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Sample records for perv-b envelope genes

  1. Regulation of bacterial virulence gene expression by cell envelope stress responses

    PubMed Central

    Flores-Kim, Josué; Darwin, Andrew J

    2014-01-01

    The bacterial cytoplasm lies within a multilayered envelope that must be protected from internal and external hazards. This protection is provided by cell envelope stress responses (ESRs), which detect threats and reprogram gene expression to ensure survival. Pathogens frequently need these ESRs to survive inside the host, where their envelopes face dangerous environmental changes and attack from antimicrobial molecules. In addition, some virulence genes have become integrated into ESR regulons. This might be because these genes can protect the cell envelope from damage by host molecules, or it might help ESRs to reduce stress by moderating the assembly of virulence factors within the envelope. Alternatively, it could simply be a mechanism to coordinate the induction of virulence gene expression with entry into the host. Here, we briefly describe some of the bacterial ESRs, followed by examples where they control virulence gene expression in both Gram-negative and Gram-positive pathogens. PMID:25603429

  2. Development of HVJ envelope vector and its application to gene therapy.

    PubMed

    Kaneda, Yasufumi; Yamamoto, Seiji; Nakajima, Toshihiro

    2005-01-01

    To create a highly efficient vector system that is minimally invasive, we initially developed liposomes that contained fusion proteins from the hemagglutinating virus of Japan (HVJ; Sendai virus). These HVJ-liposomes delivered genes and drugs to cultured cells and tissues. To simplify the vector system and develop more efficient vectors, the next approach was to convert viruses to non-viral vectors. Based on this concept, we recently developed the HVJ envelope vector. HVJ with robust fusion activity was inactivated, and exogenous DNA was incorporated into the viral envelope by detergent treatment and centrifugation. The resulting HVJ envelope vector introduced plasmid DNA efficiently and rapidly into both cultured cells in vitro and organs in vivo. Furthermore, proteins, synthetic oligonucleotides, and drugs have also been effectively introduced into cells using the HVJ envelope vector. The HVJ envelope vector is a promising tool for both ex vivo and in vivo gene therapy experiments. Hearing impairment in rats was prevented and treated by hepatocyte growth factor gene transfer to cerebrospinal fluid using HVJ envelope vector. For cancer treatment, tumor-associated antigen genes were delivered efficiently to mouse dendritic cells to evoke an anti-cancer immune response. HVJ envelope vector fused dendritic cells and tumor cells and simultaneously delivered cytokine genes, such as IL-12, to the hybrid cells. This strategy successfully prevented and treated cancers in mice by stimulating the presentation of tumor antigens and the maturation of T cells. For human gene therapy, a pilot plant to commercially produce clinical grade HVJ envelope vector has been established.

  3. Characterization of a gene encoding a Ca(2+)-ATPase-like protein in the plastid envelope.

    PubMed Central

    Huang, L; Berkelman, T; Franklin, A E; Hoffman, N E

    1993-01-01

    By screening an Arabidopsis expression library with an antiserum against chloroplast envelope proteins, we have isolated a partial cDNA with an open reading frame that encodes a polypeptide similar to P-type cation-transporting ATPases. The corresponding genomic clone was isolated and the complete coding sequence was deduced after identification and mapping of introns. The gene has been designated PEA1 (plastid envelope ATPase) and the predicted polypeptide PEA1p. PEA1p has 946 amino acids and a molecular mass of 104 kDa. This protein is 40-44% identical to various mammalian plasma membrane Ca(2+)-ATPases but lacks the C-terminal calmodulin binding domain present in the mammalian polypeptides. When aligned with mammalian plasma membrane Ca(2+)-ATPases, PEA1p has a 70- to 80-amino acid N-terminal region that extends beyond the N terminus of these enzymes. This extension has some similarity to the transit peptide of the plastid envelope phosphate translocator and may function to target the protein to the plastid. Antibodies raised against a portion of PEA1p recognize a single 90- to 95-kDa polypeptide in chloroplast inner envelope preparations. Transcript abundance as determined by RNase protection was found to be 7- to 9-fold higher in roots than in leaves. Possible roles for a plastid envelope calcium pump are suggested. Images Fig. 3 Fig. 4 Fig. 5 PMID:8234257

  4. Retroviral envelope gene captures and syncytin exaptation for placentation in marsupials

    PubMed Central

    Cornelis, Guillaume; Vernochet, Cécile; Carradec, Quentin; Souquere, Sylvie; Mulot, Baptiste; Catzeflis, François; Nilsson, Maria A.; Menzies, Brandon R.; Renfree, Marilyn B.; Pierron, Gérard; Zeller, Ulrich; Heidmann, Odile; Dupressoir, Anne; Heidmann, Thierry

    2015-01-01

    Syncytins are genes of retroviral origin captured by eutherian mammals, with a role in placentation. Here we show that some marsupials—which are the closest living relatives to eutherian mammals, although they diverged from the latter ∼190 Mya—also possess a syncytin gene. The gene identified in the South American marsupial opossum and dubbed syncytin-Opo1 has all of the characteristic features of a bona fide syncytin gene: It is fusogenic in an ex vivo cell–cell fusion assay; it is specifically expressed in the short-lived placenta at the level of the syncytial feto–maternal interface; and it is conserved in a functional state in a series of Monodelphis species. We further identify a nonfusogenic retroviral envelope gene that has been conserved for >80 My of evolution among all marsupials (including the opossum and the Australian tammar wallaby), with evidence for purifying selection and conservation of a canonical immunosuppressive domain, but with only limited expression in the placenta. This unusual captured gene, together with a third class of envelope genes from recently endogenized retroviruses—displaying strong expression in the uterine glands where retroviral particles can be detected—plausibly correspond to the different evolutionary statuses of a captured retroviral envelope gene, with only syncytin-Opo1 being the present-day bona fide syncytin active in the opossum and related species. This study would accordingly recapitulate the natural history of syncytin exaptation and evolution in a single species, and definitely extends the presence of such genes to all major placental mammalian clades. PMID:25605903

  5. Bacillus anthracis lcp Genes Support Vegetative Growth, Envelope Assembly, and Spore Formation

    PubMed Central

    Liszewski Zilla, Megan; Lunderberg, J. Mark; Schneewind, Olaf

    2015-01-01

    ABSTRACT Bacillus anthracis, a spore-forming pathogen, replicates as chains of vegetative cells by regulating the separation of septal peptidoglycan. Surface (S)-layer proteins and B. anthracis S-layer-associated proteins (BSLs) function as chain length determinants and are assembled in the envelope by binding to the secondary cell wall polysaccharide (SCWP). B. anthracis expresses six different genes encoding LytR-CpsA-Psr (LCP) enzymes (lcpB1 to -4, lcpC, and lcpD), which when expressed in Staphylococcus aureus promote attachment of wall teichoic acid to peptidoglycan. Mutations in B. anthracis lcpB3 and lcpD cause aberrations in cell size and chain length that can be explained as discrete defects in SCWP assembly; however, the function of the other lcp genes is not known. By deleting combinations of lcp genes from the B. anthracis genome, we generated variants with single lcp genes. B. anthracis expressing lcpB3 alone displayed physiological cell size, vegetative growth, spore formation, and S-layer assembly. Strains expressing lcpB1 or lcpB4 displayed defects in cell size and shape, S-layer assembly, and spore formation yet sustained vegetative growth. In contrast, the lcpB2 strain was unable to grow unless the gene was expressed from a multicopy plasmid (lcpB2++), and variants expressing lcpC or lcpD displayed severe defects in growth and cell shape. The lcpB2++, lcpC, or lcpD strains supported neither S-layer assembly nor spore formation. We propose a model whereby LCP enzymes fulfill partially overlapping functions in transferring SCWP molecules to discrete sites within the bacterial envelope. IMPORTANCE Products of genes essential for bacterial envelope assembly represent targets for antibiotic development. The LytR-CpsA-Psr (LCP) enzymes tether bactoprenol-linked intermediates of secondary cell wall polymers to the C6 hydroxyl of N-acetylmuramic acid in peptidoglycan; however, the role of LCPs as a target for antibiotic therapy is not defined. We show here

  6. The Envelope Gene of Transmitted HIV-1 Resists a Late Interferon Gamma-Induced Block

    PubMed Central

    Rihn, Suzannah J.; Foster, Toshana L.; Busnadiego, Idoia; Aziz, Muhamad Afiq; Hughes, Joseph; Neil, Stuart J. D.

    2017-01-01

    ABSTRACT Type I interferon (IFN) signaling engenders an antiviral state that likely plays an important role in constraining HIV-1 transmission and contributes to defining subsequent AIDS pathogenesis. Type II IFN (IFN-γ) also induces an antiviral state but is often primarily considered to be an immunomodulatory cytokine. We report that IFN-γ stimulation can induce an antiviral state that can be both distinct from that of type I interferon and can potently inhibit HIV-1 in primary CD4+ T cells and a number of human cell lines. Strikingly, we find that transmitted/founder (TF) HIV-1 viruses can resist a late block that is induced by type II IFN, and the use of chimeric IFN-γ-sensitive/resistant viruses indicates that interferon resistance maps to the env gene. Simultaneously, in vitro evolution also revealed that just a single amino acid substitution in the envelope can confer substantial resistance to IFN-mediated inhibition. Thus, the env gene of transmitted HIV-1 confers resistance to a late block that is phenotypically distinct from blocks previously described to be resisted by env and is therefore mediated by unknown IFN-γ-stimulated factor(s) in human CD4+ T cells and cell lines. This important unidentified block could play a key role in constraining HIV-1 transmission. IMPORTANCE The human immune system can hinder invading pathogens through interferon (IFN) signaling. One consequence of this signaling is that cells enter an antiviral state, increasing the levels of hundreds of defenses that can inhibit the replication and spread of viruses. The majority of HIV-1 infections result from a single virus particle (the transmitted/founder) that makes it past these defenses and colonizes the host. Thus, the founder virus is hypothesized to be a relatively interferon-resistant entity. Here, we show that certain HIV-1 envelope genes have the unanticipated ability to resist specific human defenses mediated by different types of interferons. Strikingly, the envelope

  7. Molecular mechanisms of recombination restriction in the envelope gene of the human immunodeficiency virus.

    PubMed

    Simon-Loriere, Etienne; Galetto, Roman; Hamoudi, Meriem; Archer, John; Lefeuvre, Pierre; Martin, Darren P; Robertson, David L; Negroni, Matteo

    2009-05-01

    The ability of pathogens to escape the host's immune response is crucial for the establishment of persistent infections and can influence virulence. Recombination has been observed to contribute to this process by generating novel genetic variants. Although distinctive recombination patterns have been described in many viral pathogens, little is known about the influence of biases in the recombination process itself relative to selective forces acting on newly formed recombinants. Understanding these influences is important for determining how recombination contributes to pathogen genome and proteome evolution. Most previous research on recombination-driven protein evolution has focused on relatively simple proteins, usually in the context of directed evolution experiments. Here, we study recombination in the envelope gene of HIV-1 between primary isolates belonging to subtypes that recombine naturally in the HIV/AIDS pandemic. By characterizing the early steps in the generation of recombinants, we provide novel insights into the evolutionary forces that shape recombination patterns within viral populations. Specifically, we show that the combined effects of mechanistic processes that determine the locations of recombination breakpoints across the HIV-1 envelope gene, and purifying selection acting against dysfunctional recombinants, can explain almost the entire distribution of breakpoints found within this gene in nature. These constraints account for the surprising paucity of recombination breakpoints found in infected individuals within this highly variable gene. Thus, the apparent randomness of HIV evolution via recombination may in fact be relatively more predictable than anticipated. In addition, the dominance of purifying selection in localized areas of the HIV genome defines regions where functional constraints on recombinants appear particularly strong, pointing to vulnerable aspects of HIV biology.

  8. Molecular Mechanisms of Recombination Restriction in the Envelope Gene of the Human Immunodeficiency Virus

    PubMed Central

    Simon-Loriere, Etienne; Galetto, Roman; Hamoudi, Meriem; Archer, John; Lefeuvre, Pierre; Martin, Darren P.; Robertson, David L.; Negroni, Matteo

    2009-01-01

    The ability of pathogens to escape the host's immune response is crucial for the establishment of persistent infections and can influence virulence. Recombination has been observed to contribute to this process by generating novel genetic variants. Although distinctive recombination patterns have been described in many viral pathogens, little is known about the influence of biases in the recombination process itself relative to selective forces acting on newly formed recombinants. Understanding these influences is important for determining how recombination contributes to pathogen genome and proteome evolution. Most previous research on recombination-driven protein evolution has focused on relatively simple proteins, usually in the context of directed evolution experiments. Here, we study recombination in the envelope gene of HIV-1 between primary isolates belonging to subtypes that recombine naturally in the HIV/AIDS pandemic. By characterizing the early steps in the generation of recombinants, we provide novel insights into the evolutionary forces that shape recombination patterns within viral populations. Specifically, we show that the combined effects of mechanistic processes that determine the locations of recombination breakpoints across the HIV-1 envelope gene, and purifying selection acting against dysfunctional recombinants, can explain almost the entire distribution of breakpoints found within this gene in nature. These constraints account for the surprising paucity of recombination breakpoints found in infected individuals within this highly variable gene. Thus, the apparent randomness of HIV evolution via recombination may in fact be relatively more predictable than anticipated. In addition, the dominance of purifying selection in localized areas of the HIV genome defines regions where functional constraints on recombinants appear particularly strong, pointing to vulnerable aspects of HIV biology. PMID:19424420

  9. Genomic studies of envelope gene sequences from mosquito and human samples from Bangkok, Thailand.

    PubMed

    Pitaksajjakul, Pannamthip; Benjathummarak, Surachet; Son, Hyun Ngoc; Thongrungkiat, Supatra; Ramasoota, Pongrama

    2016-01-01

    Dengue virus (DENV) is an RNA virus showing a high degree of genetic variation as a consequence of its proofreading inability. This variation plays an important role in virus evolution and pathogenesis. Although levels of within-host genetic variation are similar following equilibrium, variation among different hosts is frequently different. To identify dengue quasispecies present among two hosts, we collected patient samples from six acute DENV cases and two pools of Aedes aegypti mosquitoes and analyzed the genetic variation of regions of the viral envelope gene. Among human and mosquito samples, we found three major clusters originating from two subpopulations. Although several shared lineages were observed in the two hosts, only one lineage showing evidence of neutral selection was observed among two hosts. Taken together, our data provide evidence for the existence of a DENV quasispecies, with less genetic variation observed in mosquitoes than humans and with circulating lineages found in both host types.

  10. Nuclear envelope structural proteins facilitate nuclear shape changes accompanying embryonic differentiation and fidelity of gene expression.

    PubMed

    Smith, Elizabeth R; Meng, Yue; Moore, Robert; Tse, Jeffrey D; Xu, Arn G; Xu, Xiang-Xi

    2017-01-14

    Nuclear size and shape are specific to a cell type, function, and location, and can serve as indicators of disease and development. We previously found that lamin A/C and associated nuclear envelope structural proteins were upregulated when murine embryonic stem (ES) cells differentiated to primitive endoderm cells. Here we further investigated the morphological changes of nuclei that accompany this differentiation. The nuclei of undifferentiated wild type cells were found shaped as flattened, irregular ovals, whereas nuclei of Gata4-positive endoderm cells were more spherical, less flattened, and with a slightly reduced volume. The morphological change was confirmed in the trophectoderm and primitive endoderm lineages of E4.5 blastocysts, compared to larger and more irregularly shaped of the nuclei of the inner cell mass. We established ES cells genetically null for the nuclear lamina proteins lamin A/C or the inner nuclear envelope protein emerin, or compound mutant for both lamin A/C and emerin. ES cells deficient in lamin A/C differentiated to endoderm but less efficiently, and the nuclei remained flattened and failed to condense. The size and shape of emerin-deficient nuclei also remained uncondensed after treatment with RA. The emerin/lamin A/C double knockout ES cells failed to differentiate to endoderm cells, though the nuclei condensed but retained a generally flattened ellipsoid shape. Additionally, ES cells deficient for lamin A/C and/or emerin had compromised ability to undergo endoderm differentiation, where the differentiating cells often exhibited coexpression of pluripotent and differentiation markers, such as Oct3/4 and Gata4, respectively, indicating an infidelity of gene regulation. The results suggest that changes in nuclear size and shape, which are mediated by nuclear envelope structural proteins lamin A/C and/or emerin, also impact gene regulation and lineage differentiation in early embryos. Nevertheless, mice lacking both lamin A/C and

  11. Nucleotide sequence variation of the envelope protein gene identifies two distinct genotypes of yellow fever virus.

    PubMed

    Chang, G J; Cropp, B C; Kinney, R M; Trent, D W; Gubler, D J

    1995-09-01

    The evolution of yellow fever virus over 67 years was investigated by comparing the nucleotide sequences of the envelope (E) protein genes of 20 viruses isolated in Africa, the Caribbean, and South America. Uniformly weighted parsimony algorithm analysis defined two major evolutionary yellow fever virus lineages designated E genotypes I and II. E genotype I contained viruses isolated from East and Central Africa. E genotype II viruses were divided into two sublineages: IIA viruses from West Africa and IIB viruses from America, except for a 1979 virus isolated from Trinidad (TRINID79A). Unique signature patterns were identified at 111 nucleotide and 12 amino acid positions within the yellow fever virus E gene by signature pattern analysis. Yellow fever viruses from East and Central Africa contained unique signatures at 60 nucleotide and five amino acid positions, those from West Africa contained unique signatures at 25 nucleotide and two amino acid positions, and viruses from America contained such signatures at 30 nucleotide and five amino acid positions in the E gene. The dissemination of yellow fever viruses from Africa to the Americas is supported by the close genetic relatedness of genotype IIA and IIB viruses and genetic evidence of a possible second introduction of yellow fever virus from West Africa, as illustrated by the TRINID79A virus isolate. The E protein genes of American IIB yellow fever viruses had higher frequencies of amino acid substitutions than did genes of yellow fever viruses of genotypes I and IIA on the basis of comparisons with a consensus amino acid sequence for the yellow fever E gene. The great variation in the E proteins of American yellow fever virus probably results from positive selection imposed by virus interaction with different species of mosquitoes or nonhuman primates in the Americas.

  12. Nucleotide sequence variation of the envelope protein gene identifies two distinct genotypes of yellow fever virus.

    PubMed Central

    Chang, G J; Cropp, B C; Kinney, R M; Trent, D W; Gubler, D J

    1995-01-01

    The evolution of yellow fever virus over 67 years was investigated by comparing the nucleotide sequences of the envelope (E) protein genes of 20 viruses isolated in Africa, the Caribbean, and South America. Uniformly weighted parsimony algorithm analysis defined two major evolutionary yellow fever virus lineages designated E genotypes I and II. E genotype I contained viruses isolated from East and Central Africa. E genotype II viruses were divided into two sublineages: IIA viruses from West Africa and IIB viruses from America, except for a 1979 virus isolated from Trinidad (TRINID79A). Unique signature patterns were identified at 111 nucleotide and 12 amino acid positions within the yellow fever virus E gene by signature pattern analysis. Yellow fever viruses from East and Central Africa contained unique signatures at 60 nucleotide and five amino acid positions, those from West Africa contained unique signatures at 25 nucleotide and two amino acid positions, and viruses from America contained such signatures at 30 nucleotide and five amino acid positions in the E gene. The dissemination of yellow fever viruses from Africa to the Americas is supported by the close genetic relatedness of genotype IIA and IIB viruses and genetic evidence of a possible second introduction of yellow fever virus from West Africa, as illustrated by the TRINID79A virus isolate. The E protein genes of American IIB yellow fever viruses had higher frequencies of amino acid substitutions than did genes of yellow fever viruses of genotypes I and IIA on the basis of comparisons with a consensus amino acid sequence for the yellow fever E gene. The great variation in the E proteins of American yellow fever virus probably results from positive selection imposed by virus interaction with different species of mosquitoes or nonhuman primates in the Americas. PMID:7637022

  13. High Expression of Endogenous Retroviral Envelope Gene in the Equine Fetal Part of the Placenta

    PubMed Central

    Stefanetti, Valentina; Marenzoni, Maria Luisa; Passamonti, Fabrizio; Cappelli, Katia; Garcia-Etxebarria, Koldo; Coletti, Mauro; Capomaccio, Stefano

    2016-01-01

    Endogenous retroviruses (ERVs) are proviral phases of exogenous retroviruses that have co-evolved with vertebrate genomes for millions of years. Previous studies have identified the envelope (env) protein genes of retroviral origin preferentially expressed in the placenta which suggests a role in placentation based on their membrane fusogenic capacity and therefore they have been named syncytins. Until now, all the characterized syncytins have been associated with three invasive placentation types: the endotheliochorial (Carnivora), the synepitheliochorial (Ruminantia), and the hemochorial placentation (human, mouse) where they play a role in the syncytiotrophoblast formation. The purpose of the present study was to evaluate whether EqERV env RNA is expressed in horse tissues as well and investigate if the horse, possessing an epitheliochorial placenta, has “captured” a common retroviral env gene with syncytin-like properties in placental tissues. Interestingly, although in the equine placenta there is no syncytiotrophoblast layer at the maternal-fetal interface, our results showed that EqERV env RNA is highly expressed at that level, as expected for a candidate syncytin-like gene but with reduced abundance in the other somatic tissues (nearly 30-fold lower) thus suggesting a possible role in the placental tissue. Although the horse is one of the few domestic animals with a sequenced genome, few studies have been conducted about the EqERV and their expression in placental tissue has never been investigated. PMID:27176223

  14. Diversity of envelope genes from an uncloned stock of SIVmac251.

    PubMed

    Bixby, Jacqueline G; Laur, Olga; Johnson, Welkin E; Desrosiers, Ronald C

    2010-10-01

    AIDS vaccine and pathogenesis research will benefit from a more diverse array of cloned SIV challenge stocks from which to choose. Toward this end, 20 envelope genes were cloned from an extensively used, primary stock of uncloned SIVmac251. Each of the 20 clones had a unique sequence. Their translated sequences differed by as many as 26 amino acids from one another and by as many as 45 amino acids from the commonly used clone SIVmac239. Envelope sequences up to and including the membrane-spanning domain were exchanged into the infectious pathogenic SIVmac239 clone and virus stocks were produced by HEK293T cell transfection. Seventeen of the 20 recombinants were replication competent. The infectivities per ng p27 of the 17 new replication-competent recombinants in C8166-SEAP cells and in TZM-bl cells ranged from minus 32-fold to plus 7.6-fold relative to SIVmac239. A range of sensitivities to neutralization by sCD4 and by sera from SIV-infected macaques was observed but none was as sensitive to these neutralizing agents as SIVmac316, the highly macrophage-competent derivative of SIVmac239. Four strains that were most sensitive to sCD4 inhibition were also among the most sensitive to antibody-mediated neutralization. None of the new recombinant viruses replicated as well as SIVmac316 in primary alveolar macrophage cultures from rhesus monkeys but three of the strains did exhibit significant levels of delayed replication in these primary macrophages, reaching peak levels of virus production of ≥50 ng/ml p27 compared to 600-800 ng/ml p27 with SIVmac316. These new SIV clones are being contributed to the NIH AIDS Reagent Repository and are available to the scientific community.

  15. [Basic types of respiratory system structure in insect egg envelopes, and genes controlling their formation].

    PubMed

    Omelina, E S; Baricheva, É M; Fedorova, E V

    2012-01-01

    Insects is a taxon surprisingly rich with species and varieties, and its representatives are considered as the most fitted and "evolutionary successful" living things. Insects are distinguished by diversity and abundance of adaptations to environmental conditions, representatives of this class inhabit different ecological niches, they can be found practically in every corner of the Earth and, in particular, in close adjacency to man. Among them are those who man benefits from and those who man struggles against. This determines man's interest in studying peculiarities of their development as well as adaptations formed by them in the course of evolution to become more viable. In the paper, data are presented on morphological structure of respiratory systems in insect egg envelopes that ensure respiration process of developing embryo. Variability of these systems and their dependence on environmental conditions are demonstrated for different insect species. The information about genes controlling development of respiratory systems in fruit fly eggs is brought together, and occurrence of evolutionary conservative genes participating in development of such systems in other insect species is ascertained.

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

    PubMed Central

    2010-01-01

    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. PMID:20377912

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

    PubMed

    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.

  18. Coronavirus virulence genes with main focus on SARS-CoV envelope gene.

    PubMed

    DeDiego, Marta L; Nieto-Torres, Jose L; Jimenez-Guardeño, Jose M; Regla-Nava, Jose A; Castaño-Rodriguez, Carlos; Fernandez-Delgado, Raul; Usera, Fernando; Enjuanes, Luis

    2014-12-19

    Coronavirus (CoV) infection is usually detected by cellular sensors, which trigger the activation of the innate immune system. Nevertheless, CoVs have evolved viral proteins that target different signaling pathways to counteract innate immune responses. Some CoV proteins act as antagonists of interferon (IFN) by inhibiting IFN production or signaling, aspects that are briefly addressed in this review. After CoV infection, potent cytokines relevant in controlling virus infections and priming adaptive immune responses are also generated. However, an uncontrolled induction of these proinflammatory cytokines can lead to pathogenesis and disease severity as described for SARS-CoV and MERS-CoV. The cellular pathways mediated by interferon regulatory factor (IRF)-3 and -7, activating transcription factor (ATF)-2/jun, activator protein (AP)-1, nuclear factor kappa-light-chain-enhancer of activated B cells (NF-κB), and nuclear factor of activated T cells (NF-AT), are the main drivers of the inflammatory response triggered after viral infections, with NF-κB pathway the most frequently activated. Key CoV proteins involved in the regulation of these pathways and the proinflammatory immune response are revisited in this manuscript. It has been shown that the envelope (E) protein plays a variable role in CoV morphogenesis, depending on the CoV genus, being absolutely essential in some cases (genus α CoVs such as TGEV, and genus β CoVs such as MERS-CoV), but not in others (genus β CoVs such as MHV or SARS-CoV). A comprehensive accumulation of data has shown that the relatively small E protein elicits a strong influence on the interaction of SARS-CoV with the host. In fact, after infection with viruses in which this protein has been deleted, increased cellular stress and unfolded protein responses, apoptosis, and augmented host immune responses were observed. In contrast, the presence of E protein activated a pathogenic inflammatory response that may cause death in animal

  19. CORONAVIRUS VIRULENCE GENES WITH MAIN FOCUS ON SARS-CoV ENVELOPE GENE

    PubMed Central

    DeDiego, Marta L.; Nieto-Torres, Jose L.; Jimenez-Guardeño, Jose M.; Regla-Nava, Jose A.; Castaño-Rodriguez, Carlos; Fernandez-Delgado, Raul; Usera, Fernando; Enjuanes, Luis

    2014-01-01

    Coronavirus (CoV) infection is usually detected by cellular sensors, which trigger the activation of the innate immune system. Nevertheless, CoVs have evolved viral proteins that target different signaling pathways to counteract innate immune responses. Some CoV proteins act as antagonists of interferon (IFN) by inhibiting IFN production or signaling, aspects that are briefly addressed in this review. After CoV infection, potent cytokines relevant in controlling virus infections and priming adaptive immune responses are also generated. However, an uncontrolled induction of these proinflammatory cytokines can lead to pathogenesis and disease severity as described for SARS-CoV and MERS-CoV. The cellular pathways mediated by interferon regulatory factor (IRF)-3 and 7, activating transcription factor (ATF)-2/jun, activator protein (AP)-1, nuclear factor kappa-light-chain-enhancer of activated B cells (NF-κB), and nuclear factor of activated T cells (NF-AT), are the main drivers of the inflammatory response triggered after viral infections, with NF-κB pathway the most frequently activated. Key CoV proteins involved in the regulation of these pathways and the proinflammatory immune response are revisited in this manuscript. It has been shown that the envelope (E) protein plays a variable role in CoV morphogenesis, depending on the CoV genus, being absolutely essential in some cases (genus α CoVs such as TGEV, and genus β CoVs such as MERS-CoV), but not in others (genus β CoVs such as MHV or SARS-CoV). A comprehensive accumulation of data has shown that the relatively small E protein elicits a strong influence on the interaction of SARS-CoV with the host. In fact, after infection with viruses in which this protein has been deleted, increased cellular stress and unfolded protein responses, apoptosis, and augmented host immune responses were observed. In contrast, the presence of E protein activated a pathogenic inflammatory response that may cause death in animal

  20. Optimal induction of hepatitis C virus envelope-specific immunity by bicistronic plasmid DNA inoculation with the granulocyte-macrophage colony-stimulating factor gene.

    PubMed

    Lee, S W; Cho, J H; Sung, Y C

    1998-10-01

    In this study, we have constructed various DNA vaccine vectors that carried hepatitis C virus (HCV) envelope genes without and with the granulocyte-macrophage colony-stimulating factor (GM-CSF) gene in several different ways. In Buffalo rats that received plasmids carrying the HCV envelope genes, which encode envelope proteins E1 and E2, both antibody and lymphoproliferative responses against these proteins were induced. These responses were greatly enhanced by the codelivery of the GM-CSF gene. In particular, inoculation with a bicistronic plasmid that independently expressed the GM-CSF gene and the envelope genes in the same construct generated the highest antibody titers and significantly increased lymphoproliferative responses against these proteins. Moreover, strong antibody responses to homologous and heterologous hypervariable region 1 peptides were elicited in the immunized rats.

  1. Molecular clock of HIV-1 envelope genes under early immune selection.

    PubMed

    Park, Sung Yong; Love, Tanzy M T; Perelson, Alan S; Mack, Wendy J; Lee, Ha Youn

    2016-06-01

    The molecular clock hypothesis that genes or proteins evolve at a constant rate is a key tool to reveal phylogenetic relationships among species. Using the molecular clock, we can trace an infection back to transmission using HIV-1 sequences from a single time point. Whether or not a strict molecular clock applies to HIV-1's early evolution in the presence of immune selection has not yet been fully examined. We identified molecular clock signatures from 1587 previously published HIV-1 full envelope gene sequences obtained since acute infection in 15 subjects. Each subject's sequence diversity linearly increased during the first 150 days post infection, with rates ranging from [Formula: see text] to [Formula: see text] with a mean of [Formula: see text] per base per day. The rate of diversification for 12 out of the 15 subjects was comparable to the neutral evolution rate. While temporal diversification was consistent with evolution patterns in the absence of selection, mutations from the founder virus were highly clustered on statistically identified selection sites, which diversified more than 65 times faster than non-selection sites. By mathematically quantifying deviations from the molecular clock under various selection scenarios, we demonstrate that the deviation from a constant clock becomes negligible as multiple escape lineages emerge. The most recent common ancestor of a virus pair from distinct escape lineages is most likely the transmitted founder virus, indicating that HIV-1 molecular dating is feasible even after the founder viruses are no longer detectable. The ability of HIV-1 to escape from immune surveillance in many different directions is the driving force of molecular clock persistence. This finding advances our understanding of the robustness of HIV-1's molecular clock under immune selection, implying the potential for molecular dating.

  2. Ancestral capture of syncytin-Car1, a fusogenic endogenous retroviral envelope gene involved in placentation and conserved in Carnivora.

    PubMed

    Cornelis, Guillaume; Heidmann, Odile; Bernard-Stoecklin, Sibylle; Reynaud, Karine; Véron, Géraldine; Mulot, Baptiste; Dupressoir, Anne; Heidmann, Thierry

    2012-02-14

    Syncytins are envelope protein genes of retroviral origin that have been captured for a function in placentation. Two such genes have already been identified in simians, two distinct, unrelated genes have been identified in Muridae, and a fifth gene has been identified in the rabbit. Here, we searched for similar genes in the Laurasiatheria clade, which diverged from Euarchontoglires--primates, rodents, and lagomorphs--shortly after mammalian radiation (100 Mya). In silico search for envelope protein genes with full-coding capacity within the dog and cat genomes identified several candidate genes, with one common to both species that displayed placenta-specific expression, which was revealed by RT-PCR analysis of a large panel of tissues. This gene belongs to a degenerate endogenous retroviral element, with precise proviral integration at a site common to dog and cat. Cloning of the gene for an ex vivo pseudotype assay showed fusogenicity on both dog and cat cells. In situ hybridization on placenta sections from both species showed specific expression at the level of the invasive fetal villi within the placental junctional zone, where trophoblast cells fuse into a syncytiotrophoblast layer to form the maternofetal interface. Finally, we show that the gene is conserved among a series of 26 Carnivora representatives, with evidence for purifying selection and conservation of fusogenic activity. The gene is not found in the Pholidota order and, therefore, it was captured before Carnivora radiation, between 60 and 85 Mya. This gene is the oldest syncytin gene identified to date, and it is the first in a new major clade of eutherian mammals.

  3. Enhancement of antitumor activity of gammaretrovirus carrying IL-12 gene through genetic modification of envelope targeting HER2 receptor: a promising strategy for bladder cancer therapy.

    PubMed

    Tsai, Y-S; Shiau, A-L; Chen, Y-F; Tsai, H-T; Tzai, T-S; Wu, C-L

    2010-01-01

    The objective of this study was to develop an HER2-targeted, envelope-modified Moloney murine leukemia virus (MoMLV)-based gammaretroviral vector carrying interleukin (IL)-12 gene for bladder cancer therapy. It displayed a chimeric envelope protein containing a single-chain variable fragment (scFv) antibody to the HER2 receptor and carried the mouse IL-12 gene. The fragment of anti-erbB2scFv was constructed into the proline-rich region of the viral envelope of the packaging vector lacking a transmembrane subunit of the carboxyl terminal region of surface subunit. As compared with envelope-unmodified gammaretroviruses, envelope-modified ones had extended viral tropism to human HER2-expressing bladder cancer cell lines, induced apoptosis, and affected cell cycle progression despite lower viral titers. Moreover, animal studies showed that envelope-modified gammaretroviruses carrying IL-12 gene exerted higher antitumor activity in terms of retarding tumor growth and prolonging the survival of tumor-bearing mice than unmodified ones, which were associated with enhanced tumor cell apoptosis as well as increased intratumoral levels of IL-12, interferon-gamma, IL-1beta, and tumor necrosis factor-alpha proteins. Therefore, the antitumor activity of gammaretroviruses carrying the IL-12 gene was enhanced through genetic modification of the envelope targeting HER2 receptor, which may be a promising strategy for bladder cancer therapy.

  4. Human immunodeficiency virus type 1 envelope gene structure and diversity in vivo and after cocultivation in vitro.

    PubMed Central

    Kusumi, K; Conway, B; Cunningham, S; Berson, A; Evans, C; Iversen, A K; Colvin, D; Gallo, M V; Coutre, S; Shpaer, E G

    1992-01-01

    Nested-primer polymerase chain reaction (PCR) has been applied to the molecular cloning of 4.6-kb half-genome fragments of human immunodeficiency virus type 1 (HIV-1) taken directly from the peripheral blood mononuclear cells (PBMC) of an individual with neurological symptoms of HIV-1 infection. In a similar manner, gp120-coding portions of the envelope gene were cloned after PBMC from the same blood sample were cocultivated with uninfected PBMC for 28 days. The complete 1.6-kb nucleotide sequence of the gp120 gene was determined from each of 35 clones examined. Two of 13 (15%) PBMC-derived gp120 genes and 3 of 22 (14%) coculture-derived gp120 genes were defective as a result of frameshifts and an in-frame stop codon(s). Mean diversity between individual gp120-coding sequences in PBMC was fivefold greater (3.24%) than after coculture (0.65%). A predominant sequence of "strain" was found after coculture that was distinct from the diverse viral genotypes detected in vivo and therefore was selectively amplified during in vitro propagation. Multiple distinct third variable (V3) regions encoding the principal neutralizing domain of the envelope protein were detected in PBMC-derived genes, suggesting the presence of immunologic diversity of HIV env genes in vivo not reflected in the cocultured virus sample. The large size of the HIV fragments generated in this study will permit analysis of the diversity of immunologic reactivity, gene function, and pathogenicity of HIV genomes present within infected individuals, including the functional significance of the loss of diversity that occurs upon coculture. Images PMID:1731112

  5. A Mycobacterium smegmatis mutant with a defective inositol monophosphate phosphatase gene homolog has altered cell envelope permeability.

    PubMed Central

    Parish, T; Liu, J; Nikaido, H; Stoker, N G

    1997-01-01

    A bacteriophage infection mutant (strain LIMP7) of Mycobacterium smegmatis was isolated following transposon mutagenesis. The mutant showed an unusual phenotype, in that all phages tested produced larger plaques on this strain compared to the parent strain. Other phenotypic characteristics of the mutant were slower growth, increased clumping in liquid culture, increased resistance to chloramphenicol and erythromycin, and increased sensitivity to isoniazid and several beta-lactam antibiotics. Permeability studies showed decreases in the accumulation of lipophilic molecules (norfloxacin and chenodeoxycholate) and a small increase with hydrophilic molecules (cephaloridine); taken together, these characteristics indicate an altered cell envelope. The DNA adjacent to the transposon in LIMP7 was cloned and was shown to be highly similar to genes encoding bacterial and mammalian inositol monophosphate phosphatases. Inositol is important in mycobacteria as a component of the major thiol mycothiol and also in the cell wall, with phosphatidylinositol anchoring lipoarabinomannan (LAM) in the cell envelope. In LIMP7, levels of phosphatidylinositol dimannoside, the precursor of LAM, were less than half of those in the wild-type strain, confirming that the mutation had affected the synthesis of inositol-containing molecules. The impA gene is located within the histidine biosynthesis operon in both M. smegmatis and Mycobacterium tuberculosis, lying between the hisA and hisF genes. PMID:9401044

  6. Analysis of Dengue Virus Enhancing Epitopes Using Peptide Antigens Derived from the Envelope Glycoprotein Gene Sequence

    DTIC Science & Technology

    1990-11-27

    AD________ AD-A230 976 ARMY PROJECT NO: 89PP9961 TITLE: ANALYSIS OF DENGUE VIRUS ENHANCING EPITOPES USING PEPTIDE ANTIGENS DERIVED FROM THE ENVELOPE...INO. INO r CCESSION NO I1I TITLE (Include Security Classification) Analysis of Dengue Virus Enhancing Epitopes Using Peptide Antigens Derived From the...necessary and identify by block number) Antibody-dependent enhancement (ADE) ot dengue (DEN) virus infection in human mononuclear cells in vitro has been

  7. Programmed packaging of multicomponent envelope-type nanoparticle system for gene delivery

    NASA Astrophysics Data System (ADS)

    Pozzi, Daniela; Marianecci, Carlotta; Carafa, Maria; Marchini, Cristina; Montani, Maura; Amici, Augusto; Caracciolo, Giulio

    2010-05-01

    A programmed packaging strategy to develop a multicomponent envelope-type nanoparticle system (MENS) is presented. To this end, we took specific advantage of using in-house tailored liposomes that have been recently shown to exhibit intrinsic endosomal rupture properties that allow plasmid DNA to escape from endosomes and to enter the nucleus with extremely high efficiency. Transfection efficiency experiments on NIH 3T3 mouse fibroblasts indicate that MENS is a promising transfection candidate.

  8. A highly conserved baculovirus gene p48 (ac103) is essential for BV production and ODV envelopment

    SciTech Connect

    Yuan Meijin; Wu Wenbi; Liu Chao; Wang Yanjie; Hu Zhaoyang; Yang Kai Pang Yi

    2008-09-15

    Autographa californica multiple nucleopolyhedrovirus (AcMNPV) p48 (ac103) is a highly conserved baculovirus gene of unknown function. In the present study, we generated a knockout of the p48 gene in an AcMNPV bacmid and investigated the role of P48 in baculovirus life cycle. The p48-null Bacmid vAc{sup P48-KO-PH-GFP} was unable to propagate in cell culture, while a 'repair' Bacmid vAc{sup P48-REP-PH-GFP} was able to replicate in a manner similar to a wild-type Bacmid vAc{sup PH-GFP}. Titration assays and Western blotting confirmed that vAc{sup P48-KO-PH-GFP} was unable to produce budded viruses (BVs). qPCR analysis showed that p48 deletion did not affect viral DNA replication. Electron microscopy indicated that P48 was required for nucleocapsid envelopment to form occlusion-derived viruses (ODVs) and their subsequent occlusion. Confocal analysis showed that P48 prominently condensed in the centre of the nucleus. Our results demonstrate that P48 plays an essential role in BV production and ODV envelopment in the AcMNPV life cycle.

  9. A highly conserved baculovirus gene p48 (ac103) is essential for BV production and ODV envelopment.

    PubMed

    Yuan, Meijin; Wu, Wenbi; Liu, Chao; Wang, Yanjie; Hu, Zhaoyang; Yang, Kai; Pang, Yi

    2008-09-15

    Autographa californica multiple nucleopolyhedrovirus (AcMNPV) p48 (ac103) is a highly conserved baculovirus gene of unknown function. In the present study, we generated a knockout of the p48 gene in an AcMNPV bacmid and investigated the role of P48 in baculovirus life cycle. The p48-null Bacmid vAc(P48-KO-PH-GFP) was unable to propagate in cell culture, while a 'repair' Bacmid vAc(P48-REP-PH-GFP) was able to replicate in a manner similar to a wild-type Bacmid vAc(PH-GFP). Titration assays and Western blotting confirmed that vAc(P48-KO-PH-GFP) was unable to produce budded viruses (BVs). qPCR analysis showed that p48 deletion did not affect viral DNA replication. Electron microscopy indicated that P48 was required for nucleocapsid envelopment to form occlusion-derived viruses (ODVs) and their subsequent occlusion. Confocal analysis showed that P48 prominently condensed in the centre of the nucleus. Our results demonstrate that P48 plays an essential role in BV production and ODV envelopment in the AcMNPV life cycle.

  10. Chimeric porcine reproductive and respiratory syndrome virus containing shuffled multiple envelope genes confers cross-protection in pigs.

    PubMed

    Tian, Debin; Ni, Yan-Yan; Zhou, Lei; Opriessnig, Tanja; Cao, Dianjun; Piñeyro, Pablo; Yugo, Danielle M; Overend, Christopher; Cao, Qian; Lynn Heffron, C; Halbur, Patrick G; Pearce, Douglas S; Calvert, Jay G; Meng, Xiang-Jin

    2015-11-01

    The extensive genetic diversity of porcine reproductive and respiratory syndrome virus (PRRSV) strains is a major obstacle for vaccine development. We previously demonstrated that chimeric PRRSVs in which a single envelope gene (ORF3, ORF4, ORF5 or ORF6) was shuffled via DNA shuffling had an improved heterologous cross-neutralizing ability. In this study, we incorporate all of the individually-shuffled envelope genes together in different combinations into an infectious clone backbone of PRRSV MLV Fostera(®) PRRS. Five viable progeny chimeric viruses were rescued, and their growth characteristics were characterized in vitro. In a pilot pig study, two chimeric viruses (FV-SPDS-VR2,FV-SPDS-VR5) were found to induce cross-neutralizing antibodies against heterologous strains. A subsequent vaccination/challenge study in 72 pigs revealed that chimeric virus FV-SPDS-VR2 and parental virus conferred partial cross-protection when challenged with heterologous strains NADC20 or MN184B. The results have important implications for future development of an effective PRRSV vaccine that confers heterologous protection.

  11. Comprehensive analysis of the codon usage patterns in the envelope glycoprotein E2 gene of the classical swine fever virus.

    PubMed

    Chen, Ye; Li, Xinxin; Chi, Xiaojuan; Wang, Song; Ma, Yanmei; Chen, Jilong

    2017-01-01

    The classical swine fever virus (CSFV), circulating worldwide, is a highly contagious virus. Since the emergence of CSFV, it has caused great economic loss in swine industry. The envelope glycoprotein E2 gene of the CSFV is an immunoprotective antigen that induces the immune system to produce neutralizing antibodies. Therefore, it is essential to study the codon usage of the E2 gene of the CSFV. In this study, 140 coding sequences of the E2 gene were analyzed. The value of effective number of codons (ENC) showed low codon usage bias in the E2 gene. Our study showed that codon usage could be described mainly by mutation pressure ENC plot analysis combined with principal component analysis (PCA) and translational selection-correlation analysis between the general average hydropathicity (Gravy) and aromaticity (Aroma), and nucleotides at the third position of codons (A3s, T3s, G3s, C3s and GC3s). Furthermore, the neutrality analysis, which explained the relationship between GC12s and GC3s, revealed that natural selection had a key role compared with mutational bias during the evolution of the E2 gene. These results lay a foundation for further research on the molecular evolution of CSFV.

  12. Hominoid-specific SPANXA/D genes demonstrate differential expression in individuals and protein localization to a distinct nuclear envelope domain during spermatid morphogenesis.

    PubMed

    Westbrook, V A; Schoppee, P D; Vanage, G R; Klotz, K L; Diekman, A B; Flickinger, C J; Coppola, M A; Herr, J C

    2006-11-01

    Human sperm protein associated with the nucleus on the X chromosome consists of a five-member gene family (SPANXA1, SPANXA2, SPANXB, SPANXC and SPANXD) clustered at Xq27.1. Evolved from an ancestral SPANX-N gene family (at Xq27 and Xp11) present in all primates as well as in rats and mice, the SPANXA/D family is present only in humans, bonobos, chimpanzees and gorillas. Among hominoid-specific genes, the SPANXA/D gene family is considered to be undergoing rapid positive selection in its coding region. In this study, RT-PCR of human testis mRNA from individuals showed that, although all SPANXA/D genes are expressed in humans, differences are evident. In particular, SPANXC is expressed only in a subset of men. The SPANXa/d protein localized to the nuclear envelope of round, condensing and elongating spermatids, specifically to regions that do not underlie the developing acrosome. During spermiogenesis, the SPANXa/d-positive domain migrated into the base of the head as the redundant nuclear envelope that protrudes into the residual cytoplasm. Post-testicular modification of the SPANXa/d proteins was noted, as were PEST (proline, glutamic acid, serine, and threonine rich regions) domains. It is concluded that the duplication of the SPANX-N gene family that occurred 6-11 MYA resulted in a new gene family, SPANXA/D, that plays a role during spermiogenesis. The SPANXa/d gene products are among the few examples of X-linked nuclear proteins expressed following meiosis. Their localization to non-acrosomal domains of the nuclear envelope adjacent to regions of euchromatin and their redistribution to the redundant nuclear envelope during spermiogenesis provide a biomarker for the redundant nuclear envelope of spermatids and spermatozoa.

  13. p63 Transcription Factor Regulates Nuclear Shape and Expression of Nuclear Envelope-Associated Genes in Epidermal Keratinocytes.

    PubMed

    Rapisarda, Valentina; Malashchuk, Igor; Asamaowei, Inemo E; Poterlowicz, Krzysztof; Fessing, Michael Y; Sharov, Andrey A; Karakesisoglou, Iakowos; Botchkarev, Vladimir A; Mardaryev, Andrei

    2017-10-01

    The maintenance of a proper nuclear architecture and three-dimensional organization of the genes, enhancer elements, and transcription machinery plays an essential role in tissue development and regeneration. Here we show that in the developing skin, epidermal progenitor cells of mice lacking p63 transcription factor display alterations in the nuclear shape accompanied by a marked decrease in expression of several nuclear envelope-associated components (Lamin B1, Lamin A/C, Sun1, Nesprin-3, Plectin) compared with controls. Furthermore, chromatin immunoprecipitation-quantitative PCR assay showed enrichment of p63 on Sun1, Syne3, and Plec promoters, suggesting them as p63 targets. Alterations in the nuclei shape and expression of nuclear envelope-associated proteins were accompanied by altered distribution patterns of the repressive histone marks trimethylation on lysine 27 of histone H3, trimethylation on lysine 9 of histone H3, and heterochromatin protein 1-alpha in p63-null keratinocytes. These changes were also accompanied by downregulation of the transcriptional activity and relocation of the keratinocyte-specific gene loci away from the sites of active transcription toward the heterochromatin-enriched repressive nuclear compartments in p63-null cells. These data demonstrate functional links between the nuclear envelope organization, chromatin architecture, and gene expression in keratinocytes and suggest nuclear envelope-associated genes as important targets mediating p63-regulated gene expression program in the epidermis. Copyright © 2017 The Authors. Published by Elsevier Inc. All rights reserved.

  14. Impact of deletion of envelope-related genes of recombinant Sendai viruses on immune responses following pulmonary gene transfer of neonatal mice.

    PubMed

    Tanaka, S; Yonemitsu, Y; Yoshida, K; Okano, S; Kondo, H; Inoue, M; Hasegawa, M; Masumoto, K; Suita, S; Taguchi, T; Sueishi, K

    2007-07-01

    We demonstrated previously that the additive-type recombinant Sendai virus (rSeV) is highly efficient for use in pulmonary gene transfer; however, rSeV exhibits inflammatory responses. To overcome this problem, we tested newly developed non-transmissible constructs, namely, temperature-sensitive F-deleted vector, rSeV/dF (ts-rSeV/dF) and a rSeV with all the envelope-related genes deleted (rSeV/dFdMdHN), for pulmonary gene transfer in neonatal mice, by assessing their toxicity and immune responses. The gene expression in the lungs of neonatal ICR mice peaked on day 2, then gradually decreased until almost disappearing at 14 days after infection in all constructs. Loss of body weight and mortality rate, however, were dramatically improved in mice treated with SeV/dFdMdHN (mortality=0%, n=41) and ts-rSeV/dF (24.2%, n=33) compared with additive rSeV (70.7%, n=58). Although the deletion of envelope-related genes of SeV had a small impact on the production of antibody and cytotoxic T-lymphocyte activity in both adults and neonates, a dramatic reduction was found in the events related to innate responses, including the production of proinflammatory cytokines, particularly in the case of neonates. These results indicate that pulmonary gene transfer using SeV/dFdMdHN warrants further investigation for its possible use in developing safer therapeutics for neonatal lung diseases, including cystic fibrosis.

  15. Gene-based vaccination with a mismatched envelope protects against simian immunodeficiency virus infection in nonhuman primates.

    PubMed

    Flatz, Lukas; Cheng, Cheng; Wang, Lingshu; Foulds, Kathryn E; Ko, Sung-Youl; Kong, Wing-Pui; Roychoudhuri, Rahul; Shi, Wei; Bao, Saran; Todd, John-Paul; Asmal, Mohammed; Shen, Ling; Donaldson, Mitzi; Schmidt, Stephen D; Gall, Jason G D; Pinschewer, Daniel D; Letvin, Norman L; Rao, Srinivas; Mascola, John R; Roederer, Mario; Nabel, Gary J

    2012-08-01

    The RV144 trial demonstrated that an experimental AIDS vaccine can prevent human immunodeficiency virus type 1 (HIV-1) infection in humans. Because of its limited efficacy, further understanding of the mechanisms of preventive AIDS vaccines remains a priority, and nonhuman primate (NHP) models of lentiviral infection provide an opportunity to define immunogens, vectors, and correlates of immunity. In this study, we show that prime-boost vaccination with a mismatched SIV envelope (Env) gene, derived from simian immunodeficiency virus SIVmac239, prevents infection by SIVsmE660 intrarectally. Analysis of different gene-based prime-boost immunization regimens revealed that recombinant adenovirus type 5 (rAd5) prime followed by replication-defective lymphocytic choriomeningitis virus (rLCMV) boost elicited robust CD4 and CD8 T-cell and humoral immune responses. This vaccine protected against infection after repetitive mucosal challenge with efficacies of 82% per exposure and 62% cumulatively. No effect was seen on viremia in infected vaccinated monkeys compared to controls. Protection correlated with the presence of neutralizing antibodies to the challenge viruses tested in peripheral blood mononuclear cells. These data indicate that a vaccine expressing a mismatched Env gene alone can prevent SIV infection in NHPs and identifies an immune correlate that may guide immunogen selection and immune monitoring for clinical efficacy trials.

  16. Nuclear transport defects and nuclear envelope alterations are associated with mutation of the Saccharomyces cerevisiae NPL4 gene.

    PubMed Central

    DeHoratius, C; Silver, P A

    1996-01-01

    To identify components involved in nuclear protein import, we used a genetic selection to isolate mutants that mislocalized a nuclear-targeted protein. We identified temperature-sensitive mutants that accumulated several different nuclear proteins in the cytoplasm when shifted to the semipermissive temperature of 30 degrees C; these were termed npl (nuclear protein localization) mutants. We now present the properties of yeast strains bearing mutations in the NPL4 gene and report the cloning of the NPL4 gene and the characterization of the Np14 protein. The npl4-1 mutant was isolated by the previously described selection scheme. The second allele, npl4-2, was identified from an independently derived collection of temperature-sensitive mutants. The npl4-1 and npl4-2 strains accumulate nuclear-targeted proteins in the cytoplasm at the nonpermissive temperature consistent with a defect in nuclear protein import. Using an in vitro nuclear import assay, we show that nuclei prepared from temperature-shifted npl4 mutant cells are unable to import nuclear-targeted proteins, even in the presence of cytosol prepared from wild-type cells. In addition, npl4-2 cells accumulate poly(A)+ RNA in the nucleus at the nonpermissive temperature, consistent with a failure to export mRNA from the nucleus. The npl4-1 and npl4-2 cells also exhibit distinct, temperature-sensitive structural defects: npl4-1 cells project extra nuclear envelope into the cytoplasm, whereas npl4-2 cells from nuclear envelope herniations that appear to be filled with poly(A)+ RNA. The NPL4 gene encodes an essential M(r) 64,000 protein that is located at the nuclear periphery and localizes in a pattern similar to nuclear pore complex proteins. Taken together, these results indicate that this gene encodes a novel nuclear pore complex or nuclear pore complex-associated component required for nuclear membrane integrity and nuclear transport. Images PMID:8930904

  17. Multiple sclerosis retrovirus-like envelope gene: Role of the chromosome 20 insertion

    PubMed Central

    Varadé, Jezabel; García-Montojo, Marta; de la Hera, Belén; Camacho, Iris; García-Martínez, Mª. Ángel; Arroyo, Rafael; Álvarez-Lafuente, Roberto; Urcelay, Elena

    2015-01-01

    Background The genetic basis involved in multiple sclerosis (MS) susceptibility was not completely revealed by genome-wide association studies. Part of it could lie in repetitive sequences, as those corresponding to human Endogenous Retroviruses (HERVs). Retrovirus-like particles were isolated from MS patients and the genome of the MS-associated retrovirus (MSRV) was the founder of the HERV-W family. We aimed to ascertain which chromosomal origin encodes the pathogenic ENV protein by genomic analysis of the HERV-W insertions. Methods/results In silico analyses allowed to uncover putative open reading frames containing the specific sequence previously reported for MSRV-like envelope (env) detection. Out of the 261 genomic insertions of HERV-W env, only 9 copies harbor the specific primers and probe featuring MSRV-like env. The copy from chromosome 20 was further studied considering its size, a truncated homologue of the functional HERV-W env sequence encoding syncytin. High Resolution Melting analysis of this sequence identified two single nucleotide polymorphisms, subsequently genotyped by Taqman chemistry in 668 MS patients and 678 healthy controls. No significant association of these polymorphisms with MS risk was evidenced. Transcriptional activity of this MSRV-like env copy was detected in peripheral blood mononuclear cells from patients and controls. RNA expression levels of chromosome 20-specific MSRV-like env did not show significant differences between MS patients and controls, neither were related to genotypes of the two mentioned polymorphisms. Conclusions The lack of association with MS risk of the identified polymorphisms together with the transcription results discard chromosome 20 as genomic origin of MSRV-like env. PMID:26675450

  18. Fast Screening Procedures for Random Transposon Libraries of Cloned Herpesvirus Genomes: Mutational Analysis of Human Cytomegalovirus Envelope Glycoprotein Genes

    PubMed Central

    Hobom, Urs; Brune, Wolfram; Messerle, Martin; Hahn, Gabriele; Koszinowski, Ulrich H.

    2000-01-01

    We have cloned the human cytomegalovirus (HCMV) genome as an infectious bacterial artificial chromosome (BAC) in Escherichia coli. Here, we have subjected the HCMV BAC to random transposon (Tn) mutagenesis using a Tn1721-derived insertion sequence and have provided the conditions for excision of the BAC cassette. We report on a fast and efficient screening procedure for a Tn insertion library. Bacterial clones containing randomly mutated full-length HCMV genomes were transferred into 96-well microtiter plates. A PCR screening method based on two Tn primers and one primer specific for the desired genomic position of the Tn insertion was established. Within three consecutive rounds of PCR a Tn insertion of interest can be assigned to a specific bacterial clone. We applied this method to retrieve mutants of HCMV envelope glycoprotein genes. To determine the infectivities of the mutant HCMV genomes, the DNA of the identified BACs was transfected into permissive fibroblasts. In contrast to BACs with mutations in the genes coding for gB, gH, gL, and gM, which did not yield infectious virus, BACs with disruptions of open reading frame UL4 (gp48) or UL74 (gO) were viable, although gO-deficient viruses showed a severe growth deficit. Thus, gO (UL74), a component of the glycoprotein complex III, is dispensable for viral growth. We conclude that our approach of PCR screening for Tn insertions will greatly facilitate the functional analysis of herpesvirus genomes. PMID:10933677

  19. Alterations in potential sites for glycosylation predominate during evolution of the simian immunodeficiency virus envelope gene in macaques.

    PubMed Central

    Overbaugh, J; Rudensey, L M

    1992-01-01

    Genetic diversity is a hallmark of the human immunodeficiency virus (HIV) genome, but the role of distinct HIV variants in the development of AIDS is unclear. Envelope (env) is the most highly variable gene in HIV as well as in other retroviruses. We have previously demonstrated that variation in simian immunodeficiency virus (SIV) env is primarily localized in two regions (V1 and V4) during progression to simian AIDS. To determine whether there is a common genotype that evolves as AIDS develops, a total of 160 SIV env genes isolated directly from the tissue DNAs of four macaques infected with cloned virus were compared. Common amino acid sequence changes were identified within V1, V4, and, in the late stages of disease, near V3. At several positions, the same amino acid change was seen frequently in the variant genomes from all four animals. As AIDS developed, the majority of viruses evolved an extended sequence in V1 that was rich in serine and threonine residues and shared similarity with proteins modified by O-linked glycosylation. Several of the predominant common sequence changes in V1 and V4 created new sites for N-linked glycosylation. Thus, common features of the SIV variants that evolve during progression to AIDS are motifs that potentially allow for structural and functional changes in the env protein as a result of carbohydrate addition. PMID:1527847

  20. Analysis of the envelope (E) protein gene of tick-borne encephalitis viruses isolated in South Korea.

    PubMed

    Yun, Seok-Min; Kim, Su-Yeon; Han, Myung Guk; Jeong, Young Eui; Yong, Tai-Soon; Lee, Chan-Hee; Ju, Young Ran

    2009-06-01

    We determined the nucleotide and deduced amino acid sequences of the complete envelope (E) protein gene of the five tick-borne encephalitis virus (TBEV) strains KrM 93, KrM 213, KrM 215, KrM 216, and KrM 219, isolated from wild rodents in South Korea. We analyzed genetic variability within the isolates and compared them with 13 other TBEV strains. The complete E protein genes were amplified by reverse transcription polymerase chain reaction (RT-PCR), cloned into pGEM-T vectors, and sequenced. The five isolates were similar to the Western subtype in nucleotide and deduced amino acid sequences (97%-99% identity) and by phylogenetic analysis. The deduced amino acid alignments had 13 unique amino acids, as in the Western subtypes. Among the signature amino acids, those at positions 206 and 317 were unique to each subtype. We were also able to identify amino acid substitutions in each of the three domains when comparing the 5 Korean isolates with the 13 other TBEV strains. Thus, we confirmed that the 5 Korean isolates belong to the Western subtype. These data will provide useful information for the development of an effective recombinant vaccine.

  1. Human coronavirus 229E encodes a single ORF4 protein between the spike and the envelope genes

    PubMed Central

    Dijkman, Ronald; Jebbink, Maarten F; Wilbrink, Berry; Pyrc, Krzysztof; Zaaijer, Hans L; Minor, Philip D; Franklin, Sally; Berkhout, Ben; Thiel, Volker; van der Hoek, Lia

    2006-01-01

    Background The genome of coronaviruses contains structural and non-structural genes, including several so-called accessory genes. All group 1b coronaviruses encode a single accessory protein between the spike and envelope genes, except for human coronavirus (HCoV) 229E. The prototype virus has a split gene, encoding the putative ORF4a and ORF4b proteins. To determine whether primary HCoV-229E isolates exhibit this unusual genome organization, we analyzed the ORF4a/b region of five current clinical isolates from The Netherlands and three early isolates collected at the Common Cold Unit (CCU) in Salisbury, UK. Results All Dutch isolates were identical in the ORF4a/b region at amino acid level. All CCU isolates are only 98% identical to the Dutch isolates at the nucleotide level, but more closely related to the prototype HCoV-229E (>98%). Remarkably, our analyses revealed that the laboratory adapted, prototype HCoV-229E has a 2-nucleotide deletion in the ORF4a/b region, whereas all clinical isolates carry a single ORF, 660 nt in size, encoding a single protein of 219 amino acids, which is a homologue of the ORF3 proteins encoded by HCoV-NL63 and PEDV. Conclusion Thus, the genome organization of the group 1b coronaviruses HCoV-NL63, PEDV and HCoV-229E is identical. It is possible that extensive culturing of the HCoV-229E laboratory strain resulted in truncation of ORF4. This may indicate that the protein is not essential in cell culture, but the highly conserved amino acid sequence of the ORF4 protein among clinical isolates suggests that the protein plays an important role in vivo. PMID:17194306

  2. Capture of syncytin-Mar1, a Fusogenic Endogenous Retroviral Envelope Gene Involved in Placentation in the Rodentia Squirrel-Related Clade

    PubMed Central

    Redelsperger, François; Cornelis, Guillaume; Vernochet, Cécile; Tennant, Bud C.; Catzeflis, François; Mulot, Baptiste; Heidmann, Odile; Dupressoir, Anne

    2014-01-01

    ABSTRACT Syncytin genes are fusogenic envelope protein (env) genes of retroviral origin that have been captured for a function in placentation. Within rodents, two such genes have previously been identified in the mouse-related clade, allowing a demonstration of their essential role via knockout mice. Here, we searched for similar genes in a second major clade of the Rodentia order, the squirrel-related clade, taking advantage of the complete sequencing of the ground squirrel Ictidomys tridecemlineatus genome. In silico search for env genes with full coding capacity identified several candidate genes with one displaying placenta-specific expression, as revealed by quantitative reverse transcription-PCR analysis of a large panel of tissues. This gene belongs to a degenerate endogenous retroviral element, with recognizable hallmarks of an integrated provirus. Cloning of the gene in an expression vector for ex vivo cell-cell fusion and pseudotype assays demonstrated fusogenicity on a large panel of mammalian cells. In situ hybridization on placenta sections showed specific expression in domains where trophoblast cells fuse into a syncytiotrophoblast at the fetomaternal interface, consistent with a role in syncytium formation. Finally, we show that the gene is conserved among the tribe Marmotini, thus dating its capture back to about at least 25 million years ago, with evidence for purifying selection and conservation of fusogenic activity. This gene that we named syncytin-Mar1 is distinct from all seven Syncytin genes identified to date in eutherian mammals and is likely to be a major effector of placentation in its related clade. IMPORTANCE Syncytin genes are fusogenic envelope genes of retroviral origin, ancestrally captured for a function in placentation. Within rodents, two such genes had been previously identified in the mouse-related clade. Here, in the squirrel-related rodent clade, we identified the envelope gene of an endogenous retrovirus with all the

  3. Capture of syncytin-Mar1, a fusogenic endogenous retroviral envelope gene involved in placentation in the Rodentia squirrel-related clade.

    PubMed

    Redelsperger, François; Cornelis, Guillaume; Vernochet, Cécile; Tennant, Bud C; Catzeflis, François; Mulot, Baptiste; Heidmann, Odile; Heidmann, Thierry; Dupressoir, Anne

    2014-07-01

    Syncytin genes are fusogenic envelope protein (env) genes of retroviral origin that have been captured for a function in placentation. Within rodents, two such genes have previously been identified in the mouse-related clade, allowing a demonstration of their essential role via knockout mice. Here, we searched for similar genes in a second major clade of the Rodentia order, the squirrel-related clade, taking advantage of the complete sequencing of the ground squirrel Ictidomys tridecemlineatus genome. In silico search for env genes with full coding capacity identified several candidate genes with one displaying placenta-specific expression, as revealed by quantitative reverse transcription-PCR analysis of a large panel of tissues. This gene belongs to a degenerate endogenous retroviral element, with recognizable hallmarks of an integrated provirus. Cloning of the gene in an expression vector for ex vivo cell-cell fusion and pseudotype assays demonstrated fusogenicity on a large panel of mammalian cells. In situ hybridization on placenta sections showed specific expression in domains where trophoblast cells fuse into a syncytiotrophoblast at the fetomaternal interface, consistent with a role in syncytium formation. Finally, we show that the gene is conserved among the tribe Marmotini, thus dating its capture back to about at least 25 million years ago, with evidence for purifying selection and conservation of fusogenic activity. This gene that we named syncytin-Mar1 is distinct from all seven Syncytin genes identified to date in eutherian mammals and is likely to be a major effector of placentation in its related clade. Importance: Syncytin genes are fusogenic envelope genes of retroviral origin, ancestrally captured for a function in placentation. Within rodents, two such genes had been previously identified in the mouse-related clade. Here, in the squirrel-related rodent clade, we identified the envelope gene of an endogenous retrovirus with all the features of a

  4. Molecular clock of HIV-1 envelope genes under early immune selection

    DOE PAGES

    Park, Sung Yong; Love, Tanzy M. T.; Perelson, Alan S.; ...

    2016-06-01

    Here, the molecular clock hypothesis that genes or proteins evolve at a constant rate is a key tool to reveal phylogenetic relationships among species. Using the molecular clock, we can trace an infection back to transmission using HIV-1 sequences from a single time point. Whether or not a strict molecular clock applies to HIV-1’s early evolution in the presence of immune selection has not yet been fully examined.

  5. Molecular clock of HIV-1 envelope genes under early immune selection

    SciTech Connect

    Park, Sung Yong; Love, Tanzy M. T.; Perelson, Alan S.; Mack, Wendy J.; Lee, Ha Youn

    2016-06-01

    Here, the molecular clock hypothesis that genes or proteins evolve at a constant rate is a key tool to reveal phylogenetic relationships among species. Using the molecular clock, we can trace an infection back to transmission using HIV-1 sequences from a single time point. Whether or not a strict molecular clock applies to HIV-1’s early evolution in the presence of immune selection has not yet been fully examined.

  6. [Phylogenetic analysis of envelope gene of dengue virus serotype 2 in Guangzhou, 2001-2015].

