Science.gov

Sample records for membrane-proximal amino-terminal residues

  1. Structural significance of the amino terminal residues in human hemoglobin

    SciTech Connect

    Hefta, S.A.

    1986-01-01

    The amino terminal valine residues on the alpha chains of human hemoglobin are known to be important for the function of the molecule. Allosteric effectors such as protons, chloride ions and metabolic anions such as 2,3-diphosphoglycerate bind or associate with these residues and facilitate the release of oxygen. Carbon dioxide also functions as an effector as it is partly transported from the tissues to the lungs by binding to the amino terminal residues. This research describes the semisynthetic alteration of this region and the hemoglobin analogs produced were analyzed by /sup 13/C NMR.

  2. Retention by the endoplasmic reticulum of rotavirus VP7 is controlled by three adjacent amino-terminal residues.

    PubMed Central

    Maass, D R; Atkinson, P H

    1994-01-01

    The rotavirus outer capsid glycoprotein, VP7, is an endoplasmic reticulum (ER) membrane-associated glycoprotein in both infected and transfected cells. It was previously demonstrated in this laboratory and by others that both the cleaved signal sequence (H2) and the first NH2-terminal 61 amino acids of VP7 are sufficient and necessary for ER retention of this molecule. Using site-specific mutagenesis and transfection techniques, we show that residues Ile-9, Thr-10, and Gly-11 were specifically necessary for ER retention. These results further define the ER retention sequence of VP7 and demonstrate that conservative changes, apparently innocuous in only three adjacent amino acids, can lead to major solubility and compartmentalization changes. It was found that placement of the first 31 mature NH2-terminal residues of VP7, in addition to the cleaved ER translocation signal sequence, was sufficient to retain the enzymatically active chimeric alpha-amylase in the ER; this enzyme is normally secreted. Deletions of the residues Ile-9, Thr-10, and Gly-11 within the amylase chimera containing 31 VP7 amino acids resulted in secretion of enzymatically active protein. It was also observed that the residues of VP7 presented in certain chimeras were able to abolish alpha-amylase enzymatic activity. These chimeras are presumably misfolded since it was demonstrated by pulse-chase experiments that these molecules are degraded in the ER. We surmise that a favorable conformation is necessary for retention since ER retention and activity of the chimeras depend on the primary sequence context. Images PMID:8254749

  3. Amino-terminal residues of ΔNp63, mutated in ectodermal dysplasia, are required for its transcriptional activity.

    PubMed

    Lena, Anna Maria; Duca, Sara; Novelli, Flavia; Melino, Sonia; Annicchiarico-Petruzzelli, Margherita; Melino, Gerry; Candi, Eleonora

    2015-11-13

    p63, a member of the p53 family, is a crucial transcription factor for epithelial development and skin homeostasis. Heterozygous mutations in TP63 gene have been associated with human ectodermal dysplasia disorders. Most of these TP63 mutations are missense mutations causing amino acidic substitutions at p63 DNA binding or SAM domains that reduce or abolish the transcriptional activity of mutants p63. A significant number of mutants, however, resides in part of the p63 protein that apparently do not affect DNA binding and/or transcriptional activity, such as the N-terminal domain. Here, we characterize five p63 mutations at the 5' end of TP63 gene aiming to understand the pathogenesis of the diseases and to uncover the role of ΔNp63α N-terminus residues in determining its transactivation potential. PMID:26408908

  4. Demonstration of a direct interaction between residue 22 in the carboxyl-terminal half of secretin and the amino-terminal tail of the secretin receptor using photoaffinity labeling.

    PubMed

    Dong, M; Wang, Y; Pinon, D I; Hadac, E M; Miller, L J

    1999-01-01

    An understanding of the molecular basis of hormonal activation of receptors provides important insights for drug design. Toward this end, intrinsic photoaffinity labeling is a powerful tool to directly identify the ligand-binding domain. We have developed a new radioiodinatable agonist ligand of the secretin receptor that incorporates a photolabile p-benzoyl-L-phenylalanine (Bpa) into the position of Leu22 and have utilized this to identify the adjacent receptor domain. The rat [Tyr10,Bpa22]secretin-27 probe was a fully efficacious agonist, with a potency to stimulate cAMP accumulation by Chinese hamster ovary SecR cells similar to that of natural secretin (EC50 = 68 +/- 22 pM analogue and 95 +/- 25 pM secretin). It bound specifically and with high affinity (Ki = 5.0 +/- 1.1 nM) and covalently labeled the Mr = 57,000-62,000 secretin receptor. Cyanogen bromide cleavage of the receptor yielded a major labeled fragment of apparent Mr = 19,000 that shifted to Mr = 9,000 after deglycosylation. This was most consistent with either of two glycosylated domains within the amino-terminal tail of the receptor. Immunoprecipitation with antibody directed to epitope tags incorporated into each of the candidate domains established that the fragment at the amino terminus of the receptor was the site of labeling. This was further localized to the amino-terminal 30 residues of the receptor by additional proteolysis of this fragment with endoproteinase Lys-C. This provides the first direct demonstration of a contact between a secretin-like agonist and its receptor and will contribute a useful constraint to the modeling of this interaction. PMID:9873030

  5. The role of glycine (residue 89) in the central helix of EF-hand protein troponin-C exposed following amino-terminal alpha-helix deletion.

    PubMed

    Ding, X L; Akella, A B; Su, H; Gulati, J

    1994-11-01

    Because an N-terminal alpha-helical (N-helix) arm and a KGK-triplet (residues 88KGK90) in the central helix of troponin-C (TnC) are missing in calmodulin, several recent studies have attempted to elucidate the structure-function correlations of these units. Presently, with a family of genetically manipulated derivatives especially developed for this study and tested on permeabilized isolated single skeletal muscle fiber segments, we explored the specificities of the amino acid residues within the N-helix and the KGK-triplet in TnC. Noticeably, the amino acid compositions vary between the N-helices of the cardiac and skeletal TnC isoforms. On the other hand, the KGK-triplet is located similarly in both TnC isoforms. We previously indicated that deletion of the N-helix (mutant delta Nt) diminishes the tension obtained on activation with maximal calcium, but the contractile function is revived by the superimposed deletion of the 88KGK90-triplet (mutant delta Nt delta KGK; see Gulati J, Babu A, Su H, Zhang YF, 1993, J Biol Chem 268:11685-11690). Using this functional test, we find that replacement of Gly-89 with a Leu or an Ala could also overcome the contractile defect associated with N-helix deletion. On the other hand, replacement of the skeletal TnC N-helix with cardiac type N-helix was unable to restore contractile function. The findings indicate a destabilizing influence of Gly-89 residue in skeletal TnC and suggest that the N-terminal arm in normal TnC serves to moderate this effect. Moreover, specificity of the N-helix between cardiac and skeletal TnCs raises the possibility that resultant structural disparities are also important for the functional distinctions of the TnC isoforms. PMID:7703855

