; Katunský, Dušan

    2016-06-01

    Historical building envelope is characterized by a large accumulation that impact is mainly by changing the inner surface temperature over time. The minimum value of the inner surface temperature is set Code requirements. In the case of thermal technology assessment of building envelope contemplates a steady state external temperature and internal environment, thereby neglecting the heat accumulation capacity of building envelopes. Monitoring surface temperature in real terms in situ shows the real behavior of the building envelope close to reality. The recorded data can be used to create a numerical model for the simulation.

  2. Human endogenous retrovirus-K(II envelope induction protects neurons during HIV/AIDS.

    Directory of Open Access Journals (Sweden)

    Rakesh K Bhat

    Full Text Available Human endogenous retroviruses (HERVs are differentially expressed depending on the cell type and physiological circumstances. HERV-K has been implicated in the pathogenesis of several diseases although the functional consequences of its expression remain unknown. Human immunodeficiency virus (HIV infection causes neuroinflammation with neuronal damage and death. Herein, we investigated HERV-K(II/(HML-2 envelope (Env expression and its actions in the brain during HIV/AIDS. HERV-K(II Env expression was assessed in healthy brain tissues, autopsied HIV HIV- infected (HIV+ and uninfected (HIV- brains and in neural cell cultures by real time RT-PCR, massively parallel (deep sequencing, immunoblotting and immunohistochemistry. Neuronal and neural stem cells expressing HERV-K(II Env were analyzed in assays of host responses including cellular viability, immune responses and neurobehavioral outcomes. Deep sequencing of human brain transcriptomes disclosed that RNA sequences encoded by HERV-K were among the most abundant HERV sequences detected in human brain. Comparison of different cell types revealed that HERV-K(II env RNA abundance was highest in cultured human neurons but was suppressed by epidermal growth factor exposure. HERV-K(II Env immunoreactivity was increased in the cerebral cortex from persons with HIV/AIDS, principally localized in neurons. Human neuronal cells transfected with HERV-K(II Env exhibited increased NGF and BDNF expression. Expression of HERV-K(II Env in neuronal cells increased cellular viability and prevented neurotoxicity mediated by HIV-1 Vpr. Intracerebral delivery of HERV-K(II Env expressed by neural stem cells suppressed TNF-α expression and microglial activation while also improving neurobehavioral deficits in vpr/RAG1-/- mice. HERV-K(II Env was highly expressed in human neurons, especially during HIV/AIDS, but in addition exerted neuroprotective effects. These findings imply that HERV gene products might exert adaptive

  3. CISBAT 2007 - Design and renovation of building envelopes (bioclimatic architecture)

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2007-07-01

    This is the second part of the proceedings of the 2007 CISBAT conference on Renewables in a changing climate, held in Lausanne, Switzerland. On the subject of sustainable building envelopes the following oral contributions are summarised: 'Flexible photovoltaics integrated in transparent membrane and pneumatic foil constructions', 'Development of a numerical thermal model for double skin facades', 'Thermal performance analysis for an electrochromic vacuum glazing with low emittance coatings', 'Challenging the public building sector: optimization of energy performance by sustainable strategies', 'Simulation of the thermal performance of a climate adaptive skin', 'Possibilities for upgrading prefabricated concrete building envelopes', 'Experimental study of airflow and heat transfer in a double skin facade with blinds', 'Energy efficiency of a glazing system - Case study: a dynamic glazing and double skin facades - the use of venetian blinds and night ventilation for saving energy on mediterranean climate'. Poster-sessions on the subject include 'Adaptive building envelopes design ', 'GRC facade panels in Brazil', 'Solar absorptance of building opaque surfaces', 'Evaluating the thermal behavior of exterior walls (in residential buildings of hot-dry climate of Yazd)', 'Energy performance of buildings and local energy policy: the case of new residential buildings in Greve in Chianti (Firenze)', 'Space heating and domestic hot water energy demand in high-level-insulation multi-storey buildings in Tuscany (Italy)', 'Is 2000 W society possible, affordable, and socially acceptable for the Vaud existing school building?', 'Development of simplified method for measuring solar shading performance of windows', 'Studies of ecological architecture in China's Loess Plateau region', 'Contemporary mud

  4. Kinetic studies of HIV-1 and HIV-2 envelope glycoprotein-mediated fusion

    Directory of Open Access Journals (Sweden)

    Doms Robert W

    2006-12-01

    Full Text Available Abstract Background HIV envelope glycoprotein (Env-mediated fusion is driven by the concerted coalescence of the HIV gp41 N-helical and C-helical regions, which results in the formation of 6 helix bundles. Kinetics of HIV Env-mediated fusion is an important determinant of sensitivity to entry inhibitors and antibodies. However, the parameters that govern the HIV Env fusion cascade have yet to be fully elucidated. We address this issue by comparing the kinetics HIV-1IIIB Env with those mediated by HIV-2 from two strains with different affinities for CD4 and CXCR4. Results HIV-1 and HIV-2 Env-mediated cell fusion occurred with half times of about 60 and 30 min, respectively. Binding experiments of soluble HIV gp120 proteins to CD4 and co-receptor did not correlate with the differences in kinetics of fusion mediated by the three different HIV Envs. However, escape from inhibition by reagents that block gp120-CD4 binding, CD4-induced CXCR4 binding and 6-helix bundle formation, respectively, indicated large difference between HIV-1 and HIV-2 envelope glycoproteins in their CD4-induced rates of engagement with CXCR4. Conclusion The HIV-2 Env proteins studied here exhibited a significantly reduced window of time between the engagement of gp120 with CD4 and exposure of the CXCR4 binding site on gp120 as compared with HIV-1IIIB Env. The efficiency with which HIV-2 Env undergoes this CD4-induced conformational change is the major cause of the relatively rapid rate of HIV-2 Env mediated-fusion.