    PubMed

    Liu, Y; Jiang, L Y; Luo, L; Cao, Y M; Jing, Q L; Yang, Z C

    2017-01-10

    Objective: To investigate the molecular characteristics of dengue virus serotype 2 (DENV2) in Guangzhou during 2001-2015, and analyze the E gene of the strains isolated, the phylogenetic tree and molecular clock were constructed to know about the evolution of the strains. Methods: The serum samples of the patients were detected by real time PCR, and positive samples were used to isolate dengue virus by using C6/36 cells. The E gene of the isolated strains were sequenced. The phylogenetic tree was constructed by using software Mega 4.0, and the molecular clock was drawn by using software BEASTv1.8.2. Results: Twenty-six dengue virus strains were isolated between 2001 and 2015. They were all clustered into 2 genotypes, i.e. cosmopolitan genotype and Asian genotype Ⅰ. The strains isolated in Guangzhou shared high homology with Southeast Asian strains. The cosmopolitan genotype was divided into 2 sub-genotype at about 46 and 35 years ago. The substitution rate of dengue virus serotype 2 in Guangzhou was 7.1 × 10(-4) per year per site. Conclusions: There were close relationship between the Guangzhou strains and Southeast Asian strains. Guangzhou was at high risk of imported dengue fever, outbreak of dengue hemorrhagic fever and dengue shock syndrome. There might be two ways of introduction of cosmopolitan genotype. The substitution rate of the strains in Guangzhou was similar to that in the neighbor countries.

  7. Avian hemangioma retrovirus induces cell proliferation via the envelope (env) gene.

    PubMed

    Alian, A; Sela-Donenfeld, D; Panet, A; Eldor, A

    2000-10-10

    Several years ago, a field strain retrovirus, avian hemangioma virus (AHV), was isolated from hemangioma tumors in layer hens. Sequence analysis indicated that the AHV genome contains the three prototypic retroviral genes, gag, pol, and env, and is devoid of an oncogene. In cultured endothelial cells, however, AHV induced a significant cytopathic effect through a typical apoptotic cascade. We now demonstrate that AHV also induces cell proliferation and anchorage-independent growth of BSC-1 epithelial cells and NIH-3T3 fibroblasts. This was shown by measurements of (1) cell viability, (2) DNA synthesis, (3) flow cytometry analysis of the cell DNA content, and (4) clonogenic efficiency of the infected cells. Anchorage-independent cell growth was demonstrated by colony formation in soft agar. Moreover, the AHV env gene was cloned into a MuLV-based retroviral vector, and infection of NIH-3T3 cells with this vector induced cell proliferation as well as clonogenic growth. These results suggest that AHV, which is devoid of an oncogene, is a pleiotropic activator capable of inducing either apoptosis or cellular proliferation, depending on the infected cell type. Copyright 2000 Academic Press.

  8. Naturally enveloped AAV vectors for shielding neutralizing antibodies and robust gene delivery in vivo.

    PubMed

    György, Bence; Fitzpatrick, Zachary; Crommentuijn, Matheus H W; Mu, Dakai; Maguire, Casey A

    2014-08-01

    Recently adeno-associated virus (AAV) became the first clinically approved gene therapy product in the western world. To develop AAV for future clinical application in a widespread patient base, particularly in therapies which require intravenous (i.v.) administration of vector, the virus must be able to evade pre-existing antibodies to the wild type virus. Here we demonstrate that in mice, AAV vectors associated with extracellular vesicles (EVs) can evade human anti-AAV neutralizing antibodies. We observed different antibody evasion and gene transfer abilities with populations of EVs isolated by different centrifugal forces. EV-associated AAV vector (ev-AAV) was up to 136-fold more resistant over a range of neutralizing antibody concentrations relative to standard AAV vector in vitro. Importantly in mice, at a concentration of passively transferred human antibodies which decreased i.v. administered standard AAV transduction of brain by 80%, transduction of ev-AAV transduction was not reduced and was 4000-fold higher. Finally, we show that expressing a brain targeting peptide on the EV surface allowed significant enhancement of transduction compared to untargeted ev-AAV. Using ev-AAV represents an effective, clinically relevant approach to evade human neutralizing anti-AAV antibodies after systemic administration of vector.

  9. Genetic control of T cell responsiveness to the Friend murine leukemia virus envelope antigen. Identification of class II loci of the H-2 as immune response genes

    PubMed Central

    1988-01-01

    T cells primed specifically for the envelope glycoprotein of Friend murine leukemia helper virus (F-MuLV) were prepared by immunizing mice with a recombinant vaccinia virus that expressed the entire env gene of F-MuLV. Significant proliferative responses of F-MuLV envelope- specific, H-2a/b T cells were observed when the T cells were stimulated with antigen-pulsed peritoneal exudate cells (PEC) having the b allele at the K, A beta, A alpha, and E beta loci of the H-2. On the other hand, PEC having only the kappa allele at these loci did not induce the envelope-specific T cell proliferation, even when the PEC had the b allele at the E alpha, S, or D loci. F-MuLV envelope-specific proliferation of H-2a/b T cells under the stimulation of antigen- pulsed, H-2a/b PEC was specifically blocked with anti-I-Ab and anti-I- Ek mAbs but not with anti-Kb, anti-Kk, or anti-I-Ak mAbs. Moreover, (B10.MBR x A/WySn)F1 mice that have the b allele only at the K locus but not in I-A subregion were nonresponders to the envelope glycoprotein, and the bm12 mutation at the A beta locus completely abolished the T cell responsiveness to this antigen. These results indicate that proliferative T cells recognize a limited number of epitopes on F-MuLV envelope protein in the context of I-Ab, hybrid I- Ak/b, and/or hybrid I-Ek/b class II MHC molecules but fail to recognize the same envelope protein in the context of I-Ak or I-Ek molecules. This influence of the H-2I region on T cell recognition of the envelope glycoprotein appeared to control in vivo induction of protective immunity against Friend virus complex after immunization with the vaccinia-F-MuLV env vaccine. Thus, these results provide, for the first time, direct evidence for Ir gene-controlled responder/nonresponder phenotypes influencing the immune response to a pathogenic virus of mice. PMID:3141552

  10. Autographa californica multiple nucleopolyhedrovirus ac142, a core gene that is essential for BV production and ODV envelopment

    SciTech Connect

    McCarthy, Christina B.; Da, Xiaojiang; Donly, Cam; Theilmann, David A.

    2008-03-15

    Autographa californica multiple nucleopolyhedrovirus (AcMNPV) ac142 is a baculovirus core gene and encodes a protein previously shown to associate with occlusion-derived virus (ODV). To determine its role in the baculovirus life cycle, we used the AcMNPV bacmid system to generate an ac142 deletion virus (AcBAC{sup ac142KO-PH-GFP}). Fluorescence and light microscopy revealed that AcBAC{sup ac142KO-PH-GFP} exhibits a single-cell infection phenotype. Titration assays and Western blot confirmed that AcBAC{sup ac142KO-PH-GFP} is unable to produce budded virus (BV). However, viral DNA replication is unaffected and the development of occlusion bodies in AcBAC{sup ac142KO-PH-GFP}-transfected cells evidenced progression to very late phases of the viral infection. Western blot analysis showed that AC142 is expressed in the cytoplasm and nucleus throughout infection and that it is a structural component of BV and ODV which localizes to nucleocapsids. Electron microscopy indicates that ac142 is required for nucleocapsid envelopment to form ODV and their subsequent occlusion, a fundamental process to all baculoviruses.

  11. Deletion of the late cornified envelope (LCE) 3B and 3C genes as a susceptibility factor for psoriasis

    PubMed Central

    de Cid, Rafael; Riveira-Munoz, Eva; Zeeuwen, Patrick L.J.M.; Robarge, Jason; Liao, Wilson; Dannhauser, Emma N.; Giardina, Emiliano; Stuart, Philip E.; Nair, Rajan; Helms, Cynthia; Escaramís, Georgia; Ballana, Ester; Martín-Ezquerra, Gemma; den Heijer, Martin; Kamsteeg, Marijke; Joosten, Irma; Eichler, Evan E.; Lázaro, Conxi; Pujol, Ramón M.; Armengol, Lluís; Abecasis, Gonçalo; Elder, James T.; Novelli, Giuseppe; Armour, John A.L.; Kwok, Pui; Bowcock, Anne; Schalkwijk, Joost; Estivill, Xavier

    2011-01-01

    Psoriasis is a common inflammatory skin disease with a prevalence of 2% to 3% in Caucasians1. In a genome-wide search for copy number variants (CNV) using a sample pooling approach we have identified a deletion comprising LCE3B and LCE3C, members of the late cornified envelope (LCE) gene cluster2. The absence of LCE3B and LCE3C (LCE3C-LCE3B-del) is significantly associated (p=1.38E-08) with risk of psoriasis in 2,831 samples from Spain, The Netherlands, Italy and the USA, and in a family-based study (p=5.4E-04). LCE3C-LCE3B-del is tagged by rs4112788 (r2=0.93), which is also strongly associated with psoriasis (p<6.6E-09). LCE3C-LCE3B-del shows epistatic effects with the HLA-Cw6 allele on the development of psoriasis in Dutch samples, and multiplicative effects in the other samples. LCE expression can be induced in normal epidermis by skin barrier disruption and is strongly expressed in psoriatic lesions, suggesting that compromised skin barrier function plays a role in psoriasis susceptibility. PMID:19169253

  12. Autographa californica multiple nucleopolyhedrovirus ac142, a core gene that is essential for BV production and ODV envelopment.

    PubMed

    McCarthy, Christina B; Dai, Xiaojiang; Donly, Cam; Theilmann, David A

    2008-03-15

    Autographa californica multiple nucleopolyhedrovirus (AcMNPV) ac142 is a baculovirus core gene and encodes a protein previously shown to associate with occlusion-derived virus (ODV). To determine its role in the baculovirus life cycle, we used the AcMNPV bacmid system to generate an ac142 deletion virus (AcBAC(ac142KO-PH-GFP)). Fluorescence and light microscopy revealed that AcBAC(ac142KO-PH-GFP) exhibits a single-cell infection phenotype. Titration assays and Western blot confirmed that AcBAC(ac142KO-PH-GFP) is unable to produce budded virus (BV). However, viral DNA replication is unaffected and the development of occlusion bodies in AcBAC(ac142KO-PH-GFP)-transfected cells evidenced progression to very late phases of the viral infection. Western blot analysis showed that AC142 is expressed in the cytoplasm and nucleus throughout infection and that it is a structural component of BV and ODV which localizes to nucleocapsids. Electron microscopy indicates that ac142 is required for nucleocapsid envelopment to form ODV and their subsequent occlusion, a fundamental process to all baculoviruses.

  13. Deletion of the late cornified envelope LCE3B and LCE3C genes as a susceptibility factor for psoriasis.

    PubMed

    de Cid, Rafael; Riveira-Munoz, Eva; Zeeuwen, Patrick L J M; Robarge, Jason; Liao, Wilson; Dannhauser, Emma N; Giardina, Emiliano; Stuart, Philip E; Nair, Rajan; Helms, Cynthia; Escaramís, Georgia; Ballana, Ester; Martín-Ezquerra, Gemma; den Heijer, Martin; Kamsteeg, Marijke; Joosten, Irma; Eichler, Evan E; Lázaro, Conxi; Pujol, Ramón M; Armengol, Lluís; Abecasis, Gonçalo; Elder, James T; Novelli, Giuseppe; Armour, John A L; Kwok, Pui-Yan; Bowcock, Anne; Schalkwijk, Joost; Estivill, Xavier

    2009-02-01

    Psoriasis is a common inflammatory skin disease with a prevalence of 2-3% in individuals of European ancestry. In a genome-wide search for copy number variants (CNV) using a sample pooling approach, we have identified a deletion comprising LCE3B and LCE3C, members of the late cornified envelope (LCE) gene cluster. The absence of LCE3B and LCE3C (LCE3C_LCE3B-del) is significantly associated (P = 1.38E-08) with risk of psoriasis in 2,831 samples from Spain, The Netherlands, Italy and the United States, and in a family-based study (P = 5.4E-04). LCE3C_LCE3B-del is tagged by rs4112788 (r(2) = 0.93), which is also strongly associated with psoriasis (P < 6.6E-09). LCE3C_LCE3B-del shows epistatic effects with the HLA-Cw6 allele on the development of psoriasis in Dutch samples and multiplicative effects in the other samples. LCE expression can be induced in normal epidermis by skin barrier disruption and is strongly expressed in psoriatic lesions, suggesting that compromised skin barrier function has a role in psoriasis susceptibility.

  14. DNA Packaging Mutant: Repression of the Vaccinia Virus A32 Gene Results in Noninfectious, DNA-Deficient, Spherical, Enveloped Particles

    PubMed Central

    Cassetti, Maria Cristina; Merchlinsky, Michael; Wolffe, Elizabeth J.; Weisberg, Andrea S.; Moss, Bernard

    1998-01-01

    The vaccinia virus A32 open reading frame was predicted to encode a protein with a nucleoside triphosphate-binding motif and a mass of 34 kDa. To investigate the role of this protein, we constructed a mutant in which the original A32 gene was replaced by an inducible copy. The recombinant virus, vA32i, has a conditional lethal phenotype: infectious virus formation was dependent on isopropyl-β-d-thiogalactopyranoside (IPTG). Under nonpermissive conditions, the mutant synthesized early- and late-stage viral proteins, as well as viral DNA that was processed into unit-length genomes. Electron microscopy of cells infected in the absence of IPTG revealed normal-appearing crescents and immature virus particles but very few with nucleoids. Instead of brick-shaped mature particles with defined core structures, there were numerous electron-dense, spherical particles. Some of these spherical particles were wrapped with cisternal membranes, analogous to intracellular and extracellular enveloped virions. Mutant viral particles, purified by sucrose density gradient centrifugation, had low infectivity and transcriptional activity, and the majority were spherical and lacked DNA. Nevertheless, the particle preparation contained representative membrane proteins, cleaved and uncleaved core proteins, the viral RNA polymerase, the early transcription factor and several enzymes, suggesting that incorporation of these components is not strictly coupled to DNA packaging. PMID:9621036

  15. Pushing the endogenous envelope

    PubMed Central

    Henzy, Jamie E.; Johnson, Welkin E.

    2013-01-01

    The majority of retroviral envelope glycoproteins characterized to date are typical of type I viral fusion proteins, having a receptor binding subunit associated with a fusion subunit. The fusion subunits of lentiviruses and alpha-, beta-, delta- and gammaretroviruses have a very conserved domain organization and conserved features of secondary structure, making them suitable for phylogenetic analyses. Such analyses, along with sequence comparisons, reveal evidence of numerous recombination events in which retroviruses have acquired envelope glycoproteins from heterologous sequences. Thus, the envelope gene (env) can have a history separate from that of the polymerase gene (pol), which is the most commonly used gene in phylogenetic analyses of retroviruses. Focusing on the fusion subunits of the genera listed above, we describe three distinct types of retroviral envelope glycoproteins, which we refer to as gamma-type, avian gamma-type and beta-type. By tracing these types within the ‘fossil record’ provided by endogenous retroviruses, we show that they have surprisingly distinct evolutionary histories and dynamics, with important implications for cross-species transmissions and the generation of novel lineages. These findings validate the utility of env sequences in contributing phylogenetic signal that enlarges our understanding of retrovirus evolution. PMID:23938755

  16. cut11+: A Gene Required for Cell Cycle-dependent Spindle Pole Body Anchoring in the Nuclear Envelope and Bipolar Spindle Formation in Schizosaccharomyces pombe

    PubMed Central

    West, Robert R.; Vaisberg, Elena V.; Ding, Rubai; Nurse, Paul; McIntosh, J. Richard

    1998-01-01

    The “cut” mutants of Schizosaccharomyces pombe are defective in spindle formation and/or chromosome segregation, but they proceed through the cell cycle, resulting in lethality. Analysis of temperature-sensitive alleles of cut11+ suggests that this gene is required for the formation of a functional bipolar spindle. Defective spindle structure was revealed with fluorescent probes for tubulin and DNA. Three-dimensional reconstruction of mutant spindles by serial sectioning and electron microscopy showed that the spindle pole bodies (SPBs) either failed to complete normal duplication or were free floating in the nucleoplasm. Localization of Cut11p tagged with the green fluorescent protein showed punctate nuclear envelope staining throughout the cell cycle and SPBs staining from early prophase to mid anaphase. This SPB localization correlates with the time in the cell cycle when SPBs are inserted into the nuclear envelope. Immunoelectron microscopy confirmed the localization of Cut11p to mitotic SPBs and nuclear pore complexes. Cloning and sequencing showed that cut11+ encodes a novel protein with seven putative membrane-spanning domains and homology to the Saccharomyces cerevisiae gene NDC1. These data suggest that Cut11p associates with nuclear pore complexes and mitotic SPBs as an anchor in the nuclear envelope; this role is essential for mitosis. PMID:9763447

  17. Enhancement of neutralizing humoral response of DNA vaccine against duck hepatitis B virus envelope protein by co-delivery of cytokine genes.

    PubMed

    Saade, Fadi; Buronfosse, Thierry; Pradat, Pierre; Abdul, Fabien; Cova, Lucyna

    2008-09-19

    We explored in the duck hepatitis B virus (DHBV) model the impact of duck interferon gamma (Du-IFNgamma) or interleukin 2 (Du-IL2) co-delivery on humoral neutralizing response induced by DNA-based vaccine encoding DHBV preS/S large envelope protein. Co-delivery of either Du-IL2 or Du-IFNgamma encoding plasmids considerably increased the magnitude of anti-preS humoral response. Moreover, co-administration of cytokine genes led to a significant (p<0.001) enhancement of neutralizing anti-DHBV antibody response, which was more pronounced for Du-IFNgamma. Our data suggest that co-delivery of cytokine and envelope protein encoding plasmids will be a valuable approach for the development of a potent therapeutic DNA vaccine against chronic hepatitis B.

  18. Syncytin-A and syncytin-B, two fusogenic placenta-specific murine envelope genes of retroviral origin conserved in Muridae

    PubMed Central

    Dupressoir, Anne; Marceau, Geoffroy; Vernochet, Cécile; Bénit, Laurence; Kanellopoulos, Colette; Sapin, Vincent; Heidmann, Thierry

    2005-01-01

    Recently, we and others have identified two human endogenous retroviruses that entered the primate lineage 25–40 million years ago and that encode highly fusogenic retroviral envelope proteins (syncytin-1 and -2), possibly involved in the formation of the placenta syncytiotrophoblast layer generated by trophoblast cell fusion at the materno–fetal interface. A systematic in silico search throughout mouse genome databases presently identifies two fully coding envelope genes, present as unique copies and unrelated to any known murine endogenous retrovirus, that we named syncytin-A and -B. Quantitative RT-PCR demonstrates placenta-specific expression for both genes, with increasing transcript levels in this organ from 9.5 to 14.5 days postcoitum. In situ hybridization of placenta cryosections further localizes these transcripts in the syncytiotrophoblast-containing labyrinthine zona. Consistently, we show that both genes can trigger cell–cell fusion in ex vivo transfection assays, with distinct cell type specificities suggesting different receptor usage. Genes orthologous to syncytin-A and -B and disclosing a striking conservation of their coding status are found in all Muridae tested (mouse, rat, gerbil, vole, and hamster), dating their entry into the rodent lineage ≈20 million years ago. Together, these data strongly argue for a critical role of syncytin-A and -B in murine syncytiotrophoblast formation, thus unraveling a rather unique situation where two pairs of endogenous retroviruses, independently acquired by the primate and rodent lineages, would have been positively selected for a convergent physiological role. PMID:15644441

  19. Studies on the role of neutralizing antibodies against envelope genes in resolving HCV pseudo-particles infection.

    PubMed

    Rafique, Shazia; Idrees, Muhammad; Ali, Amjad; Iqbal, Muhammad

    2014-06-01

    Characterization of antibodies targeting the attachment and entry of the viral particles into host cells is important for studding antibody mediated neutralization. Antibodies against the envelope glycoproteins (EGP) have neutralizing capacity and can prevent HCV infections. System based on HCV pseudo typed-particles (HCVpp) stably expressing EGP can be used for screening of HCV anti envelope neutralizing antibodies in the serum of patients with acute and chronic HCV infections. The aim of the current study was to check HCVpp as a useful tool for the detection of anti-HCV envelope antibodies in the serum of HCV infected patients and to test the binding potential of these antiviral molecules to EGP of HCV 3a. Previously developed HCVpp harboring unmodified glycoproteins from local isolates in 293T cell line were used in this study. HCVpp were pre incubated with different concentrations of anti E1 antibody and different E2 antibodies to check antiviral activity. Further we used serum samples with low/medium (≤800,000 IU/mL), and high (>800,000 IU/mL) viral titer from chronic HCV male and female patients. Infection was done in Huh-7 cells for 1 h at 37 oC. Infectivity was checked through Luciferase assay. Considerable decrease in HCVpp infectivity with anti-envelope antibodies was observed in dose dependent manner. Maximum inhibition was seen when 5 µg/ml of monoclonal anti E1 antibody used. Further increase in concentration exhibited no decrease in infectivity which suggests that other factors are also involved in causing infection. Various well characterized E2-specific monoclonal antibodies (mAbs) have been screened for their capability to reduce infection in Huh-7 cells. Three of the four mAbs specific for the E2 had no effect on the infectivity of HCVpp. Confirmation sensitive antibody H53 showed maximum inhibition of infectivity. HCV ELISA positive samples from both male and female patients were used to neutralize the HCVpp. The neutralizing antibody response

  20. SAFEGUARDS ENVELOPE

    SciTech Connect

    Duc Cao; Richard Metcalf

    2010-07-01

    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 advanced statistical techniques that will be applied to real plant process monitoring (PM) data from the Idaho Chemical Processing Plant (ICPP). In a simulation based on this data, multi-tank and multi-attribute correlations were tested against synthetic diversion scenarios. Kernel regression smoothing was used to fit a curve to the historical data, and multivariable, residual analysis and cumulative sum techniques set parameters for operating conditions. Diversion scenarios were created and tested, showing improved results when compared with a previous study utilizing only one-variable Z-testing. A brief analysis of the impact of the safeguards optimization on the rest of plant efficiency, criticality concerns, and overall requirements is presented.

  1. Identification and characterization of a prawn white spot syndrome virus gene that encodes an envelope protein VP31

    SciTech Connect

    Li Li; Xie Xixian; Yang Feng . E-mail: mbiotech@public.xm.fj.cn

    2005-09-15

    Based on a combination of SDS-PAGE and mass spectrometry, a protein with an apparent molecular mass of 31 kDa (termed as VP31) was identified from purified shrimp white spot syndrome virus (WSSV) envelope fraction. The resulting amino acid (aa) sequence matched an open reading frame (WSV340) of the WSSV genome. This ORF contained 783 nucleotides (nt), encoding 261 aa. A fragment of WSV340 was expressed in Escherichia coli as a glutathione S-transferase (GST) fusion protein with a 6His-tag, and then specific antibody was raised. Western blot analysis and the immunoelectron microscope method (IEM) confirmed that VP31 was present exclusively in the viral envelope fraction. The neutralization experiment suggested that VP31 might play an important role in WSSV infectivity.

  2. Identification of genes in the σ²² regulon of Pseudomonas aeruginosa required for cell envelope homeostasis in either the planktonic or the sessile mode of growth.

    PubMed

    Wood, Lynn F; Ohman, Dennis E

    2012-01-01

    The Pseudomonas aeruginosa extracytoplasmic functioning (ECF) sigma factor σ(22) is encoded by algT/algU and is inhibited by anti-sigma factor MucA. σ(22) was originally discovered for its essential role in the expression of the exopolysaccharide alginate by mucoid strains associated with chronic pulmonary infection. However, σ(22) is now known to also have a large regulon associated with the response to cell wall stress. Our recent transcriptome analysis identified 293 open reading frames (ORFs) in the σ(22) stress stimulon that include genes for outer envelope biogenesis and remodeling, although most of the genes have undefined functions. To better understand the σ(22)-dependent stress response, mutants affected in 27 genes of the σ(22) stimulon were examined and expression was studied with lacZ fusions. Mutants constructed in the 27 genes showed no major change in response to cell wall-acting antibiotics or growth at elevated temperatures nor in alginate production. The mutants were examined for their effects on the expression of the σ(22)-dependent promoter of the alginate biosynthetic operon (PalgD) as a measure of σ(22) derepression from MucA. By testing PalgD expression under both planktonic and sessile growth conditions, 11 genes were found to play a role in the stress response that activates σ(22). Some mutations caused an increase or a decrease in the response to cell wall stress. Interestingly, mutations in 7 of the 11 genes caused constitutive PalgD expression under nonstressed conditions and thus showed that these genes are involved in maintaining envelope homeostasis. Mutations in PA0062 and PA1324 showed constitutive PalgD expression during both the planktonic and the sessile modes of growth. However, the PA5178 mutation caused constitutive PalgD expression only during planktonic growth. In contrast, mutations in PA2717, PA0567, PA3040, and PA0920 caused constitutive PalgD expression only in the sessile/biofilm mode of growth. This provides

  3. Highly efficient and minimally invasive in-vivo gene transfer to the mouse uterus using haemagglutinating virus of Japan (HVJ) envelope vector.

    PubMed

    Nakamura, Hitomi; Kimura, Tadashi; Ikegami, Hiroyuki; Ogita, Kazuhide; Koyama, Shinsuke; Shimoya, Koichiro; Tsujie, Tomoko; Koyama, Masayasu; Kaneda, Yasufumi; Murata, Yuji

    2003-10-01

    The uterus is obviously critical in implantation, development of the fetus and parturition. Endometrial cancer derived from endometrial epithelium is one of the common malignancies in the female reproductive tract. In order to clarify the local mechanisms of reproductive physiology and establish a non-systemic therapeutic strategy for reproductive failure as well as for endometrial cancer, we applied haemagglutinating virus of Japan envelope (HVJ-E) vector to in-vivo gene transfer into the uterine cavity of IVCS mice. Injection of HVJ-E vector into mouse uterine cavity on day 1.5 post coitum (p.c.) introduced a reporter gene approximately 120-fold more efficiently than introduction using the cationic liposome method. The expression of the introduced gene continued for at least 3 days. The plasmid vector was localized in the endometrial epithelium, whereas oligo deoxynucleotides were distributed throughout the epithelium, stromal cells and myometrium. HVJ-E vector did not affect the pregnancy rate, course of pregnancy, litter size, fetal growth in utero or parturition, and did not transfect the exogenous gene to the fetus. These results indicate that gene transfer into the uterus using HVJ-E vector is highly efficient and safe during pregnancy, and results in a well controlled distribution of the exogenous DNA. We believe that this procedure should be widely applicable for investigations of reproductive physiology as well as for methods of local gene therapy in the uterus.

  4. Genome-Wide Screening of Retroviral Envelope Genes in the Nine-Banded Armadillo (Dasypus novemcinctus, Xenarthra) Reveals an Unfixed Chimeric Endogenous Betaretrovirus Using the ASCT2 Receptor

    PubMed Central

    Malicorne, Sébastien; Vernochet, Cécile; Cornelis, Guillaume; Mulot, Baptiste; Delsuc, Frédéric; Heidmann, Odile

    2016-01-01

    ABSTRACT Retroviruses enter host cells through the interaction of their envelope (Env) protein with a cell surface receptor, which triggers the fusion of viral and cellular membranes. The sodium-dependent neutral amino acid transporter ASCT2 is the common receptor of the large RD114 retrovirus interference group, whose members display frequent env recombination events. Germ line retrovirus infections have led to numerous inherited endogenous retroviruses (ERVs) in vertebrate genomes, which provide useful insights into the coevolutionary history of retroviruses and their hosts. Rare ERV-derived genes display conserved viral functions, as illustrated by the fusogenic syncytin env genes involved in placentation. Here, we searched for functional env genes in the nine-banded armadillo (Dasypus novemcinctus) genome and identified dasy-env1.1, which clusters with RD114 interference group env genes and with two syncytin genes sharing ASCT2 receptor usage. Using ex vivo pseudotyping and cell-cell fusion assays, we demonstrated that the Dasy-Env1.1 protein is fusogenic and can use both human and armadillo ASCT2s as receptors. This gammaretroviral env gene belongs to a provirus with betaretrovirus-like features, suggesting acquisition through recombination. Provirus insertion was found in several Dasypus species, where it has not reached fixation, whereas related family members integrated before diversification of the genus Dasypus >12 million years ago (Mya). This newly described ERV lineage is potentially useful as a population genetic marker. Our results extend the usage of ASCT2 as a retrovirus receptor to the mammalian clade Xenarthra and suggest that the acquisition of an ASCT2-interacting env gene is a major selective force driving the emergence of numerous chimeric viruses in vertebrates. IMPORTANCE Retroviral infection is initiated by the binding of the viral envelope glycoprotein to a host cell receptor(s), triggering membrane fusion. Ancient germ line infections

  5. Feasibility of establishing deletion of the late cornified envelope genes LCE3B and LCE3C as a susceptibility factor for psoriasis

    PubMed Central

    Bashir, Safia; Hassan, Iffat; Majid, Sabhiya; Bhat, Yasmeen Jabeen; Farooq, Rabia

    2016-01-01

    Background: Psoriasis is a chronic hyperproliferative inflammatory disease of the skin, genetic predisposition to which is well-established. The late cornified envelope genes LCE3B and LCE3C are involved in maintaining the integrity of skin barrier especially following skin barrier disruption. The deletion of these genes would lead to an impaired epidermal response following damage to the skin barrier thus predisposing to psoriatic lesions. This study aimed to evaluate the common deletion of late cornified envelope genes (LCE 3B/3C) in psoriasis patients of Kashmiri ethnic population of North India. Materials and Methods: It was a hospital-based, case-control study which included 100 psoriasis cases and an equal number of controls. Blood samples were obtained, and DNA was extracted from all the samples by a kit-based method. To determine the LCE3C_LCE3B-del genotype, a three-primer polymerase chain reaction assay was performed. Results: The genotype for the common LCE3C_LCE3B deletion in 100 psoriasis patients and 100 controls was determined. Among the cases, 17 cases were homozygous for insertion genotype (I/I), 40 cases were heterozygous for insertion/deletion genotype (I/D) and 43 cases were homozygous for deletion genotype (D/D), compared to controls where 20 cases were homozygous for insertion genotype (I/I), 45 cases were heterozygous for insertion/deletion genotype (I/D), and 35 cases were homozygous for deletion genotype (D/D). The del/del frequency was higher among psoriatic patients compared to controls (43% vs. 35%) although the difference was not statistically significant (P = 0.507). Conclusion: We hereby infer that LCE3C_LCE3B deletion does not appear to be associated with the risk of psoriasis in our population. PMID:27376048

  6. Transcriptional regulation at the yeast nuclear envelope

    PubMed Central

    Steglich, Babett; Sazer, Shelley; Ekwall, Karl

    2013-01-01

    The spatial organization of the genome inside the nucleus affects many nuclear processes, such as DNA replication, DNA repair, and gene transcription. In metazoans, the nuclear periphery harbors mainly repressed genes that associate with the nuclear lamina. This review discusses how peripheral positioning is connected to transcriptional regulation in yeasts. Tethering of reporter genes to the nuclear envelope was found to result in transcriptional silencing. Similarly, repression of the silent mating type loci and subtelomeric genes is influenced by their position close to the nuclear envelope. In contrast, active genes are bound by nucleoporins and inducible genes associate with the nuclear pore complex upon activation. Taken together, these results portray the nuclear envelope as a platform for transcriptional regulation, both through activation at nuclear pores and silencing at the nuclear envelope. PMID:24021962

  7. Elevated temperature envelope forming

    NASA Technical Reports Server (NTRS)

    Burg, Bruce M. (Inventor); Gane, David H. (Inventor); Starowski, Robert M. (Inventor)

    1992-01-01

    Elevated temperature envelope forming includes enclosing a part blank and form tool within an envelope sealed against the atmosphere, heat treating the combination while forming pressure holds the envelope and part against the form tool, and allowing part cool down to occur in an inert atmosphere with forming pressure removed. The forming pressure is provided by evacuating the envelope and may be aided by differential force applied between the envelope and the form tool.

  8. Expression profile of key immune-related genes in Penaeus monodon juveniles after oral administration of recombinant envelope protein VP28 of white spot syndrome virus.

    PubMed

    Thomas, Ancy; Sudheer, Naduvilamuriparampu Saidumuhammed; Kiron, Viswanath; Bright Singh, Issac S; Narayanan, Rangarajan Badri

    2016-07-01

    White spot syndrome virus (WSSV) is the most catastrophic pathogen the shrimp industry has ever encountered. VP28, the abundant envelope protein of WSSV was expressed in bacteria, the purified protein administered orally to Penaeus monodon juveniles and its immune modulatory effects examined. The results indicated significant up-regulation of caspase, penaeidin, crustin, astakine, syntenin, PmRACK, Rab7, STAT and C-type lectin in animals orally administered with this antigen. This revealed the immune modulations in shrimps followed by oral administration of rVP28P which resulted in the reduced transcription of viral gene vp28 and delay in mortality after WSSV challenge. The study suggests the potential of rVP28P to elicit a non-specific immune stimulation in shrimps.

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

    PubMed

    Børsting, M W; Qvist, K B; Brockmann, E; Vindeløv, J; Pedersen, T L; Vogensen, F K; Ardö, Y

    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. lactis strains were grouped according to their CEP AA sequences and according to identified peptides after hydrolysis of milk. Finally, AA positions in the substrate binding region were suggested by the use of a new CEP template based on Streptococcus C5a CEP. Aligning the CEP AA sequences of 38 strains of Lc. lactis showed that 21 strains, which were previously classified as group d, could be subdivided into 3 groups. Independently, similar subgroupings were found based on comparison of the Lc. lactis CEP AA sequences and based on normalized quantity of identified peptides released from αS1-casein and β-casein. A model structure of Lc. lactis CEP based on the crystal structure of Streptococcus C5a CEP was used to investigate the AA positions in the substrate-binding region. New AA positions were suggested, which could be relevant for the cleavage specificity of CEP; however, these could only explain 2 out of 3 found subgroups. The third subgroup could be explained by 1 to 5 AA positions located opposite the substrate binding region. Copyright © 2015 American Dairy Science Association. Published by Elsevier Inc. All rights reserved.

  10. Computer-aided codon-pairs deoptimization of the major envelope GP5 gene attenuates porcine reproductive and respiratory syndrome virus.

    PubMed

    Ni, Yan-Yan; Zhao, Zhao; Opriessnig, Tanja; Subramaniam, Sakthivel; Zhou, Lei; Cao, Dianjun; Cao, Qian; Yang, Hanchun; Meng, Xiang-Jin

    2014-02-01

    Synthetic attenuated virus engineering (SAVE) is an emerging technology that enables rapid attenuation of viruses. In this study, by using SAVE we demonstrated rapid attenuation of an arterivirus, porcine reproductive and respiratory syndrome virus (PRRSV). The major envelope GP5 gene of PRRSV was codon-pair deoptimized aided by a computer algorithm. The codon-pair deoptimized virus, designated as SAVE5 with a deoptimized GP5 gene, was successfully rescued in vitro. The SAVE5 virus replicated at a lower level in vitro with a significant decrease of GP5 protein expression compared to the wild-type PRRSV VR2385 virus. Pigs experimentally infected with the SAVE5 virus had significantly lower viremia level up to 14 days post-infection as well as significantly reduced gross and histological lung lesions when compared to wild-type PRRSV VR2385 virus-infected pigs, indicating the attenuation of the SAVE5 virus. This study proved the feasibility of rapidly attenuating PRRSV by SAVE.

  11. Transcriptional and functional studies of Human Endogenous Retrovirus envelope EnvP(b) and EnvV genes in human trophoblasts

    SciTech Connect

    Vargas, Amandine Thiery, Maxime Lafond, Julie Barbeau, Benoit

    2012-03-30

    HERV (Human Endogenous Retrovirus)-encoded envelope proteins are implicated in the development of the placenta. Indeed, Syncytin-1 and -2 play a crucial role in the fusion of human trophoblasts, a key step in placentation. Other studies have identified two other HERV env proteins, namely EnvP(b) and EnvV, both expressed in the placenta. In this study, we have fully characterized both env transcripts and their expression pattern and have assessed their implication in trophoblast fusion. Through RACE analyses, standard spliced transcripts were detected, while EnvV transcripts demonstrated alternative splicing at its 3 Prime end. Promoter activity and expression of both genes were induced in forskolin-stimulated BeWo cells and in primary trophoblasts. Although we have confirmed the fusogenic activity of EnvP(b), overexpression or silencing experiments revealed no impact of this protein on trophoblast fusion. Our results demonstrate that both env genes are expressed in human trophoblasts but are not required for syncytialization.

  12. Comparison on virulence and immunogenicity of two recombinant vaccinia vaccines, Tian Tan and Guang9 strains, expressing the HIV-1 envelope gene.

    PubMed

    Zhu, Rong; Huang, Weijin; Wang, Wenbo; Liu, Qiang; Nie, Jianhui; Meng, Shufang; Yu, Yongxin; Wang, Youchun

    2012-01-01

    The vaccinia virus Guang9 strain (VG9), derived from the vaccinia virus Tian Tan strain (VTT) has been found to be less virulent than VTT. To investigate whether VG9 could be a potential replicating virus vector, the TK genes in VG9 and VTT were replaced with the HIV-1 envelope gene via homologous recombination, resulting in the recombinant viruses, VG9-E and VTT-E. The biology, virulence, humoral and cellular immunological responses of VG9-E and VTT-E were evaluated. Our results indicated no obvious difference in range of host cells and diffusion between two recombinant viruses. Neurovirulence for VG9-E in weanling and suckling mice, and skin virulence in rabbits, were lower than that of VTT-E. The humoral immune responses, including binding antibody and neutralizing antibody responses, induced by VG9-E were not significantly different from those for VTT-E whilst IFN-γ response which represented cellular immune response induced by VG9-E was significantly higher than that did by VTT-E. Our results indicated that VG9-E was less virulent, yet induced higher cellular immune response than VTT-E. Therefore, it could be an ideal replicating vaccinia vector for HIV vaccine research and development.

  13. Comparison on Virulence and Immunogenicity of Two Recombinant Vaccinia Vaccines, Tian Tan and Guang9 Strains, Expressing the HIV-1 Envelope Gene

    PubMed Central

    Zhu, Rong; Huang, Weijin; Wang, Wenbo; Liu, Qiang; Nie, Jianhui; Meng, Shufang; Yu, Yongxin; Wang, Youchun

    2012-01-01

    Background The vaccinia virus Guang9 strain (VG9), derived from the vaccinia virus Tian Tan strain (VTT) has been found to be less virulent than VTT. Methodology/Principal Findings To investigate whether VG9 could be a potential replicating virus vector, the TK genes in VG9 and VTT were replaced with the HIV-1 envelope gene via homologous recombination, resulting in the recombinant viruses, VG9-E and VTT-E. The biology, virulence, humoral and cellular immunological responses of VG9-E and VTT-E were evaluated. Our results indicated no obvious difference in range of host cells and diffusion between two recombinant viruses. Neurovirulence for VG9-E in weanling and suckling mice, and skin virulence in rabbits, were lower than that of VTT-E. The humoral immune responses, including binding antibody and neutralizing antibody responses, induced by VG9-E were not significantly different from those for VTT-E whilst IFN-γ response which represented cellular immune response induced by VG9-E was significantly higher than that did by VTT-E. Conclusions/Significance Our results indicated that VG9-E was less virulent, yet induced higher cellular immune response than VTT-E. Therefore, it could be an ideal replicating vaccinia vector for HIV vaccine research and development. PMID:23139778

  14. Mutations in variable domains of the HIV-1 envelope gene can have a significant impact on maraviroc and vicriviroc resistance

    PubMed Central

    2013-01-01

    Background Resistance to CCR5 inhibitors, such as maraviroc and vicriviroc is characterized by reduction of maximal percent inhibition which indicates the use of an inhibitor-bound conformation of CCR5 for human immunodeficiency virus-1(HIV-1) entry. It is accompanied by substitutions in gp120 and gp41. Variable domain 3 (V3) plays the most important role, but substitutions outside V3 could also be involved in phenotype resistance. In this work, we investigated how mutations in variable regions of the viral envelope protein gp120 can contribute to CCR5 inhibitor resistance. Methods Resistant isolates were selected by passaging CC1/85 and BaL viruses with sub-inhibitory MVC and VCV concentrations. Mutations in gp160 were identified and mutants containing V2 (V169M), V3 (L317W) and V4 (I408T) were constructed. Results MVC and VCV susceptibility and viral tropism were assessed by single cycle assay. Mutant I408T showed 4-fold change (FC) increase in the half maximal inhibitory concentration (IC50) to MVC, followed by L317W (1.52-FC), V169M (1.23-FC), V169M/I408T (4-FC) L317W/I408T (3-FC), V169M/L317W (1.30-FC), and V169M/L317W/I408T (3.31-FC). MPI reduction was observed for mutants I408T (85%), L317W (95%), V169M/I408T (84%), L317W/I408T (85%) and V169M/L317W/I408T (83%). For VCV, I408T increased the IC50 by 2-FC and few mutants showed MPI reduction less than 95%: I408T (94%), L317W/I408T (94%) and V169M/L317W/I408T (94%). All mutants remained R5-tropic and presented decreased infectivity. Conclusions These results suggest that mutations in the V4 loop of HIV-1 may contribute to MVC and VCV resistance alone or combined with mutations in V2 and V3 loops. PMID:23758814

  15. [Characterization of Serial Passage of 1b/2a Chimera Hepatitis C Virus Cell Culture System Carrying Envelope E1E2 Coding Gene from Hebei Strain of China].

    PubMed

    Lu, Sha; Zhang, Ling; Tao, Gesi; Cai, Min; Bao Lili; LI, Lian; Deng, Yao; Shen, Xiaoling; Tan, Wenjie

    2015-11-01

    To character a novel chimera(1b/2a) hepatitis C virus cell culture (HCVcc) system carrying envelope E1E2 coding gene from Hebei strain of China, chimera HCVcc (cHCVcc) was developed from Huh7.5-CD81 cells after transfection with in vitro transcribed full-length 1b/2a chimera RNA, which carrying envelope E1E2 coding gene from Hebei strain of China. Then the replication, expression and infectious titer of serial passage HCVcc were assessed by Real Time RT-PCR, indirect immunofluorescence assay (IFA) and Western blotting (WB). In addition, chimeric envelope gene from HCVcc was sequenced after serial passage. We found that the number of HCV positive focus increased gradually in cell post-transfection with chimera HCVcc (1b/2a) RNA and reach a peak platform (80% to 90%) at 41 days post-transfection; the expression of HCV protein was also confirmed by WAB during serial passage. At meantime, HCV RNA copy number in the supernatant peaked at 10(4)-10(7) copies/mL and the highest infectious titer of this 1b/2a cHCVcc reinfection were tested as 10(4) ffu/mL. Sequence analysis indicated 6 of adaptive amino acid substitutes occur among chimeric envelope E1E2 during serial passages. We con:luded that a novel 1b/2a chimera HCVcc carrying envelope E1E2 coding gene from Hebei strain of China was developed and its infectious titer increased after serial passage of HCVcc. This novel cHCVcc will be an effective tool for further evaluation of anti-virus drugs and immune effects against the major genotype from Chinese.

  16. Nucleotide Sequence of the Envelope Gene of Gardner-Arnstein Feline Leukemia Virus B Reveals Unique Sequence Homologies with a Murine Mink Cell Focus-Forming Virus †

    PubMed Central

    Elder, John H.; Mullins, James I.

    1983-01-01

    The nucleotide sequence of the envelope gene and the adjacent 3′ long terminal repeat (LTR) of Gardner-Arnstein feline leukemia virus of subgroup B (GA-FeLV-B) has been determined. Comparison of the derived amino acid sequence of the gp70-p15E polyprotein to those of several previously reported murine retroviruses revealed striking homologies between GA-FeLV-B gp70 and the gp70 of a Moloney virus-derived mink cell focus-forming virus. These homologies were located within the substituted (presumably xenotropic) portion of the mink cell focus-forming virus envelope gene and comprised amino acid sequences not present in three ecotropic virus gp70s. In addition, areas of insertions and deletions, in general, were the same between GA-FeLV-B and Moloney mink cell focus-forming virus, although the sizes of the insertions and deletions differed. Homologies between GA-FeLV-B and mink cell focus-forming virus gp70s is functionally significant in that they both possess expanded host ranges, a property dictated by gp70. The amino acid sequence of FeLV-B contains 12 Asn-X-Ser/Thr sequences, indicating 12 possible sites of N-linked glycosylation as compared with 7 or 8 for its murine counterparts. Comparison of the 3′ LTR of GA-FeLV-B to AKR and Moloney virus LTRs revealed extensive conservation in several regions including the “CCAAT” and Goldberg-Hogness (TATA) boxes thought to be involved in promotion of transcription and in the repeat region of the LTR. The inverted repeats that flanked the LTR of GA-FeLV-B were identical to the murine inverted repeats, but were one base longer than the latter. The region of U3 corresponding to the approximately 75-nucleotide “enhancer sequence” is present in GA-FeLV-B, but contains deletions relative to AKR and Moloney virus and is not repeated. An interesting pallindrome in the repeat region immediately 3′ to the U3 region was noted in all the LTRs, but was particularly pronounced in GA-FeLV-B. Possible roles for this

  17. Significant inhibition of Tembusu virus envelope and NS5 gene using an adenovirus-mediated short hairpin RNA delivery system.

    PubMed

    Wang, Hongzhi; Feng, Qiang; Wei, Lei; Zhuo, Liling; Chen, Hao; Diao, Youxiang; Tang, Yi

    2017-10-01

    Tembusu virus (TMUV) is a mosquito-borne flavivirus, which was first isolated in the tropics during the 1970s. Recently, a disease characterized by ovarian haemorrhage and neurological symptoms was observed in ducks in China, which threatens poultry production. However, there is no suitable vaccination strategy or effective antiviral drugs to combat TMUV infections. Consequently, there is an urgent need to develop a new anti-TMUV therapy. In this study, we report an efficient short hairpin RNA (shRNA) delivery strategy for the inhibition of TMUV production using an adenovirus vector system. Using specifically designed shRNAs based on the E and NS5 protein genes of TMUV, the vector-expressed viral genes, TMUV RNA replication and infectious virus production were downregulated at different levels in Vero cells, where the shRNA (NS52) was highly effective in inhibiting TMUV. Using the human adenovirus type 5 shRNA delivery system, the recombinant adenovirus (rAd-NS52) inhibited TMUV multiplication with high efficiency. Furthermore, the significant dose-dependent inhibition of viral RNA copies induced by rAd-NS52 was found in TMUV-infected cells, which could last for at least 96h post infection. Our results indicated that the adenovirus-mediated delivery of shRNAs could play an active role in future TMUV antiviral therapeutics. Copyright © 2017 Elsevier B.V. All rights reserved.

  18. 187-gene phylogeny of protozoan phylum Amoebozoa reveals a new class (Cutosea) of deep-branching, ultrastructurally unique, enveloped marine Lobosa and clarifies amoeba evolution.

    PubMed

    Cavalier-Smith, Thomas; Chao, Ema E; Lewis, Rhodri

    2016-06-01

    Monophyly of protozoan phylum Amoebozoa, and subdivision into subphyla Conosa and Lobosa each with different cytoskeletons, are well established. However early diversification of non-ciliate lobose amoebae (Lobosa) is poorly understood. To clarify it we used recently available transcriptomes to construct a 187-gene amoebozoan tree for 30 species, the most comprehensive yet. This robustly places new genus Atrichosa (formerly lumped with Trichosphaerium) within lobosan class Tubulinea, not Discosea as previously supposed. We identified an earliest diverging lobosan clade comprising marine amoebae armoured by porose scaliform cell-envelopes, here made a novel class Cutosea with two pseudopodially distinct new families. Cutosea comprise Sapocribrum, ATCC PRA-29 misidentified as 'Pessonella', plus from other evidence Squamamoeba. We confirm that Acanthamoeba and ATCC 50982 misidentified as Stereomyxa ramosa are closely related. Discosea have a strongly supported major subclade comprising Thecamoebida plus Glycostylida (suborders Dactylopodina, Stygamoebina; Vannellina) phylogenetically distinct from Centramoebida. Stygamoeba is sister to Dactylopodina. Himatismenida are either sister to Centramoebida or deeper branching. Discosea usually appear holophyletic (rarely paraphyletic). Paramoeba transcriptomes include prokinetoplastid Perkinsela-like endosymbiont sequences. Cunea, misidentified as Mayorella, is closer to Paramoeba than Vexillifera within holophyletic Dactylopodina. Taxon-rich site-heterogeneous rDNA trees confirm cutosan distinctiveness, allow improved conosan taxonomy, and reveal previous dictyostelid tree misrooting.

  19. Human endogenous retrovirus W family envelope gene activates the small conductance Ca2+-activated K+ channel in human neuroblastoma cells through CREB.

    PubMed

    Li, S; Liu, Z C; Yin, S J; Chen, Y T; Yu, H L; Zeng, J; Zhang, Q; Zhu, F

    2013-09-05

    Numerous studies have shown that human endogenous retrovirus W family (HERV-W) envelope gene (env) is related to various diseases but the underlying mechanism has remained poorly understood. Our previous study showed that there was abnormal expression of HERV-W env in sera of patients with schizophrenia. In this paper, we reported that overexpression of the HERV-W env elevated the levels of small conductance Ca(2+)-activated K(+) channel protein 3 (SK3) in human neuroblastoma cells. Using a luciferase reporter system and RNA interference method, we found that functional cAMP response element site was required for the expression of SK3 triggered by HERV-W env. In addition, it was also found that the SK3 channel was activated by HERV-W env. Further study indicated that cAMP response element-binding protein (CREB) was required for the activation of the SK3 channel. Thus, a novel signaling mechanism of how HERV-W env influences neuronal activity and contributes to mental illnesses such as schizophrenia was proposed.

  20. Short communication: phylodynamics analysis of the human immunodeficiency virus type 1 envelope gene in mother and child pairs.

    PubMed

    Santos, Luciane Amorim; Gray, Rebecca R; Monteiro-Cunha, Joana Paixão; Strazza, Evandra; Kashima, Simone; Santos, Edson de Souza; Araújo, Thessika Hialla Almeida; Gonçalves, Marilda de Souza; Salemi, Marco; Alcantara, Luiz Carlos Junior

    2015-09-01

    Characterizing the impact of HIV transmission routes on viral genetic diversity can improve the understanding of the mechanisms of virus evolution and adaptation. HIV vertical transmission can occur in utero, during delivery, or while breastfeeding. The present study investigated the phylodynamics of the HIV-1 env gene in mother-to-child transmission by analyzing one chronically infected pair from Brazil and three acutely infected pairs from Zambia, with three to five time points. Sequences from 25 clones from each sample were obtained and aligned using Clustal X. ML trees were constructed in PhyML using the best evolutionary model. Bayesian analyses testing the relaxed and strict molecular clock were performed using BEAST and a Bayesian Skyline Plot (BSP) was construed. The genetic variability of previously described epitopes was investigated and compared between each individual time point and between mother and child sequences. The relaxed molecular clock was the best-fitted model for all datasets. The tree topologies did not show differentiation in the evolutionary dynamics of the virus circulating in the mother from the viral population in the child. In the BSP, the effective population size was more constant in time in the chronically infected patients while in the acute patients it was possible to detect bottlenecks. The genetic variability within viral epitopes recognized by the human immune system was considerably higher among the chronically infected pair in comparison with acutely infected pairs. These results contribute to a better understanding of HIV-1 evolutionary dynamics in mother-to-child transmission.

  1. The plant nuclear envelope.

    PubMed

    Rose, Annkatrin; Patel, Shalaka; Meier, Iris

    2004-01-01

    This review summarizes our present knowledge about the composition and function of the plant nuclear envelope. Compared with animals or yeast, our molecular understanding of the nuclear envelope in higher plants is in its infancy. However, fundamental differences in the structure and function of the plant and animal nuclear envelope have already been found. Here, we compare and contrast these differences with respect to nuclear pore complexes, targeting of Ran signaling to the nuclear envelope, inner nuclear envelope proteins, and the role and fate of the nuclear envelope during mitosis. Further investigation of the emerging fundamental differences as well as the similarities between kingdoms might illuminate why there appears to be more than one blueprint for building a nucleus.

  2. Disruption of the baculovirus core gene ac78 results in decreased production of multiple nucleocapsid-enveloped occlusion-derived virions and the failure of primary infection in vivo.

    PubMed

    Li, Sai-Nan; Wang, Jin-Yu; Yuan, Mei-Jin; Yang, Kai

    2014-10-13

    The Autographa californica multiple nucleopolyhedrovirus (AcMNPV) ac78 gene is one of the baculovirus core genes. Recent studies showed that ac78 is essential for budded virion (BV) production and the embedding of occlusion-derived virion (ODV) into occlusion body during the AcMNPV life cycle. Here, we report that an ac78-knockout AcMNPV (vAc78KO) constructed in this study had different phenotypes than those described in the previous studies. A few infectious BVs were detected using titer assays, immunoblot analyses and plaque assays, indicating that ac78 is not essential for BV formation. Electron microscopy confirmed that the ac78 deletion did not affect nucleocapsid assembly and ODV formation. However, the numbers of multiple nucleocapsid-enveloped ODVs and ODV-embedded occlusion bodies were significantly decreased. Subsequently, the highly conserved amino acid residues 2-25 and 64-88 of Ac78, which are homologous to an oxidoreductase and cytochrome c oxidase, respectively, were demonstrated to play a crucial role in the morphogenesis of multiple nucleocapsid-enveloped ODV. Immunoblot analysis found that Ac78 was an ODV envelope-associated protein. Consistently, amino acid residues 56-93 of Ac78 were identified as an inner nuclear membrane sorting motif, which may direct the localization of Ac78 to the ODV envelope. In vivo infectivity assays showed that the occlusion bodies of vAc78KO were unable to establish primary infection in the midgut of Trichoplusia ni larvae. Taken together, our results suggest that ac78 plays an important role in BV production and proper multiple nucleocapsid-enveloped ODV formation, as well as AcMNPV primary infection in vivo.

  3. The Psp system of Mycobacterium tuberculosis integrates envelope stress-sensing and envelope-preserving functions.

    PubMed

    Datta, Pratik; Ravi, Janani; Guerrini, Valentina; Chauhan, Rinki; Neiditch, Matthew B; Shell, Scarlet S; Fortune, Sarah M; Hancioglu, Baris; Igoshin, Oleg A; Gennaro, Maria Laura

    2015-08-01

    The bacterial envelope integrates essential stress-sensing and adaptive functions; thus, envelope-preserving functions are important for survival. In Gram-negative bacteria, envelope integrity during stress is maintained by the multi-gene Psp response. Mycobacterium tuberculosis was thought to lack the Psp system since it encodes only pspA and no other psp ortholog. Intriguingly, pspA maps downstream from clgR, which encodes a transcription factor regulated by the MprAB-σ(E) envelope-stress-signaling system. clgR inactivation lowered ATP concentration during stress and protonophore treatment-induced clgR-pspA expression, suggesting that these genes express Psp-like functions. We identified a four-gene set - clgR, pspA (rv2744c), rv2743c, rv2742c - that is regulated by clgR and in turn regulates ClgR activity. Regulatory and protein-protein interactions within the set and a requirement of the four genes for functions associated with envelope integrity and surface-stress tolerance indicate that a Psp-like system has evolved in mycobacteria. Among Actinobacteria, the four-gene module occurred only in tuberculous mycobacteria and was required for intramacrophage growth, suggesting links between its function and mycobacterial virulence. Additionally, the four-gene module was required for MprAB-σ(E) stress-signaling activity. The positive feedback between envelope-stress-sensing and envelope-preserving functions allows sustained responses to multiple, envelope-perturbing signals during chronic infection, making the system uniquely suited to tuberculosis pathogenesis.

  4. Restriction of V3 region sequence divergence in the HIV-1 envelope gene during antiretroviral treatment in a cohort of recent seroconverters

    PubMed Central

    2013-01-01

    Background Dynamic changes in Human Immunodeficiency Virus 1 (HIV-1) sequence diversity and divergence are associated with immune control during primary infection and progression to AIDS. Consensus sequencing or single genome amplification sequencing of the HIV-1 envelope (env) gene, in particular the variable (V) regions, is used as a marker for HIV-1 genome diversity, but population diversity is only minimally, or semi-quantitatively sampled using these methods. Results Here we use second generation deep sequencing to determine inter-and intra-patient sequence heterogeneity and to quantify minor variants in a cohort of individuals either receiving or not receiving antiretroviral treatment following seroconversion; the SPARTAC trial. We show, through a cross-sectional study of sequence diversity of the env V3 in 30 antiretroviral-naive patients during primary infection that considerable population structure diversity exists, with some individuals exhibiting highly constrained plasma virus diversity. Diversity was independent of clinical markers (viral load, time from seroconversion, CD4 cell count) of infection. Serial sampling over 60 weeks of non-treated individuals that define three initially different diversity profiles showed that complex patterns of continuing HIV-1 sequence diversification and divergence could be readily detected. Evidence for minor sequence turnover, emergence of new variants and re-emergence of archived variants could be inferred from this analysis. Analysis of viral divergence over the same time period in patients who received short (12 weeks, ART12) or long course antiretroviral therapy (48 weeks, ART48) and a non-treated control group revealed that ART48 successfully suppressed viral divergence while ART12 did not have a significant effect. Conclusions Deep sequencing is a sensitive and reliable method for investigating the diversity of the env V3 as an important component of HIV-1 genome diversity. Detailed insights into the complex

  5. Genetic diversity of koala retroviral envelopes.

    PubMed

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

    2015-03-17

    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.

  6. Genetic Diversity of Koala Retroviral Envelopes

    PubMed Central

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

    2015-01-01

    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. PMID:25789509

  7. Evaluation of chimeric DNA vaccines consisting of premembrane and envelope genes of Japanese encephalitis and dengue viruses as a strategy for reducing induction of dengue virus infection-enhancing antibody response.

    PubMed

    Sjatha, Fithriyah; Kuwahara, Miwa; Sudiro, T Mirawati; Kameoka, Masanori; Konishi, Eiji

    2014-02-01

    Neutralizing antibodies induced by dengue virus (DENV) infection show viral infection-enhancing activities at sub-neutralizing doses. On the other hand, preimmunity against Japanese encephalitis virus (JEV), a congener of DENV, does not increase the severity of DENV infection. Several studies have demonstrated that neutralizing epitopes in the genus Flavivirus are mainly located in domain III (DIII) of the envelope (E) protein. In this study, chimeric premembrane and envelope (prM-E) gene-based expression plasmids of JEV and DENV1 with DIII substitution of each virus were constructed for use as DNA vaccines and their immunogenicity evaluated. Sera from C3H/He and ICR mice immunized with a chimeric gene containing DENV1 DIII on a JEV prM-E gene backbone showed high neutralizing antibody titers with less DENV infection-enhancing activity. Our results confirm the applicability of this approach as a new dengue vaccine development strategy. © 2014 The Societies and Wiley Publishing Asia Pty Ltd.

  8. Opacities for Stellar Envelopes

    NASA Astrophysics Data System (ADS)

    Seaton, M. J.; Yan, Y.; Mihalas, D.; Pradhan, A. K.

    1994-02-01

    We define stellar envelopes to be those regions of stellar interiors in which atoms exist and are not markedly perturbed by the plasma environment. Availability of accurate and extensive atomic data is a prime requirement for the calculation of envelope opacities. For envelopes we adopt the criterion of mass density p < 0.01 ρ≥g cm-3. We present radiative Rosseland mean opacities for envelopes obtained using atomic data calculated in an international collaboration referred to as the Opacity Project, or OP. Equations of state are calculated using an occupation-probability formalism. To a good approximation, ionization equilibria and level populations in envelopes depend only on the temperature T and electron density Ne and are insensitive to chemical mixtures. Monochromatic opacities for all abundant chemical elements are therefore calculated on a grid of (T, Ne) values and are archived. Rosseland mean opacities are then readily calculated for any chemical mixture. Tables of Rosseland means, for any required mixtures and as functions of ρ and T, are available on request in computer-readable form. The present, op, results are compared with those from another recent study, referred to as OPAL, by C. A. Iglesias and F. A. Rogers at the Lawrence Livermore National Laboratory. The agreement between the OP and OPAL calculations is generally good, although there are some differences. Both calculations give results larger than those obtained in earlier work, by factors of up to 3 or more.

  9. Gypsy transposition correlates with the production of a retroviral envelope-like protein under the tissue-specific control of the Drosophila flamenco gene.

    PubMed

    Pélisson, A; Song, S U; Prud'homme, N; Smith, P A; Bucheton, A; Corces, V G

    1994-09-15

    Gypsy displays striking similarities to vertebrate retroviruses, including the presence of a yet uncharacterized additional open reading frame (ORF3) and the recent evidence for infectivity. It is mobilized with high frequency in the germline of the progeny of females homozygous for the flamenco permissive mutation. We report the characterization of a gypsy subgenomic ORF3 RNA encoding typical retroviral envelope proteins. In females, env expression is strongly repressed by one copy of the non-permissive allele of flamenco. A less dramatic reduction in the accumulation of other transcripts and retrotranscripts is also observed. These effects correlate well with the inhibition of gypsy transposition in the progeny of these females, and are therefore likely to be responsible for this phenomenon. The effects of flamenco on gypsy expression are apparently restricted to the somatic follicle cells that surround the maternal germline. Moreover, permissive follicle cells display a typically polarized distribution of gypsy RNAs and envelope proteins, both being mainly accumulated at the apical pole, close to the oocyte. We propose a model suggesting that gypsy germinal transposition might occur only in individuals that have maternally inherited enveloped gypsy particles due to infection of the maternal germline by the soma.

  10. Gypsy transposition correlates with the production of a retroviral envelope-like protein under the tissue-specific control of the Drosophila flamenco gene.

    PubMed Central

    Pélisson, A; Song, S U; Prud'homme, N; Smith, P A; Bucheton, A; Corces, V G

    1994-01-01

    Gypsy displays striking similarities to vertebrate retroviruses, including the presence of a yet uncharacterized additional open reading frame (ORF3) and the recent evidence for infectivity. It is mobilized with high frequency in the germline of the progeny of females homozygous for the flamenco permissive mutation. We report the characterization of a gypsy subgenomic ORF3 RNA encoding typical retroviral envelope proteins. In females, env expression is strongly repressed by one copy of the non-permissive allele of flamenco. A less dramatic reduction in the accumulation of other transcripts and retrotranscripts is also observed. These effects correlate well with the inhibition of gypsy transposition in the progeny of these females, and are therefore likely to be responsible for this phenomenon. The effects of flamenco on gypsy expression are apparently restricted to the somatic follicle cells that surround the maternal germline. Moreover, permissive follicle cells display a typically polarized distribution of gypsy RNAs and envelope proteins, both being mainly accumulated at the apical pole, close to the oocyte. We propose a model suggesting that gypsy germinal transposition might occur only in individuals that have maternally inherited enveloped gypsy particles due to infection of the maternal germline by the soma. Images PMID:7925283

  11. Molecular cloning and analysis of functional envelope genes from human immunodeficiency virus type 1 sequence subtypes A through G. The WHO and NIAID Networks for HIV Isolation and Characterization.

    PubMed Central

    Gao, F; Morrison, S G; Robertson, D L; Thornton, C L; Craig, S; Karlsson, G; Sodroski, J; Morgado, M; Galvao-Castro, B; von Briesen, H

    1996-01-01

    Present knowledge of human immunodeficiency virus type 1 (HIV-1) envelope immunobiology has been derived almost exclusively from analyses of subtype B viruses, yet such viruses represent only a minority of strains currently spreading worldwide. To generate a more representative panel of genetically diverse envelope genes, we PCR amplified, cloned, and sequenced complete gp160 coding regions of 35 primary (peripheral blood mononuclear cell-propagated) HIV-1 isolates collected at major epicenters of the current AIDS pandemic. Analysis of their deduced amino acid sequences revealed several important differences from prototypic subtype B strains, including changes in the number and distribution of cysteine residues, substantial length differences in hypervariable regions, and premature truncations in the gp41 domain. Moreover, transiently expressed glycoprotein precursor molecules varied considerably in both size and carbohydrate content. Phylogenetic analyses of full-length env sequences indicated that the panel included members of all major sequence subtypes of HIV-1 group M (clades A to G), as well as an intersubtype recombinant (F/B) from an infected individual in Brazil. In addition, all subtype E and three subtype G viruses initially classified on the basis of partial env sequences were found to cluster in subtype A in the 3' half of their gp41 coding region, suggesting that they are also recombinant. The biological activity of PCR-derived env genes was examined in a single-round virus infectivity assay. This analysis identified 20 clones, including 1 from each subtype (or recombinant), which expressed fully functional envelope glycoproteins. One of these, derived from a patient with rapid CD4 cell decline, contained an amino acid substitution in a highly conserved endocytosis signal (Y721C), as mediated virus entry with very poor efficiency, although they did not contain sequence changes predicted to alter protein function. These results indicate that the env

  12. Tissue specificity in the nuclear envelope supports its functional complexity.

    PubMed

    de Las Heras, Jose I; Meinke, Peter; Batrakou, Dzmitry G; Srsen, Vlastimil; Zuleger, Nikolaj; Kerr, Alastair Rw; Schirmer, Eric C

    2013-01-01

    Nuclear envelope links to inherited disease gave the conundrum of how mutations in near-ubiquitous proteins can yield many distinct pathologies, each focused in different tissues. One conundrum-resolving hypothesis is that tissue-specific partner proteins mediate these pathologies. Such partner proteins may have now been identified with recent proteome studies determining nuclear envelope composition in different tissues. These studies revealed that the majority of the total nuclear envelope proteins are tissue restricted in their expression. Moreover, functions have been found for a number these tissue-restricted nuclear envelope proteins that fit with mechanisms proposed to explain how the nuclear envelope could mediate disease, including defects in mechanical stability, cell cycle regulation, signaling, genome organization, gene expression, nucleocytoplasmic transport, and differentiation. The wide range of functions to which these proteins contribute is consistent with not only their involvement in tissue-specific nuclear envelope disease pathologies, but also tissue evolution.

  13. Tissue specificity in the nuclear envelope supports its functional complexity

    PubMed Central

    de las Heras, Jose I; Meinke, Peter; Batrakou, Dzmitry G; Srsen, Vlastimil; Zuleger, Nikolaj; Kerr, Alastair RW; Schirmer, Eric C

    2013-01-01

    Nuclear envelope links to inherited disease gave the conundrum of how mutations in near-ubiquitous proteins can yield many distinct pathologies, each focused in different tissues. One conundrum-resolving hypothesis is that tissue-specific partner proteins mediate these pathologies. Such partner proteins may have now been identified with recent proteome studies determining nuclear envelope composition in different tissues. These studies revealed that the majority of the total nuclear envelope proteins are tissue restricted in their expression. Moreover, functions have been found for a number these tissue-restricted nuclear envelope proteins that fit with mechanisms proposed to explain how the nuclear envelope could mediate disease, including defects in mechanical stability, cell cycle regulation, signaling, genome organization, gene expression, nucleocytoplasmic transport, and differentiation. The wide range of functions to which these proteins contribute is consistent with not only their involvement in tissue-specific nuclear envelope disease pathologies, but also tissue evolution. PMID:24213376

  14. FRACTIONAL CRYSTALLIZATION FEED ENVELOPE

    SciTech Connect

    HERTING DL

    2008-03-19

    Laboratory work was completed on a set of evaporation tests designed to establish a feed envelope for the fractional crystallization process. The feed envelope defines chemical concentration limits within which the process can be operated successfully. All 38 runs in the half-factorial design matrix were completed successfully, based on the qualitative definition of success. There is no feed composition likely to be derived from saltcake dissolution that would cause the fractional crystallization process to not meet acceptable performance requirements. However, some compositions clearly would provide more successful operation than other compositions.