  6. Tiny T antigen: an autonomous polyomavirus T antigen amino-terminal domain.

    PubMed Central

    Riley, M I; Yoo, W; Mda, N Y; Folk, W R

    1997-01-01

    Three mRNAs from the murine polyomavirus early region encode the three well-characterized tumor antigens. We report the existence of a fourth alternatively spliced mRNA which encodes a fourth tumor antigen, tiny T antigen, which comprises the amino-terminal domain common to all of the T antigens but is extended by six unique amino acid residues. The amount of tiny T antigen in infected cells is small because of its short half-life. Tiny T antigen stimulates the ATPase activity of Hsc70, most likely because of its DnaJ-like motif. The common amino-terminal domain may interface with chaperone complexes to assist the T antigens in carrying out their diverse functions of replication, transcription, and transformation in the appropriate cellular compartments. PMID:9223500

  7. Porphyromonas (Bacteroides) gingivalis fimbrillin: size, amino-terminal sequence, and antigenic heterogeneity.

    PubMed Central

    Lee, J Y; Sojar, H T; Bedi, G S; Genco, R J

    1991-01-01

    Bacterial fimbriae mediate cell adhesion and are important in colonization. Fimbrial proteins from strains of Porphyromonas (Bacteroides) gingivalis isolated from different individuals were compared for their size, amino-terminal sequence, and antigenic diversity. Two major protein components of the crude fimbrial preparations differed in apparent molecular mass, ranging from 41 to 49 kDa for the fimbrillin monomer and from 61 to 78 kDa for the other major protein. The amino-terminal sequence of the antigenically related group of proteins of the fimbrillin monomer in the 41- to 49-kDa range showed significant homology; however, minor sequence heterogeneity was observed, mainly in residues 4 to 6. One of the observed amino-terminal sequences, AFGVGDDESKVAKLTVMVYNG, resembled the deduced sequence of P. gingivalis 381 (D.P. Dickinson, M. K. Kubiniec, F. Yoshimura, and R.J. Genco, J. Bacteriol. 170:1658-1665, 1988). Fimbriae from all the strains of P. gingivalis showing this sequence contained a fimbrillin monomer of 43 kDa and showed a strong reaction with both polyclonal and monoclonal antibodies directed to the fimbriae from P. gingivalis 2561 (381). Fimbriae from strains showing amino-terminal sequence variations in residues 4 to 6 (i.e., substitution of VGD with either E or NAG) were more diverse in their molecular sizes. Most of these variant fimbriae showed weak reactions with the polyclonal antibodies and no reaction with the monoclonal antibodies induced to the fimbriae of strain 2561. No correlation could be established between the molecular size and immunological reactivity of the fimbrillin monomer of P. gingivalis strains. Strains 9-14K-1 and HG 564 not only showed markedly different sequences from the other three amino-terminal sequences but also did not react with either polyclonal or monoclonal antibodies to the fimbriae of strain 2561. Strains W50, W83, and AJW 5 failed to show any immunological reactivity with the antibodies to fimbrillin or fimbriae

  8. Amino-terminal analysis of tryptophan hydroxylase: protein kinase phosphorylation occurs at serine-58.

    PubMed

    Kumer, S C; Mockus, S M; Rucker, P J; Vrana, K E

    1997-10-01

    Tryptophan hydroxylase (TPH) catalyzes the rate-limiting and committed step in serotonin biosynthesis. Within this enzyme, two distinct domains have been hypothesized to exist, an amino-terminal regulatory domain and a carboxyl-terminal catalytic domain. In the present experiments, the functional boundary between the putative domains was defined using deletion mutagenesis. A full-length cDNA clone for rabbit TPH was engineered for expression in bacteria. Five amino-terminal deletions were constructed using PCR, i.e., Ndelta50, Ndelta60, Ndelta90, Ndelta106, and Ndelta116 (referring to the number of amino acids deleted from the amino terminus). Enzymatic activity was determined for each mutant after expression in bacteria. Whereas deletion of 116 amino acids (Ndelta116) abolished enzyme activity, all of the other amino-terminal deletions exhibited increased specific activity relative to the recombinant wild-type TPH. The ability of the cyclic AMP-dependent protein kinase (PKA) to phosphorylate members of the deletion series was also examined. Deletion of the first 60 amino-terminal residues abolished the ability of the enzyme to serve as a substrate for PKA, yet the native and Ndelta50 enzymes were phosphorylated. Moreover, a serine-58 point mutant (S58A) was not phosphorylated by PKA. In conclusion, the first 106 amino acids comprise a regulatory domain that is phosphorylated by PKA at serine-58. In addition, the boundary between regulatory and catalytic domains is analogous to the domain structure observed for the related enzyme tyrosine hydroxylase. PMID:9326303

  9. Amino-terminated diamond surfaces: Photoelectron emission and photocatalytic properties

    NASA Astrophysics Data System (ADS)

    Zhu, Di; Bandy, Jason A.; Li, Shuo; Hamers, Robert J.

    2016-08-01

    We report a new approach to making stable negative electron-affinity diamond surfaces by terminating diamond with amino groups (also known as amine groups, -NH2). Previous studies have shown that negative electron affinity can be induced by terminating diamond surfaces with hydrogen, creating a surface dipole favorable toward electron emission. Here, we demonstrate that covalent tethering of positive charges in the form of protonated amino groups, -NH3+, also leads to negative electron affinity (NEA) and facile electron emission into vacuum and into water. Amino-terminated diamond was prepared using a very mild plasma discharge. Valence-band photoemission studies of the amino-terminated diamond samples show a characteristic "NEA" peak, demonstrating that the amino-terminated surface has NEA. Diamond's ability to emit electrons into water was evaluated using photochemical conversion of N2 to NH3. Time-resolved surface photovoltage studies were used to characterize charge separation at the diamond interface, and Mott-Schottky measurements were performed to characterize band-bending at the diamond-water interface. XPS studies show that the amino-terminated surfaces provide increased chemical resistance to oxidation compared with H-terminated diamond when illuminated with ultraviolet light.