  5. Analysis of jaagsiekte sheep retrovirus (JSRV) envelope protein domains in transformation.

    Science.gov (United States)

    Hull, Stacey; Lim, Joohyun; Hamil, Alexander; Nitta, Takayuki; Fan, Hung

    2012-12-01

    Jaagsiekte sheep retrovirus (JSRV) is the causative agent of a transmissible lung cancer in sheep. A unique feature is that JSRV envelope protein is also the oncogene for this virus. Previous studies have identified the cytoplasmic tail (CT) of the envelope transmembrane (TM) protein as critical for transformation although other regions of Env have also been implicated. In this study, the roles of other Env regions in transformation were investigated. Chimeras between JSRV Env and the Env of a related non-oncogenic endogenous retrovirus (enJSRV, 5F16) were used. A chimera containing the membrane-spanning region (MSR) of enJSRV inserted into JSRV Env showed substantially reduced transformation, indicating that the MSR plays a role in transformation. Transformation by this chimera was highly dependent on both Ras/Raf/MEK/MAPK and PI3K/Akt/mTOR signaling. A chimera containing the two amino acids in the TM ectodomain that distinguish JSRV and enJSRV showed modestly reduced transformation. Chimeras in the SU protein indicated that the amino terminal region of SU contributes to transformation, while the C-terminal part is not important. To test if Env trimerization is important for transformation, we mutated a leucine-rich sequence in the putative trimerization domain in the ectodomain of TM (Tri-M). This mutant could not transform cells and it did not oligomerize. However, Tri-M could complement a non-transforming mutant CT mutant (Y590F) so oligomerization is not necessary for at least some aspects of transformation. These experiments provide new insight into the regions and residues of JSRV Env protein necessary for oncogenic transformation.

  6. Characterization of hepatitis C virus envelope glycoprotein complexes expressed by recombinant vaccinia viruses.

    Science.gov (United States)

    Ralston, R; Thudium, K; Berger, K; Kuo, C; Gervase, B; Hall, J; Selby, M; Kuo, G; Houghton, M; Choo, Q L

    1993-11-01

    We constructed recombinant vaccinia virus vectors for expression of the structural region of hepatitis C virus (HCV). Infection of mammalian cells with a vector (vv/HCV1-906) encoding C-E1-E2-NS2 generated major protein species of 22 kDa (C), 33 to 35 kDa (E1), and 70 to 72 kDa (E2), as observed previously with other mammalian expression systems. The bulk of the E1 and E2 expressed by vv/HCV1-906 was found integrated into endoplasmic reticulum membranes as core-glycosylated species, suggesting that these E1 and E2 species represent intracellular forms of the HCV envelope proteins. HCV E1 and E2 formed E1-E2 complexes which were precipitated by either anti-E1 or anti-E2 serum and which sedimented at approximately 15 S on glycerol density gradients. No evidence of intermolecular disulfide bonding between E1 and E2 was detected. E1 and E2 were copurified to approximately 90% purity by mild detergent extraction followed by chromatography on Galanthus nivalus lectin-agarose and DEAE-Fractogel. Immunization of chimpanzees with purified E1-E2 generated high titers of anti-E1 and anti-E2 antibodies. Further studies, to be reported separately, demonstrated that purified E1-E2 complexes were recognized at high frequency by HCV+ human sera (D. Y. Chien, Q.-L. Choo, R. Ralston, R. Spaete, M. Tong, M. Houghton, and G. Kuo, Lancet, in press) and generated protective immunity in chimpanzees (Q.-L. Choo, G. Kuo, R. Ralston, A. Weiner, D. Chien, G. Van Nest, J. Han, K. Berger, K. Thudium, J. Kansopon, J. McFarland, A. Tabrizi, K. Ching, B. Mass, L. B. Cummins, E. Muchmore, and M. Houghton, submitted for publication), suggesting that these purified HCV envelope proteins display native HCV epitopes. PMID:8411378

  7. Lipid Exchange Envelope Penetration (LEEP) of Nanoparticles for Plant Engineering: A Universal Localization Mechanism.

    Science.gov (United States)

    Wong, Min Hao; Misra, Rahul P; Giraldo, Juan P; Kwak, Seon-Yeong; Son, Youngwoo; Landry, Markita P; Swan, James W; Blankschtein, Daniel; Strano, Michael S

    2016-02-10

    Nanoparticles offer clear advantages for both passive and active penetration into biologically important membranes. However, the uptake and localization mechanism of nanoparticles within living plants, plant cells, and organelles has yet to be elucidated.1 Here, we examine the subcellular uptake and kinetic trapping of a wide range of nanoparticles for the first time, using the plant chloroplast as a model system, but validated in vivo in living plants. Confocal visible and near-infrared fluorescent microscopy and single particle tracking of gold-cysteine-AF405 (GNP-Cys-AF405), streptavidin-quantum dot (SA-QD), dextran and poly(acrylic acid) nanoceria, and various polymer-wrapped single-walled carbon nanotubes (SWCNTs), including lipid-PEG-SWCNT, chitosan-SWCNT and 30-base (dAdT) sequence of ssDNA (AT)15 wrapped SWCNTs (hereafter referred to as ss(AT)15-SWCNT), are used to demonstrate that particle size and the magnitude, but not the sign, of the zeta potential are key in determining whether a particle is spontaneously and kinetically trapped within the organelle, despite the negative zeta potential of the envelope. We develop a mathematical model of this lipid exchange envelope and penetration (LEEP) mechanism, which agrees well with observations of this size and zeta potential dependence. The theory predicts a critical particle size below which the mechanism fails at all zeta potentials, explaining why nanoparticles are critical for this process. LEEP constitutes a powerful particulate transport and localization mechanism for nanoparticles within the plant system. PMID:26760228

  8. Morphology and Molecular Composition of Purified Bovine Viral Diarrhea Virus Envelope.

    Directory of Open Access Journals (Sweden)