  15. HIV-1 envelope glycoprotein

    DOEpatents

    Caulfield, Michael; Cupo, Albert; Dean, Hansi; Hoffenberg, Simon; King, C. Richter; Klasse, P. J.; Marozsan, Andre; Moore, John P.; Sanders, Rogier W.; Ward, Andrew; Wilson, Ian; Julien, Jean-Philippe

    2017-08-22

    The present application relates to novel HIV-1 envelope glycoproteins, which may be utilized as HIV-1 vaccine immunogens, and antigens for crystallization, electron microscopy and other biophysical, biochemical and immunological studies for the identification of broad neutralizing antibodies. The present invention encompasses the preparation and purification of immunogenic compositions, which are formulated into the vaccines of the present invention.

  16. Jacketed lamp bulb envelope

    DOEpatents

    MacLennan, Donald A.; Turner, Brian P.; Gitsevich, Aleksandr; Bass, Gary K.; Dolan, James T.; Kipling, Kent; Kirkpatrick, Douglas A.; Leng, Yongzhang; Levin, Izrail; Roy, Robert J.; Shanks, Bruce; Smith, Malcolm; Trimble, William C.; Tsai, Peter

    2001-01-01

    A jacketed lamp bulb envelope includes a ceramic cup having an open end and a partially closed end, the partially closed end defining an aperture, a lamp bulb positioned inside the ceramic cup abutting the aperture, and a reflective ceramic material at least partially covering a portion of the bulb not abutting the aperture. The reflective ceramic material may substantially fill an interior volume of the ceramic cup not occupied by the bulb. The ceramic cup may include a structural feature for aiding in alignment of the jacketed lamp bulb envelope in a lamp. The ceramic cup may include an external flange about a periphery thereof. One example of a jacketed lamp bulb envelope includes a ceramic cup having an open end and a closed end, a ceramic washer covering the open end of the ceramic cup, the washer defining an aperture therethrough, a lamp bulb positioned inside the ceramic cup abutting the aperture, and a reflective ceramic material filling an interior volume of the ceramic cup not occupied by the bulb. A method of packing a jacketed lamp bulb envelope of the type comprising a ceramic cup with a lamp bulb disposed therein includes the steps of filling the ceramic cup with a flowable slurry of reflective material, and applying centrifugal force to the cup to pack the reflective material therein.

  17. Characterizing and Mapping Porcine Endogenous Retroviruses in Westran Pigs

    PubMed Central

    Lee, Jun-Heon; Webb, Graham C.; Allen, Richard D. M.; Moran, Chris

    2002-01-01

    Since porcine endogenous retroviruses (PERVs) can infect cultured human cells, they are a potential hazard to xenotransplantation. For this reason, endogenous retroviruses from the Westran (Westmead Hospital transplantation) inbred line of pigs were analyzed by using consensus primers for the type A and type B viruses to amplify 1.8-kb envelope gene fragments. After preliminary analysis with restriction enzymes KpnI and MboI, 31 clones were sequenced. Between types A and B, five recombinant clones were identified. Fifty-five percent of clones (17 of 31) had premature stop codons within the envelope protein-encoding region. Endogenous retroviruses in Westran pigs were physically mapped by fluorescence in situ hybridization (FISH) using PERV-A and PERV-B envelope clones as probes to identify at least 32 integration sites (19 PERV-A sites and 13 PERV-B sites). The chromosomal sites of integration in the Westran strain are quite different from those in the European Large White pig. The recombinant clones suggest that defective PERVs could become infective through recombination and further that PERVs might recombine with human endogenous retroviruses in xenotransplants. PMID:11991983

  18. Model scattering envelopes of young stellar objects. II - Infalling envelopes

    NASA Technical Reports Server (NTRS)

    Whitney, Barbara A.; Hartmann, Lee

    1993-01-01

    We present scattered light images for models of young stellar objects surrounded by dusty envelopes. The envelopes are assumed to have finite angular momentum and are falling in steady flow onto a disk. The model envelopes include holes, such as might be created by energetic bipolar flows. We calculate images using the Monte Carlo method to follow the light scattered in the dusty envelope and circumstellar disk, assuming that the photons originate from the central source. Adopting typical interstellar medium dust opacities and expected mass infall rates for protostars of about 10 exp -6 solar mass/yr, we find that detectable amounts of optical radiation can escape from envelopes falling into a disk as small as about 10-100 AU, depending upon the viewing angle and the size of the bipolar flow cavity. We suggest that the extended optical and near-IR light observed around several young stars is scattered by dusty infalling envelopes rather than disks.

  19. Model scattering envelopes of young stellar objects. II - Infalling envelopes

    NASA Technical Reports Server (NTRS)

    Whitney, Barbara A.; Hartmann, Lee

    1993-01-01

    We present scattered light images for models of young stellar objects surrounded by dusty envelopes. The envelopes are assumed to have finite angular momentum and are falling in steady flow onto a disk. The model envelopes include holes, such as might be created by energetic bipolar flows. We calculate images using the Monte Carlo method to follow the light scattered in the dusty envelope and circumstellar disk, assuming that the photons originate from the central source. Adopting typical interstellar medium dust opacities and expected mass infall rates for protostars of about 10 exp -6 solar mass/yr, we find that detectable amounts of optical radiation can escape from envelopes falling into a disk as small as about 10-100 AU, depending upon the viewing angle and the size of the bipolar flow cavity. We suggest that the extended optical and near-IR light observed around several young stars is scattered by dusty infalling envelopes rather than disks.

  20. Refrigerated cryogenic envelope

    DOEpatents

    Loudon, John D.

    1976-11-16

    An elongated cryogenic envelope including an outer tube and an inner tube coaxially spaced within said inner tube so that the space therebetween forms a vacuum chamber for holding a vacuum. The inner and outer tubes are provided with means for expanding or contracting during thermal changes. A shield is located in the vacuum chamber intermediate the inner and outer tubes; and, a refrigeration tube for directing refrigeration to the shield is coiled about at least a portion of the inner tube within the vacuum chamber to permit the refrigeration tube to expand or contract along its length during thermal changes within said vacuum chamber.

  1. Simulation of random envelope processes.

    NASA Technical Reports Server (NTRS)

    Yang, J.-N.

    1972-01-01

    Efficient and practical methods of simulating stationary and nonstationary random envelope processes are presented. The stationary envelope processes are simulated by using the fast Fourier transform while the nonstationary envelope processes are simulated as the square root of the sum of a series of cosine functions and a series of sine functions with random phase angles. Typical applications of the envelope simulation are the simulations of peaks and troughs which play an important role in the analyses of the first excursion probability, fatigue and crack propagation. In particular, applications to the crack propagation under random loadings are demonstrated in detail.

  2. The use of an optimized chimeric envelope glycoprotein enhances the efficiency of retrograde gene transfer of a pseudotyped lentiviral vector in the primate brain.

    PubMed

    Tanabe, Soshi; Inoue, Ken-Ichi; Tsuge, Hitomi; Uezono, Shiori; Nagaya, Kiyomi; Fijiwara, Maki; Kato, Shigeki; Kobayashi, Kazuto; Takada, Masahiko

    2017-02-28

    Lentiviral vectors have been used not only for various basic research experiments, but also for a wide range of gene therapy trials in animal models. The development of a pseudotyped lentiviral vector with the property of retrograde infection allows us to introduce foreign genes into neurons that are localized in regions innervating the site of vector injection. Here, we report the efficiency of retrograde gene transfer of a recently developed FuG-E pseudotyped lentiviral vector in the primate brain by comparing its transduction pattern with that of the parental FuG-C pseudotyped vector. After injection of the FuG-E vector encoding green fluorescent protein (GFP) into the striatum of macaque monkeys, many GFP-immunoreactive neurons were found in regions projecting to the striatum, such as the cerebral cortex, thalamus, and substantia nigra. Quantitative analysis revealed that in all regions, the number of neurons retrogradely transduced with the FuG-E vector was larger than in the FuG-C vector injection case. It was also confirmed that the FuG-E vector displayed explicit neuronal specificity to the same extent as the FuG-C vector. This vector might promote approaches to pathway-selective gene manipulation and provide a powerful tool for effective gene therapy trials against neurological disorders through enhanced retrograde delivery.

  3. [Sequence analysis for genes encoding nucleoprotein and envelope protein of a new human coronavirus NL63 identified from a pediatric patient in Beijing by bioinformatics].

    PubMed

    Xing, Jiang-feng; Zhu, Ru-nan; Qian, Yuan; Zhao, Lin-qing; Deng, Jie; Wang, Fang; Sun, Yu

    2007-07-01

    The aim of this study was to characterize the N and E protein encoding genes of a new human coronavirus (HCoV-NL63) which was identified from one of the clinical specimens (BJ8081) collected from a 12 years-old patient with acute respiratory infection in Beijing. The complete N and E gene sequences of HCoV-NL63 were amplified from clinical sample by RT-PCR, then were cloned into the pCF-T and pUCm-T vectors respectively and sequenced. The complete sequences of N and E genes were submitted to GenBank by Sequin and compared with N and E genes of prototype HCoV-NL63 and the other coronaviruses published in GenBank. The secondary structure and the characteristics of sample BJ8081 N and E proteins were predicted by bioinformatics. It was indicated that the N and E genes amplified from sample BJ8081 were 1134 bp and 234 bp in length and the predicted proteins including 377 amino acids and 77 amino acids, respectively. The data suggested that the region of amino acids 78-85 within N protein probably was the conserved region for all coronaviruses identified so far including HCoV-NL63. The region of amino acids 15-37 for E protein was probably the transmembrane domain. In conclusion, the recombinant plasmids pCF-T-8081 N and pUCm-T-8081 E were successfully constructed and sequenced, and the data predicted by bioinformatics are helpful for the further analysis of HCoV-NL63.

  4. Fast Moreau envelope computation I

    NASA Astrophysics Data System (ADS)

    Lucet, Yves

    2006-11-01

    The present article summarizes the state of the art algorithms to compute the discrete Moreau envelope, and presents a new linear-time algorithm, named NEP for NonExpansive Proximal mapping. Numerical comparisons between the NEP and two existing algorithms: The Linear-time Legendre Transform (LLT) and the Parabolic Envelope (PE) algorithms are performed. Worst-case time complexity, convergence results, and examples are included. The fast Moreau envelope algorithms first factor the Moreau envelope as several one-dimensional transforms and then reduce the brute force quadratic worst-case time complexity to linear time by using either the equivalence with Fast Legendre Transform algorithms, the computation of a lower envelope of parabolas, or, in the convex case, the non expansiveness of the proximal mapping.

  5. Cloning and characterization of functional subtype A HIV-1 envelope variants transmitted through breastfeeding.

    PubMed

    Rainwater, Stephanie M J; Wu, Xueling; Nduati, Ruth; Nedellec, Rebecca; Mosier, Donald; John-Stewart, Grace; Mbori-Ngacha, Dorothy; Overbaugh, Julie

    2007-03-01

    Previous studies of HIV-1 variants transmitted from mother-to-infant have focused primarily on computational analyses of partial envelope gene sequences, rather than analyses of functional envelope variants. There are very few examples of well-characterized functional envelope clones from mother-infant pairs, especially from envelope variants representing the most prevalent subtypes worldwide. To address this, we amplified the envelope variants present in 4 mother-infant transmission pairs, all of whom were infected with subtype A and three of whom presumably transmitted HIV-1 during the breastfeeding period. Functional envelope clones were constructed, either encoding full-length envelope sequences from the mother and baby or by making chimeric envelope clones in a common backbone sequence. The infant envelope sequences were genetically homogeneous compared to the maternal viruses, and pseudoviruses bearing these envelopes all used CCR5 as a coreceptor. The infant viruses were generally resistant to neutralization by maternal antibodies present near the time of transmission. There were no notable differences in sensitivity of the mother and infant envelope variants to neutralization by heterologous plasma or monoclonal antibodies 2G12 and b12, or to inhibition by sCD4, PSC-RANTES or TAK779. This collection of viral envelopes, which can be used for making pseudotyped viruses, may be useful for examining the efficacy of interventions to block mother-infant transmission, including sera from vaccine candidates, purified antibodies under consideration for passive immunization and viral entry inhibitors.

  6. Dengue-1 Virus Envelope Glycoprotein Gene Expressed in Recombinant Baculovirus Elicits Virus-Neutralizing Antibody in Mice and Protects them from Virus Challenge

    DTIC Science & Technology

    1991-01-01

    Japanese encephalitis (JE), in which cific antiserum (mouse hyperimmune ascitic flu- polygenicregions, C-prM-E, prM-E-NSI-NS2A- id. MHAF. 1:200) against...assay with DEN-I virus coprotein gene and its expression in Spodoptera hyperimmune mouse ascitic fluid. This heat-in- frugiperda cells activated...itrocellulose and reacted with [)EN-l specific mouse hyperimmune ascitic fluid (MHAF) (right panel). Bands fromn a duplicate gel were stained with

  7. Binding of the Epstein-Barr virus major envelope glycoprotein gp350 results in the upregulation of the TNF-alpha gene expression in monocytic cells via NF-kappaB involving PKC, PI3-K and tyrosine kinases.

    PubMed

    D'Addario, M; Ahmad, A; Morgan, A; Menezes, J

    2000-05-19

    Epstein-Barr virus (EBV) is a human herpesvirus that interacts with various immunocompetent cells that carry the EBV receptor (CD21/CR2). EBV binds to CR2 through its major envelope glycoprotein 350 (gp350). Previously we had demonstrated that EBV and other human herpesviruses are capable of modulating cytokine synthesis through the deregulated expression of cytokine genes interleukin-1 (IL-1), interleukin-6 (IL-6), tumor necrosis factor-alpha (TNF-alpha), and interleukin-2 (IL-2). Here we show that, in contrast to infectious EBV, purified recombinant gp350 upregulates TNF-alpha gene expression in human monocyte/macrophages (M/M) as well as in a monocytoid cell line, U937. Our results also demonstrate that this increased expression is due to both enhanced transcription and stability of TNF-alpha mRNA in gp350-treated cells. The specificity of this effect is evidenced by the fact that pre-incubation of cells with anti-CR2 monoclonal antibody OKB7, which blocks binding of gp350 to CR2, inhibits the above mentioned effects of gp350. Furthermore, we demonstrate that activation of TNF-alpha by gp350 is mediated by NF-kappaB through signal transduction pathways involving PKC, PI3-K and tyrosine kinases. To our knowledge this is the first report describing the modulation of TNF-alpha gene expression by the EBV-gp350 molecule following its interaction with the viral receptor CR2 on cells of the monocytic lineage.

  8. Multifamily Envelope Leakage Model

    SciTech Connect

    Faakye, Omari; Griffiths, Dianne

    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.

  9. Masonry building envelope analysis

    NASA Astrophysics Data System (ADS)

    McMullan, Phillip C.

    1993-04-01

    Over the past five years, infrared thermography has proven an effective tool to assist in required inspections on new masonry construction. However, with more thermographers providing this inspection service, establishing a standard for conducting these inspections is imperative. To attempt to standardize these inspections, it is important to understand the nature of the inspection as well as the context in which the inspection is typically conducted. The inspection focuses on evaluating masonry construction for compliance with the design specifications with regard to structural components and thermal performance of the building envelope. The thermal performance of the building includes both the thermal resistance of the material as well as infiltration/exfiltration characteristics. Given that the inspections occur in the 'field' rather than the controlled environment of a laboratory, there are numerous variables to be considered when undertaking this type of inspection. Both weather and site conditions at the time of the inspection can vary greatly. In this paper we will look at the variables encountered during recent inspections. Additionally, the author will present the standard which was employed in collecting this field data. This method is being incorporated into a new standard to be included in the revised version of 'Guidelines for Specifying and Performing Infrared Inspections' developed by the Infraspection Institute.

  10. Envelope glycoprotein of arenaviruses.

    PubMed

    Burri, Dominique J; da Palma, Joel Ramos; Kunz, Stefan; Pasquato, Antonella

    2012-10-17

    Arenaviruses include lethal human pathogens which pose serious public health threats. So far, no FDA approved vaccines are available against arenavirus infections, and therapeutic options are limited, making the identification of novel drug targets for the development of efficacious therapeutics an urgent need. Arenaviruses are comprised of two RNA genome segments and four proteins, the polymerase L, the envelope glycoprotein GP, the matrix protein Z, and the nucleoprotein NP. A crucial step in the arenavirus life-cycle is the biosynthesis and maturation of the GP precursor (GPC) by cellular signal peptidases and the cellular enzyme Subtilisin Kexin Isozyme-1 (SKI-1)/Site-1 Protease (S1P) yielding a tripartite mature GP complex formed by GP1/GP2 and a stable signal peptide (SSP). GPC cleavage by SKI-1/S1P is crucial for fusion competence and incorporation of mature GP into nascent budding virion particles. In a first part of our review, we cover basic aspects and newer developments in the biosynthesis of arenavirus GP and its molecular interaction with SKI-1/S1P. A second part will then highlight the potential of SKI-1/S1P-mediated processing of arenavirus GPC as a novel target for therapeutic intervention to combat human pathogenic arenaviruses.

  11. Identification of human immunodeficiency virus type 1 envelope genes recombinant between subtypes B and F in two epidemiologically linked individuals from Brazil.

    PubMed Central

    Sabino, E C; Shpaer, E G; Morgado, M G; Korber, B T; Diaz, R S; Bongertz, V; Cavalcante, S; Galvão-Castro, B; Mullins, J I; Mayer, A

    1994-01-01

    Sequence analysis of a human immunodeficiency virus type 1 env gene PCR amplified from a Brazilian woman's peripheral blood mononuclear cell DNA (sample RJIO1) showed that it was likely to have been derived from a double recombination event between human immunodeficiency virus type 1 subtypes B and F. The major portion of the gp120 coding sequence belonged to the B lineage, but a segment of the C2 to V3 region (approximately 135 nucleotides) clearly associated with sequences of the F lineage. The subtype F-like segment had 15 noncontiguous signature nucleotides in common with Brazilian subtype F sequences that were not found, or were rare, in subtype B sequences. In contrast, this same segment had only 3 signature nucleotides shared with subtype B sequences and not present in the Brazilian subtype F sequences. Phylogenetic analysis, amino acid signature pattern analysis, and the pattern of synonymous mutations all supported the hypothesis of a recombinational origin of the RJIO1 sequence. Related recombinant genes were also detected in peripheral blood mononuclear cell DNA obtained from the woman's recent sexual partner, indicating that the recombination event probably occurred at some previous time in the chain of virus transmission. Divergent viral sequences in the V3 region were found in the male sexual partner, while a relatively homogeneous viral population was detected in the woman, consistent with her recent infection. PMID:8083973

  12. Genetic Diversity and Positive Selection Analysis of Classical Swine Fever Virus Envelope Protein Gene E2 in East China under C-Strain Vaccination

    PubMed Central

    Hu, Dongfang; Lv, Lin; Gu, Jinyuan; Chen, Tongyu; Xiao, Yihong; Liu, Sidang

    2016-01-01

    Classical swine fever virus (CSFV) causes an economically important and highly contagious disease of pigs worldwide. C-strain vaccination is one of the most effective ways to contain this disease. Since 2014, sporadic CSF outbreaks have been occurring in some C-strain vaccinated provinces of China. To decipher the disease etiology, 25 CSFV E2 genes from 169 clinical samples were cloned and sequenced. Phylogenetic analyses revealed that all 25 isolates belonged to subgenotype 2.1. Twenty-three of the 25 isolates were clustered in a newly defined subgenotype, 2.1d, and shared some consistent molecular characteristics. To determine whether the complete E2 gene was under positive selection pressure, we used a site-by-site analysis to identify specific codons that underwent evolutionary selection, and seven positively selected codons were found. Three positively selected sites (amino acids 17, 34, and 72) were identified in antigenicity-relevant domains B/C of the amino-terminal half of the E2 protein. In addition, another positively selected site (amino acid 200) exhibited a polarity change from hydrophilic to hydrophobic, which may change the antigenicity and virulence of CSFV. The results indicate that the circulating CSFV strains in Shandong province were mostly clustered in subgenotype 2.1d. Moreover, the identification of these positively selected sites could help to reveal molecular determinants of virulence or pathogenesis, and to clarify the driving force of CSFV evolution in East China. PMID:26903966

  13. The neurovirulence and neuroinvasiveness of chimeric tick-borne encephalitis/dengue virus can be attenuated by introducing defined mutations into the envelope and NS5 protein genes and the 3' non-coding region of the genome

    SciTech Connect

    Engel, Amber R.; Rumyantsev, Alexander A.; Maximova, Olga A.; Speicher, James M.; Heiss, Brian; Murphy, Brian R.; Pletnev, Alexander G.

    2010-09-15

    Tick-borne encephalitis (TBE) is a severe disease affecting thousands of people throughout Eurasia. Despite the use of formalin-inactivated vaccines in endemic areas, an increasing incidence of TBE emphasizes the need for an alternative vaccine that will induce a more durable immunity against TBE virus (TBEV). The chimeric attenuated virus vaccine candidate containing the structural protein genes of TBEV on a dengue virus genetic background (TBEV/DEN4) retains a high level of neurovirulence in both mice and monkeys. Therefore, attenuating mutations were introduced into the envelope (E{sub 315}) and NS5 (NS5{sub 654,655}) proteins, and into the 3' non-coding region ({Delta}30) of TBEV/DEN4. The variant that contained all three mutations (v{Delta}30/E{sub 315}/NS5{sub 654,655}) was significantly attenuated for neuroinvasiveness and neurovirulence and displayed a reduced level of replication and virus-induced histopathology in the brains of mice. The high level of safety in the central nervous system indicates that v{Delta}30/E{sub 315}/NS5{sub 654,655} should be further evaluated as a TBEV vaccine.

  14. Restricted isotype, distinct variable gene usage, and high rate of gp120 specificity of HIV-1 envelope-specific B cells in colostrum compared with those in blood of HIV-1-infected, lactating African women.

    PubMed

    Sacha, C R; Vandergrift, N; Jeffries, T L; McGuire, E; Fouda, G G; Liebl, B; Marshall, D J; Gurley, T C; Stiegel, L; Whitesides, J F; Friedman, J; Badiabo, A; Foulger, A; Yates, N L; Tomaras, G D; Kepler, T B; Liao, H X; Haynes, B F; Moody, M A; Permar, S R

    2015-03-01

    A successful HIV-1 vaccine must elicit immune responses that impede mucosal virus transmission, though functional roles of protective HIV-1 Envelope (Env)-specific mucosal antibodies remain unclear. Colostrum is a rich source of readily accessible mucosal B cells that may help define the mucosal antibody response contributing to prevention of postnatal HIV-1 transmission. To examine the HIV-1 Env-specific colostrum B-cell repertoire, single B cells were isolated from 17 chronically HIV-infected, lactating women, producing 51 blood and 39 colostrum HIV-1 Env-specific B-cell antibodies. All HIV-1 Env-specific colostrum-derived antibodies were immunoglobulin (Ig)G1 isotype and had mean heavy chain complementarity-determining region 3 (CDR3) lengths and mutation frequencies similar to those isolated from blood. However, variable heavy chain (VH) gene subfamily 1(∼)69 usage was higher among colostrum than blood HIV-1 Env-reactive antibodies (49% vs. 20%, P=0.006, Fisher's exact test). Additionally, more HIV-1 Env-specific colostrum antibodies were gp120 specific than those isolated from blood (44% vs. 16%, P=0.005, Fisher's exact test). One cross-compartment HIV-1 Env-specific clonal B-cell lineage was identified. These unique characteristics of colostrum B-cell antibodies suggest selective homing of HIV-1-specific IgG1-secreting memory B cells to the mammary gland and have implications for targeting mucosal B-cell populations by vaccination.

  15. Isolation of bacteria envelope proteins.

    PubMed

    Quan, Shu; Hiniker, Annie; Collet, Jean-François; Bardwell, James C A

    2013-01-01

    Proteomic analysis on cell envelope proteins from Gram-negative bacteria requires specific isolation techniques. We found that conventional extraction methods such as osmotic shock cause extracts to be heavily contaminated with soluble cytoplasmic proteins. These cytoplasmic protein contaminants constitute the major signal in proteomic analysis and can overwhelm the signals coming from genuine envelope components. After extensive testing of various protocols for the preparation of envelope contents, we found that a modified version of the method of Oliver and Beckwith consistently produces the cleanest extract of periplasmic and outer membrane proteins.We have designated this very simple method TSE extraction because it uses a Tris-sucrose solution supplemented with EDTA.Cytoplasmic and inner membrane protein contaminants are not evident on 1D SDS polyacrylamide gels and contribute to less than 6% of total signal in very sensitive mass spectrometry analysis. This straightforward method is therefore ideal for -analyzing specific proteomic changes in the cell envelope.

  16. Surfing the wave, cycle, life history, and genes/proteins expressed by testicular germ cells. Part 4: intercellular bridges, mitochondria, nuclear envelope, apoptosis, ubiquitination, membrane/voltage-gated channels, methylation/acetylation, and transcription factors.

    PubMed

    Hermo, Louis; Pelletier, R-Marc; Cyr, Daniel G; Smith, Charles E

    2010-04-01

    As germ cells divide and differentiate from spermatogonia to spermatozoa, they share a number of structural and functional features that are common to all generations of germ cells and these features are discussed herein. Germ cells are linked to one another by large intercellular bridges which serve to move molecules and even large organelles from the cytoplasm of one cell to another. Mitochondria take on different shapes and features and topographical arrangements to accommodate their specific needs during spermatogenesis. The nuclear envelope and pore complex also undergo extensive modifications concomitant with the development of germ cell generations. Apoptosis is an event that is normally triggered by germ cells and involves many proteins. It occurs to limit the germ cell pool and acts as a quality control mechanism. The ubiquitin pathway comprises enzymes that ubiquitinate as well as deubiquitinate target proteins and this pathway is present and functional in germ cells. Germ cells express many proteins involved in water balance and pH control as well as voltage-gated ion channel movement. In the nucleus, proteins undergo epigenetic modifications which include methylation, acetylation, and phosphorylation, with each of these modifications signaling changes in chromatin structure. Germ cells contain specialized transcription complexes that coordinate the differentiation program of spermatogenesis, and there are many male germ cell-specific differences in the components of this machinery. All of the above features of germ cells will be discussed along with the specific proteins/genes and abnormalities to fertility related to each topic. Copyright 2009 Wiley-Liss, Inc.

  17. Climbazole increases expression of cornified envelope proteins in primary keratinocytes.

    PubMed

    Pople, J E; Moore, A E; Talbot, D C S; Barrett, K E; Jones, D A; Lim, F L

    2014-10-01

    Dandruff is a troubling consumer problem characterized by flaking and pruritus of the scalp and is considered a multifactorial condition with sebum, individual susceptibility and the fungus Malassezia all thought to play a part. The condition is commonly treated with shampoo products containing antifungal ingredients such as zinc pyrithione and climbazole. It is hypothesized that these ingredients may be delivering additional scalp skin benefits besides their antifungal activity helping to relieve dandruff effectively. The objective of this study was to evaluate the anti-dandruff ingredient climbazole for potential skin benefits using genomics and in vitro assays. Microarray analysis was performed to profile gene expression changes in climbazole-treated primary human keratinocyte cells. Results were independently validated using qPCR and analysis of protein expression using ELISA and immunocytochemistry. Microarray analysis of climbazole-treated keratinocytes showed statistically significant expression changes in genes associated with the gene ontology groups encompassing epidermal differentiation, keratinization, cholesterol biosynthesis and immune response. Upregulated genes included a number encoding cornified envelope proteins such as group 3 late-cornified envelope proteins, LCE3 and group 2 small-proline-rich proteins, SPRR2. Protein analysis studies of climbazole-treated primary keratinocytes using ELISA and immunocytochemistry were able to demonstrate that the increase in gene transcripts translated into increased protein expression of these cornified envelope markers. Climbazole treatment of primary keratinocytes results in an upregulation in expression of a number of genes including those encoding proteins involved in cornified envelope formation with further studies demonstrating this did translate into increased protein expression. A climbazole-driven increase in cornified envelope proteins may improve the scalp skin barrier, which is known to be weaker

  18. Envelope Inflation or Stellar Wind?

    NASA Astrophysics Data System (ADS)

    Ro, S.; Matzner, C. D.

    We an optically-thick, transonic, steady wind model for a H-free Wolf-Rayet star. A bifurcation is found across a critical mass loss rate Mb. Slower winds M < Mb extend by several hydrostatic stellar radii, reproduce features of envelope in ation from Petrovic et al. (2006) and Gräfener et al. (2012), and are energetically unbound. This work is of particular interest for extended envelopes and winds, radiative hydrodynamic instabilities (eg. wind stagnation, clumping, etc.), and NLTE atmospheric models.

  19. Personnel occupied woven envelope robot

    NASA Technical Reports Server (NTRS)

    Wessling, F. C.

    1986-01-01

    The use of nonmetallic or fabric structures for space application is considered. The following structures are suggested: (1) unpressurized space hangars; (2) extendable tunnels for soft docking; and (3) manned habitat for space stations, storage facilities, and work structures. The uses of the tunnel as a passageway: for personnel and equipment, eliminating extravehicular activity, for access to a control cabin on a space crane and between free flyers and the space station are outlined. The personnal occupied woven envelope robot (POWER) device is shown. The woven envelope (tunnel) acts as part of the boom of a crane. Potential applications of POWER are outlined. Several possible deflection mechanisms and design criteria are determined.

  20. Carbon chemistry of circumstellar envelopes

    NASA Technical Reports Server (NTRS)

    Bieging, John H.

    1990-01-01

    The chemical composition of envelopes surrounding cool evolved stars, as determined from microwave spectroscopic observations, is reviewed. Emphasis is placed on recent observations with the new large mm-wavelength telescopes and interferometer arrays, and on new theoretical work, especially concerning ion-molecule chemistry of carbon-bearing in these envelopes. Thermal (as opposed to maser) emission lines are discussed. Much progress has been made in the past few years in the theoretical understanding of these objects. It is already clear, however, that observations with the new generation of mm-telescopes will require substantial improvements in the theoretical models to achieve a thorough understanding of the data now becoming available.

  1. Magnetically Targeted Viral Envelopes: A PET Investigation of Initial Biodistribution

    PubMed Central

    Flexman, Jennifer A.; Cross, Donna J.; Lewellen, Barbara L.; Miyoshi, Sosuke; Kim, Yongmin

    2009-01-01

    Gene and drug therapy for organ-specific diseases in part depends on the efficient delivery to a particular region of the body. We examined the biodistribution of a viral envelope commonly used as a nanoscale gene delivery vehicle using positron emission tomography (PET) and investigated the magnetic alteration of its biodistribution. Iron oxide nanoparticles and 18 F-fluoride were encapsulated by hemagglutinating virus of Japan envelopes (HVJ-Es). HVJ-Es were then injected intravenously in the rat and imaged dynamically using high-resolution PET. Control subjects received injections of encapsulated materials alone. For magnetic targeting, permanent magnets were fixed on the head during the scan. Based on the quantitative analysis of PET images, HVJ-Es accumulated in the liver and spleen and activity remained higher than control subjects for 2 h. Histological sections of the liver confirmed imaging findings. Pixel-wise activity patterns on coregistered PET images of the head showed a significantly different pattern for the subjects receiving magnetic targeting as compared to all control groups. Imaging demonstrated the initial biodistribution of a viral envelope within the rodent by providing quantitative behavior over time and in specific anatomical regions. Magnetic force altered the biodistribution of the viral envelope to a target structure, and could enable region-specific delivery of therapeutic vehicles noninvasively. PMID:18779103

  2. Safeguards Envelope Progress FY08

    SciTech Connect

    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.

  3. Heat recovery in building envelopes

    SciTech Connect

    Walker, Iain S.; Sherman, Max H.

    2003-08-01

    Infiltration has traditionally been assumed to contribute to the energy load of a building by an amount equal to the product of the infiltration flow rate and the enthalpy difference between inside and outside. Some studies have indicated that application of such a simple formula may produce an unreasonably high contribution because of heat recovery within the building envelope. The major objective of this study was to provide an improved prediction of the energy load due to infiltration by introducing a correction factor that multiplies the expression for the conventional load. This paper discusses simplified analytical modeling and CFD simulations that examine infiltration heat recovery (IHR) in an attempt to quantify the magnitude of this effect for typical building envelopes. For comparison, we will also briefly examine the results of some full-scale field measurements of IHR based on infiltration rates and energy use in real buildings. The results of this work showed that for houses with insulated walls the heat recovery is negligible due to the small fraction of the envelope that participates in heat exchange with the infiltrating air. However; there is the potential for IHR to have a significant effect for higher participation dynamic walls/ceilings or uninsulated walls. This result implies that the existing methods for evaluating infiltration related building loads provide adequate results for typical buildings.

  4. The structure of common-envelope remnants

    NASA Astrophysics Data System (ADS)

    Hall, Philip D.

    2015-05-01

    We investigate the structure and evolution of the remnants of common-envelope evolution in binary star systems. In a common-envelope phase, two stars become engulfed in a gaseous envelope and, under the influence of drag forces, spiral to smaller separations. They may merge to form a single star or the envelope may be ejected to leave the stars in a shorter period orbit. This process explains the short orbital periods of many observed binary systems, such as cataclysmic variables and low-mass X-ray binary systems. Despite the importance of these systems, and of common-envelope evolution to their formation, it remains poorly understood. Specifically, we are unable to confidently predict the outcome of a common-envelope phase from the properties at its onset. After presenting a review of work on stellar evolution, binary systems, common-envelope evolution and the computer programs used, we describe the results of three computational projects on common-envelope evolution. Our work specifically relates to the methods and prescriptions which are used for predicting the outcome. We use the Cambridge stellar-evolution code STARS to produce detailed models of the structure and evolution of remnants of common-envelope evolution. We compare different assumptions about the uncertain end-of-common envelope structure and envelope mass of remnants which successfully eject their common envelopes. In the first project, we use detailed remnant models to investigate whether planetary nebulae are predicted after common-envelope phases initiated by low-mass red giants. We focus on the requirement that a remnant evolves rapidly enough to photoionize the nebula and compare the predictions for different ideas about the structure at the end of a common-envelope phase. We find that planetary nebulae are possible for some prescriptions for the end-of-common envelope structure. In our second contribution, we compute a large set of single-star models and fit new formulae to the core radii of

  5. Cortical processing of dynamic sound envelope transitions.

    PubMed

    Zhou, Yi; Wang, Xiaoqin

    2010-12-08

    Slow envelope fluctuations in the range of 2-20 Hz provide important segmental cues for processing communication sounds. For a successful segmentation, a neural processor must capture envelope features associated with the rise and fall of signal energy, a process that is often challenged by the interference of background noise. This study investigated the neural representations of slowly varying envelopes in quiet and in background noise in the primary auditory cortex (A1) of awake marmoset monkeys. We characterized envelope features based on the local average and rate of change of sound level in envelope waveforms and identified envelope features to which neurons were selective by reverse correlation. Our results showed that envelope feature selectivity of A1 neurons was correlated with the degree of nonmonotonicity in their static rate-level functions. Nonmonotonic neurons exhibited greater feature selectivity than monotonic neurons in quiet and in background noise. The diverse envelope feature selectivity decreased spike-timing correlation among A1 neurons in response to the same envelope waveforms. As a result, the variability, but not the average, of the ensemble responses of A1 neurons represented more faithfully the dynamic transitions in low-frequency sound envelopes both in quiet and in background noise.

  6. Cell entry of enveloped viruses.

    PubMed

    Cosset, François-Loic; Lavillette, Dimitri

    2011-01-01

    Enveloped viruses penetrate their cell targets following the merging of their membrane with that of the cell. This fusion process is catalyzed by one or several viral glycoproteins incorporated on the membrane of the virus. These envelope glycoproteins (EnvGP) evolved in order to combine two features. First, they acquired a domain to bind to a specific cellular protein, named "receptor." Second, they developed, with the help of cellular proteins, a function of finely controlled fusion to optimize the replication and preserve the integrity of the cell, specific to the genus of the virus. Following the activation of the EnvGP either by binding to their receptors and/or sometimes the acid pH of the endosomes, many changes of conformation permit ultimately the action of a specific hydrophobic domain, the fusion peptide, which destabilizes the cell membrane and leads to the opening of the lipidic membrane. The comprehension of these mechanisms is essential to develop medicines of the therapeutic class of entry inhibitor like enfuvirtide (Fuzeon) against human immunodeficiency virus (HIV). In this chapter, we will summarize the different envelope glycoprotein structures that viruses develop to achieve membrane fusion and the entry of the virus. We will describe the different entry pathways and cellular proteins that viruses have subverted to allow infection of the cell and the receptors that are used. Finally, we will illustrate more precisely the recent discoveries that have been made within the field of the entry process, with a focus on the use of pseudoparticles. These pseudoparticles are suitable for high-throughput screenings that help in the development of natural or artificial inhibitors as new therapeutics of the class of entry inhibitors. Copyright © 2011 Elsevier Inc. All rights reserved.

  7. Isolating The Building Thermal Envelope

    NASA Astrophysics Data System (ADS)

    Harrje, D. T.; Dutt, G. S.; Gadsby, K. J.

    1981-01-01

    The evaluation of the thermal integrity of building envelopes by infrared scanning tech-niques is often hampered in mild weather because temperature differentials across the envelope are small. Combining the infrared scanning with positive or negative building pressures, induced by a "blower door" or the building ventilation system, considerably extends the periods during which meaningful diagnostics can be conducted. Although missing or poorly installed insulation may lead to a substantial energy penalty, it is the search for air leakage sites that often has the largest potential for energy savings. Infrared inspection of the attic floor with air forced from the occupied space through ceiling by-passes, and inspecting the interior of the building when outside air is being sucked through the envelope reveals unexpected leakage sites. Portability of the diagnostic equipment is essential in these surveys which may include access into some tight spaces. A catalog of bypass heat losses that have been detected in residential housing using the combined infrared pressure differential technique is included to point out the wide variety of leakage sites which may compromise the benefits of thermal insulation and allow excessive air infiltration. Detection and suppression of such leaks should be key items in any building energy audit program. Where a calibrated blower door is used to pressurize or evacuate the house, the leakage rate can be quantified and an excessively tight house recognized. Houses that are too tight may be improved with a minimal energy penalty by forced ventilation,preferably with a heat recuperator and/or by providing combustion air directly to the furnace.

  8. Aircraft maneuver envelope warning system

    NASA Technical Reports Server (NTRS)

    Bivens, Courtland C. (Inventor); Rosado, Joel M. (Inventor); Lee, Burnett (Inventor)

    1994-01-01

    A maneuver envelope warning system for an aircraft having operating limits, operating condition sensors and an indicator driver. The indicator driver has a plurality of visual indicators. The indicator driver determines a relationship between sensed operating conditions and the operating limits; such as, a ratio therebetween. The indicator driver illuminates a number of the indicators in proportion to the determined relationship. The position of the indicators illuminated represents to a pilot in an easily ascertainable manner whether the operational conditions are approaching operational limits of the aircraft, and the degree to which operational conditions lie within or exceed operational limits.

  9. Flexible Envelope Request Notation (FERN)

    NASA Technical Reports Server (NTRS)

    Zoch, David R.; Lavallee, David; Weinstein, Stuart

    1991-01-01

    The following topics are presented in view graph form and include the following: scheduling application; the motivation for the Flexible Envelope Request Notation (FERN); characteristics of FERN; types of information needed in requests; where information is stored in requests; FERN structures; generic requests; resource availability for pooled resources; expressive notation; temporal constraints; time formats; changes to FERN; sample FERN requests; the temporal relationship between two steps; maximum activity length to limit step delays; alternative requests; the temporal relationship between two activities; and idle resource usage between steps.

  10. Circumplanetary disc or circumplanetary envelope?

    NASA Astrophysics Data System (ADS)

    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.

  11. Safeguards Envelope Progress FY10

    SciTech Connect

    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.

  12. Nuclear envelope breakdown induced by herpes simplex virus type 1 involves the activity of viral fusion proteins

    SciTech Connect

    Maric, Martina; Haugo, Alison C.; Dauer, William; Johnson, David; Roller, Richard J.

    2014-07-15

    Herpesvirus infection reorganizes components of the nuclear lamina usually without loss of integrity of the nuclear membranes. We report that wild-type HSV infection can cause dissolution of the nuclear envelope in transformed mouse embryonic fibroblasts that do not express torsinA. Nuclear envelope breakdown is accompanied by an eight-fold inhibition of virus replication. Breakdown of the membrane is much more limited during infection with viruses that lack the gB and gH genes, suggesting that breakdown involves factors that promote fusion at the nuclear membrane. Nuclear envelope breakdown is also inhibited during infection with virus that does not express UL34, but is enhanced when the US3 gene is deleted, suggesting that envelope breakdown may be enhanced by nuclear lamina disruption. Nuclear envelope breakdown cannot compensate for deletion of the UL34 gene suggesting that mixing of nuclear and cytoplasmic contents is insufficient to bypass loss of the normal nuclear egress pathway. - Highlights: • We show that wild-type HSV can induce breakdown of the nuclear envelope in a specific cell system. • The viral fusion proteins gB and gH are required for induction of nuclear envelope breakdown. • Nuclear envelope breakdown cannot compensate for deletion of the HSV UL34 gene.

  13. Hfq reduces envelope stress by controlling expression of envelope-localized proteins and protein complexes in enteropathogenic Escherichia coli.

    PubMed

    Vogt, Stefanie L; Raivio, Tracy L

    2014-05-01

    Gram-negative bacteria possess several envelope stress responses that detect and respond to damage to this critical cellular compartment. The σ(E) envelope stress response senses the misfolding of outer membrane proteins (OMPs), while the Cpx two-component system is believed to detect the misfolding of periplasmic and inner membrane proteins. Recent studies in several Gram-negative organisms found that deletion of hfq, encoding a small RNA chaperone protein, activates the σ(E) envelope stress response. In this study, we assessed the effects of deleting hfq upon activity of the σ(E) and Cpx responses in non-pathogenic and enteropathogenic (EPEC) strains of Escherichia coli. We found that the σ(E) response was activated in Δhfq mutants of all E. coli strains tested, resulting from the misregulation of OMPs. The Cpx response was activated by loss of hfq in EPEC, but not in E. coli K-12. Cpx pathway activation resulted in part from overexpression of the bundle-forming pilus (BFP) in EPEC Δhfq. We found that Hfq repressed expression of the BFP via PerA, a master regulator of virulence in EPEC. This study shows that Hfq has a more extensive role in regulating the expression of envelope proteins and horizontally acquired virulence genes in E. coli than previously recognized.

  14. C. elegans Nuclear Envelope Proteins Emerin, MAN1, Lamin, and Nucleoporins Reveal Unique Timing of Nuclear Envelope Breakdown during Mitosis

    PubMed Central

    Lee, Kenneth K.; Gruenbaum, Yosef; Spann, Perah; Liu, Jun; Wilson, Katherine L.

    2000-01-01

    Emerin, MAN1, and LAP2 are integral membrane proteins of the vertebrate nuclear envelope. They share a 43-residue N-terminal motif termed the LEM domain. We found three putative LEM domain genes in Caenorhabditis elegans, designated emr-1, lem-2, and lem-3. We analyzed emr-l, which encodes Ce-emerin, and lem-2, which encodes Ce-MAN1. Ce-emerin and Ce-MAN1 migrate on SDS-PAGE as 17- and 52-kDa proteins, respectively. Based on their biochemical extraction properties and immunolocalization, both Ce-emerin and Ce-MAN1 are integral membrane proteins localized at the nuclear envelope. We used antibodies against Ce-MAN1, Ce-emerin, nucleoporins, and Ce-lamin to determine the timing of nuclear envelope breakdown during mitosis in C. elegans. The C. elegans nuclear envelope disassembles very late compared with vertebrates and Drosophila. The nuclear membranes remained intact everywhere except near spindle poles during metaphase and early anaphase, fully disassembling only during mid-late anaphase. Disassembly of pore complexes, and to a lesser extent the lamina, depended on embryo age: pore complexes were absent during metaphase in >30-cell embryos but existed until anaphase in 2- to 24-cell embryos. Intranuclear mRNA splicing factors disassembled after prophase. The timing of nuclear disassembly in C. elegans is novel and may reflect its evolutionary position between unicellular and more complex eukaryotes. PMID:10982402

  15. The dynamic nature of the nuclear envelope

    PubMed Central

    Arnone, James T; Walters, Alison D; Cohen-Fix, Orna

    2013-01-01

    In eukaryotes, chromosomes are encased by a dynamic nuclear envelope. In contrast to metazoans, where the nuclear envelope disassembles during mitosis, many fungi including budding yeast undergo “closed mitosis,” where the nuclear envelope remains intact throughout the cell cycle. Consequently, during closed mitosis the nuclear envelope must expand to accommodate chromosome segregation to the two daughter cells. A recent study by Witkin et al. in budding yeast showed that if progression through mitosis is delayed, for example due to checkpoint activation, the nuclear envelope continues to expand despite the block to chromosome segregation. Moreover, this expansion occurs at a specific region of the nuclear envelope- adjacent to the nucleolus- forming an extension referred to as a “flare.” These observations raise questions regarding the regulation of nuclear envelope expansion both in budding yeast and in higher eukaryotes, the mechanisms confining mitotic nuclear envelope expansion to a particular region and the possible consequences of failing to regulate nuclear envelope expansion during the cell cycle. PMID:23873576

  16. Nonstationary envelope process and first excursion probability.

    NASA Technical Reports Server (NTRS)

    Yang, J.-N.

    1972-01-01

    The definition of stationary random envelope proposed by Cramer and Leadbetter, is extended to the envelope of nonstationary random process possessing evolutionary power spectral densities. The density function, the joint density function, the moment function, and the crossing rate of a level of the nonstationary envelope process are derived. Based on the envelope statistics, approximate solutions to the first excursion probability of nonstationary random processes are obtained. In particular, applications of the first excursion probability to the earthquake engineering problems are demonstrated in detail.

  17. Testing the Definition of the ESC Envelope

    NASA Technical Reports Server (NTRS)

    Vincent, Mark A.

    2017-01-01

    The previous effort, including a successful Change Control Request, addressed shrinking the size of the Earth Science Constellations' (ESC) Envelope by reducing the Margin. Fundamental to the purpose of the Envelope is the case where the argument of perigee of the secondary object circulates from 90 degrees to 270 degrees. This ("outside of the envelope, always outside the envelope") case was tested both numerically in a spreadsheet and analytically. Results showed how it is important to include the fact that a secondary with a different semi-major axis has a different frozen eccentricity value.

  18. Plotting max/min data envelopes

    NASA Technical Reports Server (NTRS)

    Furuike, T.; Long, J. C.

    1979-01-01

    Study of maximum and minimum load distributions along structural section is aided by visual display of load distribution data. Maximum/minimum envelope plot program plots these envelopes of the stresses and shear loads at selected points in beam modeled by series of finite elements. Digital output for engineers and management is presented for quick analysis and understanding.

  19. The metabolite transporters of the plastid envelope: an update.

    PubMed

    Facchinelli, Fabio; Weber, Andreas P M

    2011-01-01

    The engulfment of a photoautotrophic cyanobacterium by a primitive mitochondria-bearing eukaryote traces back to more than 1.2 billion years ago. This single endosymbiotic event not only provided the early petroalgae with the metabolic capacity to perform oxygenic photosynthesis, but also introduced a plethora of other metabolic routes ranging from fatty acids and amino acids biosynthesis, nitrogen and sulfur assimilation to secondary compounds synthesis. This implicated the integration and coordination of the newly acquired metabolic entity with the host metabolism. The interface between the host cytosol and the plastidic stroma became of crucial importance in sorting precursors and products between the plastid and other cellular compartments. The plastid envelope membranes fulfill different tasks: they perform important metabolic functions, as they are involved in the synthesis of carotenoids, chlorophylls, and galactolipids. In addition, since most genes of cyanobacterial origin have been transferred to the nucleus, plastidial proteins encoded by nuclear genes are post-translationally transported across the envelopes through the TIC-TOC import machinery. Most importantly, chloroplasts supply the photoautotrophic cell with photosynthates in form of reduced carbon. The innermost bilayer of the plastidic envelope represents the permeability barrier for the metabolites involved in the carbon cycle and is literally stuffed with transporter proteins facilitating their transfer. The intracellular metabolite transporters consist of polytopic proteins containing membrane spans usually in the number of four or more α-helices. Phylogenetic analyses revealed that connecting the plastid with the host metabolism was mainly a process driven by the host cell. In Arabidopsis, 58% of the metabolite transporters are of host origin, whereas only 12% are attributable to the cyanobacterial endosymbiont. This review focuses on the metabolite transporters of the inner envelope

  20. Seasonal benefits of a natural propolis envelope to honey bee immunity and colony health.

    PubMed

    Borba, Renata S; Klyczek, Karen K; Mogen, Kim L; Spivak, Marla

    2015-11-01

    Honey bees, as social insects, rely on collective behavioral defenses that produce a colony-level immune phenotype, or social immunity, which in turn impacts the immune response of individuals. One behavioral defense is the collection and deposition of antimicrobial plant resins, or propolis, in the nest. We tested the effect of a naturally constructed propolis envelope within standard beekeeping equipment on the pathogen and parasite load of large field colonies, and on immune system activity, virus and storage protein levels of individual bees over the course of a year. The main effect of the propolis envelope was a decreased and more uniform baseline expression of immune genes in bees during summer and autumn months each year, compared with the immune activity in bees with no propolis envelope in the colony. The most important function of the propolis envelope may be to modulate costly immune system activity. As no differences were found in levels of bacteria, pathogens and parasites between the treatment groups, the propolis envelope may act directly on the immune system, reducing the bees' need to activate the physiologically costly production of humoral immune responses. Colonies with a natural propolis envelope had increased colony strength and vitellogenin levels after surviving the winter in one of the two years of the study, despite the fact that the biological activity of the propolis diminished over the winter. A natural propolis envelope acts as an important antimicrobial layer enshrouding the colony, benefiting individual immunity and ultimately colony health. © 2015. Published by The Company of Biologists Ltd.

  1. The theoretical polarization of pure scattering axisymmetric circumstellar envelopes

    NASA Technical Reports Server (NTRS)

    Fox, G. K.

    1994-01-01

    The Sobolev approach to the scattering of starlight through a pure scattering circumstellar envelope is developed. The theoretical polarization due to electron scattering in Be star envelopes is calculated for two geometries (an equatorially enhanced envelope and a spheroidal envelope). Only the disk-type envelope is found to yield a maximum polarization consistent with the observed range for Be stars. A lower limit, analytical approximation to the theoretical polarization from a pure scattering envelope is obtained.

  2. Grazing envelope evolution towards Type IIb supernovae

    NASA Astrophysics Data System (ADS)

    Soker, Noam

    2017-09-01

    I propose a scenario where the majority of the progenitors of Type IIb supernovae (SNe IIb) lose most of their hydrogen-rich envelope during a grazing envelope evolution (GEE). In the GEE, the orbital radius of the binary system is about equal to the radius of the giant star, and the more compact companion accretes mass through an accretion disc. The accretion disc is assumed to launch two opposite jets that efficiently remove gas from the envelope along the orbit of the companion. The efficient envelope removal by jets prevents the binary system from entering a common envelope evolution, at least for part of the time. The GEE might be continuous or intermittent. I crudely estimate the total GEE time period to be in the range of about hundreds of years, for a continuous GEE, and up to few tens of thousands of years for intermittent GEE. The key new point is that the removal of envelope gas by jets during the GEE prevents the system from entering a common envelope evolution, and by that substantially increases the volume of the stellar binary parameter space that leads to SNe IIb, both to lower secondary masses and to closer orbital separations.

  3. Influenza A virus targets a cGAS-independent STING pathway that controls enveloped RNA viruses.

    PubMed

    Holm, Christian K; Rahbek, Stine H; Gad, Hans Henrik; Bak, Rasmus O; Jakobsen, Martin R; Jiang, Zhaozaho; Hansen, Anne Louise; Jensen, Simon K; Sun, Chenglong; Thomsen, Martin K; Laustsen, Anders; Nielsen, Camilla G; Severinsen, Kasper; Xiong, Yingluo; Burdette, Dara L; Hornung, Veit; Lebbink, Robert Jan; Duch, Mogens; Fitzgerald, Katherine A; Bahrami, Shervin; Mikkelsen, Jakob Giehm; Hartmann, Rune; Paludan, Søren R

    2016-02-19

    Stimulator of interferon genes (STING) is known be involved in control of DNA viruses but has an unexplored role in control of RNA viruses. During infection with DNA viruses STING is activated downstream of cGAMP synthase (cGAS) to induce type I interferon. Here we identify a STING-dependent, cGAS-independent pathway important for full interferon production and antiviral control of enveloped RNA viruses, including influenza A virus (IAV). Further, IAV interacts with STING through its conserved hemagglutinin fusion peptide (FP). Interestingly, FP antagonizes interferon production induced by membrane fusion or IAV but not by cGAMP or DNA. Similar to the enveloped RNA viruses, membrane fusion stimulates interferon production in a STING-dependent but cGAS-independent manner. Abolishment of this pathway led to reduced interferon production and impaired control of enveloped RNA viruses. Thus, enveloped RNA viruses stimulate a cGAS-independent STING pathway, which is targeted by IAV.

  4. Influenza A virus targets a cGAS-independent STING pathway that controls enveloped RNA viruses

    PubMed Central

    Holm, Christian K.; Rahbek, Stine H.; Gad, Hans Henrik; Bak, Rasmus O.; Jakobsen, Martin R.; Jiang, Zhaozaho; Hansen, Anne Louise; Jensen, Simon K.; Sun, Chenglong; Thomsen, Martin K.; Laustsen, Anders; Nielsen, Camilla G.; Severinsen, Kasper; Xiong, Yingluo; Burdette, Dara L.; Hornung, Veit; Lebbink, Robert Jan; Duch, Mogens; Fitzgerald, Katherine A.; Bahrami, Shervin; Mikkelsen, Jakob Giehm; Hartmann, Rune; Paludan, Søren R.

    2016-01-01

    Stimulator of interferon genes (STING) is known be involved in control of DNA viruses but has an unexplored role in control of RNA viruses. During infection with DNA viruses STING is activated downstream of cGAMP synthase (cGAS) to induce type I interferon. Here we identify a STING-dependent, cGAS-independent pathway important for full interferon production and antiviral control of enveloped RNA viruses, including influenza A virus (IAV). Further, IAV interacts with STING through its conserved hemagglutinin fusion peptide (FP). Interestingly, FP antagonizes interferon production induced by membrane fusion or IAV but not by cGAMP or DNA. Similar to the enveloped RNA viruses, membrane fusion stimulates interferon production in a STING-dependent but cGAS-independent manner. Abolishment of this pathway led to reduced interferon production and impaired control of enveloped RNA viruses. Thus, enveloped RNA viruses stimulate a cGAS-independent STING pathway, which is targeted by IAV. PMID:26893169

  5. Bacillus subtilis extracytoplasmic function (ECF) sigma factors and defense of the cell envelope

    PubMed Central

    Helmann, John D.

    2016-01-01

    Summary Bacillus subtilis provides a model for investigation of the bacterial cell envelope, the first line of defense against environmental threats. Extracytoplasmic function (ECF) sigma factors activate genes that confer resistance to agents that threaten the integrity of the envelope. Although their individual regulons overlap, σW is most closely associated with membrane-active agents, σX with cationic antimicrobial peptide resistance, and σV with resistance to lysozyme. Here, I highlight the role of the σM regulon, which is strongly induced by conditions that impair peptidoglycan synthesis and includes the core pathways of envelope synthesis and cell division, as well as stress-inducible alternative enzymes. Studies of these cell envelope stress responses provide insights into how bacteria acclimate to the presence of antibiotics. PMID:26901131

  6. Bacillus subtilis extracytoplasmic function (ECF) sigma factors and defense of the cell envelope.

    PubMed

    Helmann, John D

    2016-04-01

    Bacillus subtilis provides a model for investigation of the bacterial cell envelope, the first line of defense against environmental threats. Extracytoplasmic function (ECF) sigma factors activate genes that confer resistance to agents that threaten the integrity of the envelope. Although their individual regulons overlap, σ(W) is most closely associated with membrane-active agents, σ(X) with cationic antimicrobial peptide resistance, and σ(V) with resistance to lysozyme. Here, I highlight the role of the σ(M) regulon, which is strongly induced by conditions that impair peptidoglycan synthesis and includes the core pathways of envelope synthesis and cell division, as well as stress-inducible alternative enzymes. Studies of these cell envelope stress responses provide insights into how bacteria acclimate to the presence of antibiotics.

  7. Envelope theory in spectral geometry

    NASA Astrophysics Data System (ADS)

    Hall, Richard L.

    1993-07-01

    It is shown that the discrete spectrum of Schrödinger Hamiltonians of the form H=-Δ+vf may be represented by the semiclassical expression Enl=minr≳0 {K(f)nl(r) + vf(r)}. The K functions are found to be invariant with respect to coupling and shifts: K(Af+B)=K(f). For pure power laws, f(r)=sgn(q)rq, and the log potential, they are also invariant with respect to scale, and have the simple forms (Pnl(q)/r)2 and (Lnl/r)2, respectively. K functions are also derived for sech-squared and Hulthén potentials. If f=g(h), where g is a smooth transformation, then the envelope approximation is expressed in terms of K by the relation K(f)≂K(h). When the transformation g has definite convexity, then the approximation immediately yields eigenvalue bounds for all n and l. The theory is used to prove the log-power theorem Lnl = Pnl(0), which, in turn, generates a simple eigenvalue formula for the log potential.

  8. Safeguards Envelope Progress FY09

    SciTech Connect

    Richard Metcalf; Robert Bean

    2009-09-01

    The Safeguards Envelope is a strategy to determine a set of specific operating parameters which nuclear facilities may operate within to maximize safeguards effectiveness without sacrificing safety or plant efficiency. This paper details advanced statistical techniques will be applied to real plant process monitoring (PM) data from the Idaho Chemical Processing Plant (ICPP). As a result of the U.S. having no operating nuclear chemical reprocessing plants, there has been a strong interest in obtaining process monitoring data from the ICPP. The ICPP was shut down in 1996 and a recent effort has been made to retrieve the PM data from storage in a data mining effort. In a simulation based on this data, multi-tank and multi-attribute correlations were tested against synthetic diversion scenarios. Kernel regression smoothing was used to fit a curve to the historical data, and multivariable, residual analysis and cumulative sum techniques set parameters for operating conditions. Diversion scenarios were created and tested, showing improved results when compared with a previous study utilizing only one-variable Z- testing7.

  9. Personnel occupied woven envelope robot

    NASA Technical Reports Server (NTRS)

    Wessling, Francis; Teoh, William; Ziemke, M. Carl

    1988-01-01

    The Personnel Occupied Woven Envelope Robot (POWER) provides an alternative to extravehicular activity (EVA) of space suited astronauts and/or use of long slender manipulator arms such as are used in the Shuttle Remote Manipulator System. POWER provides the capability for a shirt sleeved astronaut to perform such work by entering a control pod through air locks at both ends of an inflated flexible bellows (access tunnel). The exoskeleton of the tunnel is a series of six degrees of freedom (Six-DOF) articulated links compressible to 1/6 of their fully extended length. The operator can maneuver the control pod to almost any location within about 50 m of the base attachment to the space station. POWER can be envisioned as a series of hollow Six-DOF manipulator segments or arms wherein each arm grasps the shoulder of the next arm. Inside the hollow arms ia a bellow-type access tunnel. The control pod is the fist of the series of linked hollow arms. The fingers of the fist are conventional manipulator arms under direct visual control of the nearby operator in the pod. The applications and progress to date of the POWER system is given.

  10. Personnel occupied woven envelope robot

    NASA Technical Reports Server (NTRS)

    Wessling, Francis; Teoh, William; Ziemke, M. Carl

    1988-01-01

    The Personnel Occupied Woven Envelope Robot (POWER) provides an alternative to extravehicular activity (EVA) of space suited astronauts and/or use of long slender manipulator arms such as are used in the Shuttle Remote Manipulator System. POWER provides the capability for a shirt sleeved astronaut to perform such work by entering a control pod through air locks at both ends of an inflated flexible bellows (access tunnel). The exoskeleton of the tunnel is a series of six degrees of freedom (Six-DOF) articulated links compressible to 1/6 of their fully extended length. The operator can maneuver the control pod to almost any location within about 50 m of the base attachment to the space station. POWER can be envisioned as a series of hollow Six-DOF manipulator segments or arms wherein each arm grasps the shoulder of the next arm. Inside the hollow arms ia a bellow-type access tunnel. The control pod is the fist of the series of linked hollow arms. The fingers of the fist are conventional manipulator arms under direct visual control of the nearby operator in the pod. The applications and progress to date of the POWER system is given.

  11. New pharmacological strategies to fight enveloped viruses.

    PubMed

    Wisskirchen, Karin; Lucifora, Julie; Michler, Thomas; Protzer, Ulrike

    2014-09-01

    Enveloped viruses pose an important health threat because most of the persistent and many emerging viruses are enveloped. In particular, newly emerging viruses create a need to develop broad-spectrum antivirals, which usually are obtained by targeting host cell factors. Persistent viruses have developed efficient strategies to escape host immune control, and treatment options are limited. Targeting host cell factors essential for virus persistence, or immune-based therapies provide alternative approaches. In this review, we therefore focus on recent developments to generate antivirals targeting host cell factors or immune-based therapeutic approaches to fight infections with enveloped viruses. Copyright © 2014 Elsevier Ltd. All rights reserved.

  12. Resource envelope concepts for mission planning

    NASA Technical Reports Server (NTRS)

    Ibrahim, K. Y.; Weiler, J. D.; Tokaz, J. C.

    1991-01-01

    Seven proposed methods for creating resource envelopes for Space Station Freedom mission planning are detailed. Four reference science activity models are used to illustrate the effect of adding operational flexibility to mission timelines. For each method, a brief explanation is given along with graphs to illustrate the application of the envelopes to the power and crew resources. The benefits and costs of each method are analyzed in terms of resource utilization. In addition to the effect on individual activities, resource envelopes are analyzed at the experiment level.

  13. Radiative accelerations in stellar envelopes

    NASA Astrophysics Data System (ADS)

    Seaton, M. J.

    1997-08-01

    In stars which are sufficiently quiescent, changes in the relative abundances of the chemical elements can result from gravitational settling and from levitation produced by radiation pressure forces, usually expressed as radiative accelerations g_rad. Those changes can affect the structure of such stars, due to modifications in opacities, and can lead to marked peculiarities in observed atmospheric abundances. It is necessary to consider diffusive movements both in the atmospheres and in much deeper layers of the stellar envelopes. For the envelopes the equation of radiative transfer can be solved in a diffusion approximation and, for an element k in ionization stage j, one obtains expressions for g_rad(j, k) proportional to the total radiative flux, to the Rosseland-mean opacity kappa_R (which may depend on the abundance of k), and to a dimensionless quantity gamma(j, k) which, due to saturation effects, can be sensitive to the abundance of k. The radiative accelerations are required for each ionization stage, because the diffusion coefficients depend on j. Using atomic data obtained in the course of the work of the Opacity Project (OP), we calculate kappa_R and gamma(j, k) for the chemical elements C, N, O, Ne, Na, Mg, Al, Si, S, Ar, Ca, Cr, Mn, Fe and Ni. We start from standard Solar system abundances, and then vary the abundance of one element at a time (element k) by a factor chi. The following results are obtained and are available at the Centre de Donnees astronomiques de Strasbourg (CDS). (1) Files stages.zz (where zz specifies the nuclear charge of the selected element k) containing values of kappa_R and gamma(j, k) on a mesh of values of (T, N_e, chi), where T is temperature, and N_e is electron density. We include derivatives of kappa_R and gamma(j, k) with respect to chi, which are used for making interpolations. (2) A code add.f which reads a file stages.zz and writes a file acc.zz containing values of gamma(k) obtained on summing the gamma(j, k

  14. Personnel occupied woven envelope robot power

    NASA Technical Reports Server (NTRS)

    Wessling, F. C.

    1988-01-01

    The Personnel Occupied Woven Envelope Robot (POWER) concept has evolved over the course of the study. The goal of the project was the development of methods and algorithms for solid modeling for the flexible robot arm.

  15. Nuclear envelopathies: a complex LINC between nuclear envelope and pathology.

    PubMed

    Janin, Alexandre; Bauer, Delphine; Ratti, Francesca; Millat, Gilles; Méjat, Alexandre

    2017-08-30

    Since the identification of the first disease causing mutation in the gene coding for emerin, a transmembrane protein of the inner nuclear membrane, hundreds of mutations and variants have been found in genes encoding for nuclear envelope components. These proteins can be part of the inner nuclear membrane (INM), such as emerin or SUN proteins, outer nuclear membrane (ONM), such as Nesprins, or the nuclear lamina, such as lamins A and C. However, they physically interact with each other to insure the nuclear envelope integrity and mediate the interactions of the nuclear envelope with both the genome, on the inner side, and the cytoskeleton, on the outer side. The core of this complex, called LINC (LInker of Nucleoskeleton to Cytoskeleton) is composed of KASH and SUN homology domain proteins. SUN proteins are INM proteins which interact with lamins by their N-terminal domain and with the KASH domain of nesprins located in the ONM by their C-terminal domain.Although most of these proteins are ubiquitously expressed, their mutations have been associated with a large number of clinically unrelated pathologies affecting specific tissues. Moreover, variants in SUN proteins have been found to modulate the severity of diseases induced by mutations in other LINC components or interactors. For these reasons, the diagnosis and the identification of the molecular explanation of "nuclear envelopathies" is currently challenging.The aim of this review is to summarize the human diseases caused by mutations in genes coding for INM proteins, nuclear lamina, and ONM proteins, and to discuss their potential physiopathological mechanisms that could explain the large spectrum of observed symptoms.

  16. Creating a Lunar EVA Work Envelope

    NASA Technical Reports Server (NTRS)

    Griffin, Brand N.; Howard, Robert; Rajulu, Sudhakar; Smitherman, David

    2009-01-01

    A work envelope has been defined for weightless Extravehicular Activity (EVA) based on the Space Shuttle Extravehicular Mobility Unit (EMU), but there is no equivalent for planetary operations. The weightless work envelope is essential for planning all EVA tasks because it determines the location of removable parts, making sure they are within reach and visibility of the suited crew member. In addition, using the envelope positions the structural hard points for foot restraints that allow placing both hands on the job and provides a load path for reacting forces. EVA operations are always constrained by time. Tasks are carefully planned to ensure the crew has enough breathing oxygen, cooling water, and battery power. Planning first involves computers using a virtual work envelope to model tasks, next suited crew members in a simulated environment refine the tasks. For weightless operations, this process is well developed, but planetary EVA is different and no work envelope has been defined. The primary difference between weightless and planetary work envelopes is gravity. It influences anthropometry, horizontal and vertical mobility, and reaction load paths and introduces effort into doing "overhead" work. Additionally, the use of spacesuits other than the EMU, and their impacts on range of motion, must be taken into account. This paper presents the analysis leading to a concept for a planetary EVA work envelope with emphasis on lunar operations. There is some urgency in creating this concept because NASA has begun building and testing development hardware for the lunar surface, including rovers, habitats and cargo off-loading equipment. Just as with microgravity operations, a lunar EVA work envelope is needed to guide designers in the formative stages of the program with the objective of avoiding difficult and costly rework.