  10. The SKN-1 amino-terminal arm is a DNA specificity segment.

    PubMed

    Kophengnavong, T; Carroll, A S; Blackwell, T K

    1999-04-01

    The Caenorhabditis elegans SKN-1 protein binds DNA through a basic region like those of bZIP proteins and through a flexible amino-terminal arm segment similar to those with which numerous helix-turn-helix proteins bind to bases in the minor groove. A recent X-ray crystallographic structure suggests that the SKN-1 amino-terminal arm provides only nonspecific DNA binding. In this study, however, we demonstrate that this segment mediates recognition of an AT-rich element that is part of the preferred SKN-1 binding site and thereby significantly increases the sequence specificity with which SKN-1 binds DNA. Mutagenesis experiments show that multiple amino acid residues within the arm are involved in binding. These residues provide binding affinity through distinct but partially redundant interactions and enhance specificity by discriminating against alternate sites. The AT-rich element minor groove is important for binding of the arm, which appears to affect DNA conformation in this region. This conformational effect does not seem to involve DNA bending, however, because the arm does not appear to affect a modest DNA bend that is induced by SKN-1. The data illustrate an example of how a small, flexible protein segment can make an important contribution to DNA binding specificity through multiple interactions and mechanisms. PMID:10082571

  11. Identification of amino-terminal sequences contributing to tryptophan hydroxylase tetramer formation.

    PubMed

    Yohrling, G J; Mockus, S M; Vrana, K E

    1999-02-01

    Tryptophan hydroxylase (TPH) catalyzes the rate-limiting step in the biosynthesis of serotonin. In the rabbit, TPH exists as a tetramer of four identical 51-kDa subunits comprised of 444 amino acids each. The enzyme consists of an amino-terminal regulatory domain and a carboxyl-terminal catalytic domain. Previous studies demonstrated that within the carboxyl-terminus of TPH, there resides an intersubunit binding domain (a leucine zipper) that is essential for tetramer formation. However, it is hypothesized that a 4,3-hydrophobic repeat identified within the regulatory domain of TPH (residues 21-41) may also be involved in macromolecular assembly. To test this hypothesis, a series of amino-terminal deletions (Ndelta15, 30, 41, and 90) were created and assessed for macromolecular structure using size-exclusion chromatography. The amino-terminal deletion Ndelta15, upstream from the 4,3-hydrophobic repeat, was capable of forming tetramers. However, when a portion of the 4,3-hydrophobic repeat was deleted (Ndelta30), a heterogeneous elution pattern of tetramers, dimers, and monomers was observed. Complete removal of the 4,3-hydrophobic repeat (Ndelta41) rendered the enzyme incapable of forming tetramers; a monomeric form predominated. In addition, a double-point mutation (V28R-L31R) was created in the hydrophobic region of the enzyme. The introduction of two arginines (R) at positions 28 and 31 respectively, in the helix disrupted the native tetrameric state of TPH. According to size-exclusion chromatography analysis, the double-point mutant (V28R-L31R) formed dimers of 127 kDa. Thus, it is concluded that there is information within the amino-terminus that is necessary for tetramer formation of TPH. This additional intersubunit binding domain in the amino-terminus is similar to that found in the carboxyl-terminus. PMID:10636468

  12. Isolation and amino-terminal sequence analysis of a new pancreatic trypsinogen of the African lungfish Protopterus aethiopicus.

    PubMed

    de Haën, C; Walsh, K A; Neurath, H

    1977-10-01

    The purification and characterization of three pancreatic trypsinogens A1, A2, and A3, from the African lungfish, Protopterus aethiopicus, is reported. These zymogens are activated by trypsin, by enterokinase, by an acid protease from Aspergillus oryzae, and by autoactivation. The three trypsinogens contain the same amino-terminal amino acid sequence, beginning with the activation peptide Leu-Pro-Leu-Glu-Asp-Asp-Lys-. Like the activation peptide of the previously characterized trypsinogen B [Reeck, G. R., & Neurath, H. (1972) Biochemistry 11, 503] of the same organism, it lacks the tetraaspartyl sequence characteristic of other vertebrate trypsinogens. Two of the corresponding lungfish trypsins were found to have identical amino-terminal sequences for at least 27 residues. These data suggest that the three enzymes are allelic variants. In contrast, the amino acid sequences differ sufficiently from that of trypsinogen B of the same organism to indicate that trypsinogens A and B are the products of different gene loci. PMID:911766

  13. Ty3 Capsid Mutations Reveal Early and Late Functions of the Amino-Terminal Domain▿

    PubMed Central

    Larsen, Liza S. Z.; Zhang, Min; Beliakova-Bethell, Nadejda; Bilanchone, Virginia; Lamsa, Anne; Nagashima, Kunio; Najdi, Rani; Kosaka, Kathryn; Kovacevic, Vuk; Cheng, Jianlin; Baldi, Pierre; Hatfield, G. Wesley; Sandmeyer, Suzanne

    2007-01-01

    The Ty3 retrotransposon assembles into 50-nm virus-like particles that occur in large intracellular clusters in the case of wild-type (wt) Ty3. Within these particles, maturation of the Gag3 and Gag3-Pol3 polyproteins by Ty3 protease produces the structural proteins capsid (CA), spacer, and nucleocapsid. Secondary and tertiary structure predictions showed that, like retroviral CA, Ty3 CA contains a large amount of helical structure arranged in amino-terminal and carboxyl-terminal bundles. Twenty-six mutants in which alanines were substituted for native residues were used to study CA subdomain functions. Transposition was measured, and particle morphogenesis and localization were characterized by analysis of protein processing, cDNA production, genomic RNA protection, and sedimentation and by fluorescence and electron microscopy. These measures defined five groups of mutants. Proteins from each group could be sedimented in a large complex. Mutations in the amino-terminal domain reduced the formation of fluorescent Ty3 protein foci. In at least one major homology region mutant, Ty3 protein concentrated in foci but no wt clusters of particles were observed. One mutation in the carboxyl-terminal domain shifted assembly from spherical particles to long filaments. Two mutants formed foci separate from P bodies, the proposed sites of assembly, and formed defective particles. P-body association was therefore found to be not necessary for assembly but correlated with the production of functional particles. One mutation in the amino terminus blocked transposition after cDNA synthesis. Our data suggest that Ty3 proteins are concentrated first, assembly associated with P bodies occurs, and particle morphogenesis concludes with a post-reverse transcription, CA-dependent step. Particle formation was generally resistant to localized substitutions, possibly indicating that multiple domains are involved. PMID:17442718

  14. A Membrane-proximal Tetracysteine Motif Contributes to Assembly of CD3δε and CD3γε Dimers with the T Cell Receptor*

    PubMed Central

    Xu, Chenqi; Call, Matthew E.; Wucherpfennig, Kai W.