    Nathalie Callens

    2016-03-01

    Full Text Available The family Flaviviridae includes viruses that have different virion structures and morphogenesis mechanisms. Most cellular and molecular studies have been so far performed with viruses of the Hepacivirus and Flavivirus genera. Here, we studied bovine viral diarrhea virus (BVDV, a member of the Pestivirus genus. We set up a method to purify BVDV virions and analyzed their morphology by electron microscopy and their protein and lipid composition by mass spectrometry. Cryo-electron microscopy showed near spherical viral particles displaying an electron-dense capsid surrounded by a phospholipid bilayer with no visible spikes. Most particles had a diameter of 50 nm and about 2% were larger with a diameter of up to 65 nm, suggesting some size flexibility during BVDV morphogenesis. Morphological and biochemical data suggested a low envelope glycoprotein content of BVDV particles, E1 and E2 being apparently less abundant than Erns. Lipid content of BVDV particles displayed a ~2.3 to 3.5-fold enrichment in cholesterol, sphingomyelin and hexosyl-ceramide, concomitant with a 1.5 to 5-fold reduction of all glycerophospholipid classes, as compared to lipid content of MDBK cells. Although BVDV buds in the endoplasmic reticulum, its lipid content differs from a typical endoplasmic reticulum membrane composition. This suggests that BVDV morphogenesis includes a mechanism of lipid sorting. Functional analyses confirmed the importance of cholesterol and sphingomyelin for BVDV entry. Surprisingly, despite a high cholesterol and sphingolipid content of BVDV envelope, E2 was not found in detergent-resistant membranes. Our results indicate that there are differences between the structure and molecular composition of viral particles of Flaviviruses, Pestiviruses and Hepaciviruses within the Flaviviridae family.

  9. Light-induced membrane potential and pH gradient in Halobacterium halobium envelope vesicles.

    Science.gov (United States)

    Renthal, R; Lanyi, J K

    1976-05-18

    Illumination of envelope vesicles prepared from Halobacterium halobium cells causes translocation of protons from inside to outside, due to the light-induced cycling of bacteriorhodopsin. This process results in a pH gradient across the membranes, an electrical potential, and the movements of K+ and Na+. The electrical potential was estimated by following the fluorescence of a cyanine dye, 3,3'-dipentyloxadicarbocyanine. Illumination of H. halobium vesicles resulted in a rapid, reversible decrease of the dye fluorescence, by as much as 35%. This effect was not seen in nonvesicular patches of purple membrane. Observation of maximal fluorescence decreases upon ilumination of vesicles required an optimal dye/membrane protein ratio. The pH optimum for the lightinduced fluorescence decrease was 6.0. The decrease was linear with actinic light intensity up to about 4 X 10(5) ergs cn-2 s-1. Valinomycin, gramicidin, and triphenylmethylphosphonium ion all abolished the fluorescence changes. However, the light-induced pH change was enhanced by these agents. Conversely, buffered vesicles showed no pH change but gave the same or larger fluorescence changes. Thus, we have identified the fluorescence decrease with a light-induced membrane potential, inside negative. By using valinomycin-K+-induced membrane potentials, we calibrated the fluorescence decrease with calculated Nernst diffusion potentials. We found a linear dependence between potential and fluorescence decrease of 3 mV/%, up to 90 mV. When the envelope vesicles were illuminated, the total proton-motive force generated was dependent on the presence of Na+ and K+ and their concentration gradients across the membrane. In general, K+ appeared to be more permeable than Na+ and, thus, permitted development of greater pH gradients and lower electrical potentials. By calculating the total proton-motive force from the sum of the pH and potential terms, we found that the vesicles can produce proton-motive forces near--200 m

  10. Morphology and Molecular Composition of Purified Bovine Viral Diarrhea Virus Envelope.

    Science.gov (United States)

    Callens, Nathalie; Brügger, Britta; Bonnafous, Pierre; Drobecq, Hervé; Gerl, Mathias J; Krey, Thomas; Roman-Sosa, Gleyder; Rümenapf, Till; Lambert, Olivier; Dubuisson, Jean; Rouillé, Yves

    2016-03-01

    The family Flaviviridae includes viruses that have different virion structures and morphogenesis mechanisms. Most cellular and molecular studies have been so far performed with viruses of the Hepacivirus and Flavivirus genera. Here, we studied bovine viral diarrhea virus (BVDV), a member of the Pestivirus genus. We set up a method to purify BVDV virions and analyzed their morphology by electron microscopy and their protein and lipid composition by mass spectrometry. Cryo-electron microscopy showed near spherical viral particles displaying an electron-dense capsid surrounded by a phospholipid bilayer with no visible spikes. Most particles had a diameter of 50 nm and about 2% were larger with a diameter of up to 65 nm, suggesting some size flexibility during BVDV morphogenesis. Morphological and biochemical data suggested a low envelope glycoprotein content of BVDV particles, E1 and E2 being apparently less abundant than Erns. Lipid content of BVDV particles displayed a ~2.3 to 3.5-fold enrichment in cholesterol, sphingomyelin and hexosyl-ceramide, concomitant with a 1.5 to 5-fold reduction of all glycerophospholipid classes, as compared to lipid content of MDBK cells. Although BVDV buds in the endoplasmic reticulum, its lipid content differs from a typical endoplasmic reticulum membrane composition. This suggests that BVDV morphogenesis includes a mechanism of lipid sorting. Functional analyses confirmed the importance of cholesterol and sphingomyelin for BVDV entry. Surprisingly, despite a high cholesterol and sphingolipid content of BVDV envelope, E2 was not found in detergent-resistant membranes. Our results indicate that there are differences between the structure and molecular composition of viral particles of Flaviviruses, Pestiviruses and Hepaciviruses within the Flaviviridae family. PMID:26939061

  11. Envelope model for passive magnetic focusing of an intense proton or ion beam propagating through thin foils

    Science.gov (United States)

    Lund, Steven M.; Cohen, Ronald H.; Ni, Pavel A.

    2013-04-01

    optimistic result since placing many foils per characteristic beam radius, which one might expect to be necessary to strongly attenuate the self-electric field, would likely result in excessive scattering and loss of focusing from the current neutralization due to the beam propagating too far through solid metal. Results from the envelope model are compared with particle-in-cell simulations to help clarify limits related to envelope-model idealizations. Possible degradations of focusing in situations where strong halo can be generated and where pulse duration is short are clarified.