  17. Control load envelope shaping by live twist

    NASA Technical Reports Server (NTRS)

    Tarzanin, F. J., Jr.; Mirick, P. H.

    1974-01-01

    Rotor control systems experience a rapid load growth resulting from retreating blade stall during flight conditions of high blade loading or airspeeds. An investigation was undertaken to determine the effect of changing blade torsional properties over the rotor flight envelope. The results of this study show that reducing the blade stiffness to introduce more blade live twist significantly reduces the large retreating blade control loads, while expanding the flight envelope and reducing retreating blade stall loads.

  18. Cooling of neutron stars with diffusive envelopes

    NASA Astrophysics Data System (ADS)

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

    2016-12-01

    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 105-106 yr 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 reconstruction of the internal structure of cooling neutron stars from observations of their thermal surface emission.

  19. The joke envelope: a neglected precursor of the psychic envelope concept in Freud's writing.

    PubMed

    Spero, Moshe Halevi

    2009-01-01

    The concepts of the primeval skin ego, psychic envelope, and related pre-ego containing and wrapping functions elaborated respectively by Esther Bick, Didier Anzieu, and Francis Tustin occupy an important position in contemporary psychoanalytic theory and clinical practice. The psychic envelope begins as a virtual mental protostructure ("proto" because it is not yet based on fully symbolized representations) that holds the budding mind together pending further developments. With maturity, the enveloping functions adopt symbolized, metaphoric form (for example, the aesthetic use of cloth, the analytic framework), but can regress to more concrete and pathological forms. The aforementioned authors based their ideas on a cluster of specific allusions to the idea of a psychic covering, barrier, or envelope in Freud's work. Yet they neglected one reference, hidden in Freud's analysis of the structure ofjokes and humor: the 'joke envelope"--die witzige Einkleidung. The present essay explores Freud's use of the term Einkleidung, including his intriguing idea that a joke requires three people whereas a dream does not and the fact that Freud nowhere speaks of a "dream envelope. "I take the "joke envelope" beyond its original context and posit a relationship between laughter and the early, normative traumas of breathing, crying, and loss, and the dawn of rhythmic envelopes that enable mentalization. Jokes and joking symbolically repeat the early rupture and rapture of breathing and self-other differentiation and the internalization of maternal containing and envelopment.

  20. Nuclear envelope and genome interactions in cell fate

    PubMed Central

    Talamas, Jessica A.; Capelson, Maya

    2015-01-01

    The eukaryotic cell nucleus houses an organism’s genome and is the location within the cell where all signaling induced and development-driven gene expression programs are ultimately specified. The genome is enclosed and separated from the cytoplasm by the nuclear envelope (NE), a double-lipid membrane bilayer, which contains a large variety of trans-membrane and associated protein complexes. In recent years, research regarding multiple aspects of the cell nucleus points to a highly dynamic and coordinated concert of efforts between chromatin and the NE in regulation of gene expression. Details of how this concert is orchestrated and how it directs cell differentiation and disease are coming to light at a rapid pace. Here we review existing and emerging concepts of how interactions between the genome and the NE may contribute to tissue specific gene expression programs to determine cell fate. PMID:25852741

  1. Solitary Alfven wave envelopes and the modulational instability

    SciTech Connect

    Kennel, C.F.

    1987-06-01

    The derivative nonlinear Schroedinger equation describes the modulational instability of circularly polarized dispersive Alfven wave envelopes. It also may be used to determine the properties of finite amplitude localized stationary wave envelopes. Such envelope solitons exist only in conditions of modulational stability. This leaves open the question of whether, and if so, how, the modulational instability produces envelope solitons. 12 refs.

  2. Detection of an Immunogenic HERV-E Envelope with Selective Expression in Clear Cell Kidney Cancer.

    PubMed

    Cherkasova, Elena; Scrivani, Claire; Doh, Susan; Weisman, Quinn; Takahashi, Yoshiyuki; Harashima, Nanae; Yokoyama, Hisayuki; Srinivasan, Ramaprasad; Linehan, W Marston; Lerman, Michael I; Childs, Richard W

    2016-04-15

    VHL-deficient clear cell renal cell carcinomas (ccRCC), the most common form of kidney cancer, express transcripts derived from the novel human endogenous retrovirus HERV-E (named CT-RCC HERV-E). In this study, we define a transcript encoding the entire envelope gene of HERV-E as expressed selectively in ccRCC tumors, as distinct from normal kidney tissues or other tumor types. Sequence analysis of this envelope transcript revealed long open reading frames encoding putative surface and transmembrane envelope proteins. Retroviral envelopes are known to be capable of eliciting immunity in humans. Accordingly, we found that HLA-A*0201-restricted peptides predicted to be products of the CT-RCC HERV-E envelope transcript-stimulated CD8(+) T cells, which could recognize HLA-A*0201-positive HERV-E-expressing kidney tumor cells. Overall, our results offer evidence of unique HERV-E envelope peptides presented on the surface of ccRCC cells, offering potentially useful tumor-restricted targets for T-cell-based immunotherapy of kidney cancer. Cancer Res; 76(8); 2177-85. ©2016 AACR. ©2016 American Association for Cancer Research.

  3. Enveloped and non-enveloped viral-like particles in Trypanosoma cruzi epimastigotes

    PubMed Central

    Fernández-Presas, Ana María; Padilla-Noriega, Luis; Ingeborg-Becker; Robert, Lilia; Jiménez, José Agustín; Solano, Sandra; Delgado, Jose; Tato, Patricia; Molinari, José Luis

    2017-01-01

    ABSTRACT Electron microscopy is routinely used to identify viral infections in protozoan parasites. These viruses have been described as non-enveloped and icosahedral structures with a diameter of 30-60 nm. Most of them are classified within the non-segmented dsRNA Totiviridae family. We observed virus-like particles (VLPs) through transmission electron microscopy in the cytoplasm of Trypanosoma cruzi epimastigotes grown in cultures. Clusters of electrodense enveloped VLPs having a diameter of 48 nm were also observed. These clusters appear to have been released from distended Golgi cisternae. Furthermore, a paracrystalline array of electrodense, non-enveloped VLPs (with a diameter of 32 nm) were found in distended Golgi cisternae or as smaller clusters at a distance from the RE or Golgi. We cannot rule out that the 48 nm enveloped VLPs belong to the ssRNA Flaviviridae family because they are within its size range. The localization of enveloped VLPs is consistent with the replication strategy of these viruses that transit through the Golgi to be released at the cell surface. Due to the size and shape of the 32 nm non-enveloped VLPs, we propose that they belong to the dsRNA Totiviridae family. This is the first description of cytoplasmic enveloped and non-enveloped VLPs in T. cruzi epimastigotes. PMID:28793017

  4. Enveloped and non-enveloped viral-like particles in Trypanosoma cruzi epimastigotes.

    PubMed

    Fernández-Presas, Ana María; Padilla-Noriega, Luis; Becker, Ingeborg; Robert, Lilia; Jiménez, José Agustín; Solano, Sandra; Delgado, Jose; Tato, Patricia; Molinari, José Luis

    2017-08-07

    Electron microscopy is routinely used to identify viral infections in protozoan parasites. These viruses have been described as non-enveloped and icosahedral structures with a diameter of 30-60 nm. Most of them are classified within the non-segmented dsRNA Totiviridae family. We observed virus-like particles (VLPs) through transmission electron microscopy in the cytoplasm of Trypanosoma cruzi epimastigotes grown in cultures. Clusters of electrodense enveloped VLPs having a diameter of 48 nm were also observed. These clusters appear to have been released from distended Golgi cisternae. Furthermore, a paracrystalline array of electrodense, non-enveloped VLPs (with a diameter of 32 nm) were found in distended Golgi cisternae or as smaller clusters at a distance from the RE or Golgi. We cannot rule out that the 48 nm enveloped VLPs belong to the ssRNA Flaviviridae family because they are within its size range. The localization of enveloped VLPs is consistent with the replication strategy of these viruses that transit through the Golgi to be released at the cell surface. Due to the size and shape of the 32 nm non-enveloped VLPs, we propose that they belong to the dsRNA Totiviridae family. This is the first description of cytoplasmic enveloped and non-enveloped VLPs in T. cruzi epimastigotes.

  5. Role of HIV-2 envelope in Lv2-mediated restriction

    SciTech Connect

    Reuter, Sandra; Kaumanns, Patrick; Buschhorn, Sabine B.; Dittmar, Matthias T. . E-mail: Matthias_Dittmar@med.uni-heidelberg.de

    2005-02-05

    We have characterized envelope protein pseudotyped HIV-2 particles derived from two HIV-2 isolates termed prCBL23 and CBL23 in order to define the role of the envelope protein for the Lv2-mediated restriction to infection. Previously, it has been described that the primary isolate prCBL23 is restricted to infection of several human cell types, whereas the T cell line adapted isolate CBL23 is not restricted in these cell types. Molecular cloning of the two isolates revealed that the env and the gag gene are responsible for the observed phenotype and that this restriction is mediated by Lv2, which is distinct from Ref1/Lv1 (Schmitz, C., Marchant, D., Neil, S.J., Aubin, K., Reuter, S., Dittmar, M.T., McKnight, A., Kizhatil, K., Albritton, L.M., 2004. Lv2, a novel postentry restriction, is mediated by both capsid and envelope. J. Virol. 78 (4), 2006-2016). We generated pseudotyped viruses consisting of HIV-2 (ROD-A{delta}env-GFP, ROD-A{delta}env-RFP, or ROD-A{delta}env-REN) and the prCBL23 or CBL23 envelope proteins as well as chimeric proteins between these envelopes. We demonstrate that a single amino acid exchange at position 74 in the surface unit of CBL23-Env confers restriction to infection. This single point mutation causes tighter CD4 binding, resulting in a less efficient fusion into the cytosol of the restricted cell line. Prevention of endosome formation and prevention of endosome acidification enhance infectivity of the restricted particles for GHOST/X4 cells indicating a degradative lysosomal pathway as a cause for the reduced cytosolic entry. The described restriction to infection of the primary isolate prCBL23 is therefore largely caused by an entry defect. A remaining restriction to infection (19-fold) is preserved when endosomal acidification is prevented. This restriction to infection is also dependent on the presence of the point mutation at position 74 (G74E)

  6. Morphologically complex protostellar envelopes : structure and kinematics

    NASA Astrophysics Data System (ADS)

    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

  7. COMPLEX STRUCTURE IN CLASS 0 PROTOSTELLAR ENVELOPES

    SciTech Connect

    Tobin, John J.; Hartmann, Lee; Looney, Leslie W.; Chiang, Hsin-Fang

    2010-04-01

    We use archived Infrared Array Camera images from the Spitzer Space Telescope to show that many Class 0 protostars exhibit complex, irregular, and non-axisymmetric structure within their dusty envelopes. Our 8 {mu}m extinction maps probe some of the densest regions in these protostellar envelopes. Many of the systems are observed to have highly irregular and non-axisymmetric morphologies on scales {approx}>1000 AU, with a quarter of the sample exhibiting filamentary or flattened dense structures. Complex envelope structure is observed in regions spatially distinct from outflow cavities, and the densest structures often show no systematic alignment perpendicular to the cavities. These results indicate that mass ejection is not responsible for much of the irregular morphologies we detect; rather, we suggest that the observed envelope complexity is mostly the result of collapse from protostellar cores with initially non-equilibrium structures. The striking non-axisymmetry in many envelopes could provide favorable conditions for the formation of binary systems. We also note that protostars in the sample appear to be formed preferentially near the edges of clouds or bends in filaments, suggesting formation by gravitational focusing.

  8. Featured Image: Orbiting Stars Share an Envelope

    NASA Astrophysics Data System (ADS)

    Kohler, Susanna

    2016-03-01

    This beautiful series of snapshots from a simulation (click for a better look!) shows what happens when two stars in a binary system become enclosed in the same stellar envelope. In this binary system, one of the stars has exhausted its hydrogen fuel and become a red giant, complete with an expanding stellar envelope composed of hydrogen and helium. Eventually, the envelope expands so much that the companion star falls into it, where it releases gravitational potential energy into the common envelope. A team led by Sebastian Ohlmann (Heidelberg Institute for Theoretical Studies and University of Wrzburg) recently performed hydrodynamic simulations of this process. Ohlmann and collaborators discovered that the energy release eventually triggers large-scale flow instabilities, which leads to turbulence within the envelope. This process has important consequences for how these systems next evolve (for instance, determining whether or not a supernova occurs!). You can check out the authors video of their simulated stellar inspiral below, or see their paper for more images and results from their study.CitationSebastian T. Ohlmann et al 2016 ApJ 816 L9. doi:10.3847/2041-8205/816/1/L9

  9. The cell envelope proteome of Aggregatibacter actinomycetemcomitans.

    PubMed

    Smith, K P; Fields, J G; Voogt, R D; Deng, B; Lam, Y-W; Mintz, K P

    2015-04-01

    The cell envelope of gram-negative bacteria serves a critical role in maintenance of cellular homeostasis, resistance to external stress, and host-pathogen interactions. Envelope protein composition is influenced by the physiological and environmental demands placed on the bacterium. In this study, we report a comprehensive compilation of cell envelope proteins from the periodontal and systemic pathogen Aggregatibacter actinomycetemcomitans VT1169, an afimbriated serotype b strain. The urea-extracted membrane proteins were identified by mass spectrometry-based shotgun proteomics. The membrane proteome, isolated from actively growing bacteria under normal laboratory conditions, included 648 proteins representing 27% of the predicted open reading frames in the genome. Bioinformatic analyses were used to annotate and predict the cellular location and function of the proteins. Surface adhesins, porins, lipoproteins, numerous influx and efflux pumps, multiple sugar, amino acid and iron transporters, and components of the type I, II and V secretion systems were identified. Periplasmic space and cytoplasmic proteins with chaperone function were also identified. A total of 107 proteins with unknown function were associated with the cell envelope. Orthologs of a subset of these uncharacterized proteins are present in other bacterial genomes, whereas others are found exclusively in A. actinomycetemcomitans. This knowledge will contribute to elucidating the role of cell envelope proteins in bacterial growth and survival in the oral cavity.

  10. Adaptive Spectral Envelope Estimation for Doppler Ultrasound.

    PubMed

    Kathpalia, Aditi; Karabiyik, Yucel; Eik-Nes, Sturla; Tegnander, Eva; Ekroll, Ingvild; Kiss, Gabriel; Torp, Hans

    2016-07-07

    Estimation of accurate maximum velocities and spectral envelope in ultrasound Doppler blood flow spectrograms are both essential for clinical diagnostic purposes. However, obtaining accurate maximum velocity is not straightforward due to intrinsic spectral broadening and variance in the power spectrum estimate. The method proposed in this work for maximum velocity point detection has been developed by modifying an existing method - Signal Noise Slope Intersection (SNSI), incorporating in it steps from an altered version of another method called Geometric Method (GM). Adaptive noise estimation from the spectrogram ensures that a smooth spectral envelope is obtained post detection of these maximum velocity points. The method has been tested on simulated Doppler signal with scatterers possessing a parabolic flow velocity profile constant in time, steady and pulsatile string phantom recordings as well as in vivo recordings from uterine, umbilical, carotid and subclavian arteries. Results from simulation experiments indicate a bias of less than 2.5% in maximum velocities when estimated for a range of peak velocities, Doppler angles and SNR levels. Standard deviation in the envelope is low - less than 2% in case of experiments done by varying the peak velocity and Doppler angle for steady phantom and simulated flow; and also less than 2% in case of experiments done by varying SNR but keeping constant flow conditions for in vivo and simulated flow. Low variability in the envelope makes the prospect of using the envelope for automated blood flow measurements possible and is illustrated for the case of Pulsatility Index estimation in uterine and umbilical arteries.

  11. Inhibition of Enveloped Viruses Infectivity by Curcumin

    PubMed Central

    Wen, Hsiao-Wei; Ou, Jun-Lin; Chiou, Shyan-Song; Chen, Jo-Mei; Wong, Min-Liang; Hsu, Wei-Li

    2013-01-01

    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. PMID:23658730

  12. Motion of contrast envelopes: peace and noise.

    PubMed

    Cropper, S J; Johnston, A

    2001-09-01

    We examined the effect of changing the composition of the carrier on the perception of motion in a drifting contrast envelope. Human observers were required to discriminate the direction of motion of contrast modulations of an underlying carrier as a function of temporal frequency and scaled (carrier) contrast. The carriers were modulations of both color and luminance, defined within a cardinal color space. Random-noise carriers had either binary luminance profiles or flat (gray-scale-white) or 1/f (pink) spectral power functions. Independent variables investigated were the envelope spatial frequency and temporal-drift frequency and the fundamental spatial frequency, color, and temporal-update frequency of the carrier. The results show that observers were able to discriminate correctly the direction of envelope motion for binary-noise carriers at both high (16 Hz) and low (2 Hz) temporal-drift frequencies. Changing the carrier format from binary noise to a flat (gray-scale) or 1/f amplitude profile reduced discrimination performance slightly but only in the high-temporal-frequency condition. Manipulation of the fundamental frequency of the carrier elicited no change in performance at the low temporal frequencies but produced ambiguous or reversed motion at the higher temporal frequencies as soon as the fundamental frequency was higher than the envelope modulation frequency. We found that envelope motion detection was sensitive to the structure of the carrier.

  13. The Novel Nuclear Envelope Protein KAKU4 Modulates Nuclear Morphology in Arabidopsis[W

    PubMed Central

    Goto, Chieko; Tamura, Kentaro; Fukao, Yoichiro; Shimada, Tomoo; Hara-Nishimura, Ikuko

    2014-01-01

    In animals, the nuclear lamina is a fibrillar meshwork on the inner surface of the nuclear envelope, composed of coiled-coil lamin proteins and lamin binding membrane proteins. Plants also have a meshwork on the inner surface of the nuclear envelope, but little is known about its composition other than the presence of members of the CROWDED NUCLEI (CRWN) protein family, possible plant lamin analogs. Here, we describe a candidate lamina component, based on two Arabidopsis thaliana mutants (kaku2 and kaku4) with aberrant nuclear morphology. The responsible gene in kaku2 encodes CRWN1, and the responsible gene in kaku4 encodes a plant-specific protein of unknown function (KAKU4) that physically interacts with CRWN1 and its homolog CRWN4. Immunogold labeling revealed that KAKU4 localizes at the inner nuclear membrane. KAKU4 deforms the nuclear envelope in a dose-dependent manner, in association with nuclear membrane invagination and stack formation. The KAKU4-dependent nuclear envelope deformation was enhanced by overaccumulation of CRWN1, although KAKU4 can deform the nuclear envelope even in the absence of CRWN1 and/or CRWN4. Together, these results suggest that plants have evolved a unique lamina-like structure to modulate nuclear shape and size. PMID:24824484

  14. Deltabaculoviruses encode a functional type I budded virus envelope fusion protein

    USDA-ARS?s Scientific Manuscript database

    Envelope fusion proteins (F proteins) are major constituents of budded viruses (BVs) of alpha- and betabaculoviruses (Baculoviridae) and are essential for the systemic infection of insect larvae and insect cells in culture. An F protein homolog gene was absent in gammabaculoviruses. Here we show tha...

  15. Envelope Solitons in Acoustically Dispersive Vitreous Silica

    NASA Technical Reports Server (NTRS)

    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.

  16. Drug design from the cryptic inhibitor envelope.

    PubMed

    Lee, Chul-Jin; Liang, Xiaofei; Wu, Qinglin; Najeeb, Javaria; Zhao, Jinshi; Gopalaswamy, Ramesh; Titecat, Marie; Sebbane, Florent; Lemaitre, Nadine; Toone, Eric J; Zhou, Pei

    2016-02-25

    Conformational dynamics plays an important role in enzyme catalysis, allosteric regulation of protein functions and assembly of macromolecular complexes. Despite these well-established roles, such information has yet to be exploited for drug design. Here we show by nuclear magnetic resonance spectroscopy that inhibitors of LpxC--an essential enzyme of the lipid A biosynthetic pathway in Gram-negative bacteria and a validated novel antibiotic target--access alternative, minor population states in solution in addition to the ligand conformation observed in crystal structures. These conformations collectively delineate an inhibitor envelope that is invisible to crystallography, but is dynamically accessible by small molecules in solution. Drug design exploiting such a hidden inhibitor envelope has led to the development of potent antibiotics with inhibition constants in the single-digit picomolar range. The principle of the cryptic inhibitor envelope approach may be broadly applicable to other lead optimization campaigns to yield improved therapeutics.

  17. Drug design from the cryptic inhibitor envelope

    PubMed Central

    Lee, Chul-Jin; Liang, Xiaofei; Wu, Qinglin; Najeeb, Javaria; Zhao, Jinshi; Gopalaswamy, Ramesh; Titecat, Marie; Sebbane, Florent; Lemaitre, Nadine; Toone, Eric J.; Zhou, Pei

    2016-01-01

    Conformational dynamics plays an important role in enzyme catalysis, allosteric regulation of protein functions and assembly of macromolecular complexes. Despite these well-established roles, such information has yet to be exploited for drug design. Here we show by nuclear magnetic resonance spectroscopy that inhibitors of LpxC—an essential enzyme of the lipid A biosynthetic pathway in Gram-negative bacteria and a validated novel antibiotic target—access alternative, minor population states in solution in addition to the ligand conformation observed in crystal structures. These conformations collectively delineate an inhibitor envelope that is invisible to crystallography, but is dynamically accessible by small molecules in solution. Drug design exploiting such a hidden inhibitor envelope has led to the development of potent antibiotics with inhibition constants in the single-digit picomolar range. The principle of the cryptic inhibitor envelope approach may be broadly applicable to other lead optimization campaigns to yield improved therapeutics. PMID:26912110

  18. Ultradonut topology of the nuclear envelope

    PubMed Central

    Torbati, Mehdi; Lele, Tanmay P.; Agrawal, Ashutosh

    2016-01-01

    The nuclear envelope is a unique topological structure formed by lipid membranes in eukaryotic cells. Unlike other membrane structures, the nuclear envelope comprises two concentric membrane shells fused at numerous sites with toroid-shaped pores that impart a “geometric” genus on the order of thousands. Despite the intriguing architecture and vital biological functions of the nuclear membranes, how they achieve and maintain such a unique arrangement remains unknown. Here, we used the theory of elasticity and differential geometry to analyze the equilibrium shape and stability of this structure. Our results show that modest in- and out-of-plane stresses present in the membranes not only can define the pore geometry, but also provide a mechanism for destabilizing membranes beyond a critical size and set the stage for the formation of new pores. Our results suggest a mechanism wherein nanoscale buckling instabilities can define the global topology of a nuclear envelope-like structure. PMID:27647910

  19. The photodissociation of CO in circumstellar envelopes

    NASA Technical Reports Server (NTRS)

    Mamon, G. A.; Glassgold, A. E.; Huggins, P. J.

    1988-01-01

    The CO photodissociation rate for the unshielded ISM is calculated using recent laboratory results which confirm that photodissociation occurs by way of line absorption. A value of 2.0 x 10 to the -10th/s, an order of magnitude higher than the rate used in the past, is obtained. The new rate and a treatment of the radiative transfer and shielding are used to develop a theory for the CO abundance in the circumstellar envelopes of cool, evolved stars, and results are presented on the spatial variation of CO, C, and C(+). It is shown that these distributions play important roles in determining the observational properties of circumstellar envelopes.

  20. Consumer access to utility billing envelopes

    SciTech Connect

    Anglin, M.K.

    1984-09-13

    Billing envelope inserts are a medium of advertising used by utilities for a variety of purposes, from encouraging conservation to expressing political opinions. Recently, consumer groups have begun to assert a right of access to the same medium. A constitutional right of reply has been advocated. Commissions have found regulatory authority to direct companies to provide access on the basis of several different theories. At least two states have passed legislation permitting consumer groups to use bill inserts to solicit members and contributions. When examined, these developments reveal a trend of granting organizations access to utility billing envelopes.

  1. [NESPRINS--nuclear envelope proteins ensuring integrity].

    PubMed

    Pershina, E G; Morozova, K N; Kiseleva, E V

    2014-01-01

    This review describes the nesprins (nuclear envelope spectrin-repeat proteins), which are recently discovered family of nuclear envelope proteins. These proteins play an important role in maintaining the cellular architecture and establish the link between the nucleus and other sub-cellular compartments. Many tissue-specific diseases including lipodystrophies, hearing loss, cardiac and skeletal myopathies are associated with nesprins mutations. These proteins comprise of multiple tissue specific isoforms which contain spectrin repeats providing interaction of nesprins with other nuclear membrane proteins, cytoskeleton and intranuclear matrix. We summarize recent findings and suggestions about nesprins structural organization and function inside the cell. Human diseases caused by abnormal nesprins expression are also described.

  2. Perception and coding of envelopes in weakly electric fishes.

    PubMed

    Stamper, Sarah A; Fortune, Eric S; Chacron, Maurice J

    2013-07-01

    Natural sensory stimuli have a rich spatiotemporal structure and can often be characterized as a high frequency signal that is independently modulated at lower frequencies. This lower frequency modulation is known as the envelope. Envelopes are commonly found in a variety of sensory signals, such as contrast modulations of visual stimuli and amplitude modulations of auditory stimuli. While psychophysical studies have shown that envelopes can carry information that is essential for perception, how envelope information is processed in the brain is poorly understood. Here we review the behavioral salience and neural mechanisms for the processing of envelopes in the electrosensory system of wave-type gymnotiform weakly electric fishes. These fish can generate envelope signals through movement, interactions of their electric fields in social groups or communication signals. The envelopes that result from the first two behavioral contexts differ in their frequency content, with movement envelopes typically being of lower frequency. Recent behavioral evidence has shown that weakly electric fish respond in robust and stereotypical ways to social envelopes to increase the envelope frequency. Finally, neurophysiological results show how envelopes are processed by peripheral and central electrosensory neurons. Peripheral electrosensory neurons respond to both stimulus and envelope signals. Neurons in the primary hindbrain recipient of these afferents, the electrosensory lateral line lobe (ELL), exhibit heterogeneities in their responses to stimulus and envelope signals. Complete segregation of stimulus and envelope information is achieved in neurons in the target of ELL efferents, the midbrain torus semicircularis (Ts).

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

    SciTech Connect

    Ostlund, Cecilia; Guan, Tinglu; Figlewicz, Denise A.; Hays, Arthur P.; Worman, Howard J.; Gerace, Larry; Schirmer, Eric C.

    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.

  4. The Viner-Wong Envelope Theorem.

    ERIC Educational Resources Information Center

    Silberberg, Eugene

    1999-01-01

    Observes that the envelope theorem, a fundamental tool in duality analysis, is still a puzzle to many people. Argues that the essence of a solution proposed by Paul Samuelson (1947) is also unclear to many people, but can be communicated with a simple cost diagram. Presents and explains the proposed diagram. (DSK)

  5. 14 CFR 23.333 - Flight envelope.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... any combination of airspeed and load factor on and within the boundaries of a flight envelope (similar... altitudes between sea level and 20,000 feet. The gust velocity may be reduced linearly from 50 f.p.s. at 20... considered at altitudes between sea level and 20,000 feet. The gust velocity may be reduced linearly from...

  6. 14 CFR 23.333 - Flight envelope.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... any combination of airspeed and load factor on and within the boundaries of a flight envelope (similar... altitudes between sea level and 20,000 feet. The gust velocity may be reduced linearly from 50 f.p.s. at 20... considered at altitudes between sea level and 20,000 feet. The gust velocity may be reduced linearly from...

  7. The Methodology of Data Envelopment Analysis.

    ERIC Educational Resources Information Center

    Sexton, Thomas R.

    1986-01-01

    The methodology of data envelopment analysis, (DEA) a linear programming-based method, is described. Other procedures often used for measuring relative productive efficiency are discussed in relation to DEA, including ratio analysis and multiple regression analysis. The DEA technique is graphically illustrated for only two inputs and one output.…

  8. Ultraviolet Opacity and Fluorescence in Supernova Envelopes

    NASA Technical Reports Server (NTRS)

    Li, Hongwei; McCray, Richard

    1996-01-01

    By the time the expanding envelope of a Type 2 supernova becomes transparent in the optical continuum, most of the gamma-ray luminosity produced by radioactive Fe/Co/Ni clumps propagates into the hydrogen/helium envelope and is deposited there, if at all. The resulting fast electrons excite He 1 and H 1, the two- photon continua of which are the dominant internal sources of ultraviolet radiation. The UV radiation is blocked by scattering in thousands of resonance lines of metals and converted by fluorescence into optical and infrared emission lines that escape freely. We describe results of Monte Carlo calculations that simulate non-LTE scattering and fluorescence in more than five million allowed lines of Ca, Sc, Ti, V, Cr, Mn, Fe, Co, and Ni. For a model approximating conditions in the envelope of SN 1987A, the calculated emergent spectrum resembles the observed one. For the first 2 yr after explosion, the ultraviolet radiation (lambda less than or approximately equals 3000) is largely blocked and converted into a quasi continuum of many thousands of weak optical and infrared emission lines and some prominent emission features, such as the Ca 2 lambdalambda8600 triplet. Later, as the envelope cools and expands, it becomes more transparent, and an increasing fraction of the luminosity emerges in the UV band.

  9. Discriminating Dysarthria Type from Envelope Modulation Spectra

    ERIC Educational Resources Information Center

    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…

  10. The Methodology of Data Envelopment Analysis.

    ERIC Educational Resources Information Center

    Sexton, Thomas R.

    1986-01-01

    The methodology of data envelopment analysis, (DEA) a linear programming-based method, is described. Other procedures often used for measuring relative productive efficiency are discussed in relation to DEA, including ratio analysis and multiple regression analysis. The DEA technique is graphically illustrated for only two inputs and one output.…

  11. Discriminating Dysarthria Type from Envelope Modulation Spectra

    ERIC Educational Resources Information Center

    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…

  12. Ozone Reductions Using Residential Building Envelopes

    SciTech Connect

    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.

  13. Tegument Assembly and Secondary Envelopment of Alphaherpesviruses

    PubMed Central

    Owen, Danielle J.; Crump, Colin M.; Graham, Stephen C.

    2015-01-01

    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. PMID:26393641

  14. SAFEGUARDS ENVELOPE: PREVIOUS WORK AND EXAMPLES

    SciTech Connect

    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.

  15. Right to Light: Ralph Knowles's Solar Envelope.

    ERIC Educational Resources Information Center

    Morton, David

    1979-01-01

    At the University of Southern California solar-access design research project, Barry Knowles and students have devised a solar envelope: the largest volumetric container over a land parcel that allows solar access to all adjacent neighbors within useful time constraints. (Author/MLF)

  16. Data Envelopment Analysis: Critique and Extensions.

    ERIC Educational Resources Information Center

    Sexton, Thomas R.; And Others

    1986-01-01

    Recent methodological advances are described that enable the analyst to extract additional information from the data envelopment analysis (DEA) methodology, including goal programming to develop cross-efficiencies, cluster analysis, analysis of variance, and pooled cross section time-series analysis. Some shortcomings of DEA are discussed. (LMO)

  17. Adaptive envelope protection methods for aircraft

    NASA Astrophysics Data System (ADS)

    Unnikrishnan, Suraj

    Carefree handling refers to the ability of a pilot to operate an aircraft without the need to continuously monitor aircraft operating limits. At the heart of all carefree handling or maneuvering systems, also referred to as envelope protection systems, are algorithms and methods for predicting future limit violations. Recently, envelope protection methods that have gained more acceptance, translate limit proximity information to its equivalent in the control channel. Envelope protection algorithms either use very small prediction horizon or are static methods with no capability to adapt to changes in system configurations. Adaptive approaches maximizing prediction horizon such as dynamic trim, are only applicable to steady-state-response critical limit parameters. In this thesis, a new adaptive envelope protection method is developed that is applicable to steady-state and transient response critical limit parameters. The approach is based upon devising the most aggressive optimal control profile to the limit boundary and using it to compute control limits. Pilot-in-the-loop evaluations of the proposed approach are conducted at the Georgia Tech Carefree Maneuver lab for transient longitudinal hub moment limit protection. Carefree maneuvering is the dual of carefree handling in the realm of autonomous Uninhabited Aerial Vehicles (UAVs). Designing a flight control system to fully and effectively utilize the operational flight envelope is very difficult. With the increasing role and demands for extreme maneuverability there is a need for developing envelope protection methods for autonomous UAVs. In this thesis, a full-authority automatic envelope protection method is proposed for limit protection in UAVs. The approach uses adaptive estimate of limit parameter dynamics and finite-time horizon predictions to detect impending limit boundary violations. Limit violations are prevented by treating the limit boundary as an obstacle and by correcting nominal control

  18. Validating predictions from climate envelope models

    USGS Publications Warehouse

    Watling, J.; Bucklin, D.; Speroterra, C.; Brandt, L.; Cabal, C.; Romañach, Stephanie S.; Mazzotti, Frank J.

    2013-01-01

    Climate envelope models are a potentially important conservation tool, but their ability to accurately forecast species’ distributional shifts using independent survey data has not been fully evaluated. We created climate envelope models for 12 species of North American breeding birds previously shown to have experienced poleward range shifts. For each species, we evaluated three different approaches to climate envelope modeling that differed in the way they treated climate-induced range expansion and contraction, using random forests and maximum entropy modeling algorithms. All models were calibrated using occurrence data from 1967–1971 (t1) and evaluated using occurrence data from 1998–2002 (t2). Model sensitivity (the ability to correctly classify species presences) was greater using the maximum entropy algorithm than the random forest algorithm. Although sensitivity did not differ significantly among approaches, for many species, sensitivity was maximized using a hybrid approach that assumed range expansion, but not contraction, in t2. Species for which the hybrid approach resulted in the greatest improvement in sensitivity have been reported from more land cover types than species for which there was little difference in sensitivity between hybrid and dynamic approaches, suggesting that habitat generalists may be buffered somewhat against climate-induced range contractions. Specificity (the ability to correctly classify species absences) was maximized using the random forest algorithm and was lowest using the hybrid approach. Overall, our results suggest cautious optimism for the use of climate envelope models to forecast range shifts, but also underscore the importance of considering non-climate drivers of species range limits. The use of alternative climate envelope models that make different assumptions about range expansion and contraction is a new and potentially useful way to help inform our understanding of climate change effects on species.

  19. Adaptive Spectral Envelope Estimation for Doppler Ultrasound.

    PubMed

    Kathpalia, Aditi; Karabiyik, Yucel; Eik-Nes, Sturla H; Tegnander, Eva; Ekroll, Ingvild Kinn; Kiss, Gabriel; Torp, Hans

    2016-11-01

    Estimation of accurate maximum velocities and spectral envelope in ultrasound Doppler blood flow spectrograms are both essential for clinical diagnostic purposes. However, obtaining accurate maximum velocity is not straightforward due to intrinsic spectral broadening and variance in the power spectrum estimate. The method proposed in this paper for maximum velocity point detection has been developed by modifying an existing method-signal noise slope intersection, incorporating in it steps from an altered version of another method called geometric method. Adaptive noise estimation from the spectrogram ensures that a smooth spectral envelope is obtained postdetection of these maximum velocity points. The method has been tested on simulated Doppler signal with scatterers possessing a parabolic flow velocity profile constant in time, steady and pulsatile string phantom recordings, as well as in vivo recordings from uterine, umbilical, carotid, and subclavian arteries. The results from simulation experiments indicate a bias of less than 2.5% in maximum velocities when estimated for a range of peak velocities, Doppler angles, and SNR levels. Standard deviation in the envelope is low-less than 2% in the case of experiments done by varying the peak velocity and Doppler angle for steady phantom and simulated flow, and also less than 2% in the case of experiments done by varying SNR but keeping constant flow conditions for in vivo and simulated flow. Low variability in the envelope makes the prospect of using the envelope for automated blood flow measurements possible and is illustrated for the case of pulsatility index estimation in uterine and umbilical arteries.

  20. CO line emission from circumstellar envelopes

    NASA Astrophysics Data System (ADS)

    Teyssier, D.; Hernandez, R.; Bujarrabal, V.; Yoshida, H.; Phillips, T. G.

    2006-04-01

    Aims.We present the results of a multi-transition CO observational program conducted on a sample of AGB and post-AGB stars envelopes. We have collected maps and single pointing observations of these envelopes in 5 rotational transitions ranging from J = 1-0 to J = 6-5, including in particular new observations of the CO line at 691 GHz at the CSO. The use of such a set of mm and submm CO line on stellar envelopes is rare and limited to the work of some authors on IRC+10216. Methods: .Using a model for the CO emission of an AGB circumstellar envelope, in combination with a standard LVG approach, we have conducted a systematic modelling analysis using the whole set of CO data collected for a sample of 12 sources. We simultaneously fit all five transitions, taking into account the spatial information provided by the maps. Results: .We find mass-loss rates in the range 1 × 10-7 to 4 × 10-4 M_⊙/yr, and envelope temperatures ranging from 20 K to 1000 K at a radius of 1016 cm. There seem to be a general anti-correlation between mass loss rates and temperature, the high mass loss rate AGBs having low temperatures, and vice versa. We show that most AGB data can be fitted using a constant mass loss rate, at least within the calibration uncertainties associated with the data collected at different frequencies. For some cases though (e.g. CIT 6, R Hya, χ Cyg), a change in the mass loss rate history needs to be invoked to reconcile data at low- and high-J, a scenario already mentioned by several authors to explain observations of WX Psc.

  1. The Circumstellar Envelope of IRC +10216.

    NASA Astrophysics Data System (ADS)

    Keady, John Joseph

    1982-03-01

    Using recently obtained spatial and spectral line data on the circumstellar envelope of IRC +10216, we have attempted to semi-empirically probe the conditions in this envelope. The computational techniques utilized in our analysis accurately incorporate the effects of geometrical extension and velocity fields on the radiative transfer. We have also attempted to account for the non-equilibrium expected in the vibrational level populations of the gas phase species. Our modelling of the spatial distribution of the dust-produced circumstellar radiation field at 5 (mu)m and 11 (mu)m indicates that dust may be condensing in the circumstellar envelope. The dominant opacity source in our calculations, amorphous carbon, also seems to provide sufficient far-infrared flux. Modelling of the SiC emission feature confirms previous results that suggest a nonuniform particle-shape distribution for the SiC. We can produce multi-component absorption lines, very similar to the 2 (mu)m CO first overtone lines seen in IRC +10216, with continuous distributions of material. The requirement is regions of relatively low acceleration. Modelling of our high resolution, high signal-to-noise observations of the CO fundamental and first overtone indicates a mass -loss rate of 1.5(10('-4)) M(,(CIRCLE))/yr. Our calculations to date indicate that the gas reaches terminal velocity between 10 and 20 R(,*). The envelope mass within 100 R(,*) is 3(10('-2)) M(,(CIRCLE)), with the ratio (by mass) of dust to gas being 10('-3). The assumption of a constant mass-loss rate implies an envelope mass of (TURN)1 M(,(CIRCLE)) within 5000 R(,*). The computational techniques utilized are sufficiently adaptable and economical so that considerable future refinement of the modelling is possible.

  2. The envelope-based cyclic periodogram

    NASA Astrophysics Data System (ADS)

    Borghesani, P.

    2015-06-01

    Cyclostationary analysis has proven effective in identifying signal components for diagnostic purposes. A key descriptor in this framework is the cyclic power spectrum, traditionally estimated by the averaged cyclic periodogram and the smoothed cyclic periodogram. A lengthy debate about the best estimator finally found a solution in a cornerstone work by Antoni, who proposed a unified form for the two families, thus allowing a detailed statistical study of their properties. Since then, the focus of cyclostationary research has shifted towards algorithms, in terms of computational efficiency and simplicity of implementation. Traditional algorithms have proven computationally inefficient and the sophisticated "cyclostationary" definition of these estimators slowed their spread in the industry. The only attempt to increase the computational efficiency of cyclostationary estimators is represented by the cyclic modulation spectrum. This indicator exploits the relationship between cyclostationarity and envelope analysis. The link with envelope analysis allows a leap in computational efficiency and provides a "way in" for the understanding by industrial engineers. However, the new estimator lies outside the unified form described above and an unbiased version of the indicator has not been proposed. This paper will therefore extend the analysis of envelope-based estimators of the cyclic spectrum, proposing a new approach to include them in the unified form of cyclostationary estimators. This will enable the definition of a new envelope-based algorithm and the detailed analysis of the properties of the cyclic modulation spectrum. The computational efficiency of envelope-based algorithms will be also discussed quantitatively for the first time in comparison with the averaged cyclic periodogram. Finally, the algorithms will be validated with numerical and experimental examples.

  3. A novel family of plant nuclear envelope-associated proteins.

    PubMed

    Pawar, Vidya; Poulet, Axel; Détourné, Gwénaëlle; Tatout, Christophe; Vanrobays, Emmanuel; Evans, David E; Graumann, Katja

    2016-10-01

    This paper describes the characterisation of a new family of higher plant nuclear envelope-associated proteins (NEAPs) that interact with other proteins of the nuclear envelope. In the model plant Arabidopsis thaliana, the family consists of three genes expressed ubiquitously (AtNEAP1-3) and a pseudogene (AtNEAP4). NEAPs consist of extensive coiled-coil domains, followed by a nuclear localisation signal and a C-terminal predicted transmembrane domain. Domain deletion mutants confirm the presence of a functional nuclear localisation signal and transmembrane domain. AtNEAP proteins localise to the nuclear periphery as part of stable protein complexes, are able to form homo- and heteromers, and interact with the SUN domain proteins AtSUN1 and AtSUN2, involved in the linker of nucleoskeleton and cytoskeleton (LINC) complex. An A. thaliana cDNA library screen identified a putative transcription factor called AtbZIP18 as a novel interactor of AtNEAP1, which suggest a connection between NEAP and chromatin. An Atneap1 Atneap3 double-knockout mutant showed reduced root growth, and altered nuclear morphology and chromatin structure. Thus AtNEAPs are suggested as inner nuclear membrane-anchored coiled-coil proteins with roles in maintaining nuclear morphology and chromatin structure.

  4. Nuclear membrane: nuclear envelope PORosity in fission yeast meiosis.

    PubMed

    Sazer, Shelley

    2010-11-09

    The fission yeast Schizosaccharomyces pombe undergoes closed mitosis but 'virtual nuclear envelope breakdown' at anaphase of meiosis II, in which the nuclear envelope is structurally closed but functionally open.

  5. Thermodynamics and fluid dynamics of the double shell (envelope) house

    SciTech Connect

    Reno, V.

    1980-01-01

    The concepts of the envelope house are summarized and a systems approach to the house heat energy flows is presented. Some basic principles of physics in the area of thermodynamic conduction are discussed in relation to the envelope concept. (MHR)

  6. The action of three antiseptics/disinfectants against enveloped and non-enveloped viruses.

    PubMed

    Wood, A; Payne, D

    1998-04-01

    The antiviral action of chloroxylenol, benzalkonium chloride and cetrimide/chlorhexidine was assessed against a range of enveloped and non-enveloped human viruses using a suspension test method. Viral suspensions of 10(6)-10(7) pfu/TCID50 or sfu were prepared in each of the antiseptic/disinfectant solutions in the presence of a bovine serum/yeast extract mixture to simulate 'dirty conditions'. During incubation, aliquots were removed at predetermined timepoints up to 10 min to assess the kinetics of inactivation. Results indicate that all products were effective in inactivating the enveloped viruses herpes simplex virus type 1 and human immunodeficiency virus type 1, whilst being ineffective in inactivating human coronavirus, also enveloped, and the non-enveloped viruses. The exception to this was the benzalkonium chloride-based product (Dettol Hospital Concentrate) which was active against the non-enveloped human coxsackie virus. Four antiseptic/disinfectant solutions with chloroxylenol, benzalkonium chloride, cetrimide/chlorhexidine and povidone-iodine were also assessed for antiviral effect against human immunodeficiency virus in the presence of whole human blood. All four solutions proved to be effective within 1 min despite the cytotoxic nature of the compounds to the detection system.

  7. Effects of envelope shape on interaural envelope delay sensitivity in acoustic and electric hearing.

    PubMed

    Laback, Bernhard; Zimmermann, Inge; Majdak, Piotr; Baumgartner, Wolf-Dieter; Pok, Stefan-Marcel

    2011-09-01

    The envelope shape is important for the perception of interaural time difference (ITD) in the envelope as supported by the improved sensitivity for transposed tones compared to sinusoidally amplitude-modulated (SAM) tones. The present study investigated the effects of specific envelope parameters in nine normal-hearing (NH) and seven cochlear-implant (CI) listeners, using high-rate carriers with 27-Hz trapezoidal modulation. In NH listeners, increasing the off time (the silent interval in each modulation cycle) up to 12 ms, increasing the envelope slope from 6 to 8 dB/ms, and increasing the peak level improved ITD sensitivity. The combined effect of the off time and slope accounts for the gain in sensitivity for transposed tones relative to SAM tones. In CI listeners, increasing the off time up to 20 ms improved sensitivity, but increasing the slope showed no systematic effect. A 27-pulses/s electric pulse train, representing a special case of modulation with infinitely steep slopes and maximum possible off time, yielded considerably higher sensitivity compared to the best condition with trapezoidal modulation. Overall, the results of this study indicate that envelope-ITD sensitivity could be improved by using CI processing schemes that simultaneously increase the off time and the peak level of the signal envelope. © 2011 Acoustical Society of America

  8. Solar Effective Envelope Design Advisor (SEEDA)

    NASA Astrophysics Data System (ADS)

    Mahaek, Ekkachai

    The lack of effort by mainstream architects in integrating energy-efficient strategies in architectural designing is due to the complexity in a building's energy conscious concepts and theories, the difficulties to visualize and quantify energy consumption, and the late implementing of energy consumption analysis in the conventional design process. This task would be accomplishing by a building system's engineer where results might be determined only after the basic architectural design has been completed. An effective simple tool and method should then be available to assist architects in building's energy-efficient designing at the beginning of the design. The building's energy consumption is directly and mainly influenced by the relationship of the sun, site, and its building configuration. The solar radiations will first impact on the building's envelope, which will have a direct effect on the amount of energy a building will consume. If an architect can define or map the intensity of solar energy on the site's buildable volume, and use this information to determine the levels of solar insolation, a more energy efficient building form can be proposed. This research hypothesis has shared the fundamental techniques of the Solar Envelope projection by Professor Ralph Knowles [Knowles, 1981] of the University of Southern California. However a different approach is taken by including the influence of regional restrictions and the surrounding buildings' shadows when projecting of solar volumes and solar envelope. The research methodology will discuss the development of a computer-based approach to develop a three-dimensional architectural form based on an insolation map related to the design site. The prototype computer program is referred as the Solar Effective Envelope Design Advisor (SEEDA). The solar insolation volume of the site is determined by integrating three types of computer-generated models include the Buildable Volume model based on design constraints

  9. Application of the Envelope Difference Index to Spectrally Sparse Speech

    ERIC Educational Resources Information Center

    Souza, Pamela; Hoover, Eric; Gallun, Frederick

    2012-01-01

    Purpose: Amplitude compression is a common hearing aid processing strategy that can improve speech audibility and loudness comfort but also has the potential to alter important cues carried by the speech envelope. In previous work, a measure of envelope change, the Envelope Difference Index (EDI; Fortune, Woodruff, & Preves, 1994), was moderately…

  10. Analysis of Building Envelope Construction in 2003 CBECS

    SciTech Connect

    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 .

  11. 200 Area Deactivation Project Facilities Authorization Envelope Document

    SciTech Connect

    DODD, E.N.

    2000-03-28

    Project facilities as required by HNF-PRO-2701, Authorization Envelope and Authorization Agreement. The Authorization Agreements (AA's) do not identify the specific set of environmental safety and health requirements that are applicable to the facility. Therefore, the facility Authorization Envelopes are defined here to identify the applicable requirements. This document identifies the authorization envelopes for the 200 Area Deactivation.

  12. Application of the Envelope Difference Index to Spectrally Sparse Speech

    ERIC Educational Resources Information Center

    Souza, Pamela; Hoover, Eric; Gallun, Frederick

    2012-01-01

    Purpose: Amplitude compression is a common hearing aid processing strategy that can improve speech audibility and loudness comfort but also has the potential to alter important cues carried by the speech envelope. In previous work, a measure of envelope change, the Envelope Difference Index (EDI; Fortune, Woodruff, & Preves, 1994), was moderately…

  13. Development of High Specific Strength Envelope Materials

    NASA Astrophysics Data System (ADS)

    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. 

  14. Small carbon chains in circumstellar envelopes

    NASA Astrophysics Data System (ADS)

    Hargreaves, R. J.; Hinkle, K.; Bernath, P. F.

    2014-11-01

    Observations of carbon-rich circumstellar envelopes were made using the Phoenix spectrograph on the Gemini South telescope to determine the abundance of small carbon chain molecules. Vibration-rotation lines of the ν3 antisymmetric stretch of C3 near 2040 cm-1 (4.902 μm) have been used to determine the column density for four carbon-rich circumstellar envelopes: CRL 865, CRL 1922, CRL 2023 and IRC +10216. We additionally calculate the column density of C5 for IRC +10216, and provide an upper limit for five more objects. An upper limit estimate for the C7 column density is also provided for IRC+10216. A comparison of these column densities suggests a revision to current circumstellar chemical models may be needed.

  15. Constant envelope chirped OFDM power efficiency

    NASA Astrophysics Data System (ADS)

    Dida, Mussa A.; Hao, Huan; Anjum, M. R.; Ran, Tao

    2016-10-01

    Fractional Fourier OFDM or simply chirped OFDM performs better in time-frequency selective channel than its convectional OFDM. Although chirped OFDM outperforms OFDM it still inherits Peak to Average Power Ratio (PAPR) drawback as a convectional OFDM. To eliminate PAPR drawback Constant Envelope OFDM was developed and for better performance in time frequency selective channel Constant Envelope Fractional Fourier OFDM (CE-COFDM) is used. Its BER performance is analyzed and compared to chirped OFDM and OFDM in AWGN and Rayleigh channel. The simulations show the BER performance of CE-COFDM is the same as chirped OFDM and OFDM. The power efficiency of CE-COFDM is also studied and different simulations performed shows CE-COFDM is more power efficient than chirped OFDM and convectional OFDM for class A and class B Linear Power Amplifier (LPA).

  16. Nonlinear Analysis of Airship Envelop Aerolasticity

    NASA Astrophysics Data System (ADS)

    Liu, J. M.; Lu, C. J.; Xue, L. P.

    The large airship in flow field is a flexible body with low rigidity. The distribution of the peripheral flow field around the airship is closely related to its shape. It is essentially one of the Fluid-structure Interaction problems. Based on this, this paper aims at the numerical simulation of nonlinear airship envelop aeroelasticity by means of coupling aerodynamics and structure using an iteration method. The three-dimensional flow around the airship was studied numerically by means of SIMPLE method based on the Finite Volume Method. Two approaches, the linear method whose equilibrium equations are based on the membrance theory of thin shell and the nonlinear method which uses a nonlinear finite element method to account for the large deformation of the airship envelop, are introduced for geometrically deformation of the airship shape. A thin plate spline method is adopted as the interface of exchanging information between the fluid and structure models.

  17. Hydrogen sulfide in a circumstellar envelope

    NASA Technical Reports Server (NTRS)

    Ukita, N.; Morris, M.

    1983-01-01

    A search for hydrogen sulfide in the cool circumstellar envelopes of 25 stars was made using the 1(10)-1(01) rotational line at 1.8 mm. It was detected in the bipolar nebula/OH maser OH231.8+4.2, an object having a high rate of mass loss. An approximate analysis indicates that 1/60 of the sulfur in this outflowing envelope is in the form of H2S, a fraction which may be similar to that in the atmosphere of the central star. In addition, the shape of the observed line profile is discussed in terms of a possible variation of the outflow velocity with latitude above the system's equatorial plane.

  18. Formaldehyde in envelopes of interstellar dark clouds

    NASA Technical Reports Server (NTRS)

    Federman, S. R.; Allen, M.

    1991-01-01

    Observed formaldehyde column densities of 1 x 10 to the 12th - 3 x 10 to the 13th/sq cm in cloud envelopes along lines of sight with A(V) = 1-4 mag can not be explained with the current understanding of interstellar gas phase chemistry. However, these column densities can be reproduced by a simple time-dependent model in which H2CO is supplied to the gas phase by the erosion of icy grain mantles. The release of H2CO from the grain mantles must occur on time scales comparable to the time scales for mixing from the cloud interior to the cloud envelope. Thus, in low-density regions of clouds, it appears that formaldehyde is the second molecule whose gas phase source is primarily ejection from grains. This simple model suggests understanding gas phase steady state in clouds on macroscopic, rather than microscopic, spatial scales.

  19. Uses and misuses of bioclimatic envelope modeling.

    PubMed

    Araújo, Miguel B; Peterson, A Townsend

    2012-07-01

    Bioclimatic envelope models use associations between aspects of climate and species' occurrences to estimate the conditions that are suitable to maintain viable populations. Once bioclimatic envelopes are characterized, they can be applied to a variety of questions in ecology, evolution, and conservation. However, some have questioned the usefulness of these models, because they may be based on implausible assumptions or may be contradicted by empirical evidence. We review these areas of contention, and suggest that criticism has often been misplaced, resulting from confusion between what the models actually deliver and what users wish that they would express. Although improvements in data and methods will have some effect, the usefulness of these models is contingent on their appropriate use, and they will improve mainly via better awareness of their conceptual basis, strengths, and limitations.

  20. Nuclear envelope protein MAN1 regulates clock through BMAL1

    PubMed Central

    Lin, Shu-Ting; Zhang, Luoying; Lin, Xiaoyan; Zhang, Linda Chen; Garcia, Valentina Elizabeth; Tsai, Chen-Wei; Ptáček, Louis; Fu, Ying-Hui

    2014-01-01

    Circadian clocks serve as internal pacemakers that influence many basic homeostatic processes; consequently, the expression and function of their components are tightly regulated by intricate networks of feedback loops that fine-tune circadian processes. Our knowledge of these components and pathways is far from exhaustive. In recent decades, the nuclear envelope has emerged as a global gene regulatory machine, although its role in circadian regulation has not been explored. We report that transcription of the core clock component BMAL1 is positively modulated by the inner nuclear membrane protein MAN1, which directly binds the BMAL1 promoter and enhances its transcription. Our results establish a novel connection between the nuclear periphery and circadian rhythmicity, therefore bridging two global regulatory systems that modulate all aspects of bodily functions. DOI: http://dx.doi.org/10.7554/eLife.02981.001 PMID:25182847

  1. Inactivation of enveloped and non-enveloped viruses on seeded human tissues by gamma irradiation.

    PubMed

    Moore, Mark A

    2012-08-01

    Human tissue allografts are widely used in a variety of clinical applications with over 1.5 million implants annually in the US alone. Since the 1990s, most clinically available allografts have been disinfected to minimize risk of disease transmission. Additional safety assurance can be provided by terminal sterilization using low dose gamma irradiation. The impact of such irradiation processing at low temperatures on viruses was the subject of this study. In particular, both human tendon and cortical bone samples were seeded with a designed array of viruses and the ability of gamma irradiation to inactivate those viruses was tested. The irradiation exposures for the samples packed in dry ice were 11.6-12.9 kGy for tendon and 11.6-12.3 kGy for bone, respectively. The viruses, virus types, and log reductions on seeded tendon and bone tissue, respectively, were as follows: Human Immunodeficiency Virus (RNA, enveloped), >2.90 and >3.20; Porcine Parvovirus (DNA, non-enveloped), 1.90 and 1.58; Pseudorabies Virus (DNA, enveloped), 3.80 and 3.79; Bovine Viral Diarrhea Virus (RNA, enveloped), 2.57 and 4.56; and Hepatitis A Virus (RNA, non-enveloped), 2.54 and 2.49, respectively. While proper donor screening, aseptic technique, and current disinfection practices all help reduce the risk of viral transmission from human allograft tissues, data presented here indicate that terminal sterilization using a low temperature, low dose gamma irradiation process inactivates both enveloped and non-enveloped viruses containing either DNA or RNA, thus providing additional assurance of safety from viral transmission.

  2. Hepatitis C virus envelope glycoprotein co-evolutionary dynamics during chronic hepatitis C

    PubMed Central

    Li, Hui; McMahon, Brian J.; McArdle, Susan; Bruden, Dana; Sullivan, Daniel G.; Shelton, Dave; Deubner, Heike; Gretch, David R.

    2008-01-01

    Hepatitis C virus (HCV) envelope glycoprotein co-evolution was studied in 14 genotype 1-infected and treatment naïve subjects, including 7 with mild and 7 with severe liver disease. Cassettes encoding the envelope 1 gene (E1) and hypervariable region (HVR1) of the envelope 2 gene were isolated at 38 different time points over 81 follow-up years. There were no significant differences in age, gender, alcohol use, or viral load between the mild and severe disease groups. Virus from subjects with severe disease had significantly slower evolution in HVR1, and significant divergent evolution of E1 quasispecies, characterized by a preponderance of synonymous mutations, compared to virus from subjects with mild disease. Phylogenetic comparisons indicated higher similarity between amino acid sequences of the E1 and HVR1 regions with mild disease versus severe disease (r=0.44 versus r=0.17, respectively; P=0.01). In summary, HCV envelope quasispecies co-evolution differs during mild versus severe disease. PMID:18343477

  3. TMEM120A and B: Nuclear Envelope Transmembrane Proteins Important for Adipocyte Differentiation

    PubMed Central

    Batrakou, Dzmitry G.; de las Heras, Jose I.; Czapiewski, Rafal; Mouras, Rabah; Schirmer, Eric C.

    2015-01-01

    Recent work indicates that the nuclear envelope is a major signaling node for the cell that can influence tissue differentiation processes. Here we present two nuclear envelope trans-membrane proteins TMEM120A and TMEM120B that are paralogs encoded by the Tmem120A and Tmem120B genes. The TMEM120 proteins are expressed preferentially in fat and both are induced during 3T3-L1 adipocyte differentiation. Knockdown of one or the other protein altered expression of several genes required for adipocyte differentiation, Gata3, Fasn, Glut4, while knockdown of both together additionally affected Pparg and Adipoq. The double knockdown also increased the strength of effects, reducing for example Glut4 levels by 95% compared to control 3T3-L1 cells upon pharmacologically induced differentiation. Accordingly, TMEM120A and B knockdown individually and together impacted on adipocyte differentiation/metabolism as measured by lipid accumulation through binding of Oil Red O and coherent anti-Stokes Raman scattering microscopy (CARS). The nuclear envelope is linked to several lipodystrophies through mutations in lamin A; however, lamin A is widely expressed. Thus it is possible that the TMEM120A and B fat-specific nuclear envelope transmembrane proteins may play a contributory role in the tissue-specific pathology of this disorder or in the wider problem of obesity. PMID:26024229

  4. Bound Cyclic Systems with the Envelope Theory

    NASA Astrophysics Data System (ADS)

    Semay, Claude; Buisseret, Fabien

    2017-09-01

    Approximate but reliable solutions of a quantum system with N identical particles can be easily computed with the envelope theory, also known as the auxiliary field method. This technique has been developed for Hamiltonians with arbitrary kinematics and one- or two-body potentials. It is adapted here for cyclic systems with N identical particles, that is to say systems in which a particle i has only an interaction with particles i-1 and i+1 (with N+1≡1).

  5. Envelope instability and the fourth order resonance

    NASA Astrophysics Data System (ADS)

    Li, Chao; Zhao, Ya Liang

    2014-12-01

    The well-known envelope instability or the second order even collective mode [I. Hofmann, Phys. Rev. E 57, 4 (1998)] and the fourth order resonance 4 σ =360 ° due to the nonlinear space charge effect in high intensity beams have been studied previously. A wide stop band around 15° is found in a pure periodic focusing channel. In addition, it is illustrated that the fourth order resonance dominates over the envelope instability and practically replaces it in the stop band [D. Jeon et al., Phys. Rev. ST Accel. Beams 12, 054204 (2009)]. In this paper, for a continuous beam with remarkable space charge, our 2D self-consistent particle-in-cell simulation work with the code topopic shows these two kinds of effects respectively in a periodic focusing defocusing (FD) channel. For a fixed tune depression η =0.8 , a stop band with a width of almost 15° is also demonstrated. Moreover, it is confirmed that analytical results of the rms envelope instability diagram are a valid tool to interpret the width of the stop band. Emittance growth rates in stop band are also well explained. It is found that, for a nearly rms matched beam, the emittance growth in the stop band is almost proportional to the saturation time of the nonlinear instability of the envelope, which happens in a quick manner and takes only a few FD cells. In contrast, the fourth order resonance is independent of rms matching and will be accompanied by beam evolution as "a long term effect" once the related mechanism is excited.

  6. High-performance envelopes for wood

    Treesearch

    Roger M. Rowell

    2007-01-01

    Wood can be coated with a clear finish, stained or painted to provide protection from water and ultra violet energy. In this case the coating and wood are two different phases that coexist. Another approach is to provide protection by “coating” in the surface not on the surface. Such an approach is referred to as an envelop rather than a coating. This can be done in...

  7. Fusion of Enveloped Viruses in Endosomes.

    PubMed

    White, Judith M; Whittaker, Gary R

    2016-06-01

    Ari Helenius launched the field of enveloped virus fusion in endosomes with a seminal paper in the Journal of Cell Biology in 1980. In the intervening years, a great deal has been learned about the structures and mechanisms of viral membrane fusion proteins as well as about the endosomes in which different enveloped viruses fuse and the endosomal cues that trigger fusion. We now recognize three classes of viral membrane fusion proteins based on structural criteria and four mechanisms of fusion triggering. After reviewing general features of viral membrane fusion proteins and viral fusion in endosomes, we delve into three characterized mechanisms for viral fusion triggering in endosomes: by low pH, by receptor binding plus low pH and by receptor binding plus the action of a protease. We end with a discussion of viruses that may employ novel endosomal fusion-triggering mechanisms. A key take-home message is that enveloped viruses that enter cells by fusing in endosomes traverse the endocytic pathway until they reach an endosome that has all of the environmental conditions (pH, proteases, ions, intracellular receptors and lipid composition) to (if needed) prime and (in all cases) trigger the fusion protein and to support membrane fusion. © 2016 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

  8. Fusion of Enveloped Viruses in Endosomes

    PubMed Central

    White, Judith M.; Whittaker, Gary R.

    2016-01-01

    Ari Helenius launched the field of enveloped virus fusion in endosomes with a seminal paper in the Journal of Cell Biology in 1980. In the intervening years a great deal has been learned about the structures and mechanisms of viral membrane fusion proteins as well as about the endosomes in which different enveloped viruses fuse and the endosomal cues that trigger fusion. We now recognize three classes of viral membrane fusion proteins based on structural criteria and four mechanisms of fusion triggering. After reviewing general features of viral membrane fusion proteins and viral fusion in endosomes, we delve into three characterized mechanisms for viral fusion triggering in endosomes: by low pH, by receptor binding plus low pH, and by receptor binding plus the action of a protease. We end with a discussion of viruses that may employ novel endosomal fusion triggering mechanisms. A key take home message is that enveloped viruses that enter cells by fusing in endosomes traverse the endocytic pathway until they reach an endosome that has all of the environmental conditions (pH, proteases, ions, intracellular receptors, and lipid composition) to (if needed) prime and (in all cases) trigger the fusion protein and to support membrane fusion. PMID:26935856

  9. The cell envelope glycoconjugates of Mycobacterium tuberculosis

    PubMed Central

    Angala, Shiva Kumar; Belardinelli, Juan Manuel; Huc-Claustre, Emilie; Wheat, William H.; Jackson, Mary

    2015-01-01

    Tuberculosis (TB) remains the second most common cause of death due to a single infectious agent. The cell envelope of Mycobacterium tuberculosis (Mtb), the causative agent of the disease in humans, is a source of unique glycoconjugates and the most distinctive feature of the biology of this organism. It is the basis of much of Mtb pathogenesis and one of the major causes of its intrinsic resistance to chemotherapeutic agents. At the same time, the unique structures of Mtb cell envelope glycoconjugates, their antigenicity and essentiality for mycobacterial growth provide opportunities for drug, vaccine, diagnostic and biomarker development, as clearly illustrated by recent advances in all of these translational aspects. This review focuses on our current understanding of the structure and biogenesis of Mtb glycoconjugates with particular emphasis on one of most intriguing and least understood aspect of the physiology of mycobacteria: the translocation of these complex macromolecules across the different layers of the cell envelope. It further reviews the rather impressive progress made in the last ten years in the discovery and development of novel inhibitors targeting their biogenesis. PMID:24915502

  10. Multiscale envelope manifold for enhanced fault diagnosis of rotating machines

    NASA Astrophysics Data System (ADS)

    Wang, Jun; He, Qingbo; Kong, Fanrang

    2015-02-01

    The wavelet transform has been widely used in the field of machinery fault diagnosis for its good property of band-pass filtering. However, the filtered signal still faces the contamination of in-band noise. This paper focuses on wavelet enveloping, and proposes a new method, called multiscale envelope manifold (MEM), to extract the envelope information of fault impacts with in-band noise suppression. The MEM addresses manifold learning on the wavelet envelopes at multiple scales. Specifically, the proposed method is conducted by three following steps. First, the continuous wavelet transform (CWT) with complex Morlet wavelet base is introduced to obtain the wavelet envelopes at all scales. Second, the wavelet envelopes are restricted in one or more narrow scale bands to simply include the envelope information of fault impacts. The scale band is determined through a smoothness index-based (SI-based) selection method by considering the impulsiveness inside the power spectrum. Third, the manifold learning algorithm is conducted on the wavelet envelopes at selected scales to extract the intrinsic envelope manifold of fault-related impulses. The MEM combines the envelope information at multiple scales in a nonlinear approach, and may thus preserve the factual envelope structure of machinery fault. Simulation studies and experimental verifications confirm that the new method is effective for enhanced fault diagnosis of rotating machines.

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

    PubMed Central

    Chen, Yi-Ning; Hsueh, Yi-Huang; Hsieh, Chien-Te; Tzou, Dong-Ying; Chang, Pai-Ling

    2016-01-01

    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. PMID:27104546

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

    PubMed

    Chen, Yi-Ning; Hsueh, Yi-Huang; Hsieh, Chien-Te; Tzou, Dong-Ying; Chang, Pai-Ling

    2016-04-19

    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.