    2015-01-01

    Assembly of the T cell receptor (TCR) with its dimeric signaling modules, CD3δε, CD3γε, and ζζ, is organized by transmembrane (TM) interactions. Each of the three assembly steps requires formation of a three-helix interface involving one particular basic TCR TM residue and two acidic TM residues of the respective signaling dimer. The extracellular domains of CD3δε and CD3γε contribute to assembly, but TCR interaction sites on CD3 dimers have not been defined. The structures of the extra-cellular domains of CD3δε and CD3γε demonstrated parallel β-strands ending at the first cysteine in the CXXCXEXXX motif present in the stalk segment of each CD3 chain. Mutation of the membrane-proximal cysteines impaired assembly of either CD3 dimer with TCR, and little complex was isolated when all four membrane-proximal cysteines were mutated to alanine. These mutations had, however, no discernable effect on CD3δε or CD3γε dimerization. CD3δε assembled with a TCRα mutant that lacked both immunoglobulin domains, but shortening of the TCRα connecting peptide reduced assembly, consistent with membrane-proximal TCRα-CD3δε interactions. Chelation of divalent cations did not affect assembly, indicating that coordination of a cation by the tetracysteine motif was not required. The membrane-proximal cysteines were within close proximity but only formed covalent CD3 dimers when one cys-teine was mutated. The four cysteines may thus form two intra-chain disulfide bonds integral to the secondary structure of CD3 stalk regions. The three-chain interaction theme first established for the TM domains thus extends into the membrane-proximal domains of TCRα-CD3δε and TCRβ-CD3γε. PMID:17023417

  15. Mg and Mc: mutations within the amino-terminal region of glycophorin A.

    PubMed Central

    Furthmayr, H; Metaxas, M N; Metaxas-Bühler, M

    1981-01-01

    M and N are the two common ("normal") alleles at the MN locus of the MNSs blood group system. The antigens M and N that they determine are located within the amino-terminal region of glycophorin A. In the serologically active and glycosylated (*) fragment of glycophorin AN the sequence is Leu-Ser*-Thr*-Thr*-Glu-, and in that of glycophorin AM it is Ser-Ser*-Thr*-Thr*-Gly-. Mg and Mc are very rare ("variant") alleles of M and N; as to the corresponding antigens, Mg is serologically quite distinct from M and N, while Mc is a compound of both. Erythrocytes of genotypes MgN, MgM, MgMg, and McM, which were the object of the present study, contain normal amounts of glycophorin A in their membrane. In glycophorin AMg the amino-terminal sequence is related to that of glycophorin AN by substitution of asparagine for threonine in position 4, and it is nonglycosylated: Leu-Ser-Thr-Asn-Glu-. The corresponding structure of glycophorin AMc is Ser-Ser*-Thr*-Thr*-Glu-; it is thus closely related to that of glycophorin AN and AM, by substitution of the amino acids in positions 1 or 5, respectively. All of these substitutions can be explained by single base changes. The distinctions in chemical structure not only confirm the location of M and N in this region of glycophorin A, because they are the only differences observed, but also indicate, because they are correlated with the distinctions in antigenic specificity, that M and N are structural genes coding for amino acid sequences. The finding that Mc contains structural features of both M and N suggests that these two forms of glycophorin A have evolved from a common ancestral gene by single base substitutions at sites in the genome coding for amino acids in positions 1 and 5 of the sequence. Carbohydrate structures, however, are also necessary for full expression of antigens M and N. Glycosylation during biosynthesis of residues within the polypeptide appears to depend on a particular protein structure. PMID:6166001

  16. Prolonged exposure of the HIV-1 gp41 membrane proximal region with L669S substitution

    PubMed Central

    Shen, Xiaoying; Dennison, S. Moses; Liu, Pinghuang; Gao, Feng; Jaeger, Frederick; Montefiori, David C.; Verkoczy, Laurent; Haynes, Barton F.; Alam, S. Munir; Tomaras, Georgia D.

    2010-01-01

    The conserved membrane-proximal external region (MPER) of HIV-1 envelope is a target for the rare broadly neutralizing 2F5, Z13, and 4E10 monoclonal antibodies (mAbs). One strategy to elicit such antibodies is to design an immunogen with increased exposure of the 2F5 and 4E10 mAb epitopes. In this study we characterize a single leucine to serine substitution at position 669 (L669S) in the gp41 Env MPER that confers >250-fold more neutralization sensitivity to 2F5 and 4E10 mAbs than does the wild-type gp41 sequence. On synthetic liposomes, increased solvent exposure of MPER tryptophan residues and stable docking of 2F5 and 4E10 mAbs to mutant MPER peptide liposomes indicate more favorable membrane orientation of MPER neutralizing epitopes with L669S substitution. The time during which virus is sensitive to 2F5 mAb-mediated neutralization is approximately 3-fold longer when the mutation is present. These data suggest that a major contribution to the L669S mutant virus phenotype of enhanced susceptibility to MPER mAbs is prolonged exposure of the MPER neutralizing epitope during viral entry. PMID:20231447

  17. Aliphatic semisynthetic amino terminal variants of myoglobin: enrichment with carbon-13, determination and interpretation of terminal pK values and motions

    SciTech Connect

    Busch, M.R.