  12. An organelle-exclusion envelope assists mitosis and underlies distinct molecular crowding in the spindle region.

    Science.gov (United States)

    Schweizer, Nina; Pawar, Nisha; Weiss, Matthias; Maiato, Helder

    2015-08-31

    The mitotic spindle is a microtubular assembly required for chromosome segregation during mitosis. Additionally, a spindle matrix has long been proposed to assist this process, but its nature has remained elusive. By combining live-cell imaging with laser microsurgery, fluorescence recovery after photobleaching, and fluorescence correlation spectroscopy in Drosophila melanogaster S2 cells, we uncovered a microtubule-independent mechanism that underlies the accumulation of molecules in the spindle region. This mechanism relies on a membranous system surrounding the mitotic spindle that defines an organelle-exclusion zone that is conserved in human cells. Supported by mathematical modeling, we demonstrate that organelle exclusion by a membrane system causes spatio-temporal differences in molecular crowding states that are sufficient to drive accumulation of mitotic regulators, such as Mad2 and Megator/Tpr, as well as soluble tubulin, in the spindle region. This membranous "spindle envelope" confined spindle assembly, and its mechanical disruption compromised faithful chromosome segregation. Thus, cytoplasmic compartmentalization persists during early mitosis to promote spindle assembly and function.

  13. IFITM Proteins Restrict HIV-1 Infection by Antagonizing the Envelope Glycoprotein

    Directory of Open Access Journals (Sweden)

    Jingyou Yu

    2015-10-01

    Full Text Available The interferon-induced transmembrane (IFITM proteins have been recently shown to restrict HIV-1 and other viruses. Here, we provide evidence that IFITM proteins, particularly IFITM2 and IFITM3, specifically antagonize the HIV-1 envelope glycoprotein (Env, thereby inhibiting viral infection. IFITM proteins interact with HIV-1 Env in viral producer cells, leading to impaired Env processing and virion incorporation. Notably, the level of IFITM incorporation into HIV-1 virions does not strictly correlate with the extent of inhibition. Prolonged passage of HIV-1 in IFITM-expressing T lymphocytes leads to emergence of Env mutants that overcome IFITM restriction. The ability of IFITMs to inhibit cell-to-cell infection can be extended to HIV-1 primary isolates, HIV-2 and SIVs; however, the extent of inhibition appears to be virus-strain dependent. Overall, our study uncovers a mechanism by which IFITM proteins specifically antagonize HIV-1 Env to restrict HIV-1 infection and provides insight into the specialized role of IFITMs in HIV infection.

  14. Effects of ultraviolet radiation on structural components of enveloped RNA viruses

    Energy Technology Data Exchange (ETDEWEB)

    Silva, Mauro R.; Couceiro, Jose N.S.S.; Brito, Sieberth N.; Cabral, Maulori C. [Universidade Federal, Rio de janeiro, RJ (Brazil). Inst. de Microbiologia

    1995-01-01

    The interaction of ultraviolet radiation and virus particles of Western Equine Encephalomyelitis Virus (WEE) and Newcastle Disease Virus (NDV) which have respectively RNA of positive (RNA+) and negative (RNA-) polarity as genomes, was studied using purified particles. The purified virus preparations were irradiated at a range of 1,000 to 6,000 joules per m{sup 2} with posterior analysis of their propagation in primary cells cultures of chicken embryos. It could be observed that a radiation dose of 4,500 joules per m{sup 2} could induce 10{sup 9} TCID50 per ml as minimal loss of titer for WEE virus and NDV. The hemagglutination assay was used as a tool for evaluate the alterations caused by UV radiation on the molecular arrangement of virus proteins. Alterations of the virus hemagglutinating activity were only observed when radiation levels higher than 6,000 joules per m{sup 2} were used. The results from hemolysis assays showed the importance of the loss of the envelope integrity and the damages to nucleoprotein structures during the inactivation process, when we use radiation doses higher than 6,000 joules per m{sup 2}. This model of study can increase our comprehension of the radiation effects on the cell physiology and biological components of the cell membranes. (author). 34 refs., 3 figs., 1 tab.

  15. Extension of a quantized enveloping algebra by a Hopf algebra

    Institute of Scientific and Technical Information of China (English)

    2010-01-01

    Suppose that H is a Hopf algebra,and g is a generalized Kac-Moody algebra with Cartan matrix A =(aij)I×I,where I is an index set and is equal to either {1,2,...,n} or the natural number set N.Let f,g be two mappings from I to G(H),the set of group-like elements of H,such that the multiplication of elements in the set {f(i),g(i)|i ∈I} is commutative.Then we define a Hopf algebra Hgf Uq(g),where Uq(g) is the quantized enveloping algebra of g.

  16. Glycosylation in HIV-1 envelope glycoprotein and its biological implications

    KAUST Repository

    Ho, Yung Shwen

    2013-08-01

    Glycosylation of HIV-1 envelope proteins (Env gp120/gp41) plays a vital role in viral evasion from the host immune response, which occurs through the masking of key neutralization epitopes and the presentation of the Env glycosylation as \\'self\\' to the host immune system. Env glycosylation is generally conserved, yet its continual evolution plays an important role in modulating viral infectivity and Env immunogenicity. Thus, it is believed that Env glycosylation, which is a vital part of the HIV-1 architecture, also controls intra- and inter-clade genetic variations. Discerning intra- and inter-clade glycosylation variations could therefore yield important information for understanding the molecular and biological differences between HIV clades and may assist in effectively designing Env-based immunogens and in clearly understanding HIV vaccines. This review provides an in-depth perspective of various aspects of Env glycosylation in the context of HIV-1 pathogenesis. © 2013 Future Medicine Ltd.

  17. Solubilization of glycoproteins of envelope viruses by detergents

    Energy Technology Data Exchange (ETDEWEB)

    Berezin, V.E.; Zaides, V.M.; Artamsnov, A.F.; Isaeva, E.S.; Zhdanov, V.M.

    1986-11-20

    The action of a number of known ionic and nonionic detergents, as well as the new nonionic detergent MESK, on envelope viruses was investigated. It was shown that the nonionic detergents MESK, Triton X-100, and octyl-..beta..-D-glucopyranoside selectively solubilize the outer glycoproteins of the virus particles. The nonionic detergent MESK has the mildest action. Using MESK, purified glycoproteins of influenza, parainfluenza, Venezuelan equine encephalomyelitis, vesicular stomatitis, rabies, and herpes viruses were obtained. The procedure for obtaining glycoproteins includes incubation of the virus suspension with the detergent MESK, removal of subvirus structures by centrifuging, and purification of glycoproteins from detergents by dialysis. Isolated glycoproteins retain a native structure and biological activity and possess high immunogenicity. The detergent MESK is promising for laboratory tests and with respect to the production of subunit vaccines.