  13. Envelope Variants Circulating as Initial Neutralization Breadth Developed in Two HIV-Infected Subjects Stimulate Multiclade Neutralizing Antibodies in Rabbits

    PubMed Central

    Malherbe, Delphine C.; Pissani, Franco; Sather, D. Noah; Guo, Biwei; Pandey, Shilpi; Sutton, William F.; Stuart, Andrew B.; Robins, Harlan; Park, Byung; Krebs, Shelly J.; Schuman, Jason T.; Kalams, Spyros; Hessell, Ann J.

    2014-01-01

    ABSTRACT Identifying characteristics of the human immunodeficiency virus type 1 (HIV-1) envelope that are effective in generating broad, protective antibodies remains a hurdle to HIV vaccine design. Emerging evidence of the development of broad and potent neutralizing antibodies in HIV-infected subjects suggests that founder and subsequent progeny viruses may express unique antigenic motifs that contribute to this developmental pathway. We hypothesize that over the course of natural infection, B cells are programmed to develop broad antibodies by exposure to select populations of emerging envelope quasispecies variants. To test this hypothesis, we identified two unrelated subjects whose antibodies demonstrated increasing neutralization breadth against a panel of HIV-1 isolates over time. Full-length functional env genes were cloned longitudinally from these subjects from months after infection through 2.6 to 5.8 years of infection. Motifs associated with the development of breadth in published, cross-sectional studies were found in both subjects. We compared the immunogenicity of envelope vaccines derived from time points obtained during and after broadening of neutralization activity within these subjects. Rabbits were coimmunized four times with selected multiple gp160 DNAs and gp140-trimeric envelope proteins. The affinity of the polyclonal response increased as a function of boosting. The most rapid and persistent neutralization of multiclade tier 1 viruses was elicited by envelopes that were circulating in plasma at time points prior to the development of 50% neutralization breadth in both human subjects. The breadth elicited in rabbits was not improved by exposure to later envelope variants. These data have implications for vaccine development in describing a target time point to identify optimal envelope immunogens. IMPORTANCE Vaccine protection against viral infections correlates with the presence of neutralizing antibodies; thus, vaccine components capable

  14. Envelope variants circulating as initial neutralization breadth developed in two HIV-infected subjects stimulate multiclade neutralizing antibodies in rabbits.

    PubMed

    Malherbe, Delphine C; Pissani, Franco; Sather, D Noah; Guo, Biwei; Pandey, Shilpi; Sutton, William F; Stuart, Andrew B; Robins, Harlan; Park, Byung; Krebs, Shelly J; Schuman, Jason T; Kalams, Spyros; Hessell, Ann J; Haigwood, Nancy L

    2014-11-01

    Identifying characteristics of the human immunodeficiency virus type 1 (HIV-1) envelope that are effective in generating broad, protective antibodies remains a hurdle to HIV vaccine design. Emerging evidence of the development of broad and potent neutralizing antibodies in HIV-infected subjects suggests that founder and subsequent progeny viruses may express unique antigenic motifs that contribute to this developmental pathway. We hypothesize that over the course of natural infection, B cells are programmed to develop broad antibodies by exposure to select populations of emerging envelope quasispecies variants. To test this hypothesis, we identified two unrelated subjects whose antibodies demonstrated increasing neutralization breadth against a panel of HIV-1 isolates over time. Full-length functional env genes were cloned longitudinally from these subjects from months after infection through 2.6 to 5.8 years of infection. Motifs associated with the development of breadth in published, cross-sectional studies were found in both subjects. We compared the immunogenicity of envelope vaccines derived from time points obtained during and after broadening of neutralization activity within these subjects. Rabbits were coimmunized four times with selected multiple gp160 DNAs and gp140-trimeric envelope proteins. The affinity of the polyclonal response increased as a function of boosting. The most rapid and persistent neutralization of multiclade tier 1 viruses was elicited by envelopes that were circulating in plasma at time points prior to the development of 50% neutralization breadth in both human subjects. The breadth elicited in rabbits was not improved by exposure to later envelope variants. These data have implications for vaccine development in describing a target time point to identify optimal envelope immunogens. Vaccine protection against viral infections correlates with the presence of neutralizing antibodies; thus, vaccine components capable of generating

  15. Envelope protein requirements for the assembly of infectious virions of porcine reproductive and respiratory syndrome virus.

    PubMed

    Wissink, E H J; Kroese, M V; van Wijk, H A R; Rijsewijk, F A M; Meulenberg, J J M; Rottier, P J M

    2005-10-01

    Virions of porcine reproductive and respiratory syndrome virus (PRRSV) contain six membrane proteins: the major proteins GP5 and M and the minor proteins GP2a, E, GP3, and GP4. Here, we studied the envelope protein requirements for PRRSV particle formation and infectivity using full-length cDNA clones in which the genes encoding the membrane proteins were disrupted by site-directed mutagenesis. By transfection of RNAs transcribed from these cDNAs into BHK-21 cells and analysis of the culture medium using ultracentrifugation, radioimmunoprecipitation, and real-time reverse transcription-PCR, we observed that the production of viral particles is dependent on both major envelope proteins; no particles were released when either the GP5 or the M protein was absent. In contrast, particle production was not dependent on the minor envelope proteins. Remarkably, in the absence of any one of the latter proteins, the incorporation of all other minor envelope proteins was affected, indicating that these proteins interact with each other and are assembled into virions as a multimeric complex. Independent evidence for such complexes was obtained by coexpression of the minor envelope proteins in BHK-21 cells using a Semliki Forest virus expression system. By analyzing the maturation of their N-linked oligosaccharides, we found that the glycoproteins were each retained in the endoplasmic reticulum unless expressed together, in which case they were collectively transported through the Golgi complex to the plasma membrane and were even detected in the extracellular medium. As the PRRSV particles lacking the minor envelope proteins are not infectious, we hypothesize that the virion surface structures formed by these proteins function in viral entry by mediating receptor binding and/or virus-cell fusion.

  16. Hatching enzyme of Japanese eel Anguilla japonica and the possible evolution of the egg envelope digestion mechanism.

    PubMed

    Sano, Kaori; Kawaguchi, Mari; Yoshikawa, Masayuki; Kaneko, Toyoji; Tanaka, Toshiomi; Iuchi, Ichiro; Yasumasu, Shigeki

    2011-10-01

    We purified eel hatching enzyme (EHE) from the hatching liquid of Japanese eel Anguilla japonica belonging to Elopomorpha to a single band on SDS/PAGE. TOF-MS analysis revealed that the purified EHE contained several isozymes with similar molecular masses. Comparison of the egg envelope digestion specificities of the purified EHE and of recombinant EHE4, one of the EHE isozymes, suggested that the isozymes contained in the purified EHE were functionally the same in terms of egg envelope digestion. By electron microscopy, the egg envelope became swollen after treatment with the purified EHE. The EHE cleavage sites on the zona pellucida (ZP) protein of the egg envelope were located in the N-terminal repeat regions. In previous phylogenetic analysis, we suggested that fishes included in Elopomorpha, as basal teleosts, possess a single type of hatching enzyme genes, and that fishes in Otocephala and Euteleostei gain two types of hatching enzyme genes called clade I and II genes by duplication. Further, the clade I enzymes, zebrafish hatching enzyme (ZHE1) and medaka high choriolytic enzyme (HCE), swell the egg envelope by cleaving the N-terminal regions of ZP proteins, while the clade II enzyme, medaka low choriolytic enzyme (LCE), solubilizes the swollen envelope by cleaving the site at the middle region on the ZP domain. In this evolutionary scenario, our findings support that hatching of Japanese eel conserves the ancestral mechanism of fish egg envelope digestion. The clade I enzymes inherit the ancestral enzyme function, and the clade II enzymes gain a new function during evolution to Otocephala and Euteleostei. © 2011 The Authors Journal compilation © 2011 FEBS.

  17. Nuclear envelope breakdown induced by herpes simplex virus type 1 involves the activity of viral fusion proteins.

    PubMed

    Maric, Martina; Haugo, Alison C; Dauer, William; Johnson, David; Roller, Richard J

    2014-07-01

    Herpesvirus infection reorganizes components of the nuclear lamina usually without loss of integrity of the nuclear membranes. We report that wild-type HSV infection can cause dissolution of the nuclear envelope in transformed mouse embryonic fibroblasts that do not express torsinA. Nuclear envelope breakdown is accompanied by an eight-fold inhibition of virus replication. Breakdown of the membrane is much more limited during infection with viruses that lack the gB and gH genes, suggesting that breakdown involves factors that promote fusion at the nuclear membrane. Nuclear envelope breakdown is also inhibited during infection with virus that does not express UL34, but is enhanced when the US3 gene is deleted, suggesting that envelope breakdown may be enhanced by nuclear lamina disruption. Nuclear envelope breakdown cannot compensate for deletion of the UL34 gene suggesting that mixing of nuclear and cytoplasmic contents is insufficient to bypass loss of the normal nuclear egress pathway. Copyright © 2014 Elsevier Inc. All rights reserved.

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

    SciTech Connect

    Shi, Jian; Zhang, Huaidong; Gong, Rui; Xiao, Gengfu

    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.

  19. Modeling pollutant penetration across building envelopes

    SciTech Connect

    Liu, De-Ling; Nazaroff, William W.

    2001-04-01

    As air infiltrates through unintentional openings in building envelopes, pollutants may interact with adjacent surfaces. Such interactions can alter human exposure to air pollutants of outdoor origin. We present modeling explorations of the proportion of particles and reactive gases (e.g., ozone) that penetrate building envelopes as air enters through cracks and wall cavities. Calculations were performed for idealized rectangular cracks, assuming regular geometry, smooth inner crack surface and steady airflow. Particles of 0.1-1.0 {micro}m diameter are predicted to have the highest penetration efficiency, nearly unity for crack heights of 0.25 mm or larger, assuming a pressure difference of 4 Pa or greater and a flow path length of 3 cm or less. Supermicron and ultrafine particles are significantly removed by means of gravitational settling and Brownian diffusion, respectively. In addition to crack geometry, ozone penetration depends on its reactivity with crack surfaces, as parameterized by the reaction probability. For reaction probabilities less than {approx}10{sup -5}, penetration is complete for cracks heights greater than 1 mm. However, penetration through mm scale cracks is small if the reaction probability is {approx}10{sup -4} or greater. For wall cavities, fiberglass insulation is an efficient particle filter, but particles would penetrate efficiently through uninsulated wall cavities or through insulated cavities with significant airflow bypass. The ozone reaction probability on fiberglass fibers was measured to be 10{sup -7} for fibers previously exposed to high ozone levels and 6 x 10{sup -6} for unexposed fibers. Over this range, ozone penetration through fiberglass insulation would vary from >90% to {approx}10-40%. Thus, under many conditions penetration is high; however, there are realistic circumstances in which building envelopes can provide substantial pollutant removal. Not enough is yet known about the detailed nature of pollutant penetration

  20. Surface area coefficients for airship envelopes

    NASA Technical Reports Server (NTRS)

    Diehl, W S

    1922-01-01

    In naval architecture, it is customary to determine the wetted surface of a ship by means of some formula which involves the principal dimensions of the design and suitable constants. These formulas of naval architecture may be extended and applied to the calculation of the surface area of airship envelopes by the use of new values of the constants determined for this purpose. Surface area coefficients were calculated from the actual dimensions, surfaces, and volumes of 52 streamline bodies, which form a series covering the entire range of shapes used in the present aeronautical practice.

  1. Active Monitoring Complex-Envelope Processing

    NASA Astrophysics Data System (ADS)

    Unger, R.

    2011-12-01

    Pseudo-random 3-D signal transmission followed by quadrature signal processing significantly enhances seismic Active Monitoring (AM). The algorithm produces complex-envelope seismograms consisting of the dual time series of instantaneous amplitude and phase. Minimum-standard-deviation signal arrival detection and timing from coherent instantaneous-phase seismogram ensembles yields signal time errors inversely proportional to frequency and signal-to-noise ratio. In particular, application to piezo-electric acoustic cross well monitoring as in SAFOD experiments should result in nano-second multiple-signal detection and timing precision. The method is applicable to all types (seismic, EM, acoustic) of AM.

  2. The protein translocon of the plastid envelopes.

    PubMed

    Vojta, Aleksandar; Alavi, Marcel; Becker, Thomas; Hörmann, Friederike; Küchler, Michael; Soll, Jürgen; Thomson, Rowena; Schleiff, Enrico

    2004-05-14

    The Toc and Tic translocon facilitate import of preproteins into chloroplasts. In the past, it was speculated that several translocon subunits act specifically for different types of precursor proteins or in different tissues. To generate a comprehensive picture of the expression and tissue-specific localization of the translocon subunits, their transcript levels were analyzed in roots and leaves. Certain Tocs and Tics were found to be tissue-specific. The protein composition of the transloci in the envelope membranes of chloroplasts was analyzed to describe the function and possible stoichiometry. In contrast to Tic subunits, several Toc subunits seem to have a high turnover.

  3. Low heat-leak cryogenic envelope

    DOEpatents

    DeHaan, James R.

    1976-10-19

    A plurality of cryogenic envelope sections are joined together to form a power transmission line. Each of the sections is comprised of inner and outer tubes having multilayer metalized plastic spirally wrapped within a vacuum chamber formed between the inner and outer tubes. A refrigeration tube traverses the vacuum chamber, but exits one section and enters another through thermal standoffs for reducing heat-leak from the outer tube to the refrigeration tube. The refrigeration tube passes through a spirally wrapped shield within each section's vacuum chamber in a manner so that the refrigeration tube is in close thermal contact with the shield, but is nevertheless slideable with respect thereto.

  4. O-linked glycosylation of retroviral envelope gene products

    SciTech Connect

    Pinter, A.; Honnen, W.J. )

    1988-03-01

    Treatment of ({sup 3}H)glucosamine-labeled Friend mink cell focus-forming virus (FrMCF) gp70 with excess peptide:N-glycanase F (PNGase F) resulted in removal of the expected seven N-linked oligosaccharide chains; however, approximately 10% of the glucosamine label was retained in the resulting 49,000-M{sub r} (49K) product. For ({sup 3}H)mannose-labeled gp70, similar treatment led to removal of all the carbohydrate label from the protein. Prior digestion of the PNGase F-treated gp70 with neuraminidase resulted in an addition size shift, and treatment with O-glycanase led to the removal of almost all of the PNGase F-resistant sugars. These results indicate that gp70 possesses sialic acid-containing O-linked oligosaccharides. Analysis of intracellular env precursors demonstrated that O-linked sugars were present in gPr90{sup env}, the polyprotein intermediate which contains complex sugars, but not in the primary translation product, gPr80{sup env}, and proteolytic digestion studies allowed localization of the O-linked carbohydrates to a 10K region near the center of the gp70 molecule. similar substituents were detected on the gp70s of ecotropic and xenotropic murine leukemia viruses and two subgroups of feline leukemia virus, indicting that O-linked glycosylation is a conserved feature of retroviral env proteins.

  5. NET23/STING Promotes Chromatin Compaction from the Nuclear Envelope

    PubMed Central

    de las Heras, Jose I.; Saiz-Ros, Natalia; Makarov, Alexandr A.; Lazou, Vassiliki; Meinke, Peter; Waterfall, Martin; Kelly, David A.; Schirmer, Eric C.

    2014-01-01

    Changes in the peripheral distribution and amount of condensed chromatin are observed in a number of diseases linked to mutations in the lamin A protein of the nuclear envelope. We postulated that lamin A interactions with nuclear envelope transmembrane proteins (NETs) that affect chromatin structure might be altered in these diseases and so screened thirty-one NETs for those that promote chromatin compaction as determined by an increase in the number of chromatin clusters of high pixel intensity. One of these, NET23 (also called STING, MITA, MPYS, ERIS, Tmem173), strongly promoted chromatin compaction. A correlation between chromatin compaction and endogenous levels of NET23/STING was observed for a number of human cell lines, suggesting that NET23/STING may contribute generally to chromatin condensation. NET23/STING has separately been found to be involved in innate immune response signaling. Upon infection cells make a choice to either apoptose or to alter chromatin architecture to support focused expression of interferon genes and other response factors. We postulate that the chromatin compaction induced by NET23/STING may contribute to this choice because the cells expressing NET23/STING eventually apoptose, but the chromatin compaction effect is separate from this as the condensation was still observed when cells were treated with Z-VAD to block apoptosis. NET23/STING-induced compacted chromatin revealed changes in epigenetic marks including changes in histone methylation and acetylation. This indicates a previously uncharacterized nuclear role for NET23/STING potentially in both innate immune signaling and general chromatin architecture. PMID:25386906

  6. NET23/STING promotes chromatin compaction from the nuclear envelope.

    PubMed

    Malik, Poonam; Zuleger, Nikolaj; de las Heras, Jose I; Saiz-Ros, Natalia; Makarov, Alexandr A; Lazou, Vassiliki; Meinke, Peter; Waterfall, Martin; Kelly, David A; Schirmer, Eric C

    2014-01-01

    Changes in the peripheral distribution and amount of condensed chromatin are observed in a number of diseases linked to mutations in the lamin A protein of the nuclear envelope. We postulated that lamin A interactions with nuclear envelope transmembrane proteins (NETs) that affect chromatin structure might be altered in these diseases and so screened thirty-one NETs for those that promote chromatin compaction as determined by an increase in the number of chromatin clusters of high pixel intensity. One of these, NET23 (also called STING, MITA, MPYS, ERIS, Tmem173), strongly promoted chromatin compaction. A correlation between chromatin compaction and endogenous levels of NET23/STING was observed for a number of human cell lines, suggesting that NET23/STING may contribute generally to chromatin condensation. NET23/STING has separately been found to be involved in innate immune response signaling. Upon infection cells make a choice to either apoptose or to alter chromatin architecture to support focused expression of interferon genes and other response factors. We postulate that the chromatin compaction induced by NET23/STING may contribute to this choice because the cells expressing NET23/STING eventually apoptose, but the chromatin compaction effect is separate from this as the condensation was still observed when cells were treated with Z-VAD to block apoptosis. NET23/STING-induced compacted chromatin revealed changes in epigenetic marks including changes in histone methylation and acetylation. This indicates a previously uncharacterized nuclear role for NET23/STING potentially in both innate immune signaling and general chromatin architecture.

  7. Inducible spy Transcription Acts as a Sensor for Envelope Stress of Salmonella typhimurium

    PubMed Central

    Kim, Jin Seok; Lee, Sang Dae

    2017-01-01

    Salmonella enterica infects a broad range of host animals, and zoonostic infection threatens both public health and the livestock and meat processing industries. Many antimicrobials have been developed to target Salmonella envelope that performs essential bacterial functions; however, there are very few analytical methods that can be used to validate the efficacy of these antimicrobials. In this study, to develop a potential biosensor for Salmonella envelope stress, we examined the transcription of the S. enterica serovar typhimurium spy gene, the ortholog of which in Escherichia coli encodes Spy (spheroplast protein y). Spy is a chaperone protein expressed and localized in the periplasm of E. coli during spheroplast formation, or by exposure to protein denaturing conditions. spy expression in S. typhimurium was examined by constructing a spy-gfp transcriptional fusion. S. typhimurium spy transcription was strongly induced during spheroplast formation, and also when exposed to membrane-disrupting agents, including ethanol and the antimicrobial peptide polymyxin B. Moreover, spy induction required the activity of regulator proteins BaeR and CpxR, which are part of the major envelope stress response systems BaeS/BaeR and CpxA/CpxR, respectively. Results suggest that monitoring spy transcription may be useful to determine whether a molecule particularly cause envelope stress in Salmonella. PMID:28316480

  8. Inducible spy Transcription Acts as a Sensor for Envelope Stress of Salmonella typhimurium.

    PubMed

    Jeong, Seon Mi; Lee, Hwa Jeong; Park, Yoon Mee; Kim, Jin Seok; Lee, Sang Dae; Bang, Iel Soo

    2017-01-01

    Salmonella enterica infects a broad range of host animals, and zoonostic infection threatens both public health and the livestock and meat processing industries. Many antimicrobials have been developed to target Salmonella envelope that performs essential bacterial functions; however, there are very few analytical methods that can be used to validate the efficacy of these antimicrobials. In this study, to develop a potential biosensor for Salmonella envelope stress, we examined the transcription of the S. enterica serovar typhimurium spy gene, the ortholog of which in Escherichia coli encodes Spy (spheroplast protein y). Spy is a chaperone protein expressed and localized in the periplasm of E. coli during spheroplast formation, or by exposure to protein denaturing conditions. spy expression in S. typhimurium was examined by constructing a spy-gfp transcriptional fusion. S. typhimurium spy transcription was strongly induced during spheroplast formation, and also when exposed to membrane-disrupting agents, including ethanol and the antimicrobial peptide polymyxin B. Moreover, spy induction required the activity of regulator proteins BaeR and CpxR, which are part of the major envelope stress response systems BaeS/BaeR and CpxA/CpxR, respectively. Results suggest that monitoring spy transcription may be useful to determine whether a molecule particularly cause envelope stress in Salmonella.

  9. Characterization of human immunodeficiency virus type 2 envelope glycoproteins: Dimerization of the glycoprotein precursor during processing

    SciTech Connect

    Rey, M.A.; Krust, B.; Laurent, A.G.; Montagnier, L.; Hovanessian, A.G.

    1989-02-01

    For glycoproteins with apparent molecular weights of 300,000, 140,000, 125,000, and 36,000 (gp300, gp140, gp125, and gp36) were detectable in human immunodeficiency virus type 2 (HIV-2)-infected cells. They have identical isoelectric points, suggesting that gp300 might be a dimeric form of the immature precursor, gp140. The purified gp300 can be dissociated in a slightly acidic buffer to give rise to monomers of 140,000 molecular weight. Such dissociated monomers and the purified gp140 showed identical patterns of polypeptides after partial proteolysis with Staphylococcus aureus V8 protease. Pulse-chase experiments indicated that gp300 is formed after synthesis of gp140 and before the detection of the mature external envelope glycoprotein, gp125. These results were confirmed by using various inhibitors of glycosylation and inhibitors of trimming enzymes. Dimer formation of the envelope glycoprotein precursor was also observed in cells infected with simian immunodeficiency virus (SIV), a virus closely related to HIV-2. On the other hand, the envelope glycoprotein precursor of HIV-1 did not form a dimer during its processing. Therefore, dimer formation seems to be a specific property of HIV-2 and SIV envelope gene expression. Such transient dimerization of the glycoprotein precursor might be required for its efficient transport to the Golgi apparatus and for its processing.

  10. Envoplakin, a novel precursor of the cornified envelope that has homology to desmoplakin

    PubMed Central

    1996-01-01

    The cornified envelope is a layer of transglutaminase cross-linked protein that is deposited under the plasma membrane of keratinocytes in the outermost layers of the epidermis. We present the sequence of one of the cornified envelope precursors, a protein with an apparent molecular mass of 210 kD. The 210-kD protein is translated from a 6.5- kb mRNA that is transcribed from a single copy gene. The mRNA was upregulated during suspension-induced terminal differentiation of cultured human keratinocytes. Like other envelope precursors, the 210- kD protein became insoluble in SDS and beta-mercaptoethanol on activation of transglutaminases in cultured keratinocytes. The protein was expressed in keratinizing and nonkeratinizing stratified squamous epithelia, but not in simple epithelia or nonepithelial cells. Immunofluorescence staining showed that in epidermal keratinocytes, both in vivo and in culture, the protein was upregulated during terminal differentiation and partially colocalized with desmosomal proteins. Immunogold EM confirmed the colocalization of the 210-kD protein and desmoplakin at desmosomes and on keratin filaments throughout the differentiated layers of the epidermis. Sequence analysis showed that the 210-kD protein is homologous to the keratin- binding proteins desmoplakin, bullous pemphigoid antigen 1, and plectin. These data suggest that the 210-kD protein may link the cornified envelope to desmosomes and keratin filaments. We propose that the 210-kD protein be named "envoplakin." PMID:8707850

  11. Circumstellar envelopes and Asymptotic Giant Branch stars

    NASA Astrophysics Data System (ADS)

    Habing, H. J.

    Red giants are sometimes surrounded by envelopes, the result of the ejection of stellar matter at a large rate (dot M> 10^{-7}M_odot/yr) and at a low velocity (10 km/s). In this review the envelopes are discussed and the relation between stars and envelope: what stars combine with what envelopes? The envelope emits radiation by various processes and has been detected at all wavelengths between the visual and the microwave range. I review the observations of continuum radiation emitted by dust particles and of rotational transitions of molecules, where these molecules have been excited by thermal or by non thermal (“maser”) processes. I discuss mainly the oxygen rich stars, those of spectral type M, and only briefly the closely related carbon rich stars. By and large the density in the envelope is well described by spherically symmetric outflow at a constant velocity; on the time scale needed to flow from stellar surface to the outermost layers, i.e. 10^5 yr, the loss of mass is sometimes interrupted suddenly after which the envelope becomes “detached” from the star. The temperature decreases when moving outward; heat input is by friction between dust particles and gas and cooling occurs by line radiation by various molecules, especially by H_2O. The molecular composition is determined by formation in an equilibrium process deep in the atmosphere and by destruction in the outer parts of the outflow by interstellar UV radiation (H_2, CO, H_2O) or by depletion due to condensation on dust grains (SiO); dust particles of silicate material solidify where the radiation temperature is decreased to about 1000 K, and this is at a few stellar radii. The various continuum spectra produced by the dust particles in different stars are well modelled by a simple model of the density and dust temperature distribution plus the assumption that the particles consist of “dirty silicate”, i.e. silicate with Fe and Al ions added. A large range of optical depths,tau_{9.7

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

    NASA Astrophysics Data System (ADS)

    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.

  13. On-Line Safe Flight Envelope Determination for Impaired Aircraft

    NASA Technical Reports Server (NTRS)

    Lombaerts, Thomas; Schuet, Stefan; Acosta, Diana; Kaneshige, John

    2015-01-01

    The design and simulation of an on-line algorithm which estimates the safe maneuvering envelope of aircraft is discussed in this paper. The trim envelope is estimated using probabilistic methods and efficient high-fidelity model based computations of attainable equilibrium sets. From this trim envelope, a robust reachability analysis provides the maneuverability limitations of the aircraft through an optimal control formulation. Both envelope limits are presented to the flight crew on the primary flight display. In the results section, scenarios are considered where this adaptive algorithm is capable of computing online changes to the maneuvering envelope due to impairment. Furthermore, corresponding updates to display features on the primary flight display are provided to potentially inform the flight crew of safety critical envelope alterations caused by the impairment.

  14. Minimum cost model energy code envelope requirements

    SciTech Connect

    Connor, C.C.; Lucas, R.G.; Turchen, S.J.

    1994-08-01

    This paper describes the analysis underlying development of the U.S. Department of Energy`s proposed revisions of the Council of American Building Officials (CABO) 1993 Model Energy Code (MEC) building thermal envelope requirements for single-family and low-rise multifamily residences. This analysis resulted in revised MEC envelope conservation levels based on an objective methodology that determined the minimum-cost combination of energy efficiency measures (EEMs) for residences in different locations around the United States. The proposed MEC revision resulted from a cost-benefit analysis from the consumer`s perspective. In this analysis, the costs of the EEMs were balanced against the benefit of energy savings. Detailed construction, financial, economic, and fuel cost data were compiled, described in a technical support document, and incorporated in the analysis. A cost minimization analysis was used to compare the present value of the total long-nm costs for several alternative EEMs and to select the EEMs that achieved the lowest cost for each location studied. This cost minimization was performed for 881 cities in the United States, and the results were put into the format used by the MEC. This paper describes the methodology for determining minimum-cost energy efficiency measures for ceilings, walls, windows, and floors and presents the results in the form of proposed revisions to the MEC. The proposed MEC revisions would, on average, increase the stringency of the MEC by about 10%.

  15. TRANSPARENT HELIUM IN STRIPPED ENVELOPE SUPERNOVAE

    SciTech Connect

    Piro, Anthony L.; Morozova, Viktoriya S.

    2014-09-01

    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 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.

  16. Envelope Modes of Beams with Angular Momentum

    SciTech Connect

    Barnard, J J; Losic, B

    2000-08-21

    For a particle beam propagating in an alternating gradient focusing system, envelope equations are often employed to describe the evolution of the beam radii in the two directions transverse to the direction of propagation, and aligned with the principle axes of the alternating gradient system. When the beams have zero net angular momentum and when the alternating gradient focusing is approximated by a continuous focusing system, there are two normal modes to the envelope equations: the 'breathing' mode and a 'quadrupole' mode. In the former, the two radii oscillate in phase, and in the latter the radii oscillate 180 degrees out of phase. In this paper, we extend the analysis to include beams that have a finite angular momentum. We perturb the moment equations of ref. [1], wherein it was assumed that space charge is a distributed in a uniform density ellipse. Two additional modes are obtained. The breathing mode remains, but the quadrupole mode is split into two modes, and a new low frequency mode appears. We calculate the frequencies and eigenmodes of these four modes as a function of tune depression and a dimensionless net angular momentum. These modes can be excited by rotational errors of the quadrupoles in an alternating gradient focusing channel.

  17. Sensitivity to changes in amplitude envelope

    NASA Astrophysics Data System (ADS)

    Gallun, Erick; Hafter, Ervin R.; Bonnel, Anne-Marie

    2002-05-01

    Detection of a brief increment in a tonal pedestal is less well predicted by energy-detection (e.g., Macmillan, 1973; Bonnel and Hafter, 1997) than by sensitivity to changes in the stimulus envelope. As this implies a mechanism similar to an envelope extractor (Viemeister, 1979), sinusoidal amplitude modulation was used to mask a single ramped increment (10, 45, or 70 ms) added to a 1000-ms pedestal with carrier frequency (cf)=477 Hz. As in informational masking (Neff, 1994) and ``modulation-detection interference'' (Yost and Sheft, 1989), interference occurred with masker cfs of 477 and 2013 Hz. While slight masking was found with modulation frequencies (mfs) from 16 to 96 Hz, masking grew inversely with still lower mfs, being greatest for mf=4 Hz. This division is reminiscent of that said to separate sensations of ``roughness'' and ``beats,'' respectively (Terhardt, 1974), with the latter also being related to durations associated with auditory groupings in music and speech. Importantly, this result held for all of the signal durations and onset-offset ramps tested, suggesting that an increment on a pedestal is treated as a single auditory object whose detection is most difficult in the presence of other objects (in this case, ``beats'').

  18. Glycolate transporter of the pea chloroplast envelope

    SciTech Connect

    Howitz, K.T.

    1985-01-01

    The discovery of a glycolate transporter in the pea (Pisum sativum) chloroplast envelope is described. Several novel silicone oil centrifugation methods were developed to resolve the initial rate kinetics of (/sup 14/C)glycolate transport by isolated, intact pea chloroplasts. Chloroplast glycolate transport was found to be carrier mediated. Transport rates saturated with increasing glycolate concentration. N-Ethylmaleimide (NEM) pretreatment of chloroplasts inhibited transport, an inhibition prevented by glycolate. Glycolate distributed across the envelope in a way which equalized stromal and medium glycolic acid concentrations, limiting possible transport mechanisms to facilitated glycolic acid diffusion, proton symport or hydroxyl antiport. The effects of stomal and medium pH's on the K/sub m/ and V/sub max/ fit the predictions of mobile carrier kinetic models of hydroxyl antiport or proton symport (H/sup +/ binds first). The carrier mediated transport was fast enough to be consistent with in vivo rates of photorespiration. The 2-hydroxymonocarboxylates, glycerate, lactate and glyoxylate are competitive inhibitors of chloroplast glycolate uptake. Glyoxylate, D-lactate and D-glycerate cause glycolate counterflow, indicating that they are also substrates of the glycolate carrier. This finding was confirmed for D-glycerate by studies on glycolate effects on (1-/sup 14/C)D-glycerate transport.

  19. Functional organization of the HIV lipid envelope

    PubMed Central

    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

  20. [Electrophysiological characterisation of envelope-following responses].

    PubMed

    Mijares Nodarse, Eleina; Pérez Abalo, María Cecilia; Torres Fortuny, Alejandro; Vega Hernández, Mayrim

    2011-01-01

    The auditory ability to discriminate rapid changes in the envelope of language sounds is essential for speech comprehension. This ability is deteriorated in some neurological diseases such as multiple sclerosis, auditory neuropathy, sensorineural hearing loss, presbycusis and primary developmental language disorder. Envelope-following responses (EFRs) in humans are useful in objective measurement of temporal processing in the auditory nervous system. To evaluate EFRs in healthy younger subjects and to investigate the effects of subject states on the EFRs recorded. Eleven young subjects were included; six of them were awake and five were asleep. EFRs were evoked by white noise carrier stimuli with a sweep of modulation frequencies from 20 to 200Hz presented at 50dB HL. The EFRs we recorded were similar in all subjects. There were two principal components. During both subject sleep and wakefulness, the first component (located between 30-50Hz) was significantly larger than the second component (located between 80-110Hz). There was also a significant effect of sleep on the EFR amplitude for the modulation frequencies between 88-110, 155-165 and 190-200Hz. However, there were no significant effects of sleep on the principal EFR components. These results corroborate the usefulness of the EFR technique for objective measurement of human auditory temporal processing. Copyright © 2011 Elsevier España, S.L. All rights reserved.

  1. Precision envelope detector and linear rectifier circuitry

    DOEpatents

    Davis, Thomas J.

    1980-01-01

    Disclosed is a method and apparatus for the precise linear rectification and envelope detection of oscillatory signals. The signal is applied to a voltage-to-current converter which supplies current to a constant current sink. The connection between the converter and the sink is also applied through a diode and an output load resistor to a ground connection. The connection is also connected to ground through a second diode of opposite polarity from the diode in series with the load resistor. Very small amplitude voltage signals applied to the converter will cause a small change in the output current of the converter, and the difference between the output current and the constant current sink will be applied either directly to ground through the single diode, or across the output load resistor, dependent upon the polarity. Disclosed also is a full-wave rectifier utilizing constant current sinks and voltage-to-current converters. Additionally, disclosed is a combination of the voltage-to-current converters with differential integrated circuit preamplifiers to boost the initial signal amplitude, and with low pass filtering applied so as to obtain a video or signal envelope output.

  2. Proteomics of the chloroplast envelope membranes from Arabidopsis thaliana.

    PubMed

    Ferro, Myriam; Salvi, Daniel; Brugière, Sabine; Miras, Stéphane; Kowalski, Solène; Louwagie, Mathilde; Garin, Jérôme; Joyard, Jacques; Rolland, Norbert

    2003-05-01

    The development of chloroplasts and the integration of their function within a plant cell rely on the presence of a complex biochemical machinery located within their limiting envelope membranes. To provide the most exhaustive view of the protein repertoire of chloroplast envelope membranes, we analyzed this membrane system using proteomics. To this purpose, we first developed a procedure to prepare highly purified envelope membranes from Arabidopsis chloroplasts. We then extracted envelope proteins using different methods, i.e. chloroform/methanol extraction and alkaline or saline treatments, in order to retrieve as many proteins as possible, from the most to least hydrophobic ones. Liquid chromatography tandem mass spectrometry analyses were then performed on each envelope membrane subfraction, leading to the identification of more than 100 proteins. About 80% of the identified proteins are known to be, or are very likely, located in the chloroplast envelope. The validation of localization in the envelope of two phosphate transporters exemplifies the need for a combination of strategies to perform the most exhaustive identification of genuine chloroplast envelope proteins. Interestingly, some of the identified proteins are found to be Nalpha-acetylated, which indicates the accurate location of the N terminus of the corresponding mature protein. With regard to function, more than 50% of the identified proteins have functions known or very likely to be associated with the chloroplast envelope. These proteins are a) involved in ion and metabolite transport, b) components of the protein import machinery, and c) involved in chloroplast lipid metabolism. Some soluble proteins, like proteases, proteins involved in carbon metabolism, or proteins involved in responses to oxidative stress, were associated with envelope membranes. Almost one-third of the proteins we identified have no known function. The present work helps understanding chloroplast envelope metabolism at

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

    PubMed

    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.

  4. Defining the Core Proteome of the Chloroplast Envelope Membranes

    PubMed Central

    Simm, Stefan; Papasotiriou, Dimitrios G.; Ibrahim, Mohamed; Leisegang, Matthias S.; Müller, Bernd; Schorge, Tobias; Karas, Michael; Mirus, Oliver; Sommer, Maik S.; Schleiff, Enrico

    2013-01-01

    High-throughput protein localization studies require multiple strategies. Mass spectrometric analysis of defined cellular fractions is one of the complementary approaches to a diverse array of cell biological methods. In recent years, the protein content of different cellular (sub-)compartments was approached. Despite of all the efforts made, the analysis of membrane fractions remains difficult, in that the dissection of the proteomes of the envelope membranes of chloroplasts or mitochondria is often not reliable because sample purity is not always warranted. Moreover, proteomic studies are often restricted to single (model) species, and therefore limited in respect to differential individual evolution. In this study we analyzed the chloroplast envelope proteomes of different plant species, namely, the individual proteomes of inner and outer envelope (OE) membrane of Pisum sativum and the mixed envelope proteomes of Arabidopsis thaliana and Medicago sativa. The analysis of all three species yielded 341 identified proteins in total, 247 of them being unique. 39 proteins were genuine envelope proteins found in at least two species. Based on this and previous envelope studies we defined the core envelope proteome of chloroplasts. Comparing the general overlap of the available six independent studies (including ours) revealed only a number of 27 envelope proteins. Depending on the stringency of applied selection criteria we found 231 envelope proteins, while less stringent criteria increases this number to 649 putative envelope proteins. Based on the latter we provide a map of the outer and inner envelope core proteome, which includes many yet uncharacterized proteins predicted to be involved in transport, signaling, and response. Furthermore, a foundation for the functional characterization of yet unidentified functions of the inner and OE for further analyses is provided. PMID:23390424

  5. Sturgeon hatching enzyme and the mechanism of egg envelope digestion: Insight into changes in the mechanism of egg envelope digestion during the evolution of ray-finned fish.

    PubMed

    Nagasawa, Tatsuki; Kawaguchi, Mari; Sano, Kaori; Yasumasu, Shigeki

    2015-12-01

    We investigated the evolution of the hatching enzyme gene using bester sturgeon (hybrid of Acipencer ruthenus and Huso huso), a basal member of ray-finned fishes. We purified the bester hatching enzyme from hatching liquid, yielding a single band on SDS-PAGE, then isolated its cDNA from embryos by PCR. The sturgeon hatching enzyme consists of an astacin family protease domain and a CUB domain. The CUB domains are present in frog and bird hatching enzymes, but not in teleostei, suggesting that the domain structure of sturgeon hatching enzyme is the tetrapod type. The purified hatching enzyme swelled the egg envelope, and selectively cleaved one of five egg envelope proteins, ZPAX. Xenopus hatching enzyme preferentially digests ZPAX, thus, the egg envelope digestion process is conserved between amphibians and basal ray-finned fish. Teleostei hatching enzymes cleave the repeat sequences at the N-terminal region of ZPB and ZPC, suggesting that the targets of the teleostei hatching enzymes differ from those of amphibians and sturgeons. Such repeat sequences were not found in the N-terminal region of ZPB and ZPC of amphibians and sturgeons. Our results suggest that the change in substrates of the hatching enzymes was accompanied by the mutation of the amino acid sequence of N-terminal regions of ZPB and ZPC. We conclude that the changes in the mechanism of egg envelope digestion, including the change in the domain structure of the hatching enzymes and the switch in substrate, occurred during the evolution of teleostei, likely triggered by the teleost-specific third whole genome duplication. J. Exp. Zool. (Mol. Dev. Evol.) 324B: 720-732, 2015. © 2015 Wiley Periodicals, Inc. © 2015 Wiley Periodicals, Inc.

  6. Humoral immune response to the entire human immunodeficiency virus envelope glycoprotein made in insect cells

    SciTech Connect

    Rusche, J.R.; Lynn, D.L.; Robert-Guroff, M.; Langlois, A.J.; Lyerly, H.K.; Carson, H.; Krohn, K.; Ranki, A.; Gallo, R.C.; Bolognesi, D.P.; Putney, S.D.

    1987-10-01

    The human immunodeficiency virus envelope gene was expressed in insect cells by using a Baculovirus expression vector. The protein has an apparent molecular mass of 160 kDa, appears on the surface of infected insect cells, and does not appear to be cleaved to glycoproteins gp120 and gp41. Goats immunized with the 160-kDa protein have high titers of antibody that neutralizes virus infection as measured by viral gene expression or cell cytolysis. In addition, immune sera can block fusion of human immunodeficiency virus-infected cells in culture. Both neutralization and fusion-blocking activities are bound to and eluted from immobilized gp120.

  7. Cricket team selection using data envelopment analysis.

    PubMed

    Amin, Gholam R; Sharma, Sujeet Kumar

    2014-01-01

    This paper suggests a new method for cricket team selection using data envelopment analysis (DEA). We propose a DEA formulation for evaluation of cricket players in different capabilities using multiple outputs. This evaluation determines efficient and inefficient cricket players and ranks them on the basis of DEA scores. The ranking can be used to choose the required number of players for a cricket team in each cricketing capability. A real dataset, Indian Premier League 4 (IPL 2011), cricket players having various capabilities is used to choose the best cricket team. The proposed method has the advantage of considering multiple factors related to the performance of players in multiple capabilities collected from IPL 4 and aggregates their scores using a linear programming DEA model. This DEA Aggregation gives the scores of players objectively instead of using subjective computations. The proposed DEA method can be used to form a national cricket team from several clubs or a team of top cricketers.

  8. Fullerenes and fulleranes in circumstellar envelopes

    NASA Astrophysics Data System (ADS)

    Zhang, Yong; Kwok, Sun; Sadjadi, SeyedAbdolreza

    2016-07-01

    Three decades of search have recently led to convincing discoveries of cosmic fullerenes. The presence of C60 and C+ 60 in both circumstellar and interstellar environments suggests that these molecules and their derivatives can be efficiently formed in circumstellar envelopes and survive in harsh conditions. Detailed analysis of the infrared bands from fullerenes and their connections with the local properties can provide valuable information on the physical conditions and chemical processes that occurred in the late stages of stellar evolution. The identification of C+ 60 as the carrier of four diffuse interstellar bands (DIBs) suggests that fullerene- related compounds are abundant in interstellar space and are essential for resolving the DIB mystery. Experiments have revealed a high hydrogenation rate when C60 is exposed to atomic hydrogen, motivating the attempt to search for cosmic fulleranes. In this paper, we present a short review of current knowledge of cosmic fullerenes and fulleranes and briefly discuss the implications on circumstellar chemistry.

  9. Envelope representations for screened Coulomb potentials

    NASA Astrophysics Data System (ADS)

    Hall, Richard L.

    1985-07-01

    We study the discrete eigenvalues Enl of the Schrödinger Hamiltonian H=-(1/2)Δ+V(r), where V(r)=g(-1/r) is an increasing concave transformation of the Coulomb potential, and n is the principal (radial) quantum number. It is demonstrated by the method of potential envelopes that upper bounds are provided by the simple formula Enl<= mins>0 \\{(1/2)s+V((n+l)/s1/2)\\}, where s is a real variable. Numerical results are compared with previous work for two specific screened Coulomb potentials. In the case of the Yukawa potential V(r)=-(v/r)exp(-λr), it is shown that the inequality (n+l)2λ/v<2/e is sufficient to guarantee the existence of the eigenvalue Enl: In the case of S states, sharp upper and lower bounds are also provided by a different method.

  10. LINCing complex functions at the nuclear envelope

    PubMed Central

    Rothballer, Andrea; Schwartz, Thomas U.; Kutay, Ulrike

    2013-01-01

    Linker of nucleoskeleton and cytoskeleton (LINC) complexes span the double membrane of the nuclear envelope (NE) and physically connect nuclear structures to cytoskeletal elements. LINC complexes are envisioned as force transducers in the NE, which facilitate processes like nuclear anchorage and migration, or chromosome movements. The complexes are built from members of two evolutionary conserved families of transmembrane (TM) proteins, the SUN (Sad1/UNC-84) domain proteins in the inner nuclear membrane (INM) and the KASH (Klarsicht/ANC-1/SYNE homology) domain proteins in the outer nuclear membrane (ONM). In the lumen of the NE, the SUN and KASH domains engage in an intimate assembly to jointly form a NE bridge. Detailed insights into the molecular architecture and atomic structure of LINC complexes have recently revealed the molecular basis of nucleo-cytoskeletal coupling. They bear important implications for LINC complex function and suggest new potential and as yet unexplored roles, which the complexes may play in the cell. PMID:23324460

  11. EsrC, an envelope stress-regulated repressor of the mexCD-oprJ multidrug efflux operon in Pseudomonas aeruginosa.

    PubMed

    Purssell, Andrew; Fruci, Michael; Mikalauskas, Alaya; Gilmour, Christie; Poole, Keith

    2015-01-01

    mexCD-oprJ is an envelope stress-inducible multidrug efflux operon of Pseudomonas aeruginosa. A gene encoding a homologue of the NfxB repressor of this operon, PA4596, occurs downstream of oprJ and was proposed as a second repressor of this efflux operon. Inactivation of this gene had no impact on mexCD-oprJ expression in cells not exposed to envelope stress although its loss under envelope stress conditions yielded a > 10-fold increase in mexCD-oprJ expression. Consistent with PA4596 functioning as a mexCD-oprJ repressor, the purified protein was able to bind to a DNA fragment carrying the mexCD-oprJ promoter region. Expression of PA4596 was induced under conditions of envelope stress dependent on the AlgU envelope stress sigma factor, consistent with PA4596 operating under envelope stress conditions where it possibly serves to moderate envelope stress-inducible mexCD-oprJ expression. nfxB mutants showed elevated PA4596 expression and purified NfxB bound to DNA encompassing the PA4596 upstream region, an indication that NfxB functions as a repressor of PA4596 expression. Elimination of PA4596 in P. aeruginosa lacking nfxB and hyperexpressing mexCD-oprJ had no additional impact on mexCD-oprJ expression, regardless of the presence of envelope stress, suggesting that PA4596 repressor activity may be dependent on NfxB. This envelope stress-regulated repressor of mexCD-oprJ has been renamed esrC.

  12. Diversity in the fertilization envelopes of echinoderms.

    PubMed

    Oulhen, Nathalie; Reich, Adrian; Wong, Julian L; Ramos, Isabela; Wessel, Gary M

    2013-01-01

    Cell surface changes in an egg at fertilization are essential to begin development and for protecting the zygote. Most fertilized eggs construct a barrier around themselves by modifying their original extracellular matrix. This construction usually results from calcium-induced exocytosis of cortical granules, the contents of which in sea urchins function to form the fertilization envelope (FE), an extracellular matrix of cortical granule contents built upon a vitelline layer scaffold. Here, we examined the molecular mechanism of this process in sea stars, a close relative of the sea urchins, and analyze the evolutionary changes that likely occurred in the functionality of this structure between these two organisms. We find that the FE of sea stars is more permeable than in sea urchins, allowing diffusion of molecules in excess of 2 megadaltons. Through a proteomic and transcriptomic approach, we find that most, but not all, of the proteins present in the sea urchin envelope are present in sea stars, including SFE9, proteoliaisin, and rendezvin. The mRNAs encoding these FE proteins accumulated most densely in early oocytes, and then beginning with vitellogenesis, these mRNAs decreased in abundance to levels nearly undetectable in eggs. Antibodies to the SFE9 protein of sea stars showed that the cortical granules in sea star also accumulated most significantly in early oocytes, but different from sea urchins, they translocated to the cortex of the oocytes well before meiotic initiation. These results suggest that the preparation for cell surface changes in sea urchins has been shifted to later in oogenesis, and perhaps reflects the meiotic differences among the species-sea star oocytes are stored in prophase of meiosis and fertilized during the meiotic divisions, as in most animals, whereas sea urchins are one of the few taxons in which eggs have completed meiosis prior to fertilization.

  13. ASYMMETRIC ACCRETION FLOWS WITHIN A COMMON ENVELOPE

    SciTech Connect

    MacLeod, Morgan; Ramirez-Ruiz, Enrico

    2015-04-10

    This paper examines flows in the immediate vicinity of stars and compact objects dynamically inspiralling within a common envelope (CE). Flow in the vicinity of the embedded object is gravitationally focused, leading to drag and potentially to gas accretion. This process has been studied numerically and analytically in the context of Hoyle–Lyttleton accretion (HLA). Yet, within a CE, accretion structures may span a large fraction of the envelope radius, and in so doing sweep across a substantial radial gradient of density. We quantify these gradients using detailed stellar evolution models for a range of CE encounters. We provide estimates of typical scales in CE encounters that involve main sequence stars, white dwarfs, neutron stars, and black holes with giant-branch companions of a wide range of masses. We apply these typical scales to hydrodynamic simulations of three-dimensional HLA with an upstream density gradient. This density gradient breaks the symmetry that defines HLA flow, and imposes an angular momentum barrier to accretion. Material that is focused into the vicinity of the embedded object thus may not be able to accrete. As a result, accretion rates drop dramatically, by one to two orders of magnitude, while drag rates are only mildly affected. We provide fitting formulae to the numerically derived rates of drag and accretion as a function of the density gradient. The reduced ratio of accretion to drag suggests that objects that can efficiently gain mass during CE evolution, such as black holes and neutron stars, may grow less than implied by the HLA formalism.

  14. Diversity in the fertilization envelopes of echinoderms

    PubMed Central

    Oulhen, Nathalie; Reich, Adrian; Wong, Julian L.; Wessel, Gary M.

    2013-01-01

    Cell surface changes in an egg at fertilization are essential to begin development and for protecting the zygote. Most fertilized eggs construct a barrier around themselves by modifying their original extracellular matrix. This construction usually results from calcium induced exocytosis of cortical granules, the contents of which in sea urchins function to form the fertilization envelope (FE), an extracellular matrix of cortical granule contents built upon a vitelline layer scaffold. Here we examined the molecular mechanism of this process in sea stars, a close relative of the sea urchins, and analyze the evolutionary changes that likely occurred in the functionality of this structure between these two organisms. We find that the FE of sea stars is more permeable than in sea urchins, allowing diffusion of molecules in excess of 2 megadaltons. Through a proteomic and transcriptomic approach, we find that most, but not all of the proteins present in the sea urchin envelope are present in sea stars, including SFE9, proteoliaisin, rendezvin, and ovoperoxidase. The mRNAs encoding these FE proteins accumulated most densely in early oocytes, and then beginning with vitellogenesis, these mRNAs deceased in abundance to levels nearly undetectable in eggs. Antibodies to the SFE9 protein of sea stars showed that the cortical granules in sea star also accumulated most significantly in early oocytes, and different from sea urchins, they translocated to the cortex of the oocytes well before meiotic initiation. These results suggest that the preparation of the cell surface changes in sea urchins has been shifted to later in oogenesis and perhaps reflects the meiotic differences among the species–sea star oocytes are stored in prophase of meiosis and fertilized during the meiotic divisions, as in most animals, whereas sea urchins are one of the few taxa in which eggs have completed meiosis prior to fertilization. PMID:23331915

  15. Asymmetric Accretion Flows within a Common Envelope

    NASA Astrophysics Data System (ADS)

    MacLeod, Morgan; Ramirez-Ruiz, Enrico

    2015-04-01

    This paper examines flows in the immediate vicinity of stars and compact objects dynamically inspiralling within a common envelope (CE). Flow in the vicinity of the embedded object is gravitationally focused, leading to drag and potentially to gas accretion. This process has been studied numerically and analytically in the context of Hoyle-Lyttleton accretion (HLA). Yet, within a CE, accretion structures may span a large fraction of the envelope radius, and in so doing sweep across a substantial radial gradient of density. We quantify these gradients using detailed stellar evolution models for a range of CE encounters. We provide estimates of typical scales in CE encounters that involve main sequence stars, white dwarfs, neutron stars, and black holes with giant-branch companions of a wide range of masses. We apply these typical scales to hydrodynamic simulations of three-dimensional HLA with an upstream density gradient. This density gradient breaks the symmetry that defines HLA flow, and imposes an angular momentum barrier to accretion. Material that is focused into the vicinity of the embedded object thus may not be able to accrete. As a result, accretion rates drop dramatically, by one to two orders of magnitude, while drag rates are only mildly affected. We provide fitting formulae to the numerically derived rates of drag and accretion as a function of the density gradient. The reduced ratio of accretion to drag suggests that objects that can efficiently gain mass during CE evolution, such as black holes and neutron stars, may grow less than implied by the HLA formalism.

  16. Enhanced conformational sampling using enveloping distribution sampling.

    PubMed

    Lin, Zhixiong; van Gunsteren, Wilfred F

    2013-10-14

    To lessen the problem of insufficient conformational sampling in biomolecular simulations is still a major challenge in computational biochemistry. In this article, an application of the method of enveloping distribution sampling (EDS) is proposed that addresses this challenge and its sampling efficiency is demonstrated in simulations of a hexa-β-peptide whose conformational equilibrium encompasses two different helical folds, i.e., a right-handed 2.7(10∕12)-helix and a left-handed 3(14)-helix, separated by a high energy barrier. Standard MD simulations of this peptide using the GROMOS 53A6 force field did not reach convergence of the free enthalpy difference between the two helices even after 500 ns of simulation time. The use of soft-core non-bonded interactions in the centre of the peptide did enhance the number of transitions between the helices, but at the same time led to neglect of relevant helical configurations. In the simulations of a two-state EDS reference Hamiltonian that envelops both the physical peptide and the soft-core peptide, sampling of the conformational space of the physical peptide ensures that physically relevant conformations can be visited, and sampling of the conformational space of the soft-core peptide helps to enhance the transitions between the two helices. The EDS simulations sampled many more transitions between the two helices and showed much faster convergence of the relative free enthalpy of the two helices compared with the standard MD simulations with only a slightly larger computational effort to determine optimized EDS parameters. Combined with various methods to smoothen the potential energy surface, the proposed EDS application will be a powerful technique to enhance the sampling efficiency in biomolecular simulations.

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

    PubMed

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

    2015-12-01

    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 unmarked deletion or conditional mutants, we confirmed the in vitro essentiality of two periplasmic proteins, LptH and LolA, responsible for lipopolysaccharide and lipoproteins transport to the outer membrane respectively, and confirmed that they are important for cell envelope stability. LptH was also found to be essential for P. aeruginosa ability to cause infection in different animal models. Conversely, LolA-depleted cells appeared only partially impaired in pathogenicity, indicating that this protein likely plays a less relevant role during bacterial infection. Finally, we ruled out any involvement of the other six proteins under investigation in P. aeruginosa growth, cell envelope stability and virulence. Besides proposing LptH as a very promising drug target in P. aeruginosa, this study confirms the importance of in vitro and in vivo validation of potential essential genes identified through random transposon mutagenesis.

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

    PubMed Central

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

    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 unmarked deletion or conditional mutants, we confirmed the in vitro essentiality of two periplasmic proteins, LptH and LolA, responsible for lipopolysaccharide and lipoproteins transport to the outer membrane respectively, and confirmed that they are important for cell envelope stability. LptH was also found to be essential for P. aeruginosa ability to cause infection in different animal models. Conversely, LolA-depleted cells appeared only partially impaired in pathogenicity, indicating that this protein likely plays a less relevant role during bacterial infection. Finally, we ruled out any involvement of the other six proteins under investigation in P. aeruginosa growth, cell envelope stability and virulence. Besides proposing LptH as a very promising drug target in P. aeruginosa, this study confirms the importance of in vitro and in vivo validation of potential essential genes identified through random transposon mutagenesis. PMID:26621210

  19. Multifunctional Envelope-Type siRNA Delivery Nanoparticle Platform for Prostate Cancer Therapy.

    PubMed

    Xu, Xiaoding; Wu, Jun; Liu, Yanlan; Saw, Phei Er; Tao, Wei; Yu, Mikyung; Zope, Harshal; Si, Michelle; Victorious, Amanda; Rasmussen, Jonathan; Ayyash, Dana; Farokhzad, Omid C; Shi, Jinjun

    2017-03-28

    With the capability of specific silencing of target gene expression, RNA interference (RNAi) technology is emerging as a promising therapeutic modality for the treatment of cancer and other diseases. One key challenge for the clinical applications of RNAi is the safe and effective delivery of RNAi agents such as small interfering RNA (siRNA) to a particular nonliver diseased tissue (e.g., tumor) and cell type with sufficient cytosolic transport. In this work, we proposed a multifunctional envelope-type nanoparticle (NP) platform for prostate cancer (PCa)-specific in vivo siRNA delivery. A library of oligoarginine-functionalized and sharp pH-responsive polymers was synthesized and used for self-assembly with siRNA into NPs with the features of long blood circulation and pH-triggered oligoarginine-mediated endosomal membrane penetration. By further modification with ACUPA, a small molecular ligand specifically recognizing prostate-specific membrane antigen (PSMA) receptor, this envelope-type nanoplatform with multifunctional properties can efficiently target PSMA-expressing PCa cells and silence target gene expression. Systemic delivery of the siRNA NPs can efficiently silence the expression of prohibitin 1 (PHB1), which is upregulated in PCa and other cancers, and significantly inhibit PCa tumor growth. These results suggest that this multifunctional envelope-type nanoplatform could become an effective tool for PCa-specific therapy.

  20. 10 CFR 434.516 - Building exterior envelope.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 10 Energy 3 2014-01-01 2014-01-01 false Building exterior envelope. 434.516 Section 434.516 Energy DEPARTMENT OF ENERGY ENERGY CONSERVATION ENERGY CODE FOR NEW FEDERAL COMMERCIAL AND MULTI-FAMILY HIGH RISE RESIDENTIAL BUILDINGS Building Energy Cost Compliance Alternative § 434.516 Building exterior envelope. 516.1...

  1. Data Envelopment Analysis: Measurement of Educational Efficiency in Texas

    ERIC Educational Resources Information Center

    Carter, Lacy

    2012-01-01

    The purpose of this study was to examine the efficiency of Texas public school districts through Data Envelopment Analysis. The Data Envelopment Analysis estimation method calculated and assigned efficiency scores to each of the 931 school districts considered in the study. The efficiency scores were utilized in two phases. First, the school…

  2. An Inside Look at the Two Envelopes Paradox

    ERIC Educational Resources Information Center

    Falk, Ruma; Nickerson, Raymond S.

    2009-01-01

    When two sealed envelopes contain money, one twice as much as the other, a player should be indifferent between them. But when one envelope is opened, one's decision should vary as a function of the observed value and one's subjective probabilities.

  3. 14 CFR 25.333 - Flight maneuvering envelope.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 14 Aeronautics and Space 1 2013-01-01 2013-01-01 false Flight maneuvering envelope. 25.333 Section... AIRWORTHINESS STANDARDS: TRANSPORT CATEGORY AIRPLANES Structure Flight Maneuver and Gust Conditions § 25.333 Flight maneuvering envelope. (a) General. The strength requirements must be met at each combination of...

  4. 14 CFR 25.333 - Flight maneuvering envelope.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 14 Aeronautics and Space 1 2014-01-01 2014-01-01 false Flight maneuvering envelope. 25.333 Section... AIRWORTHINESS STANDARDS: TRANSPORT CATEGORY AIRPLANES Structure Flight Maneuver and Gust Conditions § 25.333 Flight maneuvering envelope. (a) General. The strength requirements must be met at each combination of...

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

    NASA Astrophysics Data System (ADS)

    Venturini, Julia; Alibert, Yann; Benz, Willy

    2016-12-01

    Aims: We compute for the first time self-consistent models of planet growth that include the effect of envelope enrichment. The change in envelope metallicity is assumed to be the result of planetesimal disruption or icy pebble sublimation. Methods: We solved internal structure equations taking into account global energy conservation for the envelope to compute in situ planetary growth. We considered different opacities and equations of state suited for a wide range of metallicities. Results: 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 the metallicity of the giant planets of the solar system well, while low-opacity models are suited to explain the formation of low-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 209458b, and WASP-12b we predict fractions of water higher than what is estimated from observations by at least a factor 2. Conclusions: Envelope enrichment by icy planetesimals is the natural scenario to explain the formation of a wide variety of objects, ranging from mini-Neptunes to gas giants. We predict that the total and envelope metallicity decrease with planetary mass.

  6. 14 CFR 29.87 - Height-velocity envelope.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 14 Aeronautics and Space 1 2012-01-01 2012-01-01 false Height-velocity envelope. 29.87 Section 29... AIRWORTHINESS STANDARDS: TRANSPORT CATEGORY ROTORCRAFT Flight Performance § 29.87 Height-velocity envelope. (a) If there is any combination of height and forward velocity (including hover) under which a...

  7. 14 CFR 29.87 - Height-velocity envelope.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 14 Aeronautics and Space 1 2011-01-01 2011-01-01 false Height-velocity envelope. 29.87 Section 29... AIRWORTHINESS STANDARDS: TRANSPORT CATEGORY ROTORCRAFT Flight Performance § 29.87 Height-velocity envelope. (a) If there is any combination of height and forward velocity (including hover) under which a...

  8. 14 CFR 29.87 - Height-velocity envelope.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 14 Aeronautics and Space 1 2013-01-01 2013-01-01 false Height-velocity envelope. 29.87 Section 29... AIRWORTHINESS STANDARDS: TRANSPORT CATEGORY ROTORCRAFT Flight Performance § 29.87 Height-velocity envelope. (a) If there is any combination of height and forward velocity (including hover) under which a...

  9. 14 CFR 29.87 - Height-velocity envelope.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 14 Aeronautics and Space 1 2014-01-01 2014-01-01 false Height-velocity envelope. 29.87 Section 29... AIRWORTHINESS STANDARDS: TRANSPORT CATEGORY ROTORCRAFT Flight Performance § 29.87 Height-velocity envelope. (a) If there is any combination of height and forward velocity (including hover) under which a...

  10. 14 CFR 29.87 - Height-velocity envelope.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Height-velocity envelope. 29.87 Section 29... AIRWORTHINESS STANDARDS: TRANSPORT CATEGORY ROTORCRAFT Flight Performance § 29.87 Height-velocity envelope. (a) If there is any combination of height and forward velocity (including hover) under which a...

  11. Computer-Based Instruction on Skills for Addressing Envelopes.

    ERIC Educational Resources Information Center

    Humes, Ann

    The approach to computer-based instruction for third and fourth grade elementary students which is sketched teaches component placement, capitalization, and punctuation skills of addressing envelopes within the context of a simulated envelope. Part of a larger design for a complete program of composition instruction, this program comprises a set…

  12. Rolling bearing feature frequency extraction using extreme average envelope decomposition

    NASA Astrophysics Data System (ADS)

    Shi, Kunju; Liu, Shulin; Jiang, Chao; Zhang, Hongli

    2016-09-01

    The vibration signal contains a wealth of sensitive information which reflects the running status of the equipment. It is one of the most important steps for precise diagnosis to decompose the signal and extracts the effective information properly. The traditional classical adaptive signal decomposition method, such as EMD, exists the problems of mode mixing, low decomposition accuracy etc. Aiming at those problems, EAED(extreme average envelope decomposition) method is presented based on EMD. EAED method has three advantages. Firstly, it is completed through midpoint envelopment method rather than using maximum and minimum envelopment respectively as used in EMD. Therefore, the average variability of the signal can be described accurately. Secondly, in order to reduce the envelope errors during the signal decomposition, replacing two envelopes with one envelope strategy is presented. Thirdly, the similar triangle principle is utilized to calculate the time of extreme average points accurately. Thus, the influence of sampling frequency on the calculation results can be significantly reduced. Experimental results show that EAED could separate out single frequency components from a complex signal gradually. EAED could not only isolate three kinds of typical bearing fault characteristic of vibration frequency components but also has fewer decomposition layers. EAED replaces quadratic enveloping to an envelope which ensuring to isolate the fault characteristic frequency under the condition of less decomposition layers. Therefore, the precision of signal decomposition is improved.

  13. 14 CFR 29.1517 - Limiting height-speed envelope.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 14 Aeronautics and Space 1 2011-01-01 2011-01-01 false Limiting height-speed envelope. 29.1517... Operating Limitations § 29.1517 Limiting height-speed envelope. For Category A rotorcraft, if a range of heights exists at any speed, including zero, within which it is not possible to make a safe landing...

  14. Modeling Protostar Envelopes and Disks Seen With ALMA

    NASA Astrophysics Data System (ADS)

    Terebey, Susan; Flores-Rivera, Lizxandra; Willacy, Karen

    2017-01-01

    Thermal continuum emission from protostars comes from both the envelope and circumstellar disk. The dust emits on a variety of spatial scales, ranging from sub-arcseconds for disks to roughly 10 arcseconds for envelopes for nearby protostars. We present models of what ALMA should detect that incorporate a self-consistent collapse solution, radiative transfer, and realistic dust properties.

  15. Targeting and biogenesis of transporters and channels in chloroplast envelope membranes: Unsolved questions.

    PubMed

    Oh, Young Jun; Hwang, Inhwan

    2015-07-01

    Chloroplasts produce carbohydrates, hormones, vitamins, amino acids, pigments, nucleotides, ATP, and secondary metabolites. Channels and transporters are required for the movement of molecules across the two chloroplast envelope membranes. These transporters and channel proteins are grouped into two different types, including β-barrel proteins and transmembrane-domain (TMD) containing proteins. Most β-barrel proteins are localized at the outer chloroplast membrane, and TMD-containing proteins are localized at the inner chloroplast membrane. Many of these transporters and channels are encoded by nuclear genes; therefore, they have to be imported into chloroplasts after translation on cytosolic ribosomes. These proteins should have specific targeting signals for their final destination in the chloroplast membrane and for assembly into specific complexes. In this review, we summarize recent progress in the identification, functional characterization, and biogenesis of transporters and channels at the chloroplast envelope membranes, and discuss outstanding questions regarding transporter and channel protein biogenesis.

  16. Pseudotyping of vesicular stomatitis virus with the envelope glycoproteins of highly pathogenic avian influenza viruses.

    PubMed

    Zimmer, Gert; Locher, Samira; Berger Rentsch, Marianne; Halbherr, Stefan J

    2014-08-01

    Pseudotype viruses are useful for studying the envelope proteins of harmful viruses. This work describes the pseudotyping of vesicular stomatitis virus (VSV) with the envelope glycoproteins of highly pathogenic avian influenza viruses. VSV lacking the homotypic glycoprotein (G) gene (VSVΔG) was used to express haemagglutinin (HA), neuraminidase (NA) or the combination of both. Propagation-competent pseudotype viruses were only obtained when HA and NA were expressed from the same vector genome. Pseudotype viruses containing HA from different H5 clades were neutralized specifically by immune sera directed against the corresponding clade. Fast and sensitive reading of test results was achieved by vector-mediated expression of GFP. Pseudotype viruses expressing a mutant VSV matrix protein showed restricted spread in IFN-competent cells. This pseudotype system will facilitate the detection of neutralizing antibodies against virulent influenza viruses, circumventing the need for high-level biosafety containment. © 2014 The Authors.

  17. Synthesis, Assembly, and Processing of the Env ERVWE1/Syncytin Human Endogenous Retroviral Envelope

    PubMed Central

    Cheynet, V.; Ruggieri, A.; Oriol, G.; Blond, J.-L.; Boson, B.; Vachot, L.; Verrier, B.; Cosset, F.-L.; Mallet, F.