    1985-01-01

    The synthesis of a series of myoglobins substituted in the amino terminal residue to provide variation in the aliphatic nature of the side chain and enrichment in /sup 13/C was accomplished by semisynthetic methods. The replacements of valine, the native first residue, included /sup 13/C enriched glycine, alanine, valine, leucine, and isoleucine. The products were extensively characterized and found to be virtually indistinguishable by most physical methods. /sup 13/C NMR spectroscopy showed significant differences in the amino terminal pK value, ranging from 7.72 for myoglobin to 7.15 for myoglobin. Consideration of the electrostatic effects of the charge array indicated a balance of interactions at this site not significantly altered by variations in the side chain. By examination of the crystal structure, consideration of earlier work regarding the interactions of the side chain of Leu-2, and data regarding the motions of the terminal residue, it was concluded that the interaction of the side chain of the first residue with the hydrophobic cluster formed primarily by close contact of invariant residues Leu-2 and Leu-137 was the primary cause for the reduction in the terminal pK values seen for the larger aliphatics. By restricting the freedom of the residue, this interaction limits the available hydration volume, and consequently favors the unprotonated form of the amine. The concurrent observation of both functional elements in the series of ..cap alpha.. amino terminal residues brings out the interrelated consequences for the two categories of solvent interactions controlling structural and functional properties in a graded way.

  18. Role of the Amino-Terminal Region of Porphyromonas gingivalis Fimbriae in Adherence to Epithelial Cells

    PubMed Central

    Sojar, Hakimuddin T.; Han, Yiping; Hamada, Nobushiro; Sharma, Ashu; Genco, Robert J.

    1999-01-01

    Porphyromonas gingivalis fimbriae elicit many responses in eukaryotic cells, including mitogenicity, cytokine production, epithelial cell invasion, and cellular immune response. Specific domains of the major fimbrial protein (FimA) have been shown to be important in triggering some of these functions. The goal of the present study was to identify the domain(s) of P. gingivalis FimA responsible for specific interaction with human mucosal epithelial cells. Fimbriated P. gingivalis strains have been shown to bind to buccal epithelial cells, whereas nonfimbriated strains bind at low levels or not at all. This and other studies provide evidence that FimA mediates the adherence of P. gingivalis to oral epithelial cells. To determine the specific region(s) of P. gingivalis FimA involved in epithelial cell binding, specific antipeptide antibodies were used to inhibit the binding of iodinated purified fimbriae as well as the binding of P. gingivalis cells to epithelial cells. Antibodies directed against peptides 49 to 68 (VVMANTAGAMELVGKTLAEVK) and 69 to 90 (ALTTELTAENQEAAGLIMTAEP) were found to highly inhibit both the binding of fimbriae and the binding of P. gingivalis cells to epithelial cells. The antibody against FimA peptides 69 to 90 also reacted with P. gingivalis fimbriae in immunogold labeling and immunoblot analysis, thereby indicating that this peptide domain is exposed on the surface of fimbriae. Our results suggest that the amino-terminal domain corresponding to amino acid residues 49 to 90 of the fimbrillin protein is a major epithelial cell binding domain of P. gingivalis fimbriae. PMID:10531284

  19. Resonance assignment of an engineered amino-terminal domain of a major ampullate spider silk with neutralized charge cluster.

    PubMed

    Schaal, Daniel; Bauer, Joschka; Schweimer, Kristian; Scheibel, Thomas; Rösch, Paul; Schwarzinger, Stephan

    2016-04-01

    Spider dragline fibers are predominantly made out of the major ampullate spidroins (MaSp) 1 and 2. The assembly of dissolved spidroin into a stable fiber is highly controlled for example by dimerization of its amino-terminal domain (NRN) upon acidification, as well as removal of sodium chloride along the spinning duct. Clustered residues D39, E76 and E81 are the most highly conserved residues of the five-helix bundle, and they are hypothesized to be key residues for switching between a monomeric and a dimeric conformation. Simultaneous replacement of these residues by their non-titratable analogues results in variant D39N/E76Q/E81Q, which is supposed to fold into an intermediate conformation between that of the monomeric and the dimeric state at neutral pH. Here we report the resonance assignment of Latrodectus hesperus NRN variant D39N/E76Q/E81Q at pH 7.2 obtained by high-resolution triple resonance NMR spectroscopy. PMID:26892754

  20. Membrane-proximal calcium transients in stimulated neutrophils detected by total internal reflection fluorescence.

    PubMed Central

    Omann, G M; Axelrod, D

    1996-01-01

    A novel fluorescence microscope/laser optical system was developed to measure fast transients of membrane-proximal versus bulk cytoplasmic intracellular calcium levels in cells labeled with a fluorescent calcium indicator. The method is based on the rapid chopping of illumination of the cells between optical configurations for epifluorescence, which excites predominantly the bulk intracellular region, and total internal reflection fluorescence, which excites only the region within approximately 100 nm of the cell-substrate contact. This method was applied to Fluo-3-loaded neutrophils that were activated by the chemoattractant N-formyl-met-leu-phe. Chemoattractant-activated cells showed 1) transient increases in both membrane-proximal and bulk cytosolic Ca2+ that peaked simultaneously; 2) a larger fractional change (20-60%) in membrane-proximal Ca2+ relative to bulk cytosolic Ca2+ that peaked at a time when the main Ca2+ transient was decreasing in both regions and that persisted well after the main transient was over. This method should be applicable to a wide variety of cell types and fluorescent ion indicators in which membrane-proximal ionic transients may be different from those deeper within the cytosol. Images FIGURE 1 FIGURE 2 PMID:8913625

  1. An amino-terminal variant of the central cannabinoid receptor resulting from alternative splicing.

    PubMed

    Shire, D; Carillon, C; Kaghad, M; Calandra, B; Rinaldi-Carmona, M; Le Fur, G; Caput, D; Ferrara, P