  18. Bank branch operating efficiency: evaluation with data envelopment analysis

    Directory of Open Access Journals (Sweden)

    Roozbeh Talebi Zarinkamar

    2014-10-01

    Full Text Available Measuring the relative efficiency of similar units has been a popular research especially when the units were mostly non-financial. Even, similar financial units may not be necessarily evaluated based on traditional financial figures such as return of equities, return of assets, etc. In this paper, we present an empirical investigation to measure the relative efficiency of 30 branches of an Iranian bank named Bank Mellat. The study considers four inputs including operating expenses, interest paid, capital expenditures and fixed assets. In addition, we use customers’ bank deposit, commissions and loans paid as output parameters. Using three different data envelopment analyses, the study measures the relative efficiencies of all units. The preliminary results indicate that most banks were working under desirable level of efficiency.

  19. Development of building envelope structures; Udvikling af klimaskaermskonstruktioner

    Energy Technology Data Exchange (ETDEWEB)

    Monefeldt Tommerup, H. [Danmarks Tekniske Univ., Lyngby (Denmark); Munch-Andersen, J. [Statens Byggeforskningsinstitut, Hoersholm (Denmark); Kjaer Esbensen, P. [Danmarks Tekniske Univ., Lyngby (Denmark)

    2000-08-01

    The present report concludes the work concerning the development of building envelope constructions, which can form the basis of new buildings with considerably less heat demand than in the present building regulations. It has been made probable that it is technically possible to build exterior walls with less heat loss than those just complying with the requirements of the current building regulations with no considerable added use of material apart from insulation. In their structure many of the shown constructions resemble types that are used today, while others presuppose that one part of the wall is attached to the other part or possibly to the rafters. Calculations concerning the importance of heat capacity for a 100 m{sup 2} single-family house have been made which confirm that by using heavy rather than light envelope constructions the reduction of the heating requirements is relatively small. Therefore optimisation of the insulation level can be carried out separately on the building components. A method has been developed for the evaluation of the optimum insulation level for the individual building components of the building envelope based on life cycle cost analysis. The method is based on making up the changes in the operational energy costs/ heating-costs and the cost of construction due to a change in the insulation thickness over a 30-year period. The life span of the primary parts of the building envelope is estimated at 100 years. It is assumed that the gross energy consumption that covers the heating requirements and the heat loss (determined by a simple calculation of degree days) changes concurrently with the change in the insulation thickness, which has been proved to be a reasonable approximation. The life cycle cost analysis has been carried out for a test-house of about 100 m{sup 2} and with two different energy price scenarios: 0.60 dkk/kWh (including taxes and VAT) which roughly corresponds to the present energy price level, and 1.20 dkk

  20. Efficiency Measure by Fuzzy Data Envelopment Analysis Model

    Directory of Open Access Journals (Sweden)

    Shivi Agarwal

    2014-03-01

    Full Text Available Data envelopment analysis (DEA is a non-parametric technique to measure the relative efficiencies of a set of decision making units (DMUs with common crisp inputs and outputs. Input and output data of DMUs often fluctuate. These fluctuating data can be represented as linguistic variable characterized by fuzzy numbers. This paper attempts to extend the traditional DEA model to a fuzzy framework, thus proposing a fuzzy DEA model based on α-cut approach to deal with the efficiency measuring and ranking problem with the given fuzzy input and output data. Finally, a numerical example is presented to illustrate the fuzzy DEA model. Since the efficiency measures are expressed by membership functions rather than by crisp values, more information is provided for management. By extending to fuzzy environment, the DEA approach is made more powerful for application.

  1. Complex envelope control of pulsed accelerating fields in superconducting cavities

    CERN Document Server

    Czarski, T

    2010-01-01

    A digital control system for superconducting cavities of a linear accelerator is presented in this work. FPGA (Field Programmable Gate Arrays) based controller, managed by MATLAB, was developed to investigate a novel firmware implementation. The LLRF - Low Level Radio Frequency system for FLASH project in DESY is introduced. Essential modeling of a cavity resonator with signal and power analysis is considered as a key approach to the control methods. An electrical model is represented by the non-stationary state space equation for the complex envelope of the cavity voltage driven by the current generator and the beam loading. The electromechanical model of the superconducting cavity resonator including the Lorentz force detuning has been developed for a simulation purpose. The digital signal processing is proposed for the field vector detection. The field vector sum control is considered for multiple cavities driven by one klystron. An algebraic, complex domain model is proposed for the system analysis. The c...

  2. Flight envelope protection system for unmanned aerial vehicles

    KAUST Repository

    Claudel, Christian G.

    2016-04-28

    Systems and methods to protect the flight envelope in both manual flight and flight by a commercial autopilot are provided. A system can comprise: an inertial measurement unit (IMU); a computing device in data communication with the IMU; an application executable by the computing device comprising: logic that estimates an angle of attack; a slip angle; and a speed of an unmanned aerial vehicle (UAV) based at least in part on data received from the UAV. A method can comprise estimating, via a computing device, flight data of a UAV based at least in part on data received from an IMU; comparing the estimated flight data with measured flight data; and triggering an error indication in response to a determination that the measured flight data exceeds a predefined deviation of the estimated flight data. The estimated speed can comprise an estimated airspeed, vertical speed and/or ground velocity.

  3. Efficiency of Polish metallurgical industry based on data envelopment analysis

    Directory of Open Access Journals (Sweden)

    J. Baran

    2016-04-01

    Full Text Available The main purpose of this paper is to compare the technical efficiency of 12 sectors manufacturing basic metals and metal products in Poland. This article presents the use of Data Envelopment Analysis models, to determine overall technical efficiency, pure technical efficiency and scale efficiency of metallurgical branches in Poland. The average technical efficiency of metallurgical industry in Poland was quite high. The analysis gives a possibility to create a ranking of sectors. Three branches were found to be fully efficient: manufacture of basic iron and steel and of ferroalloys, manufacture of basic precious and other non - ferrous metals and manufacture of tubes, pipes, hollow profiles and related fittings, of steel. The results point out the reasons of the inefficiency and provide improving directions for the inefficient sectors.