    2005-01-01

    Syncytin is a fusogenic protein involved in the formation of the placental syncytiotrophoblast layer. This protein is encoded by the envelope gene of the ERVWE1 proviral locus belonging to the human endogenous retrovirus W (HERV-W) family. The HERV-W infectious ancestor entered the primate lineage 25 to 40 million years ago. Although the syncytin fusion property has been clearly demonstrated, little is known about this cellular protein maturation process with respect to classical infectious retrovirus envelope proteins. Here we show that the cellular syncytin protein is synthesized as a glycosylated gPr73 precursor cleaved into two mature proteins, a gp50 surface subunit (SU) and a gp24 transmembrane subunit (TM). These SU and TM subunits are found associated as homotrimers. The intracytoplasmic tail is critical to the fusogenic phenotype, although its cleavage requirements seem to have diverged from those of classical retroviral maturation. PMID:15827173

  18. Synthesis, assembly, and processing of the Env ERVWE1/syncytin human endogenous retroviral envelope.

    PubMed

    Cheynet, V; Ruggieri, A; Oriol, G; Blond, J-L; Boson, B; Vachot, L; Verrier, B; Cosset, F-L; Mallet, F

    2005-05-01

    Syncytin is a fusogenic protein involved in the formation of the placental syncytiotrophoblast layer. This protein is encoded by the envelope gene of the ERVWE1 proviral locus belonging to the human endogenous retrovirus W (HERV-W) family. The HERV-W infectious ancestor entered the primate lineage 25 to 40 million years ago. Although the syncytin fusion property has been clearly demonstrated, little is known about this cellular protein maturation process with respect to classical infectious retrovirus envelope proteins. Here we show that the cellular syncytin protein is synthesized as a glycosylated gPr73 precursor cleaved into two mature proteins, a gp50 surface subunit (SU) and a gp24 transmembrane subunit (TM). These SU and TM subunits are found associated as homotrimers. The intracytoplasmic tail is critical to the fusogenic phenotype, although its cleavage requirements seem to have diverged from those of classical retroviral maturation.

  19. Dynamic assembly of brambleberry mediates nuclear envelope fusion during early development.

    PubMed

    Abrams, Elliott W; Zhang, Hong; Marlow, Florence L; Kapp, Lee; Lu, Sumei; Mullins, Mary C

    2012-08-03

    To accommodate the large cells following zygote formation, early blastomeres employ modified cell divisions. Karyomeres are one such modification, mitotic intermediates wherein individual chromatin masses are surrounded by nuclear envelope; the karyomeres then fuse to form a single mononucleus. We identified brambleberry, a maternal-effect zebrafish mutant that disrupts karyomere fusion, resulting in formation of multiple micronuclei. As karyomeres form, Brambleberry protein localizes to the nuclear envelope, with prominent puncta evident near karyomere-karyomere interfaces corresponding to membrane fusion sites. brambleberry corresponds to an unannotated gene with similarity to Kar5p, a protein that participates in nuclear fusion in yeast. We also demonstrate that Brambleberry is required for pronuclear fusion following fertilization in zebrafish. Our studies provide insight into the machinery required for karyomere fusion and suggest that specialized proteins are necessary for proper nuclear division in large dividing blastomeres. Copyright © 2012 Elsevier Inc. All rights reserved.

  20. A Spectral Algorithm for Envelope Reduction of Sparse Matrices

    NASA Technical Reports Server (NTRS)

    Barnard, Stephen T.; Pothen, Alex; Simon, Horst D.

    1993-01-01

    The problem of reordering a sparse symmetric matrix to reduce its envelope size is considered. A new spectral algorithm for computing an envelope-reducing reordering is obtained by associating a Laplacian matrix with the given matrix and then sorting the components of a specified eigenvector of the Laplacian. This Laplacian eigenvector solves a continuous relaxation of a discrete problem related to envelope minimization called the minimum 2-sum problem. The permutation vector computed by the spectral algorithm is a closest permutation vector to the specified Laplacian eigenvector. Numerical results show that the new reordering algorithm usually computes smaller envelope sizes than those obtained from the current standard algorithms such as Gibbs-Poole-Stockmeyer (GPS) or SPARSPAK reverse Cuthill-McKee (RCM), in some cases reducing the envelope by more than a factor of two.

  1. Design reference year for development of photovoltaic envelope systems

    NASA Astrophysics Data System (ADS)

    Mihalka, Peter; Matiasovsky, Peter

    2017-07-01

    An application of photovoltaic cells on external surfaces of building envelope represents a development of new construction element. A mutual coupling between thermal behaviour of photovoltaic layer and the other layers of the structure, with special properties, requires a specific selection of the characteristic outdoor thermal boundary conditions, necessary for optimum design of the envelope from the aspect of structure, material composition and geometry. The main design criteria are the effectiveness and elimination of overheating of photovoltaic module and the optimisation of heat distribution in the envelope structure during particular year seasons. The paper contains the results of the analysis of time courses of climatic elements during a real year as the boundary conditions for simulation of photovoltaic integrated building envelope systems, used in simulations of thermal behaviour of photovoltaics integrated with building envelope systems.

  2. Haemophilus ducreyi RpoE and CpxRA appear to play distinct yet complementary roles in regulation of envelope-related functions.

    PubMed

    Gangaiah, Dharanesh; Zhang, Xinjun; Baker, Beth; Fortney, Kate R; Liu, Yunlong; Munson, Robert S; Spinola, Stanley M

    2014-12-01

    Haemophilus ducreyi causes the sexually transmitted disease chancroid and a chronic limb ulceration syndrome in children. In humans, H. ducreyi is found in an abscess and overcomes a hostile environment to establish infection. To sense and respond to membrane stress, bacteria utilize two-component systems (TCSs) and extracytoplasmic function (ECF) sigma factors. We previously showed that activation of CpxRA, the only intact TCS in H. ducreyi, does not regulate homologues of envelope protein folding factors but does downregulate genes encoding envelope-localized proteins, including many virulence determinants. H. ducreyi also harbors a homologue of RpoE, which is the only ECF sigma factor in the organism. To potentially understand how H. ducreyi responds to membrane stress, here we defined RpoE-dependent genes using transcriptome sequencing (RNA-Seq). We identified 180 RpoE-dependent genes, of which 98% were upregulated; a major set of these genes encodes homologues of envelope maintenance and repair factors. We also identified and validated a putative RpoE promoter consensus sequence, which was enriched in the majority of RpoE-dependent targets. Comparison of RpoE-dependent genes to those controlled by CpxR showed that each transcription factor regulated a distinct set of genes. Given that RpoE activated a large number of genes encoding envelope maintenance and repair factors and that CpxRA represses genes encoding envelope-localized proteins, these data suggest that RpoE and CpxRA appear to play distinct yet complementary roles in regulating envelope homeostasis in H. ducreyi.

  3. Envelope Enhancement Increases Cortical Sensitivity to Interaural Envelope Delays with Acoustic and Electric Hearing

    PubMed Central

    Hartley, Douglas E. H.; Isaiah, Amal

    2014-01-01

    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. Consequently

  4. Understanding three-dimensional damage envelopes

    NASA Astrophysics Data System (ADS)

    Browning, John; Harland, Sophie; Meredith, Philip; Healy, David; Mitchell, Tom

    2017-04-01

    Microcrack damage leading to failure in rocks evolves in response to differential loading. This loading is often visualized in a two-dimensional stress space through the use of Mohr-Coulomb diagrams. The vast majority of experimental studies investigate damage evolution and rock failure using conventional triaxial stress states (σ1 > σ2 = σ3) in which the results can be easily represented in a Mohr-Coulomb plot. However, in nature the stress state is in general truly triaxial (σ1 > σ2 > σ3) and as such comprises a 3D stress state potentially leading to more complexity. By monitoring acoustic wave velocities and acoustic emissions we have shown that damage is generated in multiple orientations depending on the loading directions and hence principal stress directions. Furthermore, crack growth is shown to be a function of differential stress regardless of the mean stress. As such, new cracks can form due to a decrease in the minimum principal stress, which reduces mean stress but increases the differential stress. Although the size of individual cracks is not affected by the intermediate principal stress it has been shown that the σ2 plays a key role in suppressing the total amount of crack growth and concentrates this damage in a single plane. Hence, the differential stress at which rocks fail (i.e. the rock strength) will be significantly increased under true triaxial stress conditions than under the much more commonly applied condition of conventional triaxial stress. Through a series of cyclic loading tests we investigated the Kaiser effect, we show that while individual stress states are important, the stress path by which this stress state is reached is equally important. Whether or not a stress state has been 'visited' before is also vitally important in determining and understanding damage envelopes. Finally, we show that damage evolution can be anisotropic and must be considered as a three-dimensional problem. It is unclear how damage envelopes

  5. Hymenolepis nana: the fine structure of the embryonic envelopes.

    PubMed

    Fairweather, I; Threadgold, L T

    1981-06-01

    The fine structure of the envelopes surrounding hatched and unhatched oncospheres of Hymenolepis nana has been investigated by transmission and scanning electron microscopy (SEM), together with light microscope histochemical observations of JB-4 embedded material. The oncosphere is surrounded by 3 layers--the capsule, the outer envelope and the inner envelope, the latter giving rise to the embryophore and the 'oncospheral membrane'. An additional layer--the polar filament layer--lies between the 'oncospheral membrane' and the oncosphere. Shell material is deposited on the capsule as a thin layer. It is secreted by the outer envelope, which degenerates once shell formation is complete. The uterus may also contribute to shell formation. The embryophore forms a thin incomplete and peripheral layer within the inner envelope. In the basal region of this envelope, partial development of an 'oncospheral membrane' takes place, but it does not become detached as a separate layer. The polar filaments, which are characteristic of the oncosphere of H. nana, are derived from the epithelial covering of the oncosphere itself, which delaminates to form a separate polar filament layer. The filaments arise from knob-like projections at opposite poles of this layer. The design of the embryonic envelopes in H. nana show a number of modifications from the basic cyclophyllidean pattern, and these can be related to the demands of its 'direct' life-cycle.

  6. Cell Walls and the Convergent Evolution of the Viral Envelope

    PubMed Central

    Buchmann, Jan P.

    2015-01-01

    SUMMARY Why some viruses are enveloped while others lack an outer lipid bilayer is a major question in viral evolution but one that has received relatively little attention. The viral envelope serves several functions, including protecting the RNA or DNA molecule(s), evading recognition by the immune system, and facilitating virus entry. Despite these commonalities, viral envelopes come in a wide variety of shapes and configurations. The evolution of the viral envelope is made more puzzling by the fact that nonenveloped viruses are able to infect a diverse range of hosts across the tree of life. We reviewed the entry, transmission, and exit pathways of all (101) viral families on the 2013 International Committee on Taxonomy of Viruses (ICTV) list. By doing this, we revealed a strong association between the lack of a viral envelope and the presence of a cell wall in the hosts these viruses infect. We were able to propose a new hypothesis for the existence of enveloped and nonenveloped viruses, in which the latter represent an adaptation to cells surrounded by a cell wall, while the former are an adaptation to animal cells where cell walls are absent. In particular, cell walls inhibit viral entry and exit, as well as viral transport within an organism, all of which are critical waypoints for successful infection and spread. Finally, we discuss how this new model for the origin of the viral envelope impacts our overall understanding of virus evolution. PMID:26378223

  7. Vitelline envelope, chorion, and micropyle of Fundulus heteroclitus eggs

    SciTech Connect

    Dumont, J.N.; Brummet, A.R.

    1980-01-01

    The architecture and transformation of the vitelline envelope of the developing oocyte into the chorion of the mature egg of Fundulus heteroclitus have been examined by scanning and transmission electron microscopy. The mature vitelline envelope is structurally complex and consists of about nine strata. The envelope is penetrated by pore canals that contain microvilli arising from the oocyte and macrovilli from follicle cells. During the envelope's transformation into the chorion, the pore canals are lost and the envelope becomes more fibrous and compact and its stratified nature less apparent. The micropyle, or pore, through which the sperm gains access to the enclosed egg is located at the bottom of a small funnel-shaped depression in the envelope. Internally, the micropyle opens on the apex of a cone-like elevation of the chorion. During the development of the envelope, structured chorionic fibrils, the components of which are presumed to be synthesized by the follicle cells, become attached to its surface. These chorionic fibrils are thought to aid in the attachment of the egg to the substratum and perhaps to help prevent water loss during low tides when the egg may be exposed.

  8. Neural coding of echo-envelope disparities in echolocating bats.

    PubMed

    Borina, Frank; Firzlaff, Uwe; Wiegrebe, Lutz

    2011-05-01

    The effective use of echolocation requires not only measuring the delay between the emitted call and returning echo to estimate the distance of an ensonified object. To locate an object in azimuth and elevation, the bat's auditory system must analyze the returning echoes in terms of their binaural properties, i.e., the echoes' interaural intensity and time differences (IIDs and ITDs). The effectiveness of IIDs for echolocation is undisputed, but when bats ensonify complex objects, the temporal structure of echoes may facilitate the analysis of the echo envelope in terms of envelope ITDs. Using extracellular recordings from the auditory midbrain of the bat, Phyllostomus discolor, we found a population of neurons that are sensitive to envelope ITDs of echoes of their sonar calls. Moreover, the envelope-ITD sensitivity improved with increasing temporal fluctuations in the echo envelopes, a sonar parameter related to the spatial statistics of complex natural reflectors like vegetation. The data show that in bats envelope ITDs may be used not only to locate external, prey-generated rustling sounds but also in the context of echolocation. Specifically, the temporal fluctuations in the echo envelope, which are created when the sonar emission is reflected from a complex natural target, support ITD-mediated echolocation.

  9. CLOSE STELLAR BINARY SYSTEMS BY GRAZING ENVELOPE EVOLUTION

    SciTech Connect

    Soker, Noam

    2015-02-20

    I suggest a spiral-in process in which a stellar companion grazes the envelope of a giant star while both the orbital separation and the giant radius shrink simultaneously, forming a close binary system. The binary system might be viewed as evolving in a constant state of 'just entering a common envelope (CE) phase.' In cases where this process takes place, it can be an alternative to CE evolution where the secondary star is immersed in the giant's envelope. Grazing envelope evolution (GEE) is made possible only if the companion manages to accrete mass at a high rate and launches jets that remove the outskirts of the giant envelope, hence preventing the formation of a CE. The high accretion rate is made possible by the accretion disk launching jets which efficiently carry the excess angular momentum and energy from the accreted mass. The orbital decay itself is caused by the gravitational interaction of the secondary star with the envelope inward of its orbit, i.e., dynamical friction (gravitational tide). Mass loss through the second Lagrangian point can carry additional angular momentum and envelope mass. The GEE lasts for tens to hundreds of years. The high accretion rate, with peaks lasting from months to years, might lead to a bright object referred to as the intermediate luminosity optical transient (Red Novae; Red Transients). A bipolar nebula and/or equatorial ring are formed around the binary remnant.

  10. Role for phosphatidylinositol in nuclear envelope formation.

    PubMed Central

    Larijani, B; Barona, T M; Poccia, D L

    2001-01-01

    PtdIns is a minor membrane phospholipid that is important in signal transduction. Recently, derivatives of PtdIns phosphorylated at the 3-position of the inositol ring have been implicated in the regulation of constitutive membrane traffic and in membrane fusion events. Assembly of the nuclear envelope (NE), a crucial step in the progress of mitosis, is also likely to involve membrane fusion reactions. We therefore investigated the role of PtdIns and phosphoinositide 3-kinase (PI-3K) activity in NE formation in vitro. GTP-induced NE formation was blocked by wortmannin and LY294002, two specific inhibitors of PI-3K, suggesting a role for PtdIns phosphorylated at the 3-position. PtdIns-specific phospholipase C mimicked GTP hydrolysis as an inducer of NE formation. This induction was dependent on a membrane vesicle subfraction (MV1) that was highly enriched in PtdIns, as determined by heteronuclear two-dimensional NMR spectroscopy. On the basis of these results, we suggest that the MV1 population serves as a source of membranes rich in PtdIns that might facilitate fusion, possibly through the production of the membrane-destabilizing lipid diacylglycerol. PMID:11368777

  11. Real-Time Flight Envelope Monitoring System

    NASA Technical Reports Server (NTRS)

    Kerho, Michael; Bragg, Michael B.; Ansell, Phillip J.

    2012-01-01

    The objective of this effort was to show that real-time aircraft control-surface hinge-moment information could be used to provide a robust and reliable prediction of vehicle performance and control authority degradation. For a given airfoil section with a control surface -- be it a wing with an aileron, rudder, or elevator -- the control-surface hinge moment is sensitive to the aerodynamic characteristics of the section. As a result, changes in the aerodynamics of the section due to angle-of-attack or environmental effects such as icing, heavy rain, surface contaminants, bird strikes, or battle damage will affect the control surface hinge moment. These changes include both the magnitude of the hinge moment and its sign in a time-averaged sense, and the variation of the hinge moment with time. The current program attempts to take the real-time hinge moment information from the aircraft control surfaces and develop a system to predict aircraft envelope boundaries across a range of conditions, alerting the flight crew to reductions in aircraft controllability and flight boundaries.

  12. Aeroelastic Model Structure Computation for Envelope Expansion

    NASA Technical Reports Server (NTRS)

    Kukreja, Sunil L.

    2007-01-01

    Structure detection is a procedure for selecting a subset of candidate terms, from a full model description, that best describes the observed output. This is a necessary procedure to compute an efficient system description which may afford greater insight into the functionality of the system or a simpler controller design. Structure computation as a tool for black-box modeling may be of critical importance in the development of robust, parsimonious models for the flight-test community. Moreover, this approach may lead to efficient strategies for rapid envelope expansion that may save significant development time and costs. In this study, a least absolute shrinkage and selection operator (LASSO) technique is investigated for computing efficient model descriptions of non-linear aeroelastic systems. The LASSO minimises the residual sum of squares with the addition of an l(Sub 1) penalty term on the parameter vector of the traditional l(sub 2) minimisation problem. Its use for structure detection is a natural extension of this constrained minimisation approach to pseudo-linear regression problems which produces some model parameters that are exactly zero and, therefore, yields a parsimonious system description. Applicability of this technique for model structure computation for the F/A-18 (McDonnell Douglas, now The Boeing Company, Chicago, Illinois) Active Aeroelastic Wing project using flight test data is shown for several flight conditions (Mach numbers) by identifying a parsimonious system description with a high percent fit for cross-validated data.

  13. Discriminating Dysarthria Type From Envelope Modulation Spectra

    PubMed Central

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

    2013-01-01

    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 rhythmicity of speech within specified frequency bands. Method EMS was conducted on sentences produced by 43 speakers with 1 of 4 types of dysarthria and healthy controls. The EMS consisted of the spectra of the slow-rate (up to 10 Hz) amplitude modulations of the full signal and 7 octave bands ranging in center frequency from 125 to 8000 Hz. Six variables were calculated for each band relating to peak frequency and amplitude and relative energy above, below, and in the region of 4 Hz. Discriminant function analyses (DFA) determined which sets of predictor variables best discriminated between and among groups. Results Each of 6 DFAs identified 2–6 of the 48 predictor variables. These variables achieved 84%–100% classification accuracy for group membership. Conclusions Dysarthrias can be characterized by quantifiable temporal patterns in acoustic output. Because EMS analysis is automated and requires no editing or linguistic assumptions, it shows promise as a clinical and research tool. PMID:20643800

  14. Critical point analysis of phase envelope diagram

    NASA Astrophysics Data System (ADS)

    Soetikno, Darmadi; Kusdiantara, Rudy; Puspita, Dila; Sidarto, Kuntjoro A.; Siagian, Ucok W. R.; Soewono, Edy; Gunawan, Agus Y.

    2014-03-01

    Phase diagram or phase envelope is a relation between temperature and pressure that shows the condition of equilibria between the different phases of chemical compounds, mixture of compounds, and solutions. Phase diagram is an important issue in chemical thermodynamics and hydrocarbon reservoir. It is very useful for process simulation, hydrocarbon reactor design, and petroleum engineering studies. It is constructed from the bubble line, dew line, and critical point. Bubble line and dew line are composed of bubble points and dew points, respectively. Bubble point is the first point at which the gas is formed when a liquid is heated. Meanwhile, dew point is the first point where the liquid is formed when the gas is cooled. Critical point is the point where all of the properties of gases and liquids are equal, such as temperature, pressure, amount of substance, and others. Critical point is very useful in fuel processing and dissolution of certain chemicals. Here in this paper, we will show the critical point analytically. Then, it will be compared with numerical calculations of Peng-Robinson equation by using Newton-Raphson method. As case studies, several hydrocarbon mixtures are simulated using by Matlab.

  15. Aeroelastic Model Structure Computation for Envelope Expansion

    NASA Technical Reports Server (NTRS)

    Kukreja, Sunil L.

    2007-01-01

    Structure detection is a procedure for selecting a subset of candidate terms, from a full model description, that best describes the observed output. This is a necessary procedure to compute an efficient system description which may afford greater insight into the functionality of the system or a simpler controller design. Structure computation as a tool for black-box modelling may be of critical importance in the development of robust, parsimonious models for the flight-test community. Moreover, this approach may lead to efficient strategies for rapid envelope expansion which may save significant development time and costs. In this study, a least absolute shrinkage and selection operator (LASSO) technique is investigated for computing efficient model descriptions of nonlinear aeroelastic systems. The LASSO minimises the residual sum of squares by the addition of an l(sub 1) penalty term on the parameter vector of the traditional 2 minimisation problem. Its use for structure detection is a natural extension of this constrained minimisation approach to pseudolinear regression problems which produces some model parameters that are exactly zero and, therefore, yields a parsimonious system description. Applicability of this technique for model structure computation for the F/A-18 Active Aeroelastic Wing using flight test data is shown for several flight conditions (Mach numbers) by identifying a parsimonious system description with a high percent fit for cross-validated data.

  16. Critical point analysis of phase envelope diagram

    SciTech Connect

    Soetikno, Darmadi; Siagian, Ucok W. R.; Kusdiantara, Rudy Puspita, Dila Sidarto, Kuntjoro A. Soewono, Edy; Gunawan, Agus Y.

    2014-03-24

    Phase diagram or phase envelope is a relation between temperature and pressure that shows the condition of equilibria between the different phases of chemical compounds, mixture of compounds, and solutions. Phase diagram is an important issue in chemical thermodynamics and hydrocarbon reservoir. It is very useful for process simulation, hydrocarbon reactor design, and petroleum engineering studies. It is constructed from the bubble line, dew line, and critical point. Bubble line and dew line are composed of bubble points and dew points, respectively. Bubble point is the first point at which the gas is formed when a liquid is heated. Meanwhile, dew point is the first point where the liquid is formed when the gas is cooled. Critical point is the point where all of the properties of gases and liquids are equal, such as temperature, pressure, amount of substance, and others. Critical point is very useful in fuel processing and dissolution of certain chemicals. Here in this paper, we will show the critical point analytically. Then, it will be compared with numerical calculations of Peng-Robinson equation by using Newton-Raphson method. As case studies, several hydrocarbon mixtures are simulated using by Matlab.

  17. Localization of phosphatidylcholine in outer envelope membrane of spinach chloroplasts

    PubMed Central

    1985-01-01

    We have examined the effects of phospholipase C from Bacillus cereus on the extent of phospholipid hydrolysis in envelope membrane vesicles and in intact chloroplasts. When isolated envelope vesicles were incubated in presence of phospholipase C, phosphatidylcholine and phosphatidylglycerol, but not phosphatidylinositol, were totally converted into diacylglycerol if they were available to the enzyme (i.e., when the vesicles were sonicated in presence of phospholipase C). These experiments demonstrate that phospholipase C can be used to probe the availability of phosphatidylcholine and phosphatidylglycerol in the cytosolic leaflet of the outer envelope membrane from spinach chloroplasts. When isolated, purified, intact chloroplasts were incubated with low amounts of phospholipase C (0.3 U/mg chlorophyll) under very mild conditions (12 degrees C for 1 min), greater than 80% of phosphatidylcholine molecules and almost none of phosphatidylglycerol molecules were hydrolyzed. Since we have also demonstrated, by using several different methods (phase-contrast and electron microscopy, immunochemical and electrophoretic analyses) that isolated spinach chloroplasts, and especially their outer envelope membrane, remained intact after mild treatment with phospholipase C, we can conclude that there is a marked asymmetric distribution of phospholipids across the outer envelope membrane of spinach chloroplasts. Phosphatidylcholine, the major polar lipid of the outer envelope membrane, is almost entirely accessible from the cytosolic side of the membrane and therefore is probably localized in the outer leaflet of the outer envelope bilayer. On the contrary, phosphatidylglycerol, the major polar lipid in the inner envelope membrane and the thylakoids, is probably not accessible to phospholipase C from the cytosol and therefore is probably localized mostly in the inner leaflet of the outer envelope membrane and in the other chloroplast membranes. PMID:3988805

  18. On various definitions of the envelope of a random process

    NASA Astrophysics Data System (ADS)

    Langley, R. S.

    1986-03-01

    Statistical properties of the envelope deefinitions of Rice [1], Crandall and Mark [2] and Dugundji [3] are derived and compared. It is shown that the definitions of Rice [1] and Dugudji [3] are equivalent, which implies that the envelope of Rice [1] is independent of the choice of a central frequency. This contradicts results which have appeared in the literature [4, 5] and the reason for this contradiction is explained. The envelopes of Crandall and Mark [2] and Dugundji [3] are found to have the same first order probability density function but different crossing rates and mean frequencies.

  19. The absolute energy flux envelopes of B type stars.

    NASA Technical Reports Server (NTRS)

    Underhill, A. B.

    1972-01-01

    Absolute energy flux envelopes covering the region of 1100 to 6000 A for main-sequence stars of types B3, B7 and A0 derived from published, ground-based observations and from spectrum scans with OAO-II are presented. These flux envelopes are compared with the predicted flux envelopes from lightly line-blanketed model atmospheres. The line blanketing at wavelengths shorter than 3000 A is severe, about one-half the predicted light being observed at 1600 A. These results demonstrate that a model which represents well the observed visible spectrum of a star may fail seriously for representing the ultraviolet spectrum.

  20. Nuclear envelope rupture drives genome instability in cancer

    PubMed Central

    Lim, Sanghee; Quinton, Ryan J.; Ganem, Neil J.

    2016-01-01

    The nuclear envelope, composed of two lipid bilayers and numerous accessory proteins, has evolved to house the genetic material of all eukaryotic cells. In so doing, the nuclear envelope provides a physical barrier between chromosomes and the cytoplasm. Once believed to be highly stable, recent studies demonstrate that the nuclear envelope is prone to rupture. These rupture events expose chromosomal DNA to the cytoplasmic environment and have the capacity to promote DNA damage. Thus nuclear rupture may be an unappreciated mechanism of mutagenesis. PMID:27799497

  1. The nuclear envelope environment and its cancer connections

    PubMed Central

    Chow, Kin-Hoe; Factor, Rachel E.; Ullman, Katharine S.

    2014-01-01

    Because of the association between aberrant nuclear structure and tumour grade, nuclear morphology is an indispensible criterion in the current pathological assessment of cancer. Components of the nuclear envelope environment have central roles in many aspects of cell function that affect tumour development and progression. As the roles of the nuclear envelope components, including nuclear pore complexes and nuclear lamina, are being deciphered in molecular detail there are opportunities to harness this knowledge for cancer therapeutics and biomarker development. In this Review, we summarize the progress that has been made in our understanding of the nuclear envelope and the implications of changes in this environment for cancer biology. PMID:22337151

  2. Role of Cysteines in Stabilizing the Randomized Receptor Binding Domains within Feline Leukemia Virus Envelope Proteins

    PubMed Central

    Valdivieso-Torres, Leonardo; Sarangi, Anindita; Whidby, Jillian; Marcotrigiano, Joseph

    2015-01-01

    ABSTRACT Retargeting of gammaretroviral envelope proteins has shown promising results in the isolation of novel isolates with therapeutic potential. However, the optimal conditions required to obtain high-affinity retargeted envelope proteins with narrow tropism are not understood. This study highlights the advantage of constrained peptides within receptor binding domains and validates the random library screening technique of obtaining novel retargeted Env proteins. Using a modified vector backbone to screen the envelope libraries on 143B osteosarcoma cells, three novel and unique retargeted envelopes were isolated. The use of complex disulfide bonds within variable regions required for receptor binding is found within natural gammaretroviral envelope isolates. Interestingly, two of the isolates, named AII and BV2, have a pair of cysteines located within the randomized region of 11 amino acids similar to that identified within the CP Env, an isolate identified in a previous Env library screen on the human renal carcinoma Caki-1 cell line. The amino acids within the randomized region of AII and BV2 envelopes that are essential for viral infection have been identified in this study and include these cysteine residues. Through mutagenesis studies, the putative disulfide bond pairs including and beyond the randomized region were examined. In parallel, the disulfide bonds of CP Env were identified using mass spectrometry. The results indicate that this pair of cysteines creates the structural context to position key hydrophobic (F and W) and basic (K and H) residues critical for viral titer and suggest that AII, BV2, and CP internal cysteines bond together in distinct ways. IMPORTANCE Retargeted gammaretroviral particles have broad applications for therapeutic use. Although great advances have been achieved in identifying new Env-host cell receptor pairs, the rules for designing optimal Env libraries are still unclear. We have found that isolates with an additional

  3. Bacteriophage T5 gene A2 protein alters the outer membrane of Escherichia coli.

    PubMed Central

    Snyder, C E

    1984-01-01

    Evidence for changes in Escherichia coli envelope structure caused by the bacteriophage T5 gene A2 protein was obtained by the use of mutant bacteriophages, envelope fractionation procedures, electrophoretic analysis, and in vitro binding studies with purified gene A2 protein. The results suggested that the T5 gene A2 protein perturbs the host envelope as it functions to promote DNA transfer. Images PMID:6389511

  4. Reduced cell surface expression of processed human immunodeficiency virus type 1 envelope glycoprotein in the presence of Nef.

    PubMed Central

    Schwartz, O; Rivière, Y; Heard, J M; Danos, O

    1993-01-01

    nef genes from two laboratory grown human immunodeficiency virus type 1 (HIV-1) strains and from two proviruses that had not been propagated in vitro were introduced into CD4+ lymphoblastoid CEM cells. The stable expression of all four Nef proteins was associated with an almost complete abrogation of CD4 cell surface localization. The consequences of the presence of Nef on gp160 cleavage, gp120 surface localization, and envelope-induced cytopathic effect were examined in CEM cells in which the HIV-1 env gene was expressed from a vaccinia virus vector. The presence of Nef did not modify the processing of gp160 into its subunits but resulted in a significant decrease of cell surface levels of gp120, associated with a dramatic reduction of the fusion-mediated cell death. Surface levels of mutant envelope glycoproteins unable to bind CD4 were not altered in Nef-expressing cells, suggesting that the phenomenon was CD4 dependent. The intracellular accumulation of fully processed envelope glycoproteins could significantly delay the cytopathic effect associated with envelope surface expression in HIV-infected cells and may be relevant to the selective advantage associated with Nef during the in vivo infectious process. Images PMID:8497051

  5. Role of Bordetella pertussis RseA in the cell envelope stress response and adenylate cyclase toxin release

    PubMed Central

    Hanawa, Tomoko; Yonezawa, Hideo; Kawakami, Hayato; Kamiya, Shigeru; Armstrong, Sandra K.

    2013-01-01

    Bordetella pertussis is the bacterial agent of the human disease, whooping cough. In many bacteria, the extracellular function sigma factor σE is central to the response to envelope stress, and its activity is negatively controlled by the RseA anti-sigma factor. In this study, the role of RseA in B. pertussis envelope stress responses was investigated. Compared with the wild-type strain, an rseA mutant showed elevated resistance to envelope stress and enhanced growth at 25°C. rpoH and other predicted σE target genes demonstrated increased transcription in the rseA mutant compared with the wild type parent. Transcription of those genes was also increased in wild type B. pertussis and Escherichia coli under envelope stress, whereas no stress-induced increase in transcription was observed in the rseA mutant. rseA inactivation was also associated with altered levels of certain proteins in culture supernatant fluids, which showed increased adenylate cyclase toxin (CyaA) levels. The increased CyaA in the mutant was correlated with an apparent increased stability of the extracellular toxin and increased production of CyaA-containing outer membrane vesicles. Consistent with this, compared with the wild type strain, rseA mutant cells produced increased numbers of large surface-associated vesicles. PMID:23821542

  6. Characterization and interactome study of white spot syndrome virus envelope protein VP11.

    PubMed

    Liu, Wang-Jing; Shiung, Hui-Jui; Lo, Chu-Fang; Leu, Jiann-Horng; Lai, Ying-Jang; Lee, Tai-Lin; Huang, Wei-Tung; Kou, Guang-Hsiung; Chang, Yun-Shiang

    2014-01-01

    White spot syndrome virus (WSSV) is a large enveloped virus. The WSSV viral particle consists of three structural layers that surround its core DNA: an outer envelope, a tegument and a nucleocapsid. Here we characterize the WSSV structural protein VP11 (WSSV394, GenBank accession number AF440570), and use an interactome approach to analyze the possible associations between this protein and an array of other WSSV and host proteins. Temporal transcription analysis showed that vp11 is an early gene. Western blot hybridization of the intact viral particles and fractionation of the viral components, and immunoelectron microscopy showed that VP11 is an envelope protein. Membrane topology software predicted VP11 to be a type of transmembrane protein with a highly hydrophobic transmembrane domain at its N-terminal. Based on an immunofluorescence assay performed on VP11-transfected Sf9 cells and a trypsin digestion analysis of the virion, we conclude that, contrary to topology software prediction, the C-terminal of this protein is in fact inside the virion. Yeast two-hybrid screening combined with co-immunoprecipitation assays found that VP11 directly interacted with at least 12 other WSSV structural proteins as well as itself. An oligomerization assay further showed that VP11 could form dimers. VP11 is also the first reported WSSV structural protein to interact with the major nucleocapsid protein VP664.

  7. Genes

    MedlinePlus

    ... Search Search MedlinePlus GO GO About MedlinePlus Site Map FAQs Customer Support Health Topics Drugs & Supplements Videos & Tools Español You Are Here: Home → Medical Encyclopedia → Genes URL of this page: //medlineplus.gov/ency/article/ ...

  8. Differentiating founder and chronic HIV envelope sequences

    PubMed Central

    Maher, Stephen; Mota, Talia; Suzuki, Kazuo; Kelleher, Anthony D.

    2017-01-01

    Significant progress has been made in characterizing broadly neutralizing antibodies against the HIV envelope glycoprotein Env, but an effective vaccine has proven elusive. Vaccine development would be facilitated if common features of early founder virus required for transmission could be identified. Here we employ a combination of bioinformatic and operations research methods to determine the most prevalent features that distinguish 78 subtype B and 55 subtype C founder Env sequences from an equal number of chronic sequences. There were a number of equivalent optimal networks (based on the fewest covarying amino acid (AA) pairs or a measure of maximal covariance) that separated founders from chronics: 13 pairs for subtype B and 75 for subtype C. Every subtype B optimal solution contained the founder pairs 178–346 Asn-Val, 232–236 Thr-Ser, 240–340 Lys-Lys, 279–315 Asp-Lys, 291–792 Ala-Ile, 322–347 Asp-Thr, 535–620 Leu-Asp, 742–837 Arg-Phe, and 750–836 Asp-Ile; the most common optimal pairs for subtype C were 644–781 Lys-Ala (74 of 75 networks), 133–287 Ala-Gln (73/75) and 307–337 Ile-Gln (73/75). No pair was present in all optimal subtype C solutions highlighting the difficulty in targeting transmission with a single vaccine strain. Relative to the size of its domain (0.35% of Env), the α4β7 binding site occurred most frequently among optimal pairs, especially for subtype C: 4.2% of optimal pairs (1.2% for subtype B). Early sequences from 5 subtype B pre-seroconverters each exhibited at least one clone containing an optimal feature 553–624 (Ser-Asn), 724–747 (Arg-Arg), or 46–293 (Arg-Glu). PMID:28187204

  9. Differentiating founder and chronic HIV envelope sequences.

    PubMed

    Murray, John M; Maher, Stephen; Mota, Talia; Suzuki, Kazuo; Kelleher, Anthony D; Center, Rob J; Purcell, Damian

    2017-01-01

    Significant progress has been made in characterizing broadly neutralizing antibodies against the HIV envelope glycoprotein Env, but an effective vaccine has proven elusive. Vaccine development would be facilitated if common features of early founder virus required for transmission could be identified. Here we employ a combination of bioinformatic and operations research methods to determine the most prevalent features that distinguish 78 subtype B and 55 subtype C founder Env sequences from an equal number of chronic sequences. There were a number of equivalent optimal networks (based on the fewest covarying amino acid (AA) pairs or a measure of maximal covariance) that separated founders from chronics: 13 pairs for subtype B and 75 for subtype C. Every subtype B optimal solution contained the founder pairs 178-346 Asn-Val, 232-236 Thr-Ser, 240-340 Lys-Lys, 279-315 Asp-Lys, 291-792 Ala-Ile, 322-347 Asp-Thr, 535-620 Leu-Asp, 742-837 Arg-Phe, and 750-836 Asp-Ile; the most common optimal pairs for subtype C were 644-781 Lys-Ala (74 of 75 networks), 133-287 Ala-Gln (73/75) and 307-337 Ile-Gln (73/75). No pair was present in all optimal subtype C solutions highlighting the difficulty in targeting transmission with a single vaccine strain. Relative to the size of its domain (0.35% of Env), the α4β7 binding site occurred most frequently among optimal pairs, especially for subtype C: 4.2% of optimal pairs (1.2% for subtype B). Early sequences from 5 subtype B pre-seroconverters each exhibited at least one clone containing an optimal feature 553-624 (Ser-Asn), 724-747 (Arg-Arg), or 46-293 (Arg-Glu).

  10. Envelope Determinants of Equine Lentiviral Vaccine Protection

    PubMed Central

    Craigo, Jodi K.; Ezzelarab, Corin; Cook, Sheila J.; Chong, Liu; Horohov, David; Issel, Charles J.; Montelaro, Ronald C.

    2013-01-01

    Lentiviral envelope (Env) antigenic variation and associated immune evasion present major obstacles to vaccine development. The concept that Env is a critical determinant for vaccine efficacy is well accepted, however defined correlates of protection associated with Env variation have yet to be determined. We reported an attenuated equine infectious anemia virus (EIAV) vaccine study that directly examined the effect of lentiviral Env sequence variation on vaccine efficacy. The study identified a significant, inverse, linear correlation between vaccine efficacy and increasing divergence of the challenge virus Env gp90 protein compared to the vaccine virus gp90. The report demonstrated approximately 100% protection of immunized ponies from disease after challenge by virus with a homologous gp90 (EV0), and roughly 40% protection against challenge by virus (EV13) with a gp90 13% divergent from the vaccine strain. In the current study we examine whether the protection observed when challenging with the EV0 strain could be conferred to animals via chimeric challenge viruses between the EV0 and EV13 strains, allowing for mapping of protection to specific Env sequences. Viruses containing the EV13 proviral backbone and selected domains of the EV0 gp90 were constructed and in vitro and in vivo infectivity examined. Vaccine efficacy studies indicated that homology between the vaccine strain gp90 and the N-terminus of the challenge strain gp90 was capable of inducing immunity that resulted in significantly lower levels of post-challenge virus and significantly delayed the onset of disease. However, a homologous N-terminal region alone inserted in the EV13 backbone could not impart the 100% protection observed with the EV0 strain. Data presented here denote the complicated and potentially contradictory relationship between in vitro virulence and in vivo pathogenicity. The study highlights the importance of structural conformation for immunogens and emphasizes the need for

  11. Beam envelope calculations in general linear coupled lattices

    SciTech Connect

    Chung, Moses; Qin, Hong; Groening, Lars; Xiao, Chen; Davidson, Ronald C.

    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.

  12. Biogenesis of the Gram-positive bacterial cell envelope.

    PubMed

    Siegel, Sara D; Liu, Jun; Ton-That, Hung

    2016-12-01

    The Gram-positive cell envelope serves as a molecular platform for surface display of capsular polysaccharides, wall teichoic acids (WTAs), lipoteichoic acids (LTAs), lipoproteins, surface proteins and pili. WTAs, LTAs, and sortase-assembled pili are a few features that make the Gram-positive cell envelope distinct from the Gram-negative counterpart. Interestingly, a set of LytR-CpsA-Psr family proteins, found in all Gram-positives but limited to a minority of Gram-negative organisms, plays divergent functions, while decorating the cell envelope with glycans. Furthermore, a phylum of Gram-positive bacteria, the actinobacteria, appear to employ oxidative protein folding as the major folding mechanism, typically occurring in an oxidizing environment of the Gram-negative periplasm. These distinctive features will be highlighted, along with recent findings in the cell envelope biogenesis.

  13. Envelope Protection and Recovery Guidance for Upset Conditions

    NASA Technical Reports Server (NTRS)

    Lombaerts, Thomas; Schuet, Stefan; Acosta, Diana; Kaneshige, John; Shish, Kim

    2016-01-01

    The slides are an overview and summary of past and current research projects in the field of envelope protection, upset prevention and upset recovery, with the aim to avoid loss of control accidents and improve safety in air transportation.

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

    SciTech Connect

    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.

  15. 10 CFR 434.402 - Building envelope assemblies and materials.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... envelope. The position of the vapor retarder shall be determined taking into account local climate and... account local climate and indoor humidity level. The vapor retarder shall have a performance rating of 1...

  16. Envelope solitons in three-component degenerate relativistic quantum plasmas

    NASA Astrophysics Data System (ADS)

    Islam, S.; Sultana, S.; Mamun, A. A.

    2017-09-01

    The criteria for the formation of envelope solitons and their basic features in a three-component degenerate relativistic quantum plasma (DRQP) system (containing relativistically degenerate electrons, non-degenerate inertial light nuclei, and stationary heavy nuclei) are theoretically investigated. The nonlinear Schrödinger equation is derived by employing the multi-scale perturbation technique. The envelope solitons are found to be associated with the modified ion-acoustic waves in which the inertia (restoring force) is provided by the mass density of light nuclei (degenerate pressure of cold electrons). The basic features of these envelope solitons, which are found to formed in such a DRQP system, and their modulational instability criteria (on the basis of the plasma parameters associated with the degenerate pressure of electrons, number densities of degenerate electrons, inertial light nuclei, and stationary heavy nuclei) are identified. The numerical simulations are also performed to confirm the stability of the envelope solitons predicted here by analytical analysis.

  17. Envelope Protection for In-Flight Ice Contamination

    NASA Technical Reports Server (NTRS)

    Gingras, David R.; Barnhart, Billy P.; Ranaudo, Richard J.; Ratvasky, Thomas P.; Morelli, Eugene A.

    2010-01-01

    Fatal loss-of-control (LOC) accidents have been directly related to in-flight airframe icing. The prototype system presented in this paper directly addresses the need for real-time onboard envelope protection in icing conditions. The combinations of a-priori information and realtime aerodynamic estimations are shown to provide sufficient input for determining safe limits of the flight envelope during in-flight icing encounters. The Icing Contamination Envelope Protection (ICEPro) system has been designed and implemented to identify degradations in airplane performance and flying qualities resulting from ice contamination and provide safe flight-envelope cues to the pilot. Components of ICEPro are described and results from preliminary tests are presented.

  18. Laboratory simulation of graphite formation in stellar envelopes

    NASA Technical Reports Server (NTRS)

    Dorfeld, W. G.; Hudson, J. B.

    1973-01-01

    A technique has been developed which permits laboratory simulation of graphite condensation in the envelopes of cool, late sequence stars. Processes in the stellar envelope were simulated by allowing hydrogen-carbon mixtures of typical circumstellar composition and temperature to expand freely into vacuum, cooling and supersaturating the vapor. Expansion products were determined mass spectrometrically through the use of molecular beam techniques. The results of laboratory expansions were scaled to those occurring near M and N stars by comparing the number of collisional events in each case. Kinetic considerations indicate that the important rate process in rarefied envelopes will be C2 formation; consequently scaling by termolecular collisions was employed. Results of this study imply that envelope expansions near M giants contribute at most .01 of the observed interstellar grain density. In the case of pulsating N stars, on the other hand, the results are not inconsistent with previous predictions of essentially complete carbon condensation.

  19. Evolution of Space Shuttle Range Safety Ascent Flight Envelope Design

    NASA Technical Reports Server (NTRS)

    Brewer, Joan; Davis, Jerel; Glenn, Christopher

    2011-01-01

    For every space vehicle launch from the Eastern Range in Florida, the range user must provide specific Range Safety (RS) data products to the Air Force's 45th Space Wing in order to obtain flight plan approval. One of these data products is a set of RS ascent flight envelope trajectories that define the normal operating region of the vehicle during powered flight. With the Shuttle Program launching 135 manned missions over a 30-year period, 135 envelope sets were delivered to the range. During this time, the envelope methodology and design process evolved to support mission changes, maintain high data quality, and reduce costs. The purpose of this document is to outline the shuttle envelope design evolution and capture the lessons learned that could apply to future spaceflight endeavors.

  20. Testing Common Envelopes on Double White Dwarf Binaries

    NASA Astrophysics Data System (ADS)

    Nandez, Jose L. A.; Ivanova, Natalia; Lombardi, James C., Jr.

    2015-06-01

    The formation of a double white dwarf binary likely involves a common envelope (CE) event between a red giant and a white dwarf (WD) during the most recent episode of Roche lobe overflow mass transfer. We study the role of recombination energy with hydrodynamic simulations of such stellar interactions. We find that the recombination energy helps to expel the common envelope entirely, while if recombination energy is not taken into account, a significant fraction of the common envelope remains bound. We apply our numerical methods to constrain the progenitor system for WD 1101+364 - a double WD binary that has well-measured mass ratio of q=0.87±0.03 and an orbital period of 0.145 days. Our best-fit progenitor for the pre-common envelope donor is a 1.5 ⊙ red giant.

  1. Periodic envelopes of waves over non-uniform depth

    NASA Astrophysics Data System (ADS)

    Rajan, Girish K.; Bayram, Saziye; Henderson, Diane M.

    2016-04-01

    The envelope of narrow-banded, periodic, surface-gravity waves propagating in one dimension over water of finite, non-uniform depth may be modeled by the Djordjević and Redekopp ["On the development of packets of surface gravity waves moving over an uneven bottom," Z. Angew. Math. Phys. 29, 950-962 (1978)] equation (DRE). Here we find five approximate solutions of the DRE that are in the form of Jacobi-elliptic functions and discuss them within the framework of ocean swell. We find that in all cases, the maximum envelope-amplitude decreases/increases when the wave group propagates on water of decreasing/increasing depth. In the limit of the elliptic modulus approaching one, three of the solutions reduce to the envelope soliton solution. In the limit of the elliptic modulus approaching zero, two of the solutions reduce to an envelope-amplitude that is uniform in an appropriate reference frame.

  2. Differential binding of the HIV-1 envelope to phosphatidylserine receptors.

    PubMed

    Gu, Linlin; Sims, Brian; Krendelchtchikov, Alexandre; Tabengwa, Edlue; Matthews, Qiana L

    2017-10-01

    Prior work has shown that the HIV-1 envelope of the human immunodeficiency virus (HIV) interacts directly with T-cell immunoglobulin mucin (TIM) family proteins. Herein, we demonstrate that HIV-1 envelope glycoproteins from varying HIV-1 clades bind differentially to TIM proteins and functionally similar proteins acting as phosphatidylserine (PtdSer) receptors. Using enzyme-linked immunosorbent assay (ELISA) and surface plasmon resonance (SPR) technology, we show that lysate containing HIV-1 envelope and recombinant HIV-1 envelope glycoproteins bind TIM-4 and advanced glycosylation end product-specific receptor (AGER). The complex binding of HIV-1 UG21 gp140 to TIM-4 or AGER suggests a biphasic interaction with these proteins. Copyright © 2017 The Authors. Published by Elsevier B.V. All rights reserved.

  3. A Systematic Approach to Evaluating the Building Envelope.

    ERIC Educational Resources Information Center

    Lindberg, Jon F.; Stewart, Edward J.; Morand, David A.

    2002-01-01

    Describes a process for evaluating a building's envelope (roof, walls, windows, waterproofing, and structure). Steps are grouped into the following categories: building history, field inspection, access methods, identifying defects, testing methods, and engineering analysis. (EV)

  4. Solubilization and reconstitution of vesicular stomatitis virus envelope using octylglucoside.

    PubMed Central

    Paternostre, M; Viard, M; Meyer, O; Ghanam, M; Ollivon, M; Blumenthal, R

    1997-01-01

    Reconstituted vesicular stomatitis virus envelopes or virosomes are formed by detergent removal from solubilized intact virus. We have monitored the solubilization process of the intact vesicular stomatitis virus by the nonionic surfactant octylglucoside at various initial virus concentrations by employing turbidity measurements. This allowed us to determine the phase boundaries between the membrane and the mixed micelles domains. We have also characterized the lipid and protein content of the solubilized material and of the reconstituted envelope. Both G and M proteins and all of the lipids of the envelope were extracted by octylglucoside and recovered in the reconstituted envelope. Fusion activity of the virosomes tested either on Vero cells or on liposomes showed kinetics and pH dependence similar to those of the intact virus. Images FIGURE 4 PMID:9083672

  5. SIRT2 regulates nuclear envelope reassembly through ANKLE2 deacetylation.

    PubMed

    Kaufmann, Tanja; Kukolj, Eva; Brachner, Andreas; Beltzung, Etienne; Bruno, Melania; Kostrhon, Sebastian; Opravil, Susanne; Hudecz, Otto; Mechtler, Karl; Warren, Graham; Slade, Dea

    2016-12-15

    Sirtuin 2 (SIRT2) is an NAD-dependent deacetylase known to regulate microtubule dynamics and cell cycle progression. SIRT2 has also been implicated in the pathology of cancer, neurodegenerative diseases and progeria. Here, we show that SIRT2 depletion or overexpression causes nuclear envelope reassembly defects. We link this phenotype to the recently identified regulator of nuclear envelope reassembly ANKLE2. ANKLE2 acetylation at K302 and phosphorylation at S662 are dynamically regulated throughout the cell cycle by SIRT2 and are essential for normal nuclear envelope reassembly. The function of SIRT2 therefore extends beyond the regulation of microtubules to include the regulation of nuclear envelope dynamics. © 2016. Published by The Company of Biologists Ltd.

  6. SIRT2 regulates nuclear envelope reassembly through ANKLE2 deacetylation

    PubMed Central

    Kaufmann, Tanja; Kukolj, Eva; Brachner, Andreas; Beltzung, Etienne; Bruno, Melania; Kostrhon, Sebastian; Opravil, Susanne; Hudecz, Otto; Mechtler, Karl; Warren, Graham

    2016-01-01

    ABSTRACT Sirtuin 2 (SIRT2) is an NAD-dependent deacetylase known to regulate microtubule dynamics and cell cycle progression. SIRT2 has also been implicated in the pathology of cancer, neurodegenerative diseases and progeria. Here, we show that SIRT2 depletion or overexpression causes nuclear envelope reassembly defects. We link this phenotype to the recently identified regulator of nuclear envelope reassembly ANKLE2. ANKLE2 acetylation at K302 and phosphorylation at S662 are dynamically regulated throughout the cell cycle by SIRT2 and are essential for normal nuclear envelope reassembly. The function of SIRT2 therefore extends beyond the regulation of microtubules to include the regulation of nuclear envelope dynamics. PMID:27875273

  7. Border safety: quality control at the nuclear envelope

    PubMed Central

    Webster, Brant M.; Lusk, C. Patrick

    2015-01-01

    The unique biochemical identity of the nuclear envelope confers its capacity to establish a barrier that protects the nuclear compartment and directly contributes to nuclear function. Recent work uncovered quality control mechanisms employing the ESCRT machinery and a new arm of ERAD to counteract the unfolding, damage or misassembly of nuclear envelope proteins and ensure the integrity of the nuclear envelope membranes. Moreover, cells have the capacity to recognize and triage defective nuclear pore complexes in order to prevent their inheritance and preserve the longevity of progeny. These mechanisms serve to highlight the diverse strategies used by cells to maintain nuclear compartmentalization; we suggest they mitigate the progression and severity of diseases associated with nuclear envelope malfunction like the laminopathies. PMID:26437591

  8. The nucleoporin gp210/Nup210 controls muscle differentiation by regulating nuclear envelope/ER homeostasis.

    PubMed

    Gomez-Cavazos, J Sebastian; Hetzer, Martin W

    2015-03-16

    Previously, we identified the nucleoporin gp210/Nup210 as a critical regulator of muscle and neuronal differentiation, but how this nucleoporin exerts its function and whether it modulates nuclear pore complex (NPC) activity remain unknown. Here, we show that gp210/Nup210 mediates muscle cell differentiation in vitro via its conserved N-terminal domain that extends into the perinuclear space. Removal of the C-terminal domain, which partially mislocalizes gp210/Nup210 away from NPCs, efficiently rescues the differentiation defect caused by the knockdown of endogenous gp210/Nup210. Unexpectedly, a gp210/Nup210 mutant lacking the NPC-targeting transmembrane and C-terminal domains is sufficient for C2C12 myoblast differentiation. We demonstrate that the endoplasmic reticulum (ER) stress-specific caspase cascade is exacerbated during Nup210 depletion and that blocking ER stress-mediated apoptosis rescues differentiation of Nup210-deficient cells. Our results suggest that the role of gp210/Nup210 in cell differentiation is mediated by its large luminal domain, which can act independently of NPC association and appears to play a pivotal role in the maintenance of nuclear envelope/ER homeostasis. © 2015 Gomez-Cavazos and Hetzer.

  9. The nucleoporin gp210/Nup210 controls muscle differentiation by regulating nuclear envelope/ER homeostasis

    PubMed Central

    Gomez-Cavazos, J. Sebastian

    2015-01-01

    Previously, we identified the nucleoporin gp210/Nup210 as a critical regulator of muscle and neuronal differentiation, but how this nucleoporin exerts its function and whether it modulates nuclear pore complex (NPC) activity remain unknown. Here, we show that gp210/Nup210 mediates muscle cell differentiation in vitro via its conserved N-terminal domain that extends into the perinuclear space. Removal of the C-terminal domain, which partially mislocalizes gp210/Nup210 away from NPCs, efficiently rescues the differentiation defect caused by the knockdown of endogenous gp210/Nup210. Unexpectedly, a gp210/Nup210 mutant lacking the NPC-targeting transmembrane and C-terminal domains is sufficient for C2C12 myoblast differentiation. We demonstrate that the endoplasmic reticulum (ER) stress-specific caspase cascade is exacerbated during Nup210 depletion and that blocking ER stress-mediated apoptosis rescues differentiation of Nup210-deficient cells. Our results suggest that the role of gp210/Nup210 in cell differentiation is mediated by its large luminal domain, which can act independently of NPC association and appears to play a pivotal role in the maintenance of nuclear envelope/ER homeostasis. PMID:25778917

  10. Advances in Understanding Durability of the Building Envelope: ORNL Research

    SciTech Connect

    Kehrer, Manfred; Desjarlais, Andre Omer

    2013-01-01

    Moisture, and its accompanying outriders things like mold, corrosion, freeze damage, and decay present powerful threats to the durability and long-term performance of a building envelope. Miscalculating the impact of environmental factors like rain, solar radiation, temperature, humidity, and indoor sources of moisture can cause significant damage to many types of building envelope components and materials, and also can lead to unhealthy indoor living environments.

  11. 300 Area Liquid Effluent Facilities (LEF) Authorization Envelope

    SciTech Connect

    WRIGHT, E.J.; STORDEUR, R.T.

    2000-04-07

    The purpose of this document is to establish the facility Authorization Envelope (AE) for the 300 Liquid Effluent Facilities (LEP )Project and identify the requirements related to the maintenance of the AE as Specified in HNF-PRO-2701, Authorization Envelope and Authorization Agreement. The 300 LEF Project consists of two separate facilities operating under one management organization. They are the 310 Facility and the 340 Facility. The AE documents the limits of operations for all 300 LEF Project activities.

  12. RMS ENVELOPE BACK-PROPAGATION IN THE XAL ONLINE MODEL

    SciTech Connect

    Allen, Christopher K; Sako, Hiroyuki; Ikegami, Masanori

    2009-01-01

    The ability to back-propagate RMS envelopes was added to the J-PARC XAL online model. Specifically, given an arbitrary downstream location, the online model can propagate the RMS envelopes backward to an arbitrary upstream location. This feature provides support for algorithms estimating upstream conditions from downstream data. The upgrade required significant refactoring, which we outline. We also show simulations using the new feature.

  13. Episodic mass ejections from common-envelope objects

    NASA Astrophysics Data System (ADS)

    Clayton, Matthew; Podsiadlowski, Philipp; Ivanova, Natasha; Justham, Stephen

    2017-09-01

    After the initial fast spiral-in phase experienced by a common-envelope binary, the system may enter a slow, self-regulated phase, possibly lasting hundreds of years, in which all the energy released by orbital decay can be efficiently transported to the surface, where it is radiated away. If the remaining envelope is to be removed during this phase, this removal must occur through some as-yet-undetermined mechanism. We carried out 1D hydrodynamic simulations of a low-mass red giant undergoing a synthetic common-envelope event in such a slow spiral-in phase, using the stellar evolutionary code mesa. We simulated the heating of the envelope due to frictional dissipation from a binary companion's orbit in multiple configurations and investigated the response of the giant's envelope. We find that our model envelopes become dynamically unstable and develop large-amplitude pulsations, with periods in the range 3-20 yr and very short growth time-scales of similar order. The shocks and associated rebounds that emerge as these pulsations grow are in some cases strong enough to dynamically eject shells of matter of up to 0.1 M⊙, ∼10 per cent of the mass of the envelope, from the stellar surface at above escape velocity. These ejections are seen to repeat within a few decades, leading to a time-averaged mass-loss rate of the order of 10-3 M⊙ yr-1, which is sufficiently high to represent a candidate mechanism for removing the entire envelope over the duration of the slow spiral-in phase.

  14. Universal enveloping crossed module of Leibniz crossed modules and representations

    NASA Astrophysics Data System (ADS)

    Casado, Rafael F.; García-Martínez, Xabier; Ladra, Manuel

    2016-03-01

    The universal enveloping algebra functor UL: Lb → Alg, defined by Loday and Pirashvili [1], is extended to crossed modules. Then we construct an isomorphism between the category of representations of a Leibniz crossed module and the category of left modules over its universal enveloping crossed module of algebras. Note that the procedure followed in the proof for the Lie case cannot be adapted, since the actor in the category of Leibniz crossed modules does not always exist.

  15. A Partial Differential Equation for the Rank One Convex Envelope

    NASA Astrophysics Data System (ADS)

    Oberman, Adam M.; Ruan, Yuanlong

    2017-02-01

    A partial differential equation (PDE) for the rank one convex envelope is introduced. The existence and uniqueness of viscosity solutions to the PDE is established. Elliptic finite difference schemes are constructed and convergence of finite difference solutions to the viscosity solution of the PDE is proven. Computational results are presented and laminates are computed from the envelopes. Results include the Kohn-Strang example, the classical four gradient example, and an example with eight gradients which produces nontrivial laminates.

  16. Fine-Tuning of the Cpx Envelope Stress Response Is Required for Cell Wall Homeostasis in Escherichia coli

    PubMed Central

    Delhaye, Antoine; Collet, Jean-François

    2016-01-01

    ABSTRACT The envelope of Gram-negative bacteria is an essential compartment that constitutes a protective and permeability barrier between the cell and its environment. The envelope also hosts the cell wall, a mesh-like structure made of peptidoglycan (PG) that determines cell shape and provides osmotic protection. Since the PG must grow and divide in a cell-cycle-synchronized manner, its synthesis and remodeling are tightly regulated. Here, we discovered that PG homeostasis is intimately linked to the levels of activation of the Cpx system, an envelope stress response system traditionally viewed as being involved in protein quality control in the envelope. We first show that Cpx is activated when PG integrity is challenged and that this activation provides protection to cells exposed to antibiotics inhibiting PG synthesis. By rerouting the outer membrane lipoprotein NlpE, a known Cpx activator, to a different envelope subcompartment, we managed to manipulate Cpx activation levels. We found that Cpx overactivation leads to aberrant cellular morphologies, to an increased sensitivity to β-lactams, and to dramatic division and growth defects, consistent with a loss of PG homeostasis. Remarkably, these phenotypes were largely abrogated by the deletion of ldtD, a Cpx-induced gene involved in noncanonical PG cross-linkage, suggesting that this transpeptidase is an important link between PG homeostasis and the Cpx system. Altogether our data show that fine-tuning of an envelope quality control system constitutes an important layer of regulation of the highly organized cell wall structure. PMID:26908573

  17. Name that percussive tune: Associative memory and amplitude envelope.

    PubMed

    Schutz, Michael; Stefanucci, Jeanine K; H Baum, Sarah; Roth, Amber

    2017-07-01

    A series of experiments demonstrated novel effects of amplitude envelope on associative memory, with tones exhibiting naturally decaying amplitude envelopes (e.g., those made by two wine glasses clinking) better associated with target objects than amplitude-invariant tones. In Experiment 1 participants learned associations between household objects and 4-note tone sequences constructed of spectrally matched pure tones with either "flat" or "percussive" amplitude envelopes. Those hearing percussive tones correctly recalled significantly more sequence-object associations. Experiment 2 demonstrated that participants hearing percussive tones learned the associations more quickly. Experiment 3 used "reverse percussive" tones (percussive tones played backwards) to test whether differences in overall energy might account for this effect, finding they did not lead to the same level of performance as percussive tones. Experiment 4 varied the envelope at encoding and retrieval to determine which stage of the task was most affected by the envelope manipulation. Participants hearing percussive tones at both encoding and retrieval performed significantly better than the other three groups (i.e., flat at encoding/percussive at retrieval, etc.). We conclude that amplitude envelope plays an important role in learning and memory, a finding with relevance to psychological research on audition and associative memory, as well as practical relevance for improving human-computer interface design.

  18. Disassembly of the cystovirus ϕ6 envelope by montmorillonite clay.

    PubMed

    Block, Karin A; Trusiak, Adrianna; Katz, Al; Gottlieb, Paul; Alimova, Alexandra; Wei, Hui; Morales, Jorge; Rice, William J; Steiner, Jeffrey C

    2014-02-01

    Prior studies of clay-virus interactions have focused on the stability and infectivity of nonenveloped viruses, yielding contradictory results. We hypothesize that the surface charge distribution of the clay and virus envelope dictates how the components react and affect aggregation, viral stability, and infectivity. The bacteriophage Cystoviridae species φ6 used in this study is a good model for enveloped pathogens. The interaction between φ6 and montmorillonite (MMT) clay (the primary component of bentonite) is explored by transmission electron microscopy. The analyses show that MMT-φ6 mixtures undergo heteroaggregation, forming structures in which virtually all the virions are either sequestered between MMT platelet layers or attached to platelet edges. The virions swell and undergo disassembly resulting in partial or total envelope loss. Edge-attached viral envelopes distort to increase contact area with the positively charged platelet edges indicating that the virion surface is negatively charged. The nucleocapsid (NCs) remaining after envelope removal also exhibit distortion, in contrast to detergent-produced NCs which exhibit no distortion. This visually discernible disassembly is a mechanism for loss of infectivity previously unreported by studies of nonenveloped viruses. The MMT-mediated sequestration and disassembly result in reduced infectivity, suggesting that clays may reduce infectivity of enveloped pathogenic viruses in soils and sediments.

  19. Preserving Envelope Efficiency in Performance Based Code Compliance

    SciTech Connect

    Thornton, Brian A.; Sullivan, Greg P.; Rosenberg, Michael I.; Baechler, Michael C.

    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.

  20. Disassembly of the cystovirus ϕ6 envelope by montmorillonite clay

    PubMed Central

    Block, Karin A; Trusiak, Adrianna; Katz, Al; Gottlieb, Paul; Alimova, Alexandra; Wei, Hui; Morales, Jorge; Rice, William J; Steiner, Jeffrey C

    2014-01-01

    Prior studies of clay–virus interactions have focused on the stability and infectivity of nonenveloped viruses, yielding contradictory results. We hypothesize that the surface charge distribution of the clay and virus envelope dictates how the components react and affect aggregation, viral stability, and infectivity. The bacteriophage Cystoviridae species φ6 used in this study is a good model for enveloped pathogens. The interaction between φ6 and montmorillonite (MMT) clay (the primary component of bentonite) is explored by transmission electron microscopy. The analyses show that MMT–φ6 mixtures undergo heteroaggregation, forming structures in which virtually all the virions are either sequestered between MMT platelet layers or attached to platelet edges. The virions swell and undergo disassembly resulting in partial or total envelope loss. Edge-attached viral envelopes distort to increase contact area with the positively charged platelet edges indicating that the virion surface is negatively charged. The nucleocapsid (NCs) remaining after envelope removal also exhibit distortion, in contrast to detergent-produced NCs which exhibit no distortion. This visually discernible disassembly is a mechanism for loss of infectivity previously unreported by studies of nonenveloped viruses. The MMT-mediated sequestration and disassembly result in reduced infectivity, suggesting that clays may reduce infectivity of enveloped pathogenic viruses in soils and sediments. PMID:24357622

  1. The Herschel Orion Protostar Survey: Luminosity and Envelope Evolution

    NASA Astrophysics Data System (ADS)

    Fischer, William J.; Megeath, S. Thomas; Furlan, Elise; Ali, Babar; Stutz, Amelia M.; Tobin, John J.; Osorio, Mayra; Stanke, Thomas; Manoj, P.; Poteet, Charles A.; Booker, Joseph J.; Hartmann, Lee; Wilson, Thomas L.; Myers, Philip C.; Watson, Dan M.

    2017-05-01

    The Herschel Orion Protostar Survey obtained well-sampled 1.2-870 μm spectral energy distributions (SEDs) of over 300 protostars in the Orion molecular clouds, home to most of the young stellar objects (YSOs) in the nearest 500 pc. We plot the bolometric luminosities and temperatures for 330 Orion YSOs, 315 of which have bolometric temperatures characteristic of protostars. The histogram of the bolometric temperature is roughly flat; 29% of the protostars are in Class 0. The median luminosity decreases by a factor of four with increasing bolometric temperature; consequently, the Class 0 protostars are systematically brighter than the Class I protostars, with a median luminosity of 2.3 L⊙ as opposed to 0.87 L⊙. At a given bolometric temperature, the scatter in luminosities is three orders of magnitude. Using fits to the SEDs, we analyze how the luminosities corrected for inclination and foreground reddening relate to the mass in the inner 2500 au of the best-fit model envelopes. The histogram of the envelope mass is roughly flat, while the median-corrected luminosity peaks at 15 L⊙ for young envelopes and falls to 1.7 L⊙ for late-stage protostars with remnant envelopes. The spread in luminosity at each envelope mass is three orders of magnitude. Envelope masses that decline exponentially with time explain the flat mass histogram and the decrease in luminosity, while the formation of a range of stellar masses explains the dispersion in luminosity.