    1995-02-24

    The cDNA sequences encoding the central cannabinoid receptor, CB1, are known for two species, rat and human. However, little information concerning the flanking, noncoding regions is presently available. We have isolated two overlapping clones from a human lung cDNA library with CB1 cDNA inserts. One of these, cann7, contains a short stretch of the CB1 coding region and 4 kilobase pairs (kb) of the 3'-untranslated region (UTR), including two polyadenylation signals. The other, cann6, is identical to cann7 upstream from the first polyadenylation signal, and in addition, it contains the whole coding region and extends for 1.8 kb into the 5'-UTR. Comparison of cann6 with the published sequence (Gérard, C. M., Mollereau, C., Vassart, G., and Parmentier, M. (1991) Biochem. J. 279, 129-134) shows the coding regions to be identical, but reveals important differences in the flanking regions. Notably, the cann6 sequence appears to be that of an immature transcript, containing 1.8 kb of an intronic sequence in the 5'-UTR. In addition, polymerase chain reaction amplification of the CB1 coding region in the IM-9 cell line cDNA resulted in two fragments, one containing the whole CB1 coding region and the second lacking a 167-base pair intron within the sequence encoding the amino-terminal tail of the receptor. This alternatively spliced form would translate to an NH2-terminal modified isoform (CB1A) of the receptor, shorter than CB1 by 61 amino acids. In addition, the first 28 amino acids of the putative truncated receptor are completely different from those of CB1, containing more hydrophobic residues. Rat CB1 mRNA is similarly alternatively spliced. A study of the distribution of the human CB1 and CB1A mRNAs by reverse transcription-polymerase chain reaction analysis showed the presence of both CB1 and CB1A throughout the brain and in all the peripheral tissues examined, with CB1A being present in amounts of up to 20% of CB1. PMID:7876112

  2. Structure of the HIV-1 gp41 Membrane-Proximal Ectodomain Region in a Putative Prefusion Conformation

    SciTech Connect

    Liu, J.; Deng, Y; Dey, A; Moore, J; Lu, M

    2009-01-01

    The conserved membrane-proximal external region (MPER) of the HIV-1 gp41 envelope protein is the established target for very rare but broadly neutralizing monoclonal antibodies (NAbs) elicited during natural human infection. Nevertheless, attempts to generate an HIV-1 neutralizing antibody response with immunogens bearing MPER epitopes have met with limited success. Here we show that the MPER peptide (residues 662-683) forms a labile ?-helical trimer in aqueous solution and report the crystal structure of this autonomous folding subdomain stabilized by addition of a C-terminal isoleucine zipper motif. The structure reveals a parallel triple-stranded coiled coil in which the neutralization epitope residues are buried within the interface between the associating MPER helices. Accordingly, both the 2F5 and 4E10 NAbs recognize the isolated MPER peptide but fail to bind the trimeric MPER subdomain. We propose that the trimeric MPER structure represents the prefusion conformation of gp41, preceding the putative prehairpin intermediate and the postfusion trimer-of-hairpins structure. As such, the MPER trimer should inform the design of new HIV-1 immunogens to elicit broadly neutralizing antibodies.

  3. Biophysical Characterization of a Vaccine Candidate against HIV-1: The Transmembrane and Membrane Proximal Domains of HIV-1 gp41 as a Maltose Binding Protein Fusion

    PubMed Central

    Gong, Zhen; Martin-Garcia, Jose M.; Daskalova, Sasha M.; Craciunescu, Felicia M.; Song, Lusheng; Dörner, Katerina; Hansen, Debra T.; Yang, Jay-How; LaBaer, Joshua; Hogue, Brenda G.; Mor, Tsafrir S.; Fromme, Petra

    2015-01-01

    The membrane proximal region (MPR, residues 649–683) and transmembrane domain (TMD, residues 684–705) of the gp41 subunit of HIV-1’s envelope protein are highly conserved and are important in viral mucosal transmission, virus attachment and membrane fusion with target cells. Several structures of the trimeric membrane proximal external region (residues 662–683) of MPR have been reported at the atomic level; however, the atomic structure of the TMD still remains unknown. To elucidate the structure of both MPR and TMD, we expressed the region spanning both domains, MPR-TM (residues 649–705), in Escherichia coli as a fusion protein with maltose binding protein (MBP). MPR-TM was initially fused to the C-terminus of MBP via a 42 aa-long linker containing a TEV protease recognition site (MBP-linker-MPR-TM). Biophysical characterization indicated that the purified MBP-linker-MPR-TM protein was a monodisperse and stable candidate for crystallization. However, crystals of the MBP-linker-MPR-TM protein could not be obtained in extensive crystallization screens. It is possible that the 42 residue-long linker between MBP and MPR-TM was interfering with crystal formation. To test this hypothesis, the 42 residue-long linker was replaced with three alanine residues. The fusion protein, MBP-AAA-MPR-TM, was similarly purified and characterized. Significantly, both the MBP-linker-MPR-TM and MBP-AAA-MPR-TM proteins strongly interacted with broadly neutralizing monoclonal antibodies 2F5 and 4E10. With epitopes accessible to the broadly neutralizing antibodies, these MBP/MPR-TM recombinant proteins may be in immunologically relevant conformations that mimic a pre-hairpin intermediate of gp41. PMID:26295457

  4. Multifunctional cholesterol-based peroxide for modification of amino-terminated surfaces: Synthesis, structure and characterization of grafted layer

    NASA Astrophysics Data System (ADS)

    Stetsyshyn, Y.; Kostruba, A.; Harhay, K.; Donchak, V.; Ohar, H.; Savaryn, V.; Kulyk, B.; Ripak, L.; Nastishin, Yu. A.

    2015-08-01

    A multifunctional cholesterol-based peroxide modifier - monoperoxided monocholesteryl pyromellitate (PChP) with residual acid chloride groups has been synthesized. The structure of the peroxide modifier was confirmed using IR and 1H NMR spectroscopies. Grafted PChP coating was successfully fabricated onto amino-terminated glass surfaces. Thickness and refractive index of the coated layer, its morphology, wettability, and alignment of elongated PChP molecules, attached to the surface at different grafting times were characterized by means of ellipsometry, AFM, measurements of wetting contact angle and testing alignment of a nematic liquid crystal on the coatings. In a flat cell assembled of a pair of glass substrates coated with the PChP layer nematic molecules align preferentially tilted with respect to the cell normal, though in some place one finds homeotropic alignment, where nematic molecules are perpendicular to the surface. Liquid crystal textures visualize inhomogeneities in surface profile of the coated layer. Homeotropic alignment is observed in places where roughness of the layer is completely randomized in agreement with AFM data, providing visualization of evolution of the surface profile. Concentration of grafted molecules per area of the surface deduced from ellipsometry data suggests that PChP molecules are grafted to the surface rather densely already in about ten minutes.