  4. Modulated envelope localized wavepackets associated with electrostatic plasma waves

    CERN Document Server

    Kourakis, I; Kourakis, Ioannis; Shukla, Padma Kant

    2004-01-01

    The nonlinear amplitude modulation of known electrostatic plasma modes is examined in a generic manner, by applying a collisionless fluid model. Both cold (zero-temperature) and warm fluid descriptions are discussed and the results are compared. The moderately nonlinear oscillation regime is investigated by applying a multiple scale technique. The calculation leads to a Nonlinear Schrodinger-type Equation (NLSE), which describes the evolution of the slowly varying wave amplitude in time and space. The NLSE admits localized envelope (solitary wave) solutions of bright- (pulses) or dark- (holes, voids) type, whose characteristics (maximum amplitude, width) depend on intrinsic plasma parameters. Effects like amplitude perturbation obliqueness, finite temperature and defect (dust) concetration are explicitly considered. The relevance with similar highly localized modulated wave structures observed during recent satellite missions is discussed.

  5. Acoustic frequency combs for carrier-envelope phase stabilization.

    Science.gov (United States)

    Borchers, Bastian; Lücking, Fabian; Steinmeyer, Günter

    2014-02-01

    A method for improved performance of feed-forward carrier-envelope phase stabilization in amplified laser sources is presented and experimentally demonstrated. The phase stabilization scheme is applicable for a broad range of repetition rates spanning from subhertz to 100 kHz. The method relies on driving an acousto-optic frequency shifter by few-cycle transients. The phase of these transients suitably controls the grating phase of the generated index grating inside the shifter material. This approach removes beam pointing as well as amplitude noise issues observed in continuously driven feed-forward schemes. The synthesis of these gratings can be understood as the acoustic equivalent of mode-locking or acoustic frequency combs. PMID:24487861

  6. External Shaping of Circumstellar Envelopes of Evolved Stars

    Science.gov (United States)

    Cox, N. L. J.

    2015-08-01

    The circumstellar envelopes of asymptotic giant branch (AGB) stars and red supergiants (RSGs) are complex chemical and physical environments, and the specifics of their mass-loss history are important for both stellar and galactic evolution. One key aspect in this is to understand how the circumstellar medium of these stars can be shaped and affected by both internal and external mechanisms. These influences can skew our view on the (dust) chemistry and mass-loss history of these stars, and hence their role in the chemical enrichment of galaxies. This contribution focuses on the external mechanism related to the interaction between the slow dusty stellar wind and the local ambient medium. I will discuss what recent observations and hydrodynamical simulations have revealed and how these can help us learn more about AGB stars and RSGs, as well as the interstellar medium (ISM).

  7. ASSESSMENT OF REGIONAL EFFICIENCY IN CROATIA USING DATA ENVELOPMENT ANALYSIS

    Directory of Open Access Journals (Sweden)

    Danijela Rabar

    2013-02-01

    Full Text Available In this paper, regional efficiency of Croatian counties is measured in three-year period (2005-2007 using Data Envelopment Analysis (DEA. The set of inputs and outputs consists of seven socioeconomic indicators. Analysis is carried out using models with assumption of variable returns-to-scale. DEA identifies efficient counties as benchmark members and inefficient counties that are analyzed in detail to determine the sources and the amounts of their inefficiency in each source. To enable proper monitoring of development dynamics, window analysis is applied. Based on the results, guidelines for implementing necessary improvements to achieve efficiency are given. Analysis reveals great disparities among counties. In order to alleviate naturally, historically and politically conditioned unequal county positions over which economic policy makers do not have total control, categorical approach is introduced as an extension to the basic DEA models. This approach, combined with window analysis, changes relations among efficiency scores in favor of continental counties.

  8. Heating and cooling of magnetars with accreted envelopes

    CERN Document Server

    Kaminker, A D; Yakovlev, D G; Chabrier, G

    2009-01-01

    We study the thermal structure and evolution of magnetars as cooling neutron stars with a phenomenological heat source in an internal layer. We focus on the effect of magnetized (B > 10^{14} G) non-accreted and accreted outermost envelopes composed of different elements, from iron to hydrogen or helium. We discuss a combined effect of thermal conduction and neutrino emission in the outer neutron star crust and calculate the cooling of magnetars with a dipole magnetic field for various locations of the heat layer, heat rates and magnetic field strengths. Combined effects of strong magnetic fields and light-element composition simplify the interpretation of magnetars in our model: these effects allow one to interpret observations assuming less extreme (therefore, more realistic) heating. Massive magnetars, with fast neutrino cooling in their cores, can have higher thermal surface luminosity.

  9. Construction Project Success ranking through the Data Envelopment Analysis

    Directory of Open Access Journals (Sweden)

    Mazyar Zahedi-Seresht

    2014-09-01

    Full Text Available The purpose of this paper is to rank construction projects' success in a post delivery phase. To attain this objective, a data envelopment analysis (DEA approach is used. The model's output is a project success index which is calculated based on five project success criteria. These criteria which are determined by a two-round Delphi questionnaire survey are time performance, cost performance, quality, HSE, and customer satisfaction. The input factors which have effects on the output measures are Organizational Sponsorship, Project Manager Competency, Customer Organization, Project Operational Environment and Organizational Experience. The tool adopted to determine these factors is questionnaire. This model is applied for 9 projects with different importance of output and input factors and the reasonable result is achieved for ranking these projects.

  10. Envelope based nonlinear blind deconvolution approach for ultrasound imaging

    Directory of Open Access Journals (Sweden)

    L.T. Chira

    2012-06-01

    Full Text Available The resolution of ultrasound medical images is yet an important problem despite of the researchers efforts. In this paper we presents a nonlinear blind deconvolution to eliminate the blurring effect based on the measured radio-frequency signal envelope. This algorithm is executed in two steps. Firslty we make an estimation for Point Spread Function (PSF and, secondly we use the estimated PSF to remove, iteratively their effect. The proposed algorithm is a greedy algorithm, called also matching pursuit or CLEAN. The use of this algorithm is motivated beacause theorically it avoid the so called inverse problem, which usually needs regularization to obtain an optimal solution. The results are presented using 1D simulated signals in term of visual evaluation and nMSE in comparison with the two most kwown regularisation solution methods for least square problem, Thikonov regularization or l2-norm and Total Variation or l1 norm.