  2. Outfits for different occasions: tissue-specific roles of Nuclear Envelope proteins

    PubMed Central

    Gomez-Cavazos, J Sebastian; Hetzer, Martin W

    2013-01-01

    The Nuclear Envelope (NE) contains over 100 different proteins that associate with nuclear components such as chromatin, the lamina and the transcription machinery. Mutations in genes encoding NE proteins have been shown to result in tissue-specific defects and disease, suggesting cell-type specific differences in NE composition and function. Consistent with these observations, recent studies have revealed unexpected functions for numerous NE associated proteins during cell differentiation and development. Here we review the latest insights into the roles played by the NE in cell differentiation, development, disease and aging, focusing primarily on inner nuclear membrane (INM) proteins and nuclear pore components. PMID:22995343

  3. Envelope-like retrotransposons in the plant kingdom: evidence of their presence in gymnosperms (Pinus pinaster).

    PubMed

    Miguel, Célia; Simões, Marta; Oliveira, Maria Margarida; Rocheta, Margarida

    2008-11-01

    Retroviruses differ from retrotransposons due to their infective capacity, which depends critically on the encoded envelope. Some plant retroelements contain domains reminiscent of the env of animal retroviruses but the number of such elements described to date is restricted to angiosperms. We show here the first evidence of the presence of putative env-like gene sequences in a gymnosperm species, Pinus pinaster (maritime pine). Using a degenerate primer approach for conserved domains of RNaseH gene, three clones from putative envelope-like retrotransposons (PpRT2, PpRT3, and PpRT4) were identified. The env-like sequences of P. pinaster clones are predicted to encode proteins with transmembrane domains. These sequences showed identity scores of up to 30% with env-like sequences belonging to different organisms. A phylogenetic analysis based on protein alignment of deduced aminoacid sequences revealed that these clones clustered with env-containing plant retrotransposons, as well as with retrotransposons from invertebrate organisms. The differences found among the sequences of maritime pine clones isolated here suggest the existence of different putative classes of env-like retroelements. The identification for the first time of env-like genes in a gymnosperm species may support the ancestrality of retroviruses among plants shedding light on their role in plant evolution.

  4. ORF7 of Varicella-Zoster Virus Is Required for Viral Cytoplasmic Envelopment in Differentiated Neuronal Cells.

    PubMed

    Jiang, Hai-Fei; Wang, Wei; Jiang, Xuan; Zeng, Wen-Bo; Shen, Zhang-Zhou; Song, Yi-Ge; Yang, Hong; Liu, Xi-Juan; Dong, Xiao; Zhou, Jing; Sun, Jin-Yan; Yu, Fei-Long; Guo, Lin; Cheng, Tong; Rayner, Simon; Zhao, Fei; Zhu, Hua; Luo, Min-Hua

    2017-06-15

    Although a varicella-zoster virus (VZV) vaccine has been used for many years, the neuropathy caused by VZV infection is still a major health concern. Open reading frame 7 (ORF7) of VZV has been recognized as a neurotropic gene in vivo, but its neurovirulent role remains unclear. In the present study, we investigated the effect of ORF7 deletion on VZV replication cycle at virus entry, genome replication, gene expression, capsid assembly and cytoplasmic envelopment, and transcellular transmission in differentiated neural progenitor cells (dNPCs) and neuroblastoma SH-SY5Y (dSY5Y) cells. Our results demonstrate that the ORF7 protein is a component of the tegument layer of VZV virions. Deleting ORF7 did not affect viral entry, viral genome replication, or the expression of typical viral genes but clearly impacted cytoplasmic envelopment of VZV capsids, resulting in a dramatic increase of envelope-defective particles and a decrease in intact virions. The defect was more severe in differentiated neuronal cells of dNPCs and dSY5Y. ORF7 deletion also impaired transmission of ORF7-deficient virus among the neuronal cells. These results indicate that ORF7 is required for cytoplasmic envelopment of VZV capsids, virus transmission among neuronal cells, and probably the neuropathy induced by VZV infection.IMPORTANCE The neurological damage caused by varicella-zoster virus (VZV) reactivation is commonly manifested as clinical problems. Thus, identifying viral neurovirulent genes and characterizing their functions are important for relieving VZV related neurological complications. ORF7 has been previously identified as a potential neurotropic gene, but its involvement in VZV replication is unclear. In this study, we found that ORF7 is required for VZV cytoplasmic envelopment in differentiated neuronal cells, and the envelopment deficiency caused by ORF7 deletion results in poor dissemination of VZV among neuronal cells. These findings imply that ORF7 plays a role in neuropathy

  5. Phenylalanines at positions 88 and 159 of Ebolavirus envelope glycoprotein differentially impact envelope function

    SciTech Connect

    Ou Wu; King, Harlan; Delisle, Josie; Shi Dashuang; Wilson, Carolyn A.

    2010-01-05

    The envelope glycoprotein (GP) of Ebolavirus (EBOV) mediates viral entry into host cells. Through mutagenesis, we and other groups reported that two phenylalanines at positions 88 and 159 of GP are critical for viral entry. However, it remains elusive which steps of viral entry are impaired by F88 or F159 mutations and how. In this study, we further characterized these two phenylalanines through mutagenesis and examined the impact on GP expression, function, and structure. Our data suggest that F159 plays an indirect role in viral entry by maintaining EBOV GP's overall structure. In contrast, we did not detect any evidence for conformational differences in GP with F88 mutations. The data suggest that F88 influences viral entry during a step after cathepsin processing, presumably impacting viral fusion.

  6. Metallicity dependence of envelope inflation in massive stars

    NASA Astrophysics Data System (ADS)

    Sanyal, D.; Langer, N.; Szécsi, D.; -C Yoon, S.; Grassitelli, L.

    2017-01-01

    Context. Recently it has been found that models of massive stars reach the Eddington limit in their interior, which leads to dilute extended envelopes. Aims: We perform a comparative study of the envelope properties of massive stars at different metallicities, with the aim to establish the impact of the stellar metallicity on the effect of envelope inflation. Methods: We analysed published grids of core-hydrogen burning massive star models computed with metallicities appropriate for massive stars in the Milky Way, the Large Magellanic Cloud, and the Small Magellanic Cloud, the very metal poor dwarf galaxy I Zwicky 18, and for metal-free chemical composition. Results: Stellar models of all the investigated metallicities reach and exceed the Eddington limit in their interior, aided by the opacity peaks of iron, helium, and hydrogen, and consequently develop inflated envelopes. Envelope inflation leads to a redward bending of the zero-age main sequence and a broadening of the main-sequence band in the upper part of the Hertzsprung-Russell diagram. We derive the limiting L/M-values as a function of the stellar surface temperature above which inflation occurs, and find them to be higher for lower metallicity. While Galactic models show inflation above 29 M⊙, the corresponding mass limit for Population III stars is 150 M⊙. While the masses of the inflated envelopes are generally low, we find that they can reach 1-100 M⊙ in models with effective temperatures below 8000 K, with higher masses reached by models of lower metallicity. Conclusions: Envelope inflation is expected to occur in sufficiently massive stars at all metallicities, and is expected to lead to rapidly growing pulsations, high macroturbulent velocities, and might well be related to the unexplained variability observed in luminous blue variables such as S Doradus and η Carina.

  7. Rotavirus protein rearrangements in purified membrane-enveloped intermediate particles.

    PubMed Central

    Poruchynsky, M S; Atkinson, P H

    1991-01-01

    Rotavirus, a double-shelled nonenveloped member of the REoviridae family, becomes transiently membrane enveloped during its maturation process, as single-shelled particles bud from cytoplasmic viroplasm structures into the adjacent endoplasmic reticulum. The present study describes the isolation of these membrane-enveloped viral intermediates from rotavirus SA11-infected Ma104 cells. The enveloped intermediates comprised the proteins VP1, VP2, VP4, VP6, VP7, and NS28 and small amounts of NS35 and NS34. VP7 in the intermediate particles was recognized by either a polyclonal antibody to VP7, which previous studies had shown recognizes the membrane-associated form of VP7, or a monoclonal antibody which recognizes VP7 on mature virus. NS28, VP7, and VP4 could be complexed to a higher-molecular-weight form when the membrane-permeable cross-linker dithiobis(succinimidylproprionate) was used. However, when an impermeable cross-linker was used, the structural proteins, including VP7, were not accessible to cross-linking. Velocity sedimentation of cross-linked immunoisolated enveloped virus particles showed that VP7 and VP4 were located in the same fractions only when the membrane-permeable cross-linker was used, implying their heterooligomeric association during outer capsid formation. When intermediate enveloped virus particles were treated with protease, VP6 and VP7 were protected, but not in the presence of detergent. Taken together, these results support the idea that in the membrane-enveloped intermediate, VP7 is repositioned from its location in the endoplasmic reticulum lumen back across the viral membrane envelope to the inferior of the virus particle during the maturation process. Images PMID:1651404

  8. Different sympathetic pathways control the metabolism of distinct bone envelopes.

    PubMed

    Bataille, Caroline; Mauprivez, Cédric; Haÿ, Eric; Baroukh, Brigitte; Brun, Adrian; Chaussain, Catherine; Marie, Pierre J; Saffar, Jean-Louis; Cherruau, Marc

    2012-05-01

    Bone remodeling, the mechanism that modulates bone mass adaptation, is controlled by the sympathetic nervous system through the catecholaminergic pathway. However, resorption in the mandible periosteum envelope is associated with cholinergic Vasoactive Intestinal Peptide (VIP)-positive nerve fibers sensitive to sympathetic neurotoxics, suggesting that different sympathetic pathways may control distinct bone envelopes. In this study, we assessed the role of distinct sympathetic pathways on rat femur and mandible envelopes. To this goal, adult male Wistar rats were chemically sympathectomized or treated with agonists/antagonists of the catecholaminergic and cholinergic pathways; femora and mandibles were sampled. Histomorphometric analysis showed that sympathectomy decreased the number of preosteoclasts and RANKL-expressing osteoblasts in mandible periosteum but had no effect on femur trabecular bone. In contrast, pharmacological stimulation or repression of the catecholaminergic cell receptors impacted the femur trabecular bone and mandible endosteal retromolar zone. VIP treatment of sympathectomized rats rescued the disturbances of the mandible periosteum and alveolar wall whereas the cholinergic pathway had no effect on the catecholaminergic-dependent envelopes. We also found that VIP receptor-1 was weakly expressed in periosteal osteoblasts in the mandible and was increased by VIP treatment, whereas osteoblasts of the retromolar envelope that was innervated only by tyrosine hydroxylase-immunoreactive fibers, constitutively expressed beta-2 adrenergic receptors. These data highlight the complexity of the sympathetic control of bone metabolism. Both the embryological origin of the bone (endochondral for the femur, membranous for the mandibular periosteum and the socket wall) and environmental factors specific to the innervated envelope may influence the phenotype of the sympathetic innervation. We suggest that an origin-dependent imprint of bone cells through

  9. Sensitivity to Envelope Interaural Time Differences at High Modulation Rates

    PubMed Central

    Bleeck, Stefan; McAlpine, David

    2015-01-01

    Sensitivity to interaural time differences (ITDs) conveyed in the temporal fine structure of low-frequency tones and the modulated envelopes of high-frequency sounds are considered comparable, particularly for envelopes shaped to transmit similar fidelity of temporal information normally present for low-frequency sounds. Nevertheless, discrimination performance for envelope modulation rates above a few hundred Hertz is reported to be poor—to the point of discrimination thresholds being unattainable—compared with the much higher (>1,000 Hz) limit for low-frequency ITD sensitivity, suggesting the presence of a low-pass filter in the envelope domain. Further, performance for identical modulation rates appears to decline with increasing carrier frequency, supporting the view that the low-pass characteristics observed for envelope ITD processing is carrier-frequency dependent. Here, we assessed listeners’ sensitivity to ITDs conveyed in pure tones and in the modulated envelopes of high-frequency tones. ITD discrimination for the modulated high-frequency tones was measured as a function of both modulation rate and carrier frequency. Some well-trained listeners appear able to discriminate ITDs extremely well, even at modulation rates well beyond 500 Hz, for 4-kHz carriers. For one listener, thresholds were even obtained for a modulation rate of 800 Hz. The highest modulation rate for which thresholds could be obtained declined with increasing carrier frequency for all listeners. At 10 kHz, the highest modulation rate at which thresholds could be obtained was 600 Hz. The upper limit of sensitivity to ITDs conveyed in the envelope of high-frequency modulated sounds appears to be higher than previously considered. PMID:26721926

  10. Planet formation from the ejecta of common envelopes

    NASA Astrophysics Data System (ADS)

    Schleicher, Dominik R. G.; Dreizler, Stefan

    2014-03-01

    Context. 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 are probably inconsistent with planet formation before the mass loss. Aims: 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. Methods: We employed the Kashi & Soker model to estimate the amount of mass that is retained during the ejection event and inferred the properties of the resulting disk from the conservation of mass and angular momentum. The resulting planetary masses were estimated from models with and without radiative feedback. Results: 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 compare the expected mass scale of planets for 11 additional systems with observational results and find hints of two populations, one consistent with planet formation from the ejecta of common envelopes and the other a separate population that may have formed earlier. Conclusions: The formation of the observed planets from the ejecta of common envelopes seems feasible. The model proposed here can be tested through refined observations of additional post-common envelope systems. While it appears observationally challenging to distinguish between the accretion on pre-existing planets and their growth from new fragments, it may be possible to further constrain the properties of the protoplanetary disk through additional observations of current planetary candidates and post-common envelope binary systems.

  11. Types of gaseous envelopes of "hot Jupiter" exoplanets

    NASA Astrophysics Data System (ADS)

    Bisikalo, D. V.; Kaigorodov, P. V.; Ionov, D. E.; Shematovich, V. I.

    2013-10-01

    As a rule, the orbital velocities of "hot Jupiters," i.e., exoplanets with masses comparable to the mass of Jupiter and orbital semi-major axes less than 0.1 AU, are supersonic relative to the stellar wind, resulting in the formation of a bow shock. Gas-dynamical modeling shows that the gaseous envelopes around hot Jupiters can belong to two classes, depending on the position of the collision point. if the collision point is inside the Roche lobe of the planet, the envelopes have the almost spherical shapes of classical atmospheres, slightly distorted by the influence of the star and interactions with the stellar-wind gas; if the collision point is located outside the Roche lobe, outflows from the vicinity of the Lagrangian points L1 and L2 arise, and the envelope becomes substantially asymmetrical. The latter class of objects can also be divided into two types. If the dynamical pressure of the stellar-wind gas is high enough to stop the most powerful outflow from the vicinity of the inner Lagrangian point L1, a closed quasi-spherical envelope with a complex shape forms in the system. If the wind is unable to stop the outflow from L1, an open aspherical envelope forms. The possible existence of atmospheres of these three types is confirmed by 3D numerical modeling. Using the typical hot Jupiter HD 209458b as an example, it is shown that all three types of atmospheres could exist within the range of estimated parameters of this planet. Since different types of envelopes have different observational manifestations, determining the type of envelope in HD 209458b could apply additional constrains on the parameters of this exoplanet.

  12. Sensitivity to Envelope Interaural Time Differences at High Modulation Rates.

    PubMed

    Monaghan, Jessica J M; Bleeck, Stefan; McAlpine, David

    2015-12-30

    Sensitivity to interaural time differences (ITDs) conveyed in the temporal fine structure of low-frequency tones and the modulated envelopes of high-frequency sounds are considered comparable, particularly for envelopes shaped to transmit similar fidelity of temporal information normally present for low-frequency sounds. Nevertheless, discrimination performance for envelope modulation rates above a few hundred Hertz is reported to be poor-to the point of discrimination thresholds being unattainable-compared with the much higher (>1,000 Hz) limit for low-frequency ITD sensitivity, suggesting the presence of a low-pass filter in the envelope domain. Further, performance for identical modulation rates appears to decline with increasing carrier frequency, supporting the view that the low-pass characteristics observed for envelope ITD processing is carrier-frequency dependent. Here, we assessed listeners' sensitivity to ITDs conveyed in pure tones and in the modulated envelopes of high-frequency tones. ITD discrimination for the modulated high-frequency tones was measured as a function of both modulation rate and carrier frequency. Some well-trained listeners appear able to discriminate ITDs extremely well, even at modulation rates well beyond 500 Hz, for 4-kHz carriers. For one listener, thresholds were even obtained for a modulation rate of 800 Hz. The highest modulation rate for which thresholds could be obtained declined with increasing carrier frequency for all listeners. At 10 kHz, the highest modulation rate at which thresholds could be obtained was 600 Hz. The upper limit of sensitivity to ITDs conveyed in the envelope of high-frequency modulated sounds appears to be higher than previously considered. © The Author(s) 2015.

  13. Selective transduction of astrocytic and neuronal CNS subpopulations by lentiviral vectors pseudotyped with Chikungunya virus envelope.

    PubMed

    Eleftheriadou, Ioanna; Dieringer, Michael; Poh, Xuan Ying; Sanchez-Garrido, Julia; Gao, Yunan; Sgourou, Argyro; Simmons, Laura E; Mazarakis, Nicholas D

    2017-04-01

    Lentiviral vectors are gene delivery vehicles that integrate into the host genome of dividing and non-dividing mammalian cells facilitating long-term transgene expression. Lentiviral vector versatility is greatly increased by incorporating heterologous viral envelope proteins onto the vector particles instead of the native envelope, conferring on these pseudotyped vectors a modified tropism and host range specificity. We investigated the pseudotyping efficiency of HIV-1 based lentiviral vectors with alphaviral envelope proteins from the Chikungunya Virus (CHIKV-G) and Sindbis Virus (SINV-G). Following vector production optimisation, titres for the CHIKV-G pseudotype were comparable to the VSV-G pseudotype but those for the SINV-G pseudotype were significantly lower. High titre CHIKV-G pseudotyped vector efficiently transduced various human and mouse neural cell lines and normal human astrocytes (NHA) in vitro. Although transduction was broad, tropism for NHAs was observed. In vivo stereotaxic delivery in striatum, thalamus and hippocampus respectively in the adult rat brain revealed localised transduction restricted to striatal astrocytes and hippocampal dentate granule neurons. Transduction of different subtypes of granule neurons from precursor to post-mitotic stages of differentiation was evident in the sub-granular zone and dentate granule cell layer. No significant inflammatory response was observed, but comparable to that of VSV-G pseudotyped lentiviral vectors. Robust long-term expression followed for three months post-transduction along with absence of neuroinflammation, coupled to the selective and unique neuron/glial tropism indicates that these vectors could be useful for modelling and gene therapy studies in the CNS.

  14. The nuclear envelope lamina network has elasticity and a compressibility limit suggestive of a molecular shock absorber.

    PubMed

    Dahl, Kris Noel; Kahn, Samuel M; Wilson, Katherine L; Discher, Dennis E

    2004-09-15

    Mechanical properties of the nuclear envelope have implications for cell and nuclear architecture as well as gene regulation. Using isolated Xenopus oocyte nuclei, we have established swelling conditions that separate the intact nuclear envelope (membranes, pore complexes and underlying lamin filament network) from nucleoplasm and the majority of chromatin. Swelling proves reversible with addition of high molecular mass dextrans. Micropipette aspiration of swollen and unswollen nuclear envelopes is also reversible and yields a network elastic modulus, unaffected by nucleoplasm, that averages 25 mN/m. Compared to plasma membranes of cells, the nuclear envelope is much stiffer and more resilient. Our results suggest that the nuclear lamina forms a compressed network shell of interconnected rods that is extensible but limited in compressibility from the native state, thus acting as a 'molecular shock absorber'. In light of the conservation of B-type lamins in metazoan evolution, the mechanical properties determined in this investigation suggest physical mechanisms by which mutated lamins can either destabilize nuclear architecture or influence nuclear responses to mechanical signals in Emery-Dreifuss muscular dystrophy, cardiomyopathy, progeria syndromes (premature 'aging') and other laminopathies.

  15. A tamB homolog is involved in maintenance of cell envelope integrity and stress resistance of Deinococcus radiodurans

    PubMed Central

    Yu, Jiangliu; Li, Tao; Dai, Shang; Weng, Yulan; Li, Jiulong; Li, Qinghao; Xu, Hong; Hua, Yuejin; Tian, Bing

    2017-01-01

    The translocation and assembly module (TAM) in bacteria consists of TamA and TamB that form a complex to control the transport and secretion of outer membrane proteins. Herein, we demonstrated that the DR_1462-DR_1461-DR_1460 gene loci on chromosome 1 of Deinococcus radiodurans, which lacks tamA homologs, is a tamB homolog (DR_146T) with two tamB motifs and a DUF490 motif. Mutation of DR_146T resulted in cell envelope peeling and a decrease in resistance to shear stress and osmotic pressure, as well as an increase in oxidative stress resistance, consistent with the phenotype of a surface layer (S-layer) protein SlpA (DR_2577) mutant, demonstrating the involvement of DR_146T in maintenance of cell envelope integrity. The 123 kDa SlpA was absent and only its fragments were present in the cell envelope of DR_146T mutant, suggesting that DR_146T might be involved in maintenance of the S-layer. A mutant lacking the DUF490 motif displayed only a slight alteration in phenotype compared with the wild type, suggesting DUF490 is less important than tamB motif for the function of DR_146T. These findings enhance our understanding of the properties of the multilayered envelope in extremophilic D. radiodurans, as well as the diversity and functions of TAMs in bacteria. PMID:28383523

  16. Dysregulated interactions between lamin A and SUN1 induce abnormalities in the nuclear envelope and endoplasmic reticulum in progeric laminopathies.

    PubMed

    Chen, Zi-Jie; Wang, Wan-Ping; Chen, Yu-Ching; Wang, Jing-Ya; Lin, Wen-Hsin; Tai, Lin-Ai; Liou, Gan-Guang; Yang, Chung-Shi; Chi, Ya-Hui

    2014-04-15

    Hutchinson-Gilford progeria syndrome (HGPS) is a human progeroid disease caused by a point mutation on the LMNA gene. We reported previously that the accumulation of the nuclear envelope protein SUN1 contributes to HGPS nuclear aberrancies. However, the mechanism by which interactions between mutant lamin A (also known as progerin or LAΔ50) and SUN1 produce HGPS cellular phenotypes requires further elucidation. Using light and electron microscopy, this study demonstrated that SUN1 contributes to progerin-elicited structural changes in the nuclear envelope and the endoplasmic reticulum (ER) network. We further identified two domains through which full-length lamin A associates with SUN1, and determined that the farnesylated cysteine within the CaaX motif of lamin A has a stronger affinity for SUN1 than does the lamin A region containing amino acids 607 to 656. Farnesylation of progerin enhanced its interaction with SUN1 and reduced SUN1 mobility, thereby promoting the aberrant recruitment of progerin to the ER membrane during postmitotic assembly of the nuclear envelope, resulting in the accumulation of SUN1 over consecutive cellular divisions. These results indicate that the dysregulated interaction of SUN1 and progerin in the ER during nuclear envelope reformation determines the progression of HGPS.

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

    PubMed

    Bagdonaite, Ieva; Nordén, Rickard; Joshi, Hiren J; Dabelsteen, Sally; Nyström, Kristina; Vakhrushev, Sergey Y; Olofsson, Sigvard; Wandall, Hans H

    2015-04-01

    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.

  18. A Strategy for O-Glycoproteomics of Enveloped Viruses—the O-Glycoproteome of Herpes Simplex Virus Type 1

    PubMed Central

    Bagdonaite, Ieva; Nordén, Rickard; Joshi, Hiren J.; Dabelsteen, Sally; Nyström, Kristina; Vakhrushev, Sergey Y.; Olofsson, Sigvard; Wandall, Hans H.

    2015-01-01

    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. PMID:25830354

  19. Maturation of HIV envelope glycoprotein precursors by cellular endoproteases.

    PubMed

    Moulard, M; Decroly, E

    2000-11-10

    The entry of enveloped viruses into its host cells is a crucial step for the propagation of viral infection. The envelope glycoprotein complex controls viral tropism and promotes the membrane fusion process. The surface glycoproteins of enveloped viruses are synthesized as inactive precursors and sorted through the constitutive secretory pathway of the infected cells. To be infectious, most of the viruses require viral envelope glycoprotein maturation by host cell endoproteases. In spite of the strong variability of primary sequences observed within different viral envelope glycoproteins, the endoproteolytical cleavage occurs mainly in a highly conserved domain at the carboxy terminus of the basic consensus sequence (Arg-X-Lys/Arg-Arg downward arrow). The same consensus sequence is recognized by the kexin/subtilisin-like serine proteinases (so called convertases) in many cellular substrates such as prohormones, proprotein of receptors, plasma proteins, growth factors and bacterial toxins. Therefore, several groups of investigators have evaluated the implication of convertases in viral envelope glycoprotein cleavage. Using the vaccinia virus overexpression system, furin was first shown to mediate the proteolytic maturation of both human immunodeficiency virus (HIV-1) and influenza virus envelope glycoproteins. In vitro studies demonstrated that purified convertases directly and specifically cleave viral envelope glycoproteins. Although these studies suggested the participation of several enzymes belonging to the convertases family, recent data suggest that other protease families may also participate in the HIV envelope glycoprotein processing. Their role in the physiological maturation process is still hypothetical and the molecular mechanism of the cleavage is not well documented. Crystallization of the hemagglutinin precursor (HA0) of influenza virus allowed further understanding of the molecular interaction between viral precursors and the cellular endoproteases

  20. Pseudorabies Virus pUL46 Induces Activation of ERK1/2 and Regulates Herpesvirus-Induced Nuclear Envelope Breakdown

    PubMed Central

    Schulz, Katharina S.; Liu, XueQiao; Klupp, Barbara G.; Granzow, Harald; Cohen, Jeffrey I.

    2014-01-01

    ABSTRACT Herpesvirus capsid morphogenesis occurs in the nucleus, while final maturation takes place in the cytosol, requiring translocation of capsids through the nuclear envelope. The nuclear egress complex, consisting of homologs of herpes simplex virus pUL31 and pUL34, is required for efficient nuclear egress via primary envelopment and de-envelopment. Recently, we described an alternative mode of nuclear escape by fragmentation of the nuclear envelope induced by replication-competent pUL31 and pUL34 deletion mutants of the alphaherpesvirus pseudorabies virus (PrV), which had been selected by serial passaging in cell culture. Both passaged viruses carry congruent mutations in seven genes, including UL46, which encodes one of the major tegument proteins. Herpesvirus pUL46 homologs have recently been shown to activate the PI3K-Akt and ERK1/2 signaling pathways, which are involved in regulation of mitosis and apoptosis. Since in uninfected cells fragmentation of the nuclear envelope occurs during mitosis and apoptosis, we analyzed whether pUL46 of PrV is involved in signaling events impairing the integrity of the nuclear envelope. We show here that PrV pUL46 is able to induce phosphorylation of ERK1/2 and, thus, expression of ERK1/2 target genes but fails to activate the PI3K-Akt pathway. Deletion of UL46 from PrV-ΔUL34Pass and PrV-ΔUL31Pass or replacement by wild-type UL46 resulted in enhanced nuclear envelope breakdown, indicating that the mutations in pUL46 may limit the extent of NEBD. Thus, although pUL46 induces ERK1/2 phosphorylation, controlling the integrity of the nuclear envelope is independent of the ERK1/2 signaling pathway. IMPORTANCE Herpesvirus nucleocapsids can leave the nucleus by regulated, vesicle-mediated transport through the nuclear envelope, designated nuclear egress, or by inducing nuclear envelope breakdown (NEBD). The viral proteins involved in NEBD are unknown. We show here that the pseudorabies virus tegument protein pUL46 induces the

  1. Diacylglycerol induces fusion of nuclear envelope membrane precursor vesicles.

    PubMed

    Barona, Teresa; Byrne, Richard D; Pettitt, Trevor R; Wakelam, Michael J O; Larijani, Banafshe; Poccia, Dominic L

    2005-12-16

    Purified membrane vesicles isolated from sea urchin eggs form nuclear envelopes around sperm nuclei following GTP hydrolysis in the presence of cytosol. A low density subfraction of these vesicles (MV1), highly enriched in phosphatidylinositol (PtdIns), is required for nuclear envelope formation. Membrane fusion of MV1 with a second fraction that contributes most of the nuclear envelope can be initiated without GTP by an exogenous bacterial PtdIns-specific phospholipase C (PI-PLC) which hydrolyzes PtdIns to form diacylglycerides and inositol 1-phosphate. This PI-PLC hydrolyzes a subset of sea urchin membrane vesicle PtdIns into diglycerides enriched in long chain, polyunsaturated species as revealed by a novel liquid chromatography-mass spectrometry analysis. Large unilammelar vesicles (LUVs) enriched in PtdIns can substitute for MV1 in PI-PLC induced nuclear envelope formation. Moreover, MV1 prehydrolyzed with PI-PLC and washed to remove inositols leads to spontaneous nuclear envelope formation with MV2 without further PI-PLC treatment. LUVs enriched in diacylglycerol mimic prehydrolyzed MV1. These results indicate that production of membrane-destabilizing diglycerides in membranes enriched in PtdIns may facilitate membrane fusion in a natural membrane system and suggest that MV1, which binds only to two places on the sperm nucleus, may initiate fusion locally.

  2. The South Carolina bridge-scour envelope curves

    USGS Publications Warehouse

    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.

  3. Application of the envelope difference index to spectrally sparse speech.

    PubMed

    Souza, Pamela; Hoover, Eric; Gallun, Frederick

    2012-06-01

    Amplitude compression is a common hearing aid processing strategy that can improve speech audibility and loudness comfort but also has the potential to alter important cues carried by the speech envelope. In previous work, a measure of envelope change, the Envelope Difference Index (EDI; Fortune, Woodruff, & Preves, 1994), was moderately related to recognition of spectrally robust consonants. This follow-up study investigated the relationship between the EDI and recognition of spectrally sparse consonants. Stimuli were vowel-consonant-vowel tokens processed to reduce spectral cues. Compression parameters were chosen to achieve a range of EDI values. Recognition was measured for 20 listeners with normal hearing. Both overall recognition and perception of consonant features were reduced at higher EDI values. Similar effects were noted with noise-vocoded and sine-vocoded processing and regardless of whether periodicity cues were available. The data provide information about the acceptable limits of envelope distortion under constrained conditions. These limits can be used to consider the impact of envelope distortions in situations where other cues are available to varying extents.

  4. The ionization structure of the circumstellar envelope of Alpha Orionis

    NASA Technical Reports Server (NTRS)

    Glassgold, A. E.; Huggins, P. J.

    1986-01-01

    The physical processes which affect the ionization of the outer circumstellar envelope of Alpha Ori are analyzed and evaluated. The ultraviolet radiation fields of the chromosphere and the interstellar medium dominate the envelope, and the most common forms of all species are neutral atoms and first ions. Hydrogen recombines just outside the chromosphere, where atoms with smaller ionization potential are essentially fully ionized. The heavier ions gradually recombine with increasing distance from the star, until the interstellar radiation field reverses this trend. The electron fraction in the outer envelope is approximately equal to the abundance of all such heavy atoms, i.e., of the order of 0.0001. The analysis is applied to the case of neutral K, whose density in the envelope has been determined by scattering experiments. The theory predicts that the slope of the K I density distribution should decrease from -1.5 to -3.5 in the outer envelope. The mass loss rate of Alpha Ori implied by the K I scattering experiments is 4 x 10 to the -6th solar mass/yr.

  5. Molecular biology of the baculovirus occlusion-derived virus envelope.

    PubMed

    Braunagel, Sharon C; Summers, Max D

    2007-10-01

    Study of the biology of the occlusion-derived virus (ODV) of the baculovirus Autographa californica nucleopolyhedrovirus provides opportunities to reveal new discoveries into the mechanism of several cellular pathways. The synchronous pulse of multiple ODV envelope proteins that integrate into the endoplasmic reticulum (ER) and traffic to the nuclear membranes on their way to the ODV envelope provide a unique tool to study the mechanisms of integral membrane protein trafficking from the ER to the outer and inner nuclear membrane. Studies of the formation of virus-induced, intranuclear membrane microvesicles provide insight on mechanisms that alter fluidity and regulate budding of the inner nuclear membrane. Since ODV is specially adapted for primary infection of the insect gut, studies of the structure and function of ODV envelope proteins reveals insights on the mechanism of viral invasion of the gut and this knowledge is fundamental for the development of new strategies for insect control. This review focuses on recent advances in understanding the source of the ODV envelope and the molecular events that sort and traffic integral membrane proteins from the ER to the ODV envelope. The composition of ODV is reviewed, however it is worth noting that the function of many ODV proteins are currently unknown.

  6. Virtual breakdown of the nuclear envelope in fission yeast meiosis.

    PubMed

    Asakawa, Haruhiko; Kojidani, Tomoko; Mori, Chie; Osakada, Hiroko; Sato, Mamiko; Ding, Da-Qiao; Hiraoka, Yasushi; Haraguchi, Tokuko

    2010-11-09

    Asymmetric localization of Ran regulators (RanGAP1 and RanGEF/RCC1) produces a gradient of RanGTP across the nuclear envelope. In higher eukaryotes, the nuclear envelope breaks down as the cell enters mitosis (designated "open" mitosis). This nuclear envelope breakdown (NEBD) leads to collapse of the RanGTP gradient and the diffusion of nuclear and cytoplasmic macromolecules in the cell, resulting in irreversible progression of the cell cycle. On the other hand, in many fungi, chromosome segregation takes place without NEBD (designated "closed" mitosis). Here we report that in the fission yeast Schizosaccharomyces pombe, despite the nuclear envelope and the nuclear pore complex remaining intact throughout both the meiotic and mitotic cell cycles, nuclear proteins diffuse into the cytoplasm transiently for a few minutes at the onset of anaphase of meiosis II. We also found that nuclear protein diffusion into the cytoplasm occurred coincidently with nuclear localization of Rna1, an S. pombe RanGAP1 homolog that is usually localized in the cytoplasm. These results suggest that nuclear localization of RanGAP1 and depression of RanGTP activity in the nucleus may be mechanistically tied to meiosis-specific diffusion of nuclear proteins into the cytoplasm. This nucleocytoplasmic shuffling of RanGAP1 and nuclear proteins represents virtual breakdown of the nuclear envelope.

  7. Optically thick envelopes around ULXs powered by accreating neutron stars

    NASA Astrophysics Data System (ADS)

    Mushtukov, Alexander A.; Suleimanov, Valery F.; Tsygankov, Sergey S.; Ingram, Adam

    2017-01-01

    Magnetized neutron stars power at least some ultra-luminous X-ray sources. The accretion flow in these cases is interrupted at the magnetospheric radius and then reaches the surface of a neutron star following magnetic field lines. Accreting matter moving along magnetic field lines forms the accretion envelope around the central object. We show that, in case of high mass accretion rates ≳ 1019 g s-1 the envelope becomes closed and optically thick, which influences the dynamics of the accretion flow and the observational manifestation of the neutron star hidden behind the envelope. Particularly, the optically thick accretion envelope results in a multi-color black-body spectrum originating from the magnetospheric surface. The spectrum and photon energy flux vary with the viewing angle, which gives rise to pulsations characterized by high pulsed fraction and typically smooth pulse profiles. The reprocessing of radiation due to interaction with the envelope leads to the disappearance of cyclotron scattering features from the spectrum. We speculate that the super-orbital variability of ultra-luminous X-ray sources powered by accreting neutron stars can be attributed to precession of the neutron star due to interaction of magnetic dipole with the accretion disc.

  8. Optically thick envelopes around ULXs powered by accreating neutron stars

    NASA Astrophysics Data System (ADS)

    Mushtukov, Alexander A.; Suleimanov, Valery F.; Tsygankov, Sergey S.; Ingram, Adam

    2017-05-01

    Magnetized neutron stars power at least some ultraluminous X-ray sources. The accretion flow in these cases is interrupted at the magnetospheric radius and then reaches the surface of a neutron star following magnetic field lines. Accreting matter moving along magnetic field lines forms the accretion envelope around the central object. We show that in case of high-mass accretion rates ≳ 1019 g s-1 the envelope becomes closed and optically thick, which influences the dynamics of the accretion flow and the observational manifestation of the neutron star hidden behind the envelope. Particularly, the optically thick accretion envelope results in a multi-colour blackbody spectrum originating from the magnetospheric surface. The spectrum and photon energy flux vary with the viewing angle, which gives rise to pulsations characterized by high pulsed fraction and typically smooth pulse profiles. The reprocessing of radiation due to interaction with the envelope leads to the disappearance of cyclotron scattering features from the spectrum. We speculate that the super-orbital variability of ultraluminous X-ray sources powered by accreting neutron stars can be attributed to precession of the neutron star due to interaction of magnetic dipole with the accretion disc.

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

    SciTech Connect

    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.

  10. COMPLEX STRUCTURE IN CLASS 0 PROTOSTELLAR ENVELOPES. III. VELOCITY GRADIENTS IN NON-AXISYMMETRIC ENVELOPES, INFALL, OR ROTATION?

    SciTech Connect

    Tobin, John J.; Hartmann, Lee; Bergin, Edwin; Chiang, Hsin-Fang; Looney, Leslie W.; Maret, Sebastien

    2012-03-20

    We present an interferometric kinematic study of morphologically complex protostellar envelopes based on observations of the dense gas tracers N{sub 2}H{sup +} and NH{sub 3}. The strong asymmetric nature of most envelopes in our sample leads us to question the common interpretation of velocity gradients as rotation, given the possibility of projection effects in the observed velocities. Several 'idealized' sources with well-ordered velocity fields and envelope structures are now analyzed in more detail. We compare the interferometric data to position-velocity (PV) diagrams of kinematic models for spherical rotating collapse and filamentary rotating collapse. For this purpose, we developed a filamentary parameterization of the rotating collapse model to explore the effects of geometric projection on the observed velocity structures. We find that most envelopes in our sample have PV structures that can be reproduced by an infalling filamentary envelope projected at different angles within the plane of the sky. The infalling filament produces velocity shifts across the envelope that can mimic rotation, especially when viewed at single-dish resolutions and the axisymmetric rotating collapse model does not uniquely describe any data set. Furthermore, if the velocities are assumed to reflect rotation, then the inferred centrifugal radii are quite large in most cases, indicating significant fragmentation potential or more likely another component to the line-center velocity. We conclude that ordered velocity gradients cannot be interpreted as rotation alone when envelopes are non-axisymmetric and that projected infall velocities likely dominate the velocity field on scales larger than 1000 AU.

  11. Large Scale RNAi Reveals the Requirement of Nuclear Envelope Breakdown for Nuclear Import of Human Papillomaviruses

    PubMed Central

    Snijder, Berend; Samperio Ventayol, Pilar; Kühbacher, Andreas; Becker, Miriam; Day, Patricia M.; Schiller, John T.; Kann, Michael; Pelkmans, Lucas; Helenius, Ari; Schelhaas, Mario

    2014-01-01

    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. PMID:24874089

  12. Untethering the Nuclear Envelope and Cytoskeleton: Biologically Distinct Dystonias Arising from a Common Cellular Dysfunction

    PubMed Central

    Atai, Nadia A.; Ryan, Scott D.; Kothary, Rashmi; Breakefield, Xandra O.; Nery, Flávia C.

    2012-01-01

    Most cases of early onset DYT1 dystonia in humans are caused by a GAG deletion in the TOR1A gene leading to loss of a glutamic acid (ΔE) in the torsinA protein, which underlies a movement disorder associated with neuronal dysfunction without apparent neurodegeneration. Mutation/deletion of the gene (Dst) encoding dystonin in mice results in a dystonic movement disorder termed dystonia musculorum, which resembles aspects of dystonia in humans. While torsinA and dystonin proteins do not share modular domain architecture, they participate in a similar function by modulating a structural link between the nuclear envelope and the cytoskeleton in neuronal cells. We suggest that through a shared interaction with the nuclear envelope protein nesprin-3α, torsinA and the neuronal dystonin-a2 isoform comprise a bridge complex between the outer nuclear membrane and the cytoskeleton, which is critical for some aspects of neuronal development and function. Elucidation of the overlapping roles of torsinA and dystonin-a2 in nuclear/endoplasmic reticulum dynamics should provide insights into the cellular mechanisms underlying the dystonic phenotype. PMID:22611399

  13. The nuclear envelope protein Nesprin-2 has roles in cell proliferation and differentiation during wound healing.

    PubMed

    Rashmi, R N; Eckes, Beate; Glöckner, Gernot; Groth, Marco; Neumann, Sascha; Gloy, Joachim; Sellin, Lorenz; Walz, Gerd; Schneider, Maria; Karakesisoglou, Iakowos; Eichinger, Ludwig; Noegel, Angelika A

    2012-03-01

    Nesprin-2, a type II transmembrane protein of the nuclear envelope, is a component of the LINC complex that connects the nuclear lamina with the actin cytoskeleton. To elucidate its physiological role we studied wound healing in Nesprin-2 Giant deficient mice and found that a loss of the protein affected wound healing particularly at later stages during fibroblast differentiation and keratinocyte proliferation leading to delayed wound closure. We identified altered expression and localization of transcription factors as one of the underlying mechanisms. Furthermore, the actin cytoskeleton which surrounds the nucleus was altered and keratinocyte migration was slowed down and focal adhesion formation enhanced. We also uncovered a new activity of Nesprin-2. When we probed for an interaction of Nesprin-2 Giant with chromatin we observed in ChIP Seq experiments an association of the protein with heterochromatic and centromeric DNA. Through this activity Nesprin-2 can affect the nuclear landscape and gene regulation. Our findings suggest functions for Nesprin-2 at the nuclear envelope (NE) in gene regulation and in regulation of the actin cytoskeleton which impact on wound healing.

  14. The Vibrio cholerae Cpx Envelope Stress Response Senses and Mediates Adaptation to Low Iron

    PubMed Central

    Acosta, Nicole; Pukatzki, Stefan

    2014-01-01

    The Cpx pathway, a two-component system that employs the sensor histidine kinase CpxA and the response regulator CpxR, regulates crucial envelope stress responses across bacterial species and affects antibiotic resistance. To characterize the CpxR regulon in Vibrio cholerae, the transcriptional profile of the pandemic V. cholerae El Tor C6706 strain was examined upon overexpression of cpxR. Our data show that the Cpx regulon of V. cholerae is enriched in genes encoding membrane-localized and transport proteins, including a large number of genes known or predicted to be iron regulated. Activation of the Cpx pathway further led to the expression of TolC, the major outer membrane pore, and of components of two RND efflux systems in V. cholerae. We show that iron chelation, toxic compounds, or deletion of specific RND efflux components leads to Cpx pathway activation. Furthermore, mutations that eliminate the Cpx response or members of its regulon result in growth phenotypes in the presence of these inducers that, together with Cpx pathway activation, are partially suppressed by iron. Cumulatively, our results suggest that a major function of the Cpx response in V. cholerae is to mediate adaptation to envelope perturbations caused by toxic compounds and the depletion of iron. PMID:25368298

  15. A Cytosine Methytransferase Modulates the Cell Envelope Stress Response in the Cholera Pathogen

    PubMed Central

    Chao, Michael C.; Zhu, Shijia; Kimura, Satoshi; Davis, Brigid M.; Schadt, Eric E.; Fang, Gang; Waldor, Matthew K.

    2015-01-01

    DNA methylation is a key epigenetic regulator in all domains of life, yet the effects of most bacterial DNA methyltransferases on cellular processes are largely undefined. Here, we used diverse techniques, including bisulfite sequencing, transcriptomics, and transposon insertion site sequencing to extensively characterize a 5-methylcytosine (5mC) methyltransferase, VchM, in the cholera pathogen, Vibrio cholerae. We have comprehensively defined VchM’s DNA targets, its genetic interactions and the gene networks that it regulates. Although VchM is a relatively new component of the V. cholerae genome, it is required for optimal V. cholerae growth in vitro and during infection. Unexpectedly, the usually essential σE cell envelope stress pathway is dispensable in ∆vchM V. cholerae, likely due to its lower activation in this mutant and the capacity for VchM methylation to limit expression of some cell envelope modifying genes. Our work illuminates how an acquired DNA methyltransferase can become integrated within complex cell circuits to control critical housekeeping processes. PMID:26588462

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

    PubMed

    Aydin, Inci; Weber, Susanne; Snijder, Berend; Samperio Ventayol, Pilar; Kühbacher, Andreas; Becker, Miriam; Day, Patricia M; Schiller, John T; Kann, Michael; Pelkmans, Lucas; Helenius, Ari; Schelhaas, Mario

    2014-05-01

    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.

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

    NASA Astrophysics Data System (ADS)

    Sangyuenyongpipat, S.; Yu, L. D.; Vilaithong, T.; Brown, I. G.

    2006-01-01

    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.

  18. The nuclear envelope protein Nesprin-2 has roles in cell proliferation and differentiation during wound healing

    PubMed Central

    Rashmi, R.N.; Eckes, Beate; Glöckner, Gernot; Groth, Marco; Neumann, Sascha; Gloy, Joachim; Sellin, Lorenz; Walz, Gerd; Schneider, Maria; Karakesisoglou, Iakowos; Eichinger, Ludwig; Noegel, Angelika A.

    2012-01-01

    Nesprin-2, a type II transmembrane protein of the nuclear envelope, is a component of the LINC complex that connects the nuclear lamina with the actin cytoskeleton. To elucidate its physiological role we studied wound healing in Nesprin-2 Giant deficient mice and found that a loss of the protein affected wound healing particularly at later stages during fibroblast differentiation and keratinocyte proliferation leading to delayed wound closure. We identified altered expression and localization of transcription factors as one of the underlying mechanisms. Furthermore, the actin cytoskeleton which surrounds the nucleus was altered and keratinocyte migration was slowed down and focal adhesion formation enhanced. We also uncovered a new activity of Nesprin-2. When we probed for an interaction of Nesprin-2 Giant with chromatin we observed in ChIP Seq experiments an association of the protein with heterochromatic and centromeric DNA. Through this activity Nesprin-2 can affect the nuclear landscape and gene regulation. Our findings suggest functions for Nesprin-2 at the nuclear envelope (NE) in gene regulation and in regulation of the actin cytoskeleton which impact on wound healing. PMID:22198684

  19. Method and apparatus for controlling carrier envelope phase

    DOEpatents

    Chang, Zenghu [Manhattan, KS; Li, Chengquan [Sunnyvale, CA; Moon, Eric [Manhattan, KS

    2011-12-06

    A chirped pulse amplification laser system. The system generally comprises a laser source, a pulse modification apparatus including first and second pulse modification elements separated by a separation distance, a positioning element, a measurement device, and a feedback controller. The laser source is operable to generate a laser pulse and the pulse modification apparatus operable to modify at least a portion of the laser pulse. The positioning element is operable to reposition at least a portion of the pulse modification apparatus to vary the separation distance. The measurement device is operable to measure the carrier envelope phase of the generated laser pulse and the feedback controller is operable to control the positioning element based on the measured carrier envelope phase to vary the separation distance of the pulse modification elements and control the carrier envelope phase of laser pulses generated by the laser source.

  20. Enveloped particles in the serum of chronic hepatitis C patients

    SciTech Connect

    Petit, Marie-Anne . E-mail: petit@lyon.inserm.fr; Lievre, Marjory . E-mail: marjory.lievre@free.fr; Peyrol, Simone . E-mail: peyrol@laennec.univ-lyon1.fr; De Sequeira, Sylvie . E-mail: desequeira@lyon.inserm.fr; Berthillon, Pascale . E-mail: berthillon@lyon.inserm.fr; Ruigrok, Rob W.H. . E-mail: ruigrok@embl-grenoble.fr; Trepo, Christian . E-mail: trepo@lyon.inserm.fr

    2005-06-05

    HCV particles were isolated from the plasma of chronically infected patients. The virus was analysed by sucrose density gradient centrifugation. The fractions were tested for viral RNA, core antigen and envelope proteins by using a monoclonal antibody directed against the natural E1E2 complex (D32.10). Two populations of particles containing RNA plus core antigen were separated: the first with a density of 1.06-1.08 g/ml did not contain the envelope proteins; the second with a density between 1.17 and 1.21 g/ml expressed both E1 and E2 glycoproteins. Electron microscopy of the enveloped population after immunoprecipitation with D32.10 showed spherical particles with a rather featureless surface and with a diameter around 40 nm. Immuno-gold staining gave evidence that the E1E2 complex was indeed positioned at the surface of these particles.

  1. Structure of Phage P22 Cell Envelope-Penetrating Needle

    SciTech Connect

    Olia, A.S.; Casjens, S.; Cingolani, G.

    2009-06-02

    Bacteriophage P22 infects Salmonella enterica by injecting its genetic material through the cell envelope. During infection, a specialized tail needle, gp26, is injected into the host, likely piercing a hole in the host cell envelope. The 2.1-{angstrom} crystal structure of gp26 reveals a 240-{angstrom} elongated protein fiber formed by two trimeric coiled-coil domains interrupted by a triple {beta}-helix. The N terminus of gp26 plugs the portal protein channel, retaining the genetic material inside the virion. The C-terminal tip of the fiber exposes {beta}-hairpins with hydrophobic tips similar to those seen in class II fusion peptides. The {alpha}-helical core connecting these two functionally polarized tips presents four trimerization octads with consensus sequence IXXLXXXV. The slender conformation of the gp26 fiber minimizes the surface exposed to solvent, which is consistent with the idea that gp26 traverses the cell envelope lipid bilayers.

  2. Is Sindbis a simple picornavirus with an envelope?

    PubMed Central

    Fuller, S D; Argos, P

    1987-01-01

    A three-dimensional image reconstruction was performed from cryo-electron micrographs of isolated Sindbis (SNV) nucleocapsids. The isolated capsid is a smooth but fenestrated T = 3 structure. Comparison with the nucleocapsid seen within the whole virion indicated that the structure resembles the swollen forms which some non-enveloped viruses adopt after removal of divalent cations. A sensitive comparison method was used to align SNV capsid protein sequences with those of picornavirus vp3 capsid proteins whose high resolution structures display an eight-stranded beta-barrel fold found in many icosahedral viruses. The alignment predicted a similar folding for the Sindbis protein which juxtaposes several sets of residues known to be essential for its serine proteolytic activity. These results suggest that the capsid proteins of the enveloped alphaviruses and the non-enveloped picornaviruses may have arisen through divergent evolution from a simple, vp3-like ancestor. Images Fig. 1. Fig. 2. PMID:3595557

  3. Photochemistry and molecular ions in carbon-rich circumstellar envelopes

    NASA Technical Reports Server (NTRS)

    Glassgold, A. E.; Mamon, G. A.; Omont, A.; Lucas, R.

    1987-01-01

    An earlier theory of ionization of C-rich circumstellar envelopes based on the photochemical model is extended to include the temperature dependence of ion-molecule reactions with polar molecules, particularly HCN, and line self-shielding of CO dissociating radiation. The results are applied to the abundances of HCO(+) and HNC in C-rich circumstellar envelopes. With standard parameters for IRC + 10216, the model is found to be consistent with the new upper limit to the antenna temperature of the J = 1-0 line of HCO(+) obtained with the IRAM 30-m telescope. The photochemical model provides a natural explanation of the relatively large ratio of HCN to HNC observed for C-rich circumstellar envelopes, and good agreement is obtained for the H(C-13)N/HNC antenna temperature ratio measured for IRC + 10216.

  4. Nuclear envelope fission is linked to cytokinesis in budding yeast.

    PubMed

    Lippincott, J; Li, R

    2000-11-01

    We have investigated the relationship between nuclear envelope fission and cytokinesis during mitotic cell division in budding yeast. By carrying out time-lapse and optical sectioning video microscopy analysis of cells that express green fluorescent protein (GFP)-tagged nuclear envelope and actomyosin ring components, we found that nuclear division is temporally coupled to cytokinesis. Light and electron microscopy analysis also showed that nuclear envelope fission and the division of the nucleoplasm are severely delayed in cytokinesis mutants, resulting in discoupling between the nuclear division cycle and the budding cycle. These results suggest that homotypic membrane fusion may be activated by components or the mechanical action of cytokinetic structures and presents a mechanism for the equal partitioning of the nucleus and the temporal coordination of this event with chromosome segregation during mitosis.

  5. Autopresentation of hepatitis B virus envelope antigens by T cells.

    PubMed Central

    Ferrari, C; Pilli, M; Penna, A; Bertoletti, A; Valli, A; Cavalli, A; Pasetti, G; Fiaccadori, F

    1992-01-01

    Processing and presentation by T cells appear to be limited to antigens that can directly interact with the T-cell surface, thereby overcoming the T-cell inefficiency in antigen capture and internalization. Our study provides evidence that the hepatitis B virus (HBV) envelope proteins can also be efficiently processed and presented by CD4+ and CD8+ T cells to other T cells in a human leukocyte antigen class II-restricted fashion. This phenomenon suggests a receptor-mediated interaction between T cells and the HBV envelope and defines a system that can, we hope, be exploited for the identification of the receptor binding site within the HBV envelope and for the characterization of the putative cellular HBV receptor. PMID:1548778

  6. Photochemistry and molecular ions in carbon-rich circumstellar envelopes

    NASA Technical Reports Server (NTRS)

    Glassgold, A. E.; Mamon, G. A.; Omont, A.; Lucas, R.

    1987-01-01

    An earlier theory of ionization of C-rich circumstellar envelopes based on the photochemical model is extended to include the temperature dependence of ion-molecule reactions with polar molecules, particularly HCN, and line self-shielding of CO dissociating radiation. The results are applied to the abundances of HCO(+) and HNC in C-rich circumstellar envelopes. With standard parameters for IRC + 10216, the model is found to be consistent with the new upper limit to the antenna temperature of the J = 1-0 line of HCO(+) obtained with the IRAM 30-m telescope. The photochemical model provides a natural explanation of the relatively large ratio of HCN to HNC observed for C-rich circumstellar envelopes, and good agreement is obtained for the H(C-13)N/HNC antenna temperature ratio measured for IRC + 10216.

  7. Second-order envelope equation of graphene electrons

    NASA Astrophysics Data System (ADS)

    Luo, Ji

    2014-10-01

    A treatment of graphene's electronic states based on the tight-binding method is presented. Like Dirac equation, this treatment uses envelope functions to eliminate crystal potential. Besides, a density-functional-theory Kohn-Sham (KS) orbital of an isolated carbon atom is employed. By locally expanding envelope functions into second-order polynomials and by involving up to third-nearest atoms in calculating orbital integrals, the second-order envelope equation is obtained. This equation does not contain any experimental data except graphene's crystal structure, and its coefficients are determined through several kinds of integrals of the carbon KS orbital. As an improvement, it leads to more accurate energy dispersion than Dirac equation including the triangular warping effect and asymmetry for electrons and holes, and gives the Fermi velocity which is in good agreement with the experimental value.

  8. Small non-spherical grains in envelopes of M giants

    NASA Astrophysics Data System (ADS)

    Il'In, V. B.

    1994-01-01

    The drift of spheroidal and spherical grains in the envelopes of M giants is considered. It is found that for small metallic grains, the velocity relative to the gas should strongly depend on the grain shape. For example, the velocity of a dirty iron spheroid with a semiaxes ratio of 2-4 is about 1.5-3 times larger than the velocity of an equal volume sphere, the difference of the velocities being as large as a 1 km/s. Probably, a dependence of the velocity on grain shape also occurs for normal size silicate grains. Thus, in modeling the dynamics of the envelopes, one should bear in mind the possibility of a much more efficient interaction of radiation with dust than usually proposed due to a deviation of grains' shape from a spherical one. The same effect could occur in the envelopes of carbon-rich giants and protostars.

  9. Structure of Phage P22 Cell Envelope-Penetrating Needle

    SciTech Connect

    Olia,A.; Casjens, S.; Cingolani, G.

    2007-01-01

    Bacteriophage P22 infects Salmonella enterica by injecting its genetic material through the cell envelope. During infection, a specialized tail needle, gp26, is injected into the host, likely piercing a hole in the host cell envelope. The 2.1-Angstroms crystal structure of gp26 reveals a 240-Angstroms elongated protein fiber formed by two trimeric coiled-coil domains interrupted by a triple beta-helix. The N terminus of gp26 plugs the portal protein channel, retaining the genetic material inside the virion. The C-terminal tip of the fiber exposes beta-hairpins with hydrophobic tips similar to those seen in class II fusion peptides. The alpha-helical core connecting these two functionally polarized tips presents four trimerization octads with consensus sequence IXXLXXXV. The slender conformation of the gp26 fiber minimizes the surface exposed to solvent, which is consistent with the idea that gp26 traverses the cell envelope lipid bilayers.

  10. Classification of oscillometric envelope shape using frequent sequence mining.

    PubMed

    Diao, Hung-Wen; Hu, Weichih; Lan, Gong-Yau; Shyu, Liang-Yu

    2013-01-01

    The shape of the oscillometric envelope is known to affect the accuracy of automatic noninvasive blood pressure (NIBP) measurement devices that use the oscillometric principle to determine systolic and diastolic blood pressures. This study proposes a novel shape classification method that uses data mining techniques to determine the characteristic sequences for different envelope shapes. The results indicate that the proposed method effectively determines the characteristic sequences for different subject groups. Subjects in the high- score group and in the low- score group tend to have an envelope with a broader plateau and are bell-shaped, respectively. This information about shape can be used for future determination of the correct algorithm for systolic and diastolic blood pressures determination in NIBP devices.

  11. Autoantibodies to nuclear envelope antigens in chronic fatigue syndrome.

    PubMed Central

    Konstantinov, K; von Mikecz, A; Buchwald, D; Jones, J; Gerace, L; Tan, E M

    1996-01-01

    We have identified and partially characterized the autoantibodies in sera of 60 patients with chronic fatigue syndrome. Approximately 52% of the sera were found to react with nuclear envelope antigens. The combination of nuclear rim staining observed in immunofluorescence microscopy and immunoblot analysis of highly purified nuclear envelope proteins provided initial characterization of these autoantibodies. Further characterization showed that some sera immunoprecipitated the in vitro transcription and translation product of a human cDNA clone encoding the nuclear envelope protein lamin B1. The autoantibodies were of the IgG isotype. The occurrence of autoantibodies to a conserved intracellular protein like lamin B1 provides new laboratory evidence for an autoimmune component in chronic fatigue syndrome. PMID:8878441

  12. Scattering Polarization of Arbitrary Envelopes by Anisotropic Stellar Illumination

    NASA Astrophysics Data System (ADS)

    Carson, J. C.; Ignace, R.

    2008-05-01

    We model the polarization arising from electron scattering of light by a circumstellar envelope of an arbitrary shape. This is accomplished by describing the scattering function, stellar flux, and envelope density distribution in general terms using spherical harmonics and then applying their orthogonality relationships in integral expressions that describe the net observed polarization. We then take a specific example of a uniform stellar light source surrounded by an ellipsoidal shell. As an example, a polarization of 25 percent is found for the case of a disk-like star that is viewed edge-on and that is surrounded by a a disk-like envelope oriented viewed face-on to the observer.

  13. The envelope Hamiltonian for electron interaction with ultrashort pulses

    NASA Astrophysics Data System (ADS)

    Toyota, Koudai; Saalmann, Ulf; Rost, Jan M.

    2015-07-01

    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 a 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.

  14. PAH formation in carbon-rich circumstellar envelopes

    NASA Technical Reports Server (NTRS)

    Feigelson, Eric D.; Frenklach, Michael

    1989-01-01

    While there is growing observational evidence that some fraction of interstellar carbon is in polycyclic aromatic hydrocarbons (PAH's), the mechanisms by which these molecules might be formed have not been extensively studied. A detailed investigation of PAH production in the outflowing molecular envelopes of carbon-rich red giant star is presented. The gasphase kinetics of a chemical reaction mechanism developed to study soot production in hydrocarbon flames is modified to apply in circumstellar environments. It was found that astrophysically significant quantities of PAH's can be formed in carbon star envelopes provided the gas is sufficiently dense and resides for a long time in the temperature range of 900 to 1100 k. The precise yield of PAH's is very sensitive to astronomical parameters of the envelope (e.g., mass loss rate, outflow velocity, and acetylene abundance) and certain poorly determined chemical reaction rates.

  15. Simulating the onset of grazing envelope evolution of binary stars

    NASA Astrophysics Data System (ADS)

    Shiber, Sagiv; Kashi, Amit; Soker, Noam

    2017-02-01

    We present the first three-dimensional gas-dynamical simulations of the grazing envelope evolution (GEE) of stars, 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.

  16. Efficiency of planetesimal ablation in giant planetary envelopes

    NASA Astrophysics Data System (ADS)

    Pinhas, Arazi; Madhusudhan, Nikku; Clarke, Cathie

    2016-12-01

    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-1 are found to ablate by ˜60-80 per cent 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.

  17. The Tracking of Speech Envelope in the Human Cortex

    PubMed Central

    Kubanek, Jan; Brunner, Peter; Gunduz, Aysegul; Poeppel, David; Schalk, Gerwin

    2013-01-01

    Humans are highly adept at processing speech. Recently, it has been shown that slow temporal information in speech (i.e., the envelope of speech) is critical for speech comprehension. Furthermore, it has been found that evoked electric potentials in human cortex are correlated with the speech envelope. However, it has been unclear whether this essential linguistic feature is encoded differentially in specific regions, or whether it is represented throughout the auditory system. To answer this question, we recorded neural data with high temporal resolution directly from the cortex while human subjects listened to a spoken story. We found that the gamma activity in human auditory cortex robustly tracks the speech envelope. The effect is so marked that it is observed during a single presentation of the spoken story to each subject. The effect is stronger in regions situated relatively early in the auditory pathway (belt areas) compared to other regions involved in speech processing, including the superior temporal gyrus (STG) and the posterior inferior frontal gyrus (Broca's region). To further distinguish whether speech envelope is encoded in the auditory system as a phonological (speech-related), or instead as a more general acoustic feature, we also probed the auditory system with a melodic stimulus. We found that belt areas track melody envelope weakly, and as the only region considered. Together, our data provide the first direct electrophysiological evidence that the envelope of speech is robustly tracked in non-primary auditory cortex (belt areas in particular), and suggest that the considered higher-order regions (STG and Broca's region) partake in a more abstract linguistic analysis. PMID:23408924

  18. A Mycobacterium tuberculosis Sigma Factor Network Responds to Cell-Envelope Damage by the Promising Anti-Mycobacterial Thioridazine

    PubMed Central

    Dutta, Noton K.; Mehra, Smriti; Kaushal, Deepak

    2010-01-01

    Background Novel therapeutics are urgently needed to control tuberculosis (TB). Thioridazine (THZ) is a candidate for the therapy of multidrug and extensively drug-resistant TB. Methodology/Principal Findings We studied the impact of THZ on Mycobacterium tuberculosis (Mtb) by analyzing gene expression profiles after treatment at the minimal inhibitory (1x MIC) or highly inhibitory (4x MIC) concentrations between 1–6 hours. THZ modulated the expression of genes encoding membrane proteins, efflux pumps, oxido-reductases and enzymes involved in fatty acid metabolism and aerobic respiration. The Rv3160c-Rv3161c operon, a multi-drug transporter and the Rv3614c/3615c/3616c regulon, were highly induced in response to THZ. A significantly high number of Mtb genes co-expressed with σB (the σB regulon) was turned on by THZ treatment. σB has recently been shown to protect Mtb from envelope-damage. We hypothesized that THZ damages the Mtb cell-envelope, turning on the expression of the σB regulon. Consistent with this hypothesis, we present electron-microscopy data which shows that THZ modulates cell-envelope integrity. Moreover, the Mtb mutants in σH and σE, two alternate stress response sigma factors that induce the expression of σB, exhibited higher sensitivity to THZ, indicating that the presence and expression of σB allows Mtb to resist the impact of THZ. Conditional induction of σB levels increased the survival of Mtb in the presence of THZ. Conclusions/Significance THZ targets different pathways and can thus be used as a multi-target inhibitor itself as well as provide strategies for multi-target drug development for combination chemotherapy. Our results show that the Mtb sigma factor network comprising of σH, σE and σB plays a crucial role in protecting the pathogen against cell-envelope damage. PMID:20386700

  19. The dynamic nature of the nuclear envelope: lessons from closed mitosis.

    PubMed

    Arnone, James T; Walters, Alison D; Cohen-Fix, Orna

    2013-01-01

    In eukaryotes, chromosomes are encased by a dynamic nuclear envelope. In contrast to metazoans, where the nuclear envelope disassembles during mitosis, many fungi including budding yeast undergo "closed mitosis," where the nuclear envelope remains intact throughout the cell cycle. Consequently, during closed mitosis the nuclear envelope must expand to accommodate chromosome segregation to the two daughter cells. A recent study by Witkin et al. in budding yeast showed that if progression through mitosis is delayed, for example due to checkpoint activation, the nuclear envelope continues to expand despite the block to chromosome segregation. Moreover, this expansion occurs at a specific region of the nuclear envelope- adjacent to the nucleolus- forming an extension referred to as a "flare." These observations raise questions regarding the regulation of nuclear envelope expansion both in budding yeast and in higher eukaryotes, the mechanisms confining mitotic nuclear envelope expansion to a particular region and the possible consequences of failing to regulate nuclear envelope expansion during the cell cycle.

  20. A Phase-Change Composite for Use in Building Envelopes

    SciTech Connect

    Graves, Ron S.

    1992-06-15

    The objective of this project is to develop composite thermal insulations containing phase-change materials for use in the building envelope. The use of a phase-change insulation composite in the building envelope could result in a significant increase in energy efficiency. PhD Research provided candidate phase-change composites, and ORNL performed analytical and experimental evaluations of their thermal performance. The thermal resistance of the prototype panels was somewhat less than that of commercial products, although their thermal capacity was greater. Using these results, PhD Research has been working to modify the design and to produce practical building elements that incorporate phase-change material.

  1. Planetesimal dissolution in the envelopes of the forming, giant planets

    NASA Technical Reports Server (NTRS)

    Pollack, J. B.; Podolak, M.; Bodenheimer, P.; Christofferson, B.

    1986-01-01

    An evaluation is made of the capacity of planetesimals to penetrate the envelopes of giant planets during their growth phase, by means of a core instability mechanism in which the growing core becomes gradually more adept in the gravitational concentration of gas from its solar nebula environment, until a runaway gas accretion occurs. If most of the accreted mass is contained in planetesimals larger that about 1 km, the critical core mass for runaway accretion will not significantly change when planetesimal dissolution is taken into account; it is accordingly suggested that giant planet envelopes should contain above-solar proportions of virtually all elements, relative to hydrogen.

  2. Maximum Torque and Momentum Envelopes for Reaction Wheel Arrays

    NASA Technical Reports Server (NTRS)

    Reynolds, R. G.; Markley, F. Landis

    2001-01-01

    Spacecraft reaction wheel maneuvers are limited by the maximum torque and/or angular momentum which 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 implementation strategies for specific wheel configurations are also considered.

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

    NASA Astrophysics Data System (ADS)

    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

  4. A spectral algorithm for envelope reduction of sparse matrices

    NASA Technical Reports Server (NTRS)

    Barnard, Stephen T.; Pothen, Alex; Simon, Horst D.