  5. Cooperative DNA Binding and Sequence-Selective Recognition Conferred by the STAT Amino-Terminal Domain

    NASA Astrophysics Data System (ADS)

    Xu, Xiang; Sun, Ya-Lin; Hoey, Timothy

    1996-08-01

    STAT proteins (signal transducers and activators of transcription) activate distinct target genes despite having similar DNA binding preferences. The transcriptional specificity of STAT proteins was investigated on natural STAT binding sites near the interferon-gamma gene. These sites are arranged in multiple copies and required cooperative interactions for STAT binding. The conserved amino-terminal domain of STAT proteins was required for cooperative DNA binding, although this domain was not essential for dimerization or binding to a single site. Cooperative binding interactions enabled the STAT proteins to recognize variations of the consensus site. These sites can be specific for the different STAT proteins and may function to direct selective transcriptional activation.

  6. Direct Contacts Between Extracellular Membrane-Proximal Domains are Required for VEGF Receptor Activation and Cell Signaling

    SciTech Connect

    Yang, Y.; Xie, P; Opatowsky, Y; Schlessinger, J

    2010-01-01

    Structural analyses of the extracellular region of stem cell factor (SCF) receptor (also designated KIT) in complex with SCF revealed a sequence motif in a loop in the fourth Ig-like domain (D4) that is responsible for forming homotypic receptor contacts and for ligand-induced KIT activation and cell signaling. An identical motif was identified in the most membrane-proximal seventh Ig-like domain (D7) of vascular endothelial growth factor receptor 1 (VEGFR1), VEGFR2, and VEGFR3. In this report we demonstrate that ligand-induced tyrosine autophosphorylation and cell signaling via VEGFR1 or VEGFR2 harboring mutations in critical residues (Arg726 or Asp731) in D7 are strongly impaired. We also describe the crystal structure of D7 of VEGFR2 to a resolution of 2.7 {angstrom}. The structure shows that homotypic D7 contacts are mediated by salt bridges and van der Waals contacts formed between Arg726 of one protomer and Asp731 of the other protomer. The structure of D7 dimer is very similar to the structure of D4 dimers seen in the crystal structure of KIT extracellular region in complex with SCF. The high similarity between VEGFR D7 and KIT D4 in both structure and function provides further evidence for common ancestral origins of type III and type V RTKs. It also reveals a conserved mechanism for RTK activation and a novel target for pharmacological intervention of pathologically activated RTKs.

  7. Immunogenic properties of a trimeric gp41-based immunogen containing an exposed membrane-proximal external region.

    PubMed

    Habte, Habtom H; Banerjee, Saikat; Shi, Heliang; Qin, Yali; Cho, Michael W

    2015-12-01

    The membrane-proximal external region (MPER) of HIV-1 gp41 is an attractive target for vaccine development. Thus, better understanding of its immunogenic properties in various structural contexts is important. We previously described the crystal structure of a trimeric protein complex named gp41-HR1-54Q, which consists of the heptad repeat regions 1 and 2 and the MPER. The protein was efficiently recognized by broadly neutralizing antibodies. Here, we describe its immunogenic properties in rabbits. The protein was highly immunogenic, especially the C-terminal end of the MPER containing 4E10 and 10E8 epitopes ((671)NWFDITNWLWYIK(683)). Although antibodies exhibited strong competition activity against 4E10 and 10E8, neutralizing activity was not detected. Detailed mapping analyses indicated that amino acid residues critical for recognition resided on faces of the alpha helix that are either opposite of or perpendicular to the epitopes recognized by 4E10 and 10E8. These results provide critical information for designing the next generation of MPER-based immunogens. PMID:26454663

  8. Characterization of translational inhibitors from Phytolacca americana. Amino-terminal sequence determination and antibody-inhibitor conjugates.

    PubMed

    Bjorn, M J; Larrick, J; Piatak, M; Wilson, K J

    1984-10-23

    Two translational inhibitors (pokeweed antiviral protein and pokeweed antiviral protein II) isolated from the leaves of the pokeweed plant, Phytolacca americana, were characterized as to their behavior during reverse-phase HPLC and their amino-terminal sequences. Alignment of the sequences demonstrated that a substantial degree of homology was present (10 of 29 identical residues). Pokeweed antiviral protein was shown by reverse-phase chromatography to be composed of at least two components, pokeweed antiviral proteina and pokeweed antiviral proteinb, which comigrated on sodium dodecyl sulfate polyacrylamide gel electrophoresis, shared identical N-terminal amino-acid sequences through residue 31, and had similar specific activities in a cell-free translation inhibition assay. Pokeweed antiviral protein II was covalently coupled to a monoclonal antibody that recognizes the transferrin receptor (anti-transferrin receptor). The disulfide-linked conjugate inhibited protein synthesis in the human breast tumor cell line MCF-7, whereas anti-transferrin receptor, pokeweed antiviral protein II, or an immunotoxin composed of an irrelevant antiserum and pokeweed antiviral protein II, were nontoxic. The inhibitory dose 50% of anti-transferrin receptor-pokeweed antiviral protein II for MCF-7 cells was 0.7 nM, whereas the corresponding ricin A chain conjugate (anti-transferrin receptor-ricin A chain) was more potent with a inhibitory dose 50% of 0.1 nM. Pokeweed antiviral protein II can be added to the growing list of translation inhibitors that are effective as components of immunotoxins in vitro. Additional studies will be needed to determine whether pokeweed antiviral protein II immunotoxins provide advantageous properties for in vivo applications. PMID:6091760

  9. Immunological Functions of the Membrane Proximal Region of MHC Class II Molecules

    PubMed Central

    Harton, Jonathan; Jin, Lei; Hahn, Amy; Drake, Jim

    2016-01-01

    Major histocompatibility complex (MHC) class II molecules present exogenously derived antigen peptides to CD4 T cells, driving activation of naïve T cells and supporting CD4-driven immune functions. However, MHC class II molecules are not inert protein pedestals that simply bind and present peptides. These molecules also serve as multi-functional signaling molecules delivering activation, differentiation, or death signals (or a combination of these) to B cells, macrophages, as well as MHC class II-expressing T cells and tumor cells. Although multiple proteins are known to associate with MHC class II, interaction with STING (stimulator of interferon genes) and CD79 is essential for signaling. In addition, alternative transmembrane domain pairing between class II α and β chains influences association with membrane lipid sub-domains, impacting both signaling and antigen presentation. In contrast to the membrane-distal region of the class II molecule responsible for peptide binding and T-cell receptor engagement, the membrane-proximal region (composed of the connecting peptide, transmembrane domain, and cytoplasmic tail) mediates these “non-traditional” class II functions. Here, we review the literature on the function of the membrane-proximal region of the MHC class II molecule and discuss the impact of this aspect of class II immunobiology on immune regulation and human disease. PMID:27006762