  11. A New Measure of Distributive Justice by Data Envelopment Analysis

    Directory of Open Access Journals (Sweden)

    Yutaka Ueda

    2013-04-01

    Full Text Available Traditionally, distributive justice has been measured with multiple question items to which respondents indicate the degree to which their working situation corresponds with those described in the question items. This article proposes an alternative method to measure distributive justice, using the data envelopment analysis (DEA approach. We apply an efficiency measure calculated in DEA for the inputs/outcomes ratio to judge distributive justice in the organization. Using the data collected from accounting workers who live in the Tokyo metropolitan area, the results of correlation analysis show that this new measure of distributive justice has significant positive correlations with all three satisfaction variables in a male sample, and with one satisfaction variable in a female sample, providing some justification for using this new variable as a measure of distributive justice.

  12. Predoction Model of Data Envelopment Analysis with Undesirable Outputs

    Institute of Scientific and Technical Information of China (English)

    边馥萍; 范宇

    2004-01-01

    Data envelopment analysis (DEA) has become a standard non-parametric approach to productivity analysis, especially to relative efficiency analysis of decision making units (DMUs). Extended to the prediction field, it can solve the prediction problem with multiple inputs and outputs which can not be solved easily by the regression analysis method.But the traditional DEA models can not solve the problem with undesirable outputs,so in this paper the inherent relationship between goal programming and the DEA method based on the relationship between multiple goal programming and goal programming is explored,and a mixed DEA model which can make all factors of inputs and undesirable outputs decrease in different proportions is built.And at the same time,all the factors of desirable outputs increase in different proportions.

  13. First Evidence of a Precessing Jet Excavating a Protostellar Envelope

    CERN Document Server

    Ybarra, J E; Haisch, K E; Jarrett, T H; Sahai, R; Weinberger, A J; Ybarra, Jason E.; Barsony, Mary; Haisch, Karl E.; Jarrett, Thomas H.; Sahai, Raghvendra; Weinberger, Alycia J.

    2006-01-01

    We present new, sensitive, near-infrared images of the Class I protostar, Elias 29, in the Ophiuchus cloud core. To explore the relationship between the infall envelope and the outflow, narrowband H2 1-0 S(1), Br-gamma, and narrowband K-continuum filters were used to image the source with the Wide-Field Infrared Camera on the Hale 5m telescope and with Persson's Auxiliary Nasmyth Infrared Camera on the Baade 6.5 m telescope. The source appears as a bipolar, scattered light nebula, with a wide opening angle in all filters, as is typical for late-stage protostars. However, the pure H2 emission-line images point to the presence of a heretofore undetected precessing jet. It is argued that high-velocity, narrow, precessing jets provide the mechanism for creating the observed wide-angled outflow cavity in this source.

  14. Low-Cost Phase Change Material for Building Envelopes

    Energy Technology Data Exchange (ETDEWEB)

    Abhari, Ramin [Renewable Energy Group

    2015-08-06

    A low-cost PCM process consisting of conversion of fats and oils to PCM-range paraffins, and subsequent “encapsulation” of the paraffin using conventional plastic compounding/pelletizing equipment was demonstrated. The PCM pellets produced were field-tested in a building envelope application. This involved combining the PCM pellets with cellulose insulation, whereby 33% reduction in peak heat flux and 12% reduction in heat gain was observed (average summertime performance). The selling price of the PCM pellets produced according to this low-cost process is expected to be in the $1.50-$3.00/lb range, compared to current encapsulated PCM price of about $7.00/lb. Whole-building simulations using corresponding PCM thermal analysis data suggest a payback time of 8 to 16 years (at current energy prices) for an attic insulation retrofit project in the Phoenix climate area.

  15. Nonlinear Landau damping of wave envelopes in a quantum plasma

    CERN Document Server

    Chatterjee, D

    2016-01-01

    The nonlinear theory of Landau damping of electrostatic wave envelopes (WEs) is revisited in a quantum electron-positron (EP) pair plasma. Starting from a Wigner-Moyal equation coupled to the Poisson equation and applying the multiple scale technique, we derive a nonlinear Schr{\\"o}dinger (NLS) equation which governs the evolution of electrostatic WEs. It is shown that the coefficients of the NLS equation, including the nonlocal nonlinear term, which appears due to the resonant particles having group velocity of the WEs, are significantly modified by the particle dispersion. The effects of the quantum parameter $H$ (the ratio of the plasmon energy to the thermal energy densities), associated with the particle dispersion, are examined on the Landau damping rate of carrier waves, as well as on the modulational instability of WEs. It is found that the Landau damping rate and the decay of the solitary wave amplitude become faster the larger are the values of $H$.

  16. Implementation of envelope tracking for RF solid state amplifiers

    Science.gov (United States)

    Larter, Thomas Leigh

    The Facility for Rare Isotope Beams (FRIB) is currently in its development stages at Michigan State University. The facility uses a large linear accelerator system to accelerate ionized particles which are then collided with other particles in the hopes of finding rare isotopes of elements. This accelerating action depends on several systems to function, with one of the major systems being superconducting cavity structures. These cavities are driven by high-power RF amplifiers which account for a large portion of the accelerator's power consumption. It is important to maximize the efficiency of these amplifiers in order to keep energy costs for the facility low. One of the ways to increase efficiency is to choose an amplifier topology that is highly efficient. A study was done for FRIB testing the prospect of using amplifiers with the envelope tracking (ET) topology. An amplifier's efficiency relies on its output power and the power supplied to it, which are in turn directly related to the output signal voltage and supply rail voltage. In an ET RF amplifier, the supply voltage is made to closely follow the envelope of the output signal voltage. This tracking action allows the RF amplifier to operate with much improved efficiency at low power levels and nearly constant efficiency at high power levels. The ET tests performed for FRIB attempted to verify the validity of ET efficiency gains for RF amplifiers. These tests included the characterization of an RF amplifier, development and verification of an ET control algorithm, and implementation of an ET test bench using FRIB equipment. These tests should attest to the purported increase in efficiency possible with ET and prove that the power consumption budget for the FRIB will benefit from the use of such amplifiers.