    1993-01-01

    A new algorithm for reducing the envelope of a sparse matrix is presented. This algorithm is based on the computation of eigenvectors of the Laplacian matrix associated with the graph of the sparse matrix. A reordering of the sparse matrix is determined based on the numerical values of the entries of an eigenvector of the Laplacian matrix. Numerical results show that the new reordering algorithm can in some cases reduce the envelope by more than a factor of two over the current standard algorithms such as Gibbs-Poole-Stockmeyer (GPS) or SPARSPAK's reverse Cuthill-McKee (RCM).

  5. HIV envelope: challenges and opportunities for development of entry inhibitors

    PubMed Central

    Caffrey, Michael

    2011-01-01

    The HIV envelope proteins gp120 and gp41 play critical roles in HIV entry and thus are of extreme interest for the development of novel therapeutics. Study by diverse methods, including structural biology and mutagenesis, has resulted in a detailed model for envelope-mediated entry, which consists of multiple conformations, each a potential target for therapeutic intervention. In this review we discuss the challenges, strategies and progress to date for developing novel entry inhibitors directed at disrupting HIV gp120 and gp41 function. PMID:21377881

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

    SciTech Connect

    Lawrence, Robert M.; Conrad, Chelsie E.; Zatsepin, Nadia A.; Grant, Thomas D.; Liu, Haiguang; James, Daniel; Nelson, Garrett; Subramanian, Ganesh; Aquila, Andrew; Hunter, Mark S.; Liang, Mengning; Boutet, Sébastien; Coe, Jesse; Spence, John C. H.; Weierstall, Uwe; Liu, Wei; Fromme, Petra; Cherezov, Vadim; Hogue, Brenda G.

    2015-08-20

    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 a pertinent step toward determining room temperature structures from virus microcrystals that may enable time-resolved studies of enveloped viruses.

  7. Planetesimal dissolution in the envelopes of the forming, giant planets

    NASA Technical Reports Server (NTRS)

    Pollack, J. B.; Podolak, M.; Bodenheimer, P.; Christofferson, B.

    1986-01-01

    An evaluation is made of the capacity of planetesimals to penetrate the envelopes of giant planets during their growth phase, by means of a core instability mechanism in which the growing core becomes gradually more adept in the gravitational concentration of gas from its solar nebula environment, until a runaway gas accretion occurs. If most of the accreted mass is contained in planetesimals larger that about 1 km, the critical core mass for runaway accretion will not significantly change when planetesimal dissolution is taken into account; it is accordingly suggested that giant planet envelopes should contain above-solar proportions of virtually all elements, relative to hydrogen.

  8. Role of Envelopment in the HEV Life Cycle

    PubMed Central

    Yin, Xin; Li, Xinlei; Feng, Zongdi

    2016-01-01

    Hepatitis E virus (HEV), an enterically transmitted hepatotropic virus, was thought to be non-enveloped for decades. However, recent studies have revealed that the virus circulating in the patient’s blood is completely cloaked in host membranes and resistant to neutralizing antibodies. The discovery of this novel enveloped form of HEV has raised a series of questions about the fundamental biology of HEV and the way this virus, which has been understudied in the past, interacts with its host. Here, we review recent advances towards understanding this phenomenon and discuss its potential impact on various aspects of the HEV life cycle and immunity. PMID:27548201

  9. Photochemistry and molecular ions in oxygen-rich circumstellar envelopes

    NASA Technical Reports Server (NTRS)

    Mamon, G. A.; Glassgold, A. E.; Omont, A.

    1987-01-01

    A theory for the ionization of the circumstellar envelopes around O-rich red giants is developed from the photochemical model. The main source of ionization is photoionization of H2O, OH, and C by the interstellar UV radiation field, supplemented by cosmic-ray ionization of hydrogen. Significant amounts of H3O(+) and HCO(+) are produced, with peak abundances of about 10 to the -7th at intermediate distances from the star. Although H3O(+) may be difficult to detect with current instrumentation, HCO(+) is probably detectable in nearby O-rich envelopes with large millimeter-wave telescopes.

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

    DOE PAGES

    Lawrence, Robert M.; Conrad, Chelsie E.; Zatsepin, Nadia A.; ...

    2015-08-20

    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 a pertinent step toward determining room temperature structures from virus microcrystals that may enable time-resolved studies of enveloped viruses.

  11. Selective Gammatone Envelope Feature for Robust Sound Event Recognition

    NASA Astrophysics Data System (ADS)

    Leng, Yi Ren; Tran, Huy Dat; Kitaoka, Norihide; Li, Haizhou

    Conventional features for Automatic Speech Recognition and Sound Event Recognition such as Mel-Frequency Cepstral Coefficients (MFCCs) have been shown to perform poorly in noisy conditions. We introduce an auditory feature based on the gammatone filterbank, the Selective Gammatone Envelope Feature (SGEF), for Robust Sound Event Recognition where channel selection and the filterbank envelope is used to reduce the effect of noise for specific noise environments. In the experiments with Hidden Markov Model (HMM) recognizers, we shall show that our feature outperforms MFCCs significantly in four different noisy environments at various signal-to-noise ratios.

  12. Photochemistry and molecular ions in oxygen-rich circumstellar envelopes

    NASA Technical Reports Server (NTRS)

    Mamon, G. A.; Glassgold, A. E.; Omont, A.

    1987-01-01

    A theory for the ionization of the circumstellar envelopes around O-rich red giants is developed from the photochemical model. The main source of ionization is photoionization of H2O, OH, and C by the interstellar UV radiation field, supplemented by cosmic-ray ionization of hydrogen. Significant amounts of H3O(+) and HCO(+) are produced, with peak abundances of about 10 to the -7th at intermediate distances from the star. Although H3O(+) may be difficult to detect with current instrumentation, HCO(+) is probably detectable in nearby O-rich envelopes with large millimeter-wave telescopes.

  13. Refractive index dispersion measurement using carrier-envelope phasemeters

    NASA Astrophysics Data System (ADS)

    Hansinger, Peter; Töpfer, Philipp; Dimitrov, Nikolay; Adolph, Daniel; Hoff, Dominik; Rathje, Tim; Sayler, A. Max; Dreischuh, Alexander; Paulus, Gerhard G.

    2017-02-01

    We introduce a novel method for direct and accurate measurement of refractive index dispersion based on carrier-envelope phase detection of few-cycle laser pulses, exploiting the difference between phase and group velocity in a dispersive medium. In a layout similar to an interferometer, two carrier-envelope phasemeters are capable of measuring the dispersion of a transparent or reflective sample, where one phasemeter serves as the reference and the other records the influence of the sample. Here we report on proof-of-principle measurements that already reach relative uncertainties of a few 10‑4. Further development is expected to allow for unprecedented precision.

  14. Immunohistochemistry on a panel of Emery-Dreifuss muscular dystrophy samples reveals nuclear envelope proteins as inconsistent markers for pathology.

    PubMed

    Le Thanh, Phu; Meinke, Peter; Korfali, Nadia; Srsen, Vlastimil; Robson, Michael I; Wehnert, Manfred; Schoser, Benedikt; Sewry, Caroline A; Schirmer, Eric C

    2017-04-01

    Reports of aberrant distribution for some nuclear envelope proteins in cells expressing a few Emery-Dreifuss muscular dystrophy mutations raised the possibility that such protein redistribution could underlie pathology and/or be diagnostic. However, this disorder is linked to 8 different genes encoding nuclear envelope proteins, raising the question of whether a particular protein is most relevant. Therefore, myoblast/fibroblast cultures from biopsy and tissue sections from a panel of nine Emery-Dreifuss muscular dystrophy patients (4 male, 5 female) including those carrying emerin and FHL1 (X-linked) and several lamin A (autosomal dominant) mutations were stained for the proteins linked to the disorder. As tissue-specific nuclear envelope proteins have been postulated to mediate the tissue-specific pathologies of different nuclear envelopathies, patient samples were also stained for several muscle-specific nuclear membrane proteins. Although linked proteins nesprin 1 and SUN2 and muscle-specific proteins NET5/Samp1 and Tmem214 yielded aberrant distributions in individual patient cells, none exhibited defects through the larger patient panel. Muscle-specific Tmem38A normally appeared in both the nuclear envelope and sarcoplasmic reticulum, but most patient samples exhibited a moderate redistribution favouring the sarcoplasmic reticulum. The absence of striking uniform defects in nuclear envelope protein distribution indicates that such staining will be unavailing for general diagnostics, though it remains possible that specific mutations exhibiting protein distribution defects might reflect a particular clinical variant. These findings further argue that multiple pathways can lead to the generally similar pathologies of this disorder while at the same time the different cellular phenotypes observed possibly may help explain the considerable clinical variation of EDMD.

  15. A previously uncharacterized tetratricopeptide-repeat-containing protein is involved in cell envelope function in Rhizobium leguminosarum.

    PubMed

    Neudorf, Kara D; Vanderlinde, Elizabeth M; Tambalo, Dinah D; Yost, Christopher K

    2015-01-01

    Rhizobium leguminosarum is a soil bacterium that is an intracellular symbiont of leguminous plants through the formation of nitrogen-fixing root nodules. Due to the changing environments that rhizobia encounter, the cell is often faced with a variety of cell altering stressors that can compromise the cell envelope integrity. A previously uncharacterized operon (RL3499-RL3502) has been linked to proper cell envelope function, and mutants display pleiotropic phenotypes including an inability to grow on peptide-rich media. In order to identify functional partners to the operon, suppressor mutants capable of growth on complex, peptide-rich media were isolated. A suppressor mutant of a non-polar mutation to RL3500 was chosen for further characterization. Transposon mutagenesis, screening for loss of the suppressor phenotype, led to the identification of a Tn5 insertion in an uncharacterized tetratricopeptide-repeat-containing protein RL0936. Furthermore, RL0936 had a 3.5-fold increase in gene expression in the suppressor strain when compared with the WT and a 1.5-fold increase in the original RL3500 mutant. Mutation of RL0936 decreased desiccation tolerance and lowered the ability to form biofilms when compared with the WT strain. This work has identified a potential interaction between RL0936 and the RL3499-RL3502 operon that is involved in cell envelope development in R. leguminosarum, and has described phenotypic activities to a previously uncharacterized conserved hypothetical gene. © 2015 The Authors.

  16. Herpes Simplex Virus 1 Protein UL37 Interacts with Viral Glycoprotein gK and Membrane Protein UL20 and Functions in Cytoplasmic Virion Envelopment

    PubMed Central

    Jambunathan, Nithya; Chouljenko, Dmitry; Desai, Prashant; Charles, Anu-Susan; Subramanian, Ramesh; Chouljenko, Vladimir N.

    2014-01-01

    ABSTRACT We have shown that glycoprotein K (gK) and its interacting partner, the UL20 protein, play crucial roles in virion envelopment. Specifically, virions lacking either gK or UL20 fail to acquire an envelope, thus causing accumulation of capsids in the cytoplasm of infected cells. The herpes simplex virus 1 (HSV-1) UL37 protein has also been implicated in cytoplasmic virion envelopment. To further investigate the role of UL37 in virion envelopment, the recombinant virus DC480 was constructed by insertion of a 12-amino-acid protein C (protC) epitope tag within the UL37 amino acid sequence immediately after amino acid 480. The DC480 mutant virus expressed full-size UL37 as detected by the anti-protC antibody in Western immunoblots, accumulated unenveloped capsids in the cytoplasm of infected cells, and produced very small plaques on African green monkey kidney (Vero) cells that were similar in size to those produced by the UL20-null and UL37-null viruses. The DC480 virus replicated nearly 4 log less efficiently than the parental wild-type virus when grown on Vero cells. However, DC480 mutant virus titers increased nearly 20-fold when the virus was grown on FRT cells engineered to express the UL20 gene in comparison to the titers on Vero cells, while the UL37-null virus replicated approximately 20-fold less efficiently than the DC480 virus on FRT cells. Coimmunoprecipitation experiments and proximity ligation assays showed that gK and UL20 interact with the UL37 protein in infected cells. Collectively, these results indicate that UL37 interacts with the gK-UL20 protein complex to facilitate cytoplasmic virion envelopment. IMPORTANCE Herpes simplex viruses acquire their final envelopes by budding into cytoplasmic membranes derived from the trans-Golgi network (TGN). The tegument proteins UL36 and UL37 are known to be transported to the TGN sites of virus envelopment and to function in virion envelopment, since mutants lacking UL37 accumulate capsids in the

  17. COMMON ENVELOPE EVOLUTION LEADING TO SUPERNOVAE WITH DENSE INTERACTION

    SciTech Connect

    Chevalier, Roger A.

    2012-06-10

    A variety of supernova events, including Type IIn supernovae and ultraluminous supernovae, appear to have lost up to solar masses of their envelopes in tens to hundreds of years leading up to the explosion. In order to explain the close timing of the mass loss and supernova events, we explore the possibility that the mass loss is driven by common envelope evolution of a compact object (neutron star or black hole) in the envelope of a massive star and the supernova is triggered by the inspiral of the compact object to the central core of the companion star. The expected rate of such events is smaller than the observed rate of Type IIn supernovae but the rates may agree within the uncertainties. The mass loss velocity is related to the escape velocity from the common envelope system and is comparable to the observed velocity of hundreds of kilometers per second in Type IIn events. The mass loss is expected to be denser near the equatorial plane of the binary system and there is good evidence that the circumstellar media in Type IIn supernovae are asymmetric. Some of these supernova types show evidence for energies in excess of the canonical 10{sup 51} erg, which might be the result of explosions from rapid accretion onto a compact object through a disk.

  18. The Two Envelope Problem: There Is No Conundrum

    ERIC Educational Resources Information Center

    Mitchell, S. L.; O'Brien, S. B. G.

    2014-01-01

    We consider the famous two envelope conundrum and show, in a very simple way, that there is no conundrum. Our discussion is supported by numerical simulations. We use the problem to raise the issue of disputes in mathematics, rarely touched upon in mathematics education. We suggest that it is worthwhile to expose students of mathematics to such…

  19. Envelopment technique and topographic overlays in bite mark analysis

    PubMed Central

    Djeapragassam, Parimala; Daniel, Mariappan Jonathan; Srinivasan, Subramanian Vasudevan; Ramadoss, Koliyan; Jimsha, Vannathan Kumaran

    2015-01-01

    Aims and Objectives: The aims and objectives of our study were to compare four sequential overlays generated using the envelopment technique and to evaluate inter- and intraoperator reliability of the overlays obtained by the envelopment technique. Materials and Methods: Dental stone models were prepared from impressions made from healthy individuals; photographs were taken and computer-assisted overlays were generated. The models were then enveloped in a different-color dental stone. After this, four sequential cuts were made at a thickness of 1mm each. Each sectional cut was photographed and overlays were generated. Thus, 125 overlays were generated and compared. Results: The scoring was done based on matching accuracy and the data were analyzed. The Kruskal-Wallis one-way analysis of variance (ANOVA) test was used to compare four sequential overlays and Spearman's rank correlation tests were used to evaluate the inter- and intraoperator reliability of the overlays obtained by the envelopment technique. Conclusion: Through our study, we conclude that the third and fourth cuts were the best among the four cuts and inter- and intraoperator reliability were found to be statistically significant at 5% level that is 95% confidence interval (P < 0.05). PMID:26816458

  20. Causes and consequences of nuclear envelope alterations in tumour progression.

    PubMed

    Bell, Emily S; Lammerding, Jan

    2016-11-01

    Morphological changes in the size and shape of the nucleus are highly prevalent in cancer, but the underlying molecular mechanisms and the functional relevance remain poorly understood. Nuclear envelope proteins, which can modulate nuclear shape and organization, have emerged as key components in a variety of signalling pathways long implicated in tumourigenesis and metastasis. The expression of nuclear envelope proteins is altered in many cancers, and changes in levels of nuclear envelope proteins lamins A and C are associated with poor prognosis in multiple human cancers. In this review we highlight the role of the nuclear envelope in different processes important for tumour initiation and cancer progression, with a focus on lamins A and C. Lamin A/C controls many cellular processes with key roles in cancer, including cell invasion, stemness, genomic stability, signal transduction, transcriptional regulation, and resistance to mechanical stress. In addition, we discuss potential mechanisms mediating the changes in lamin levels observed in many cancers. A better understanding of cause-and-effect relationships between lamin expression and tumour progression could reveal important mechanisms for coordinated regulation of oncogenic processes, and indicate therapeutic vulnerabilities that could be exploited for improved patient outcome.

  1. Two Improved Algorithms for Envelope and Wavefront Reduction

    NASA Technical Reports Server (NTRS)

    Kumfert, Gary; Pothen, Alex

    1997-01-01

    Two algorithms for reordering sparse, symmetric matrices or undirected graphs to reduce envelope and wavefront are considered. The first is a combinatorial algorithm introduced by Sloan and further developed by Duff, Reid, and Scott; we describe enhancements to the Sloan algorithm that improve its quality and reduce its run time. Our test problems fall into two classes with differing asymptotic behavior of their envelope parameters as a function of the weights in the Sloan algorithm. We describe an efficient 0(nlogn + m) time implementation of the Sloan algorithm, where n is the number of rows (vertices), and m is the number of nonzeros (edges). On a collection of test problems, the improved Sloan algorithm required, on the average, only twice the time required by the simpler Reverse Cuthill-Mckee algorithm while improving the mean square wavefront by a factor of three. The second algorithm is a hybrid that combines a spectral algorithm for envelope and wavefront reduction with a refinement step that uses a modified Sloan algorithm. The hybrid algorithm reduces the envelope size and mean square wavefront obtained from the Sloan algorithm at the cost of greater running times. We illustrate how these reductions translate into tangible benefits for frontal Cholesky factorization and incomplete factorization preconditioning.

  2. Nuclear envelope reformation and chromosome decondensation are dissociable events.

    PubMed

    Ghosh, S; Paweletz, N; Armas-Portela, R

    1988-06-01

    Cells treated with 2,4-dinitrophenol, a metabolic inhibitor, show a strong retardation of anaphase movement. At the ultrastructural level these cells reveal nuclear envelope reformation without concurrent decondensation of the chromosomes which indicates that these are possibly two dissociable late mitotic events.

  3. Arms Race between Enveloped Viruses and the Host ERAD Machinery

    PubMed Central

    Frabutt, Dylan A.; Zheng, Yong-Hui

    2016-01-01

    Enveloped viruses represent a significant category of pathogens that cause serious diseases in animals. These viruses express envelope glycoproteins that are singularly important during the infection of host cells by mediating fusion between the viral envelope and host cell membranes. Despite low homology at protein levels, three classes of viral fusion proteins have, as of yet, been identified based on structural similarities. Their incorporation into viral particles is dependent upon their proper sub-cellular localization after being expressed and folded properly in the endoplasmic reticulum (ER). However, viral protein expression can cause stress in the ER, and host cells respond to alleviate the ER stress in the form of the unfolded protein response (UPR); the effects of which have been observed to potentiate or inhibit viral infection. One important arm of UPR is to elevate the capacity of the ER-associated protein degradation (ERAD) pathway, which is comprised of host quality control machinery that ensures proper protein folding. In this review, we provide relevant details regarding viral envelope glycoproteins, UPR, ERAD, and their interactions in host cells. PMID:27657106

  4. A model for the sustainable selection of building envelope assemblies

    SciTech Connect

    Huedo, Patricia; Mulet, Elena; López-Mesa, Belinda

    2016-02-15

    The aim of this article is to define an evaluation model for the environmental impacts of building envelopes to support planners in the early phases of materials selection. The model is intended to estimate environmental impacts for different combinations of building envelope assemblies based on scientifically recognised sustainability indicators. These indicators will increase the amount of information that existing catalogues show to support planners in the selection of building assemblies. To define the model, first the environmental indicators were selected based on the specific aims of the intended sustainability assessment. Then, a simplified LCA methodology was developed to estimate the impacts applicable to three types of dwellings considering different envelope assemblies, building orientations and climate zones. This methodology takes into account the manufacturing, installation, maintenance and use phases of the building. Finally, the model was validated and a matrix in Excel was created as implementation of the model. - Highlights: • Method to assess the envelope impacts based on a simplified LCA • To be used at an earlier phase than the existing methods in a simple way. • It assigns a score by means of known sustainability indicators. • It estimates data about the embodied and operating environmental impacts. • It compares the investment costs with the costs of the consumed energy.

  5. 10 CFR 434.516 - Building exterior envelope.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... default assumptions for computing the Design Energy Consumption. The solar absorptivity of opaque elements... 10 Energy 3 2010-01-01 2010-01-01 false Building exterior envelope. 434.516 Section 434.516 Energy DEPARTMENT OF ENERGY ENERGY CONSERVATION ENERGY CODE FOR NEW FEDERAL COMMERCIAL AND MULTI-FAMILY HIGH RISE...

  6. 10 CFR 434.516 - Building exterior envelope.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... default assumptions for computing the Design Energy Consumption. The solar absorptivity of opaque elements... 10 Energy 3 2012-01-01 2012-01-01 false Building exterior envelope. 434.516 Section 434.516 Energy DEPARTMENT OF ENERGY ENERGY CONSERVATION ENERGY CODE FOR NEW FEDERAL COMMERCIAL AND MULTI-FAMILY HIGH RISE...

  7. 10 CFR 434.516 - Building exterior envelope.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... default assumptions for computing the Design Energy Consumption. The solar absorptivity of opaque elements... 10 Energy 3 2013-01-01 2013-01-01 false Building exterior envelope. 434.516 Section 434.516 Energy DEPARTMENT OF ENERGY ENERGY CONSERVATION ENERGY CODE FOR NEW FEDERAL COMMERCIAL AND MULTI-FAMILY HIGH RISE...

  8. 10 CFR 434.516 - Building exterior envelope.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... default assumptions for computing the Design Energy Consumption. The solar absorptivity of opaque elements... 10 Energy 3 2011-01-01 2011-01-01 false Building exterior envelope. 434.516 Section 434.516 Energy DEPARTMENT OF ENERGY ENERGY CONSERVATION ENERGY CODE FOR NEW FEDERAL COMMERCIAL AND MULTI-FAMILY HIGH RISE...

  9. Effects of masker envelope coherence on intensity discrimination

    PubMed Central

    Buss, Emily; Hall, Joseph W.

    2009-01-01

    Masked detection threshold for a pure tone signal depends on the coherence of masker envelope fluctuation across frequency, with lower thresholds for coherent fluctuation under some conditions. The benefit of coherent masker modulation is larger for detection than for suprathreshold tasks, such as pure tone intensity discrimination [Hall, J. W. and Grose, J. H. (1995). J. Acoust. Soc. Am. 98, 847–852]. In the present study, sensitivity to increments in signal intensity was measured for a 1000-Hz signal, either a tone or a 20-Hz-wide narrowband noise. In one set of conditions the masker was one or more bands of noise, each 20 Hz wide, and in another set of conditions the masker was a single 1620-Hz-wide band of Gaussian noise or noise multiplied by the envelope of a 20-Hz bandpass noise. Coherent masker envelope fluctuation improved detection thresholds in all conditions. Intensity discrimination for a tonal standard in comodulated noise was elevated for standard levels near detection threshold and improved with increasing signal-to-noise ratio, whereas performance was uniformly poor across level for the noise standard. Results are most consistent with the interpretation that the reduced benefit of coherent masker modulation in suprathreshold intensity discrimination is due to the disruptive effects of envelope fluctuation. PMID:19894827

  10. New tools for the analysis and design of building envelopes

    SciTech Connect

    Papamichael, K.; Winkelmann, F.C.; Buhl, W.F.; Chauvet, H.

    1994-08-01

    We describe the integrated development of PowerDOE, a new version of the DOE-2 building energy analysis program, and the Building Design Advisor (BDA), a multimedia-based design tool that assists building designers with the concurrent consideration of multiple design solutions with respect to multiple design criteria. PowerDOE has a windows-based Graphical User Interface (GUI) that makes it easier to use than DOE-2, while retaining DOE-2`s calculation power and accuracy. BDA, with a similar GUI, is designed to link to multiple analytical models and databases. In its first release it is linked to PowerDOE and a Daylighting Analysis Module, as well as to a Case Studies Database and a Schematic Graphic Editor. These allow building designers to set performance goals and address key building envelope parameters from the initial, schematic phases of building design to the detailed specification of building components and systems required by PowerDOE. The consideration of the thermal performance of building envelopes through PowerDOE and BDA is integrated with non-thermal envelope performance aspects, such as daylighting, as well as with the performance of non-envelope building components and systems, such as electric lighting and HVAC. Future versions of BDA will support links to CAD and electronic product catalogs, as well as provide context-dependent design advice to improve performance.

  11. Preparation of privatization samples for envelopes `A` and `C`

    SciTech Connect

    Winters, W.I., Westinghouse Hanford

    1996-07-17

    As part of the TWRS Privatization process, the DOE has committed to provide each of the two contractors who submitted successful bids with ten 125 mL samples of Hanford tank waste meeting chemical and radionuclide criteria specified as Waste Envelope A, B, and C. This test plan describes how the samples will be prepared before shipment.

  12. Hygrothermal Simulation: A Tool for Building Envelope Design Analysis

    Treesearch

    Samuel V. Glass; Anton TenWolde; Samuel L. Zelinka

    2013-01-01

    Is it possible to gauge the risk of moisture problems while designing the building envelope? This article provides a brief introduction to computer-based hygrothermal (heat and moisture) simulation, shows how simulation can be useful as a design tool, and points out a number of im-portant considerations regarding model inputs and limita-tions. Hygrothermal simulation...

  13. 14 CFR 29.1517 - Limiting height-speed envelope.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... AIRCRAFT AIRWORTHINESS STANDARDS: TRANSPORT CATEGORY ROTORCRAFT Operating Limitations and Information Operating Limitations § 29.1517 Limiting height-speed envelope. For Category A rotorcraft, if a range of... following power failure, the range of heights and its variation with forward speed must be...

  14. 14 CFR 29.1517 - Limiting height-speed envelope.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... AIRCRAFT AIRWORTHINESS STANDARDS: TRANSPORT CATEGORY ROTORCRAFT Operating Limitations and Information Operating Limitations § 29.1517 Limiting height-speed envelope. For Category A rotorcraft, if a range of... following power failure, the range of heights and its variation with forward speed must be...

  15. 14 CFR 29.1517 - Limiting height-speed envelope.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... AIRCRAFT AIRWORTHINESS STANDARDS: TRANSPORT CATEGORY ROTORCRAFT Operating Limitations and Information Operating Limitations § 29.1517 Limiting height-speed envelope. For Category A rotorcraft, if a range of... following power failure, the range of heights and its variation with forward speed must be...

  16. 14 CFR 29.1517 - Limiting height-speed envelope.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... AIRCRAFT AIRWORTHINESS STANDARDS: TRANSPORT CATEGORY ROTORCRAFT Operating Limitations and Information Operating Limitations § 29.1517 Limiting height-speed envelope. For Category A rotorcraft, if a range of... following power failure, the range of heights and its variation with forward speed must be...

  17. Spectral Envelopes and Additive + Residual Analysis/Synthesis

    NASA Astrophysics Data System (ADS)

    Rodet, Xavier; Schwarz, Diemo

    The subject of this chapter is the estimation, representation, modification, and use of spectral envelopes in the context of sinusoidal-additive-plus-residual analysis/synthesis. A spectral envelope is an amplitude-vs-frequency function, which may be obtained from the envelope of a short-time spectrum (Rodet et al., 1987; Schwarz, 1998). [Precise definitions of such an envelope and short-time spectrum (STS) are given in Section 2.] The additive-plus-residual analysis/synthesis method is based on a representation of signals in terms of a sum of time-varying sinusoids and of a non-sinusoidal residual signal [e.g., see Serra (1989), Laroche et al. (1993), McAulay and Quatieri (1995), and Ding and Qian (1997)]. Many musical sound signals may be described as a combination of a nearly periodic waveform and colored noise. The nearly periodic part of the signal can be viewed as a sum of sinusoidal components, called partials, with time-varying frequency and amplitude. Such sinusoidal components are easily observed on a spectral analysis display (Fig. 5.1) as obtained, for instance, from a discrete Fourier transform.

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

    PubMed

    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.

  19. Neural coding of sound envelope in reverberant environments.

    PubMed

    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.

  20. Modeling of heat and mass transfer in lateritic building envelopes

    NASA Astrophysics Data System (ADS)

    Meukam, Pierre; Noumowe, Albert

    2005-12-01

    The aim of the present work is to investigate the behavior of building envelopes made of local lateritic soil bricks subjected to different climatic conditions. The building envelopes studied in this work consist of lateritic soil bricks with incorporation of natural pozzolan or sawdust in order to obtain small thermal conductivity and low-density materials. In order to describe coupled heat and moisture transfer in wet porous materials, the coupled equations were solved by the introduction of diffusion coefficients. A numerical model HMtrans, developed for prediction of heat and moisture transfer in multi-layered building components, was used to simulate the temperature, water content and relative humidity profiles within the building envelopes. The results allow the prediction of the duration of the exposed building walls to the local weather conditions. They show that the durability of building envelopes made of lateritic soil bricks with incorporation of natural pozzolan or sawdust is not strongly affected by the climatic conditions in tropical and equatorial areas.

  1. Modification of selected South Carolina bridge-scour envelope curves

    USGS Publications Warehouse

    Benedict, Stephen T.; Caldwell, Andral W.

    2012-01-01

    Historic scour was investigated at 231 bridges in the Piedmont and Coastal Plain physiographic provinces of South Carolina by the U.S. Geological Survey in cooperation with the South Carolina Department of Transportation. These investigations led to the development of field-derived envelope curves that provided supplementary tools to assess the potential for scour at bridges in South Carolina for selected scour components that included clear-water abutment, contraction, and pier scour, and live-bed pier and contraction scour. The envelope curves consist of a single curve with one explanatory variable encompassing all of the measured field data for the respective scour components. In the current investigation, the clear-water abutment-scour and live-bed contraction-scour envelope curves were modified to include a family of curves that utilized two explanatory variables, providing a means to further refine the assessment of scour potential for those specific scour components. The modified envelope curves and guidance for their application are presented in this report.

  2. The Two Envelope Problem: There Is No Conundrum

    ERIC Educational Resources Information Center

    Mitchell, S. L.; O'Brien, S. B. G.

    2014-01-01

    We consider the famous two envelope conundrum and show, in a very simple way, that there is no conundrum. Our discussion is supported by numerical simulations. We use the problem to raise the issue of disputes in mathematics, rarely touched upon in mathematics education. We suggest that it is worthwhile to expose students of mathematics to such…

  3. Use and interpretation of climate envelope models: a practical guide

    USGS Publications Warehouse

    Watling, James I.; Brandt, Laura A.; Mazzotti, Frank J.; Romañach, Stephanie S.

    2013-01-01

    This guidebook is intended to provide a practical overview of climate envelope modeling for conservation professionals and natural resource managers. The material is intended for people with little background or experience in climate envelope modeling who want to better understand and interpret models developed by others and the results generated by such models, or want to do some modeling themselves. This is not an exhaustive review of climate envelope modeling, but rather a brief introduction to some key concepts in the discipline. Readers interested in a more in-depth treatment of much of the material presented here are referred to an excellent book, Mapping Species Distributions: Spatial Inference and Prediction by Janet Franklin. Also, a recent review (Araújo & Peterson 2012) provides an excellent, though more technical, discussion of many of the issues dealt with here. Here we treat selected topics from a practical perspective, using minimal jargon to explain and illustrate some of the many issues that one has to be aware of when using climate envelope models. When we do introduce specialized terminology in the guidebook, we bold the term when it is first used; a glossary of these terms is included at the back of the guidebook.

  4. Neural Coding of Sound Envelope in Reverberant Environments

    PubMed Central

    Slama, Michaël C.C.

    2015-01-01

    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. PMID:25762687

  5. Infalling Envelopes and Pre-Main Sequence Disks

    NASA Technical Reports Server (NTRS)

    Hartmann, Lee W.

    1997-01-01

    The goal of this project is to understand the observed infrared emission of young stellar objects, and explore the implications of this emission for the evolution of dusty envelopes and circumstellar disks. We are using sophisticated radiative transfer methods to compare models with observations, thereby making critical tests of the standard picture of low-mass star formation.

  6. Edge envelope equation for a ballistically focused neutralized ion beam

    SciTech Connect

    Lemons, D.S.; Thode, L.E.

    1980-11-01

    An envelope equation for a cold ion beam with overall charge and current neutralization provided by a coflowing electron gas obeying an adiabatic equation of state is derived. The derivation assumes the beam evolves self-similarly with the ion at the edge of a uniform density ion profile. Numerical and approximate analytical solutions are calculated.

  7. Dynamic Flight Envelope Assessment with Flight Safety Applications

    NASA Astrophysics Data System (ADS)

    Pandita, Rohit

    Aircraft have a manufacturer prescribed operating flight envelope for safe operation, exceeding these limits can result in unrecoverable departures or even structural failure. Numerous commercial aircraft accidents in the past have been attributed to loss-of-control (LOC) resulting from exceeding the safe operating flight envelope. Hence, real-time knowledge of the safe operating flight envelope is essential for safe flight operation, a problem known as dynamic flight envelope assessment. This dissertation explores dynamic flight envelope assessment from a control theoretic perspective. Two notions of the flight envelope, namely, the reachable sets and the region-of-attraction analysis are investigated. The NASA generic transport model (GTM) aircraft dynamics is used as an application problem. Linear and nonlinear techniques for flight envelope assessment are formulated in the linear matrix inequality (LMI) and sum-of-squares (SOS) framework, respectively. LMI and SOS problems are computationally tractable convex optimization problems for which many semi-definite programming solvers are available. This thesis also investigated fault detection and isolation strategies. Commercial jet transport aircrafts make extensive use of active controls. Faults or failures in the flight control system (FCS) elements like sensors or control effectors can lead to catastrophic failure. Model-based fault detection and isolation (FDI) filters can provide analytical redundancy by reliably detecting such faults in the system. Practical application of model-based FDI filters is limited so far due to poor performance, false alarms and missed detection arising out of uncertain dynamics of the aircraft, effect of nonlinearities in the system and the influence of closed-loop controllers. An application of closed-loop metrics to assess worst case FDI filter performance in the presence of a controller and uncertain dynamics is presented. Longitudinal GTM dynamics are considered. An Hinfinity

  8. Differentiation and ultrastructure of oncospheral and uterine envelopes in the nematotaeniid cestode, Nematotaenia dispar (Goeze, 1782).

    PubMed

    Swiderski, Z; Tkach, V

    1997-09-01

    The oncospheral envelopes of infective eggs in Nematotaenia dispar include the outer envelope with 2 sublayers, the inner envelope with a fibrillar embryophore and 2 cytoplasmic sublayers, and the oncospheral membrane. They differentiate from 3 primary embryonic envelopes, capsule, outer and inner envelope. The uterine envelopes are formed around the early embryos by processes of uterine epithelial cells, which surround the capsules. They degenerate rapidly in later stages; however, some structural components of the uterine envelopes were still visible in gravid proglottids as flattened perikarya with pyknotic, lobate nuclei, residual membranous structures and cellular debris situated usually between eggs. The following ultrastructural features of oncospheral envelopes differentiation appear to be characteristic for N. dispar: (1) lack of the outer capsule or shell in the fully mature eggs; (2) bi-layered structure of the outer envelope and tri-layered structure of the inner envelope; (3) absence of hook region membrane resulting probably from its early disintegration; (4) presence of small vesicles or "pits" incorporated into the inner envelope plasma membrane; (5) presence of densely packed microtubules in the external layer of the inner envelope; (6) changes in number of mitochondria and free ribosomes in the external and internal layers of inner envelope during egg maturation; and (7) probable "passage" of mitochondria and free ribosomes through the embryophoral pores in the developing eggs.

  9. Optimization of HIV-1 Envelope DNA Vaccine Candidates within Three Different Animal Models, Guinea Pigs, Rabbits and Cynomolgus Macaques

    PubMed Central

    Borggren, Marie; Vinner, Lasse; Andresen, Betina Skovgaard; Grevstad, Berit; Repits, Johanna; Melchers, Mark; Elvang, Tara Laura; Sanders, Rogier W; Martinon, Frédéric; Dereuddre-Bosquet, Nathalie; Bowles, Emma Joanne; Stewart-Jones, Guillaume; Biswas, Priscilla; Scarlatti, Gabriella; Jansson, Marianne; Heyndrickx, Leo; Le Grand, Roger; Fomsgaard, Anders

    2013-01-01

    HIV-1 DNA vaccines have many advantageous features. Evaluation of HIV-1 vaccine candidates often starts in small animal models before macaque and human trials. Here, we selected and optimized DNA vaccine candidates through systematic testing in rabbits for the induction of broadly neutralizing antibodies (bNAb). We compared three different animal models: guinea pigs, rabbits and cynomolgus macaques. Envelope genes from the prototype isolate HIV-1 Bx08 and two elite neutralizers were included. Codon-optimized genes, encoded secreted gp140 or membrane bound gp150, were modified for expression of stabilized soluble trimer gene products, and delivered individually or mixed. Specific IgG after repeated i.d. inoculations with electroporation confirmed in vivo expression and immunogenicity. Evaluations of rabbits and guinea pigs displayed similar results. The superior DNA construct in rabbits was a trivalent mix of non-modified codon-optimized gp140 envelope genes. Despite NAb responses with some potency and breadth in guinea pigs and rabbits, the DNA vaccinated macaques displayed less bNAb activity. It was concluded that a trivalent mix of non-modified gp140 genes from rationally selected clinical isolates was, in this study, the best option to induce high and broad NAb in the rabbit model, but this optimization does not directly translate into similar responses in cynomolgus macaques. PMID:26344115

  10. Choristoneura fumiferana Granulovirus p74 protein, a highly conserved baculoviral envelope protein.

    PubMed

    Rashidan, Kianoush Khajeh; Nassoury, Nasha; Tazi, Samia; Giannopoulos, Paresa N; Guertin, Claude

    2003-09-30

    A gene that encodes a homologue to baculoviral p74, an envelope-associated viral structural protein, has been identified and sequenced on the genome of Choristoneura fumiferana granulovirus (ChfuGV). A part of the ChfuGV p74 gene was located on an 8.9 kb BamHI subgenomic fragment using different sets of degenerated primers. These were designed using the results of the protein sequencing of a major 74 kDa structural protein that is associated with the occlusion-derived virus (ODV). The gene has a 1992 nucleotide (nt) open-reading frame (ORF) that encodes a protein with 663 amino acids with a predicted molecular mass of 74,812 Da. Comparative studies revealed the presence of two major conserved regions in the ChfuGV p74 protein. This study also shows that all of the p74 proteins contain two putative transmembrane domains at their C-terminal segments. At the nucleotide sequence level, two late promoter motifs (TAAG and GTAAG) were located upstream of the first ATG of the p74 gene. The gene contained a canonical poly(A) signal, AATAAA, at its 3 non-translated region. A phylogenetic tree for baculoviral p74 was constructed using a maximum parsimony analysis. The phylogenetic estimation demonstrated that ChfuGV p74 is related the closest to those of Cydia pomonella granulovirus (CpGV) and Phthorimaea operculella granulovirus (PhopGV).

  11. FILAMENTARY STAR FORMATION: OBSERVING THE EVOLUTION TOWARD FLATTENED ENVELOPES

    SciTech Connect

    Lee, Katherine; Looney, Leslie; Johnstone, Doug; Tobin, John E-mail: lwl@illinois.edu E-mail: jtobin@nrao.edu

    2012-12-20

    Filamentary structures are ubiquitous from large-scale molecular clouds (a few parsecs) to small-scale circumstellar envelopes around Class 0 sources ({approx}1000 AU to {approx}0.1 pc). In particular, recent observations with the Herschel Space Observatory emphasize the importance of large-scale filaments (a few parsecs) and star formation. The small-scale flattened envelopes around Class 0 sources are reminiscent of the large-scale filaments. We propose an observationally derived scenario for filamentary star formation that describes the evolution of filaments as part of the process for formation of cores and circumstellar envelopes. If such a scenario is correct, small-scale filamentary structures (0.1 pc in length) with higher densities embedded in starless cores should exist, although to date almost all the interferometers have failed to observe such structures. We perform synthetic observations of filaments at the prestellar stage by modeling the known Class 0 flattened envelope in L1157 using both the Combined Array for Research in Millimeter-wave Astronomy (CARMA) and the Atacama Large Millimeter/Submillimeter Array (ALMA). We show that with reasonable estimates for the column density through the flattened envelope, the CARMA D array at 3 mm wavelengths is not able to detect such filamentary structure, so previous studies would not have detected them. However, the substructures may be detected with the CARMA D+E array at 3 mm and the CARMA E array at 1 mm as a result of more appropriate resolution and sensitivity. ALMA is also capable of detecting the substructures and showing the structures in detail compared to the CARMA results with its unprecedented sensitivity. Such detection will confirm the new proposed paradigm of non-spherical star formation.

  12. Metal cladding envelope problems, retrofit solutions, and quality control investigations

    NASA Astrophysics Data System (ADS)

    Colantonio, Antonio

    1992-04-01

    This paper deals with a case study of a building envelope retrofit of an insulated sheet steel and corrugated metal clad building. The building in discussion is a satellite testing facility which requires specific clean room conditions with controlled interior temperature (22 degree(s)C +/- 1 degree(s)C) and high relative humidity conditions (45% +/- 3%) to facilitate satellite testing programs. Preliminary mechanical system inspections indicated substantial increase in air intake to make up for air leakage losses. An infrared inspection along with an approximate air leakage test of the building envelope was requested by the client to determine the magnitude of the building envelope problem. This investigation concluded that significant air leakage was present throughout the building envelope and that existing mechanical systems did not have sufficient capacity to pressurize the building and negate wind and stack effect. Exfiltration particularly through openings on the top sections of the building were causing interior moisture to saturate wall insulation and render it ineffective. Concern for rusting of metal components was indicated. The subsequent envelope analysis discovered a number of typical metal building details that led to poor air tightness and wall insulation ineffectiveness. These were correlated to infrared investigation data. The retrofit solutions produced for this building not only apply to this building but to other similar building types. Further investigations indicated that air leakage and mechanical system performance were significant problems with buildings using metal cladding systems comparable to this building. Quality control before, during and after construction was identified as an important function of the architectural commissioning of the retrofit work and infrared investigations were used to verify locations of air leakage and insulation effectiveness.

  13. Antigenic Properties of the HIV Envelope on Virions in Solution

    PubMed Central

    Mengistu, Meron; Lewis, George K.; Lakowicz, Joseph R.

    2014-01-01

    The structural flexibility found in human immunodeficiency virus (HIV) envelope glycoproteins creates a complex relationship between antigenicity and sensitivity to antiviral antibodies. The study of this issue in the context of viral particles is particularly problematic as conventional virus capture approaches can perturb antigenicity profiles. Here, we employed a unique analytical system based on fluorescence correlation spectroscopy (FCS), which measures antibody-virion binding with all reactants continuously in solution. Panels of nine anti-envelope monoclonal antibodies (MAbs) and five virus types were used to connect antibody binding profiles with neutralizing activities. Anti-gp120 MAbs against the 2G12 or b12 epitope, which marks functional envelope structures, neutralized viruses expressing CCR5-tropic envelopes and exhibited efficient virion binding in solution. MAbs against CD4-induced (CD4i) epitopes considered hidden on functional envelope structures poorly bound these viruses and were not neutralizing. Anti-gp41 MAb 2F5 was neutralizing despite limited virion binding. Similar antigenicity patterns occurred on CXCR4-tropic viruses, except that anti-CD4i MAbs 17b and 19e were neutralizing despite little or no virion binding. Notably, anti-gp120 MAb PG9 and anti-gp41 MAb F240 bound to both CCR5-tropic and CXCR4-tropic viruses without exerting neutralizing activity. Differences in the virus production system altered the binding efficiencies of some antibodies but did not enhance antigenicity of aberrant gp120 structures. Of all viruses tested, only JRFL pseudoviruses showed a direct relationship between MAb binding efficiency and neutralizing potency. Collectively, these data indicate that the antigenic profiles of free HIV particles generally favor the exposure of functional over aberrant gp120 structures. However, the efficiency of virion-antibody interactions in solution inconsistently predicts neutralizing activity in vitro. PMID:24284318

  14. Probability distributions of the electroencephalogram envelope of preterm infants.

    PubMed

    Saji, Ryoya; Hirasawa, Kyoko; Ito, Masako; Kusuda, Satoshi; Konishi, Yukuo; Taga, Gentaro

    2015-06-01

    To determine the stationary characteristics of electroencephalogram (EEG) envelopes for prematurely born (preterm) infants and investigate the intrinsic characteristics of early brain development in preterm infants. Twenty neurologically normal sets of EEGs recorded in infants with a post-conceptional age (PCA) range of 26-44 weeks (mean 37.5 ± 5.0 weeks) were analyzed. Hilbert transform was applied to extract the envelope. We determined the suitable probability distribution of the envelope and performed a statistical analysis. It was found that (i) the probability distributions for preterm EEG envelopes were best fitted by lognormal distributions at 38 weeks PCA or less, and by gamma distributions at 44 weeks PCA; (ii) the scale parameter of the lognormal distribution had positive correlations with PCA as well as a strong negative correlation with the percentage of low-voltage activity; (iii) the shape parameter of the lognormal distribution had significant positive correlations with PCA; (iv) the statistics of mode showed significant linear relationships with PCA, and, therefore, it was considered a useful index in PCA prediction. These statistics, including the scale parameter of the lognormal distribution and the skewness and mode derived from a suitable probability distribution, may be good indexes for estimating stationary nature in developing brain activity in preterm infants. The stationary characteristics, such as discontinuity, asymmetry, and unimodality, of preterm EEGs are well indicated by the statistics estimated from the probability distribution of the preterm EEG envelopes. Copyright © 2014 International Federation of Clinical Neurophysiology. Published by Elsevier Ireland Ltd. All rights reserved.

  15. The autographa californica multiple nucleopolyhedrovirus ODV-E56 envelope protein is required for oral infectivity and can be functionally substituted by rachiplusia ou multiple nucleopolyhedrovirus ODV-E56

    USDA-ARS?s Scientific Manuscript database

    The Autographa californica multiple nucleopolyhedrovirus (AcMNPV) odv-e56 gene encodes an occlusion-derived virus (ODV)-specific envelope protein, ODV-E56. In a previous analysis, the odv-e56 gene was found to be under positive selection pressure, suggesting that it may be a determinant of viral ho...

  16. Identification and analysis of an Autographa californica nuclear polyhedrosis virus structural protein of the occlusion-derived virus envelope: ODV-E56.

    PubMed

    Braunagel, S C; Elton, D M; Ma, H; Summers, M D

    1996-03-01

    An Autographa californica nuclear polyhedrosis virus gene encoding an occlusion-derived virus (ODV) envelope protein of 56 kDa was identified and sequenced. Transcription initiates from a conserved baculovirus late motif (ATAAG) with transcripts detected from 16 through 72 hr p.i. The protein is detected in infected cell extracts from 36 hr p.i. Western blot assay of ODV, BV, viral envelope, and nucleocapsid preparations coupled with immunoelectron microscopy reveal that this protein localizes to the ODV envelope. This protein is named ODV-E56 to identify its viral origin, envelope location, and apparent molecular weight. ODV-E56 is enriched in viral induced intranuclear microvesicles as determined by immunogold labeling. A mutant was constructed with the C-terminal portion of the protein replaced with beta-galactosidase. The fusion protein, E56-beta-gal, locates to the viral nucleocapsids and not to the ODV envelope or intranuclear microvesicles. This suggests that the signals necessary for transport and/or retention into these structures lies within the C-terminal portion of ODV-E56. Additionally, both ODV-E56 and E56-beta-gal are enriched in electron dense regions that cluster around the inner nuclear membrane and within the nucleoplasm.

  17. Insights into the Function of YciM, a Heat Shock Membrane Protein Required To Maintain Envelope Integrity in Escherichia coli

    PubMed Central

    Nicolaes, Valérie; El Hajjaji, Hayat; Davis, Rebecca M.; Van der Henst, Charles; Depuydt, Matthieu; Leverrier, Pauline; Aertsen, Abram; Haufroid, Vincent; Ollagnier de Choudens, Sandrine; De Bolle, Xavier; Ruiz, Natividad

    2013-01-01

    The cell envelope of Gram-negative bacteria is an essential organelle that is important for cell shape and protection from toxic compounds. Proteins involved in envelope biogenesis are therefore attractive targets for the design of new antibacterial agents. In a search for new envelope assembly factors, we screened a collection of Escherichia coli deletion mutants for sensitivity to detergents and hydrophobic antibiotics, a phenotype indicative of defects in the cell envelope. Strains lacking yciM were among the most sensitive strains of the mutant collection. Further characterization of yciM mutants revealed that they display a thermosensitive growth defect on low-osmolarity medium and that they have a significantly altered cell morphology. At elevated temperatures, yciM mutants form bulges containing cytoplasmic material and subsequently lyse. We also discovered that yciM genetically interacts with envC, a gene encoding a regulator of the activity of peptidoglycan amidases. Altogether, these results indicate that YciM is required for envelope integrity. Biochemical characterization of the protein showed that YciM is anchored to the inner membrane via its N terminus, the rest of the protein being exposed to the cytoplasm. Two CXXC motifs are present at the C terminus of YciM and serve to coordinate a redox-sensitive iron center of the rubredoxin type. Both the N-terminal membrane anchor and the C-terminal iron center of YciM are important for function. PMID:24187084

  18. The Consonant-Weighted Envelope Difference Index (cEDI): A Proposed Technique for Quantifying Envelope Distortion

    ERIC Educational Resources Information Center

    Hoover, Eric C.; Souza, Pamela E.; Gallun, Frederick J.

    2012-01-01

    Purpose: The benefits of amplitude compression in hearing aids may be limited by distortion resulting from rapid gain adjustment. To evaluate this, it is convenient to quantify distortion by using a metric that is sensitive to the changes in the processed signal that decrease consonant recognition, such as the Envelope Difference Index (EDI;…

  19. The Consonant-Weighted Envelope Difference Index (cEDI): A Proposed Technique for Quantifying Envelope Distortion

    ERIC Educational Resources Information Center

    Hoover, Eric C.; Souza, Pamela E.; Gallun, Frederick J.

    2012-01-01

    Purpose: The benefits of amplitude compression in hearing aids may be limited by distortion resulting from rapid gain adjustment. To evaluate this, it is convenient to quantify distortion by using a metric that is sensitive to the changes in the processed signal that decrease consonant recognition, such as the Envelope Difference Index (EDI;…

  20. Guanylate binding protein 5: Impairing virion infectivity by targeting retroviral envelope glycoproteins.

    PubMed

    Hotter, Dominik; Sauter, Daniel; Kirchhoff, Frank

    2017-01-02

    Guanylate binding proteins (GBPs) are interferon-inducible cellular factors that belong to the superfamily of guanosine triphosphatases (GTPases) and play important roles in the cell-intrinsic defense against bacteria, protozoa and viruses. In a recent report in Cell Host & Microbe, we identify GBP5 as novel restriction factor of HIV-1 that reduces the infectivity of progeny virions by interfering with processing and incorporation of the viral envelope (Env) glycoprotein. The inhibitory activity of GBP5 requires C-terminal isoprenylation, mediating Golgi-association, but not its GTPase function. Notably, GBP5 expression levels vary considerably in human macrophages and inversely correlate with infectious virus yield. We demonstrate that GBP5 can be evaded by an unusual tradeoff mechanism: Naturally occurring mutations in the start codon of the viral accessory gene vpu attenuate GBP5 inhibition by increasing Env expression at the cost of Vpu function. Whether direct counteraction mechanisms or more subtle changes balancing Vpu and Env expression also affect HIV-1 inhibition by GBP5 remains to be clarified. Other open questions are whether GBP5 restricts HIV-1 in CD4(+) T cells and if other GBP family members also decrease infectivity of HIV and/or additional enveloped viruses.

  1. Cell envelope stress response in cell wall-deficient L-forms of Bacillus subtilis.

    PubMed

    Wolf, Diana; Domínguez-Cuevas, Patricia; Daniel, Richard A; Mascher, Thorsten

    2012-11-01

    L-forms are cell wall-deficient bacteria that can grow and proliferate in osmotically stabilizing media. Recently, a strain of the Gram-positive model bacterium Bacillus subtilis was constructed that allowed controlled switching between rod-shaped wild-type cells and corresponding L-forms. Both states can be stably maintained under suitable culture conditions. Because of the absence of a cell wall, L-forms are known to be insensitive to β-lactam antibiotics, but reports on the susceptibility of L-forms to other antibiotics that interfere with membrane-anchored steps of cell wall biosynthesis are sparse, conflicting, and strongly influenced by strain background and method of L-form generation. Here we investigated the response of B. subtilis to the presence of cell envelope antibiotics, with regard to both antibiotic resistance and the induction of the known LiaRS- and BceRS-dependent cell envelope stress biosensors. Our results show that B. subtilis L-forms are resistant to antibiotics that interfere with the bactoprenol cycle, such as bacitracin, vancomycin, and mersacidin, but are hypersensitive to nisin and daptomycin, which both affect membrane integrity. Moreover, we established a lacZ-based reporter gene assay for L-forms and provide evidence that LiaRS senses its inducers indirectly (damage sensing), while the Bce module detects its inducers directly (drug sensing).

  2. Guanylate binding protein 5: Impairing virion infectivity by targeting retroviral envelope glycoproteins

    PubMed Central

    Hotter, Dominik; Sauter, Daniel; Kirchhoff, Frank

    2017-01-01

    ABSTRACT Guanylate binding proteins (GBPs) are interferon-inducible cellular factors that belong to the superfamily of guanosine triphosphatases (GTPases) and play important roles in the cell-intrinsic defense against bacteria, protozoa and viruses. In a recent report in Cell Host & Microbe, we identify GBP5 as novel restriction factor of HIV-1 that reduces the infectivity of progeny virions by interfering with processing and incorporation of the viral envelope (Env) glycoprotein. The inhibitory activity of GBP5 requires C-terminal isoprenylation, mediating Golgi-association, but not its GTPase function. Notably, GBP5 expression levels vary considerably in human macrophages and inversely correlate with infectious virus yield. We demonstrate that GBP5 can be evaded by an unusual tradeoff mechanism: Naturally occurring mutations in the start codon of the viral accessory gene vpu attenuate GBP5 inhibition by increasing Env expression at the cost of Vpu function. Whether direct counteraction mechanisms or more subtle changes balancing Vpu and Env expression also affect HIV-1 inhibition by GBP5 remains to be clarified. Other open questions are whether GBP5 restricts HIV-1 in CD4+ T cells and if other GBP family members also decrease infectivity of HIV and/or additional enveloped viruses. PMID:27275775

  3. Cell Envelope Stress Response in Cell Wall-Deficient L-Forms of Bacillus subtilis

    PubMed Central

    Wolf, Diana; Domínguez-Cuevas, Patricia; Daniel, Richard A.

    2012-01-01

    L-forms are cell wall-deficient bacteria that can grow and proliferate in osmotically stabilizing media. Recently, a strain of the Gram-positive model bacterium Bacillus subtilis was constructed that allowed controlled switching between rod-shaped wild-type cells and corresponding L-forms. Both states can be stably maintained under suitable culture conditions. Because of the absence of a cell wall, L-forms are known to be insensitive to β-lactam antibiotics, but reports on the susceptibility of L-forms to other antibiotics that interfere with membrane-anchored steps of cell wall biosynthesis are sparse, conflicting, and strongly influenced by strain background and method of L-form generation. Here we investigated the response of B. subtilis to the presence of cell envelope antibiotics, with regard to both antibiotic resistance and the induction of the known LiaRS- and BceRS-dependent cell envelope stress biosensors. Our results show that B. subtilis L-forms are resistant to antibiotics that interfere with the bactoprenol cycle, such as bacitracin, vancomycin, and mersacidin, but are hypersensitive to nisin and daptomycin, which both affect membrane integrity. Moreover, we established a lacZ-based reporter gene assay for L-forms and provide evidence that LiaRS senses its inducers indirectly (damage sensing), while the Bce module detects its inducers directly (drug sensing). PMID:22964256

  4. 40 CFR 426.110 - Applicability; description of the television picture tube envelope manufacturing subcategory.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... television picture tube envelope manufacturing subcategory. 426.110 Section 426.110 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) EFFLUENT GUIDELINES AND STANDARDS (CONTINUED) GLASS MANUFACTURING POINT SOURCE CATEGORY Television Picture Tube Envelope Manufacturing Subcategory § 426.110...

  5. 40 CFR 426.120 - Applicability; description of the incandescent lamp envelope manufacturing subcategory.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

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

  6. 40 CFR 426.110 - Applicability; description of the television picture tube envelope manufacturing subcategory.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... television picture tube envelope manufacturing subcategory. 426.110 Section 426.110 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) EFFLUENT GUIDELINES AND STANDARDS (CONTINUED) GLASS MANUFACTURING POINT SOURCE CATEGORY Television Picture Tube Envelope Manufacturing Subcategory § 426.110...

  7. 40 CFR 426.120 - Applicability; description of the incandescent lamp envelope manufacturing subcategory.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

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

  8. 40 CFR 426.120 - Applicability; description of the incandescent lamp envelope manufacturing subcategory.

    Code of Federal Regulations, 2010 CFR

    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...

  9. 40 CFR 426.110 - Applicability; description of the television picture tube envelope manufacturing subcategory.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... television picture tube envelope manufacturing subcategory. 426.110 Section 426.110 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) EFFLUENT GUIDELINES AND STANDARDS (CONTINUED) GLASS MANUFACTURING POINT SOURCE CATEGORY Television Picture Tube Envelope Manufacturing Subcategory § 426.110...

  10. 40 CFR 426.120 - Applicability; description of the incandescent lamp envelope manufacturing subcategory.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 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...

  11. 40 CFR 426.120 - Applicability; description of the incandescent lamp envelope manufacturing subcategory.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

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

  12. Feline immunodeficiency virus envelope glycoproteins antagonize tetherin through a distinctive mechanism that requires virion incorporation.

    PubMed

    Morrison, James H; Guevara, Rebekah B; Marcano, Adriana C; Saenz, Dyana T; Fadel, Hind J; Rogstad, Daniel K; Poeschla, Eric M

    2014-03-01

    BST2/tetherin inhibits the release of enveloped viruses from cells. Primate lentiviruses have evolved specific antagonists (Vpu, Nef, and Env). Here we characterized tetherin proteins of species representing both branches of the order Carnivora. Comparison of tiger and cat (Feliformia) to dog and ferret (Caniformia) genes demonstrated that the tiger and cat share a start codon mutation that truncated most of the tetherin cytoplasmic tail early in the Feliformia lineage (19 of 27 amino acids, including the dual tyrosine motif). Alpha interferon (IFN-α) induced tetherin and blocked feline immunodeficiency virus (FIV) replication in lymphoid and nonlymphoid feline cells. Budding of bald FIV and HIV particles was blocked by carnivore tetherins. However, infectious FIV particles were resistant, and spreading FIV replication was uninhibited. Antagonism mapped to the envelope glycoprotein (Env), which rescued FIV from carnivore tetherin restriction when expressed in trans but, in contrast to known antagonists, did not rescue noncognate particles. Also unlike the primate lentiviral antagonists, but similar to the Ebola virus glycoprotein, FIV Env did not reduce intracellular or cell surface tetherin levels. Furthermore, FIV-enveloped FIV particles actually required tetherin for optimal release from cells. The results show that FIV Envs mediate a distinctive tetherin evasion. Well adapted to a phylogenetically ancient tetherin tail truncation in the Felidae, it requires functional virion incorporation of Env, and it shields the budding particle without downregulating plasma membrane tetherin. Moreover, FIV has evolved dependence on this protein: particles containing FIV Env need tetherin for optimal release from the cell, while Env(-) particles do not. HIV-1 antagonizes the restriction factor tetherin with the accessory protein Vpu, while HIV-2 and the filovirus Ebola use their envelope (Env) glycoproteins for this purpose. It turns out that the FIV tetherin antagonist is

  13. The HERV-K Human Endogenous Retrovirus Envelope Protein Antagonizes Tetherin Antiviral Activity

    PubMed Central

    Lemaître, Cécile; Harper, Francis; Pierron, Gérard

    2014-01-01

    inhibit Tetherin activity, allowing them to efficiently infect and replicate in their host. Here, we show that human HERV-K(HML2) elements, the remnants of an ancient retroviral infection, possess an anti-Tetherin activity which is mediated by the envelope protein. It is likely that this activity was an important factor that contributed to the recent, human-specific amplification of this family of elements. Also, due to their recent amplification, HERV-K(HML2) elements are highly polymorphic in the human population. Since Tetherin is a mediator of innate immunity, interindividual variations among HERV-K(HML2) Env genes may result in differences in immune responses to infection. PMID:25210194

  14. Feline Immunodeficiency Virus Envelope Glycoproteins Antagonize Tetherin through a Distinctive Mechanism That Requires Virion Incorporation

    PubMed Central

    Guevara, Rebekah B.; Marcano, Adriana C.; Saenz, Dyana T.; Fadel, Hind J.; Rogstad, Daniel K.

    2014-01-01

    ABSTRACT BST2/tetherin inhibits the release of enveloped viruses from cells. Primate lentiviruses have evolved specific antagonists (Vpu, Nef, and Env). Here we characterized tetherin proteins of species representing both branches of the order Carnivora. Comparison of tiger and cat (Feliformia) to dog and ferret (Caniformia) genes demonstrated that the tiger and cat share a start codon mutation that truncated most of the tetherin cytoplasmic tail early in the Feliformia lineage (19 of 27 amino acids, including the dual tyrosine motif). Alpha interferon (IFN-α) induced tetherin and blocked feline immunodeficiency virus (FIV) replication in lymphoid and nonlymphoid feline cells. Budding of bald FIV and HIV particles was blocked by carnivore tetherins. However, infectious FIV particles were resistant, and spreading FIV replication was uninhibited. Antagonism mapped to the envelope glycoprotein (Env), which rescued FIV from carnivore tetherin restriction when expressed in trans but, in contrast to known antagonists, did not rescue noncognate particles. Also unlike the primate lentiviral antagonists, but similar to the Ebola virus glycoprotein, FIV Env did not reduce intracellular or cell surface tetherin levels. Furthermore, FIV-enveloped FIV particles actually required tetherin for optimal release from cells. The results show that FIV Envs mediate a distinctive tetherin evasion. Well adapted to a phylogenetically ancient tetherin tail truncation in the Felidae, it requires functional virion incorporation of Env, and it shields the budding particle without downregulating plasma membrane tetherin. Moreover, FIV has evolved dependence on this protein: particles containing FIV Env need tetherin for optimal release from the cell, while Env− particles do not. IMPORTANCE HIV-1 antagonizes the restriction factor tetherin with the accessory protein Vpu, while HIV-2 and the filovirus Ebola use their envelope (Env) glycoproteins for this purpose. It turns out that the FIV

  15. Habitat classification modeling with incomplete data: Pushing the habitat envelope

    USGS Publications Warehouse

    Zarnetske, P.L.; Edwards, T.C.; Moisen, G.G.

    2007-01-01

    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 be used. Traditional techniques generate pseudoabsence 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, thresholdindependent receiver operating characteristic (ROC) plots, adjusted deviance (Dadj2), 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, suggesting

  16. 78 FR 19981 - Special Conditions: Embraer S.A., Model EMB-550 Airplanes; Flight Envelope Protection: High Speed...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-04-03

    ...; Flight Envelope Protection: High Speed Limiting AGENCY: Federal Aviation Administration (FAA), DOT... 11562). The document issued special conditions pertaining flight envelope protection: high...

  17. Susceptibility of domestic animals to a pseudotype virus bearing RD-114 virus envelope protein.

    PubMed

    Miyaho, Rie Nakaoka; Nakagawa, So; Hashimoto-Gotoh, Akira; Nakaya, Yuki; Shimode, Sayumi; Sakaguchi, Shoichi; Yoshikawa, Rokusuke; Takahashi, Mahoko Ueda; Miyazawa, Takayuki

    2015-08-10

    Retroviral vectors are used for gene transduction into cells and have been applied to gene therapy. Retroviral vectors using envelope protein (Env) of RD-114 virus, a feline endogenous retrovirus, have been used for gene transduction. In this study, we investigated the susceptibility to RD-114 Env-pseudotyped virus in twelve domestic animals including cattle, sheep, horse, pig, dog, cat, ferret, mink, rabbit, rat, mouse, and quail. Comparison of nucleotide sequences of ASCT2 (SLC1A5), a receptor of RD-114 virus, in 10 mammalian and 2 avian species revealed that insertion and deletion events at the region C of ASCT2 where RD-114 viral Env interacts occurred independently in the mouse and rat lineage and in the chicken and quail lineage. By the pseudotype virus infection assay, we found that RD-114 Env-pseudotyped virus could efficiently infect all cell lines except those from mouse and rat. Furthermore, we confirmed that bovine ASCT2 (bASCT2) functions as a receptor for RD-114 virus infection. We also investigated bASCT2 mRNA expression in cattle tissues and found that it is expressed in various tissues including lung, spleen and kidney. These results indicate that retrovirus vectors with RD-114 virus Env can be used for gene therapy in large domestic animals in addition to companion animals such as cat and dog.

  18. Grain growth in the envelopes of Class I protostars

    NASA Astrophysics Data System (ADS)

    Miotello, Anna; Testi, Leonardo; Lodato, Giuseppe; Ricci, Luca; Rosotti, Giovanni; Brooks, Kate; Maury, Anaelle; Natta, Antonella

    2013-07-01

    Many observational results (e.g. Ricci et al. 2010) indicate that nearly all the protoplanetary disks in the Class II phase contain mm- and cm-sized grains showing that the formation of these large particles is a fast process which begins during previous evolutionary stages. Pagani et al. (2011) have shown that micron-sized grains are already present in prestellar cores, while mm-sized particles have been detected in Class 0 YSOs (Chiang et al. 2012). The aim of this work is to constrain the level of grain growth in Class I YSOs, where the contribution of the envelope emission can be separated by the disk one, using mm-interferometry. We find evidence of mm-sized pebbles already formed in the envelopes, which may set new initial condition to the grain growth process in the protoplanetary disks. From our modeling procedure we conclude moreover that the embedded disks are possibly very compact.

  19. Maximum Torque and Momentum Envelopes for Reaction Wheel Arrays

    NASA Technical Reports Server (NTRS)

    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.

  20. 1612 MHz OH maser emission from axisymmetric circumstellar envelopes - Miras

    NASA Technical Reports Server (NTRS)

    Collison, Alan J.; Fix, John D.

    1992-01-01

    Radiative transfer calculations are performed using a modified form of the Sobolev approximation to determine the inversion of the 1612 MHz line of OH in axisymmetric circumstellar envelopes around Miras. The mass loss is assumed to be occurring in the form of a smooth wind. Line profiles and maps are presented for three models of varying degrees of asymmetry and for various orientations of the envelopes. It is concluded that the axisymmetric models can reproduce many of the features of observed profiles and maps which both the standard, spherically symmetric model and the discrete emission model cannot easily explain. The model profiles reproduce all of the general features seen in the line profiles of real sources.