  17. B-type nuclear lamin and the nuclear pore complex Nup107-160 influences maintenance of the spindle envelope required for cytokinesis in Drosophila male meiosis

    Science.gov (United States)

    Hayashi, Daisuke; Tanabe, Karin; Katsube, Hiroka

    2016-01-01

    ABSTRACT In higher eukaryotes, nuclear envelope (NE) disassembly allows chromatin to condense and spindle microtubules to access kinetochores. The nuclear lamina, which strengthens the NE, is composed of a polymer meshwork made of A- and B-type lamins. We found that the B-type lamin (Lam) is not fully disassembled and continues to localize along the spindle envelope structure during Drosophila male meiosis I, while the A-type lamin (LamC) is completely dispersed throughout the cytoplasm. Among the nuclear pore complex proteins, Nup107 co-localized with Lam during this meiotic division. Surprisingly, Lam depletion resulted in a higher frequency of cytokinesis failure in male meiosis. We also observed the similar meiotic phenotype in Nup107-depleted cells. Abnormal localization of Lam was found in the Nup-depleted cells at premeiotic and meiotic stages. The central spindle microtubules became abnormal and recruitment of a contractile ring component to the cleavage sites was disrupted in Lam-depleted cells and Nup107-depleted cells. Therefore, we speculate that both proteins are required for a reinforcement of the spindle envelope, which supports the formation of central spindle microtubules essential for cytokinesis in Drosophila male meiosis. PMID:27402967

  18. Characterization of the TolB-Pal trans-envelope complex from Xylella fastidiosa reveals a dynamic and coordinated protein expression profile during the biofilm development process.

    Science.gov (United States)

    Santos, Clelton A; Janissen, Richard; Toledo, Marcelo A S; Beloti, Lilian L; Azzoni, Adriano R; Cotta, Monica A; Souza, Anete P

    2015-10-01

    The intriguing roles of the bacterial Tol-Pal trans-envelope protein complex range from maintenance of cell envelope integrity to potential participation in the process of cell division. In this study, we report the characterization of the XfTolB and XfPal proteins of the Tol-Pal complex of Xylella fastidiosa. X. fastidiosa is a major plant pathogen that forms biofilms inside xylem vessels, triggering the development of diseases in important cultivable plants around the word. Based on functional complementation experiments in Escherichia coli tolB and pal mutant strains, we confirmed the role of xftolB and xfpal in outer membrane integrity. In addition, we observed a dynamic and coordinated protein expression profile during the X. fastidiosa biofilm development process. Using small-angle X-ray scattering (SAXS), the low-resolution structure of the isolated XfTolB-XfPal complex in solution was solved for the first time. Finally, the localization of the XfTolB and XfPal polar ends was visualized via immunofluorescence labeling in vivo during bacterial cell growth. Our results highlight the major role of the components of the cell envelope, particularly the TolB-Pal complex, during the different phases of bacterial biofilm development. PMID:26049080

  19. B-type nuclear lamin and the nuclear pore complex Nup107-160 influences maintenance of the spindle envelope required for cytokinesis in Drosophila male meiosis

    Directory of Open Access Journals (Sweden)

    Daisuke Hayashi

    2016-08-01

    Full Text Available In higher eukaryotes, nuclear envelope (NE disassembly allows chromatin to condense and spindle microtubules to access kinetochores. The nuclear lamina, which strengthens the NE, is composed of a polymer meshwork made of A- and B-type lamins. We found that the B-type lamin (Lam is not fully disassembled and continues to localize along the spindle envelope structure during Drosophila male meiosis I, while the A-type lamin (LamC is completely dispersed throughout the cytoplasm. Among the nuclear pore complex proteins, Nup107 co-localized with Lam during this meiotic division. Surprisingly, Lam depletion resulted in a higher frequency of cytokinesis failure in male meiosis. We also observed the similar meiotic phenotype in Nup107-depleted cells. Abnormal localization of Lam was found in the Nup-depleted cells at premeiotic and meiotic stages. The central spindle microtubules became abnormal and recruitment of a contractile ring component to the cleavage sites was disrupted in Lam-depleted cells and Nup107-depleted cells. Therefore, we speculate that both proteins are required for a reinforcement of the spindle envelope, which supports the formation of central spindle microtubules essential for cytokinesis in Drosophila male meiosis.

  20. B-type nuclear lamin and the nuclear pore complex Nup107-160 influences maintenance of the spindle envelope required for cytokinesis in Drosophila male meiosis.

    Science.gov (United States)

    Hayashi, Daisuke; Tanabe, Karin; Katsube, Hiroka; Inoue, Yoshihiro H

    2016-01-01

    In higher eukaryotes, nuclear envelope (NE) disassembly allows chromatin to condense and spindle microtubules to access kinetochores. The nuclear lamina, which strengthens the NE, is composed of a polymer meshwork made of A- and B-type lamins. We found that the B-type lamin (Lam) is not fully disassembled and continues to localize along the spindle envelope structure during Drosophila male meiosis I, while the A-type lamin (LamC) is completely dispersed throughout the cytoplasm. Among the nuclear pore complex proteins, Nup107 co-localized with Lam during this meiotic division. Surprisingly, Lam depletion resulted in a higher frequency of cytokinesis failure in male meiosis. We also observed the similar meiotic phenotype in Nup107-depleted cells. Abnormal localization of Lam was found in the Nup-depleted cells at premeiotic and meiotic stages. The central spindle microtubules became abnormal and recruitment of a contractile ring component to the cleavage sites was disrupted in Lam-depleted cells and Nup107-depleted cells. Therefore, we speculate that both proteins are required for a reinforcement of the spindle envelope, which supports the formation of central spindle microtubules essential for cytokinesis in Drosophila male meiosis. PMID:27402967