  10. Endocytosis and degradative sorting of NMDA receptors by conserved membrane-proximal signals.

    PubMed

    Scott, Derek B; Michailidis, Ioannis; Mu, Yuanyue; Logothetis, Diomedes; Ehlers, Michael D

    2004-08-11

    Regulation of the abundance of NMDA receptors (NMDARs) at excitatory synapses is critical during changes in synaptic efficacy underlying learning and memory as well as during synapse formation throughout neural development. However, the molecular signals that govern NMDAR delivery, maintenance, and internalization remain unclear. In this study, we identify a conserved family of membrane-proximal endocytic signals, two within the NMDAR type 1 (NR1) subunit and one within the NR2A and NR2B subunits, necessary and sufficient to drive the internalization of NMDARs. These endocytic motifs reside in the region of NMDAR subunits immediately after the fourth membrane segment, a region implicated in use-dependent rundown and NMDA channel inactivation. Although endocytosis driven by the distal C-terminal domain of NR2B is followed by rapid recycling, internalization mediated by membrane-proximal motifs selectively targets receptors to late endosomes and accelerates degradation. These results define a novel conserved signature of NMDARs regulating internalization and postendocytic trafficking. PMID:15306643

  11. Radioimmunoassay of Pro-. gamma. -melanotropin, the amino-terminal fragment of proopiolipomelanocortin. [Swine

    SciTech Connect

    Ekman, R.; Hakanson, R.; Larsson, I.; Sundler, F.; Thorell, J.I.

    1982-08-01

    A RIA has been developed for natural porcine pro-..gamma..-MSH, the 103-amino acid peptide that represents the amino-terminal part of proopiolipomelanocortin. Rabbits were immunized with the purified peptide polymerized with glutaraldehyde. The antiserum is directed against the amino-terminial end of the antigen and does not cross-react with corticotropin, ..beta..-lipotropin, ..beta..-endorphin, ..gamma../sub 3/MSH, or ..gamma../sub 2/MSH. The minimum detectable concentration is 0.15 ng/ml standard pro-..gamma..MSH (15 pg/tube). Pro-..gamma..MSH-like immunoreactivity was detected in plasma and extracts of the hypothalamus and pituitary of pigs. Gel chromatography of these extracts revealed at least three immunoreactive peaks in the anterior and neurointermediate lobes of the pituitary, wheras two immunoreactive peaks were found in extracts of the hypothalalmus. (Endocrinology 111:578,1982)

  12. A new strategy for assembling multifunctional nanocomposites with iron oxide and amino-terminated PAMAM dendrimers.

    PubMed

    Zhang, Ying; Liu, Jing-Ying; Yang, Fang; Zhang, Ya-Jing; Yao, Qi; Cui, Tie-Yu; Zhao, Xiang; Zhang, Zhi-Dong

    2009-12-01

    A new strategy for assembling multifunctional nanocomposites with magnetic particles and amino dendrimers was reported. In this strategy, the amino terminated PAMAM G5.0 and Fe(3)O(4) NPs prepared by co-deposition method and further modified by aminosilane by two sol-gel processes were combined with the hydrophilic spacer of PEG dicarboxylate by amidation. The nanocomposites were characterized by means of X-ray diffraction (XRD), transmission electron microscopy (TEM), X-ray photoelectron spectroscopy (XPS), atom force microscopy (AFM), superconducting quantum interference device (SQUID) magnetometer, and hydrophilicity analysis. The results showed that the multifunctional nanocomposites were spherical with the mean diameter of 180 nm and exhibited good dispersion and hydrophilicity. The new strategy put forward here provides an effective route to functionalizing Fe(3)O(4) NPs with various amino dendrimers for drug and gene delivery as well as biological detection. PMID:19578982

  13. A cluster of negative charges at the amino terminal tail of CFTR regulates ATP-dependent channel gating

    PubMed Central

    Fu, Jian; Ji, Hong-Long; Naren, Anjaparavanda P; Kirk, Kevin L

    2001-01-01

    The cystic fibrosis transmembrane conductance regulator (CFTR) chloride channel is activated by protein kinase A (PKA) phosphorylation of its R domain and by ATP binding at its nucleotide-binding domains (NBDs). Here we investigated the functional role of a cluster of acidic residues in the amino terminal tail (N-tail) that also modulate CFTR channel gating by an unknown mechanism.A disease-associated mutant that lacks one of these acidic residues (D58N CFTR) exhibited lower macroscopic currents in Xenopus oocytes and faster deactivation following washout of a cAMP -activating cocktail than wild-type CFTR.In excised membrane patches D58N CFTR exhibited a two-fold reduction in single channel open probability due primarily to shortened open channel bursts.Replacing this and two nearby acidic residues with alanines (D47A, E54A, D58A) also reduced channel activity, but had negligible effects on bulk PKA phosphorylation or on the ATP dependence of channel activation.Conversely, the N-tail triple mutant exhibited a markedly inhibited response to AMP-PNP, a poorly hydrolysable ATP analogue that can nearly lock open the wild-type channel. The N-tail mutant had both a slower response to AMP-PNP (activation half-time of 140 ± 20 s vs. 21 ± 4 s for wild type) and a lower steady-state open probability following AMP-PNP addition (0.68 ± 0.08 vs. 0.92 ± 0.03 for wild type).Introducing the N-tail mutations into K1250A CFTR, an NBD2 hydrolysis mutant that normally exhibits very long open channel bursts, destabilized the activity of this mutant as evidenced by decreased macroscopic currents and shortened open channel bursts.We propose that this cluster of acidic residues modulates the stability of CFTR channel openings at a step that is downstream of ATP binding and upstream of ATP hydrolysis, probably at NBD2. PMID:11600681

  14. Conformational flexibility in the apolipoprotein E amino-terminal domain structure determined from three new crystal forms: implications for lipid binding.

    PubMed Central

    Segelke, B. W.; Forstner, M.; Knapp, M.; Trakhanov, S. D.; Parkin, S.; Newhouse, Y. M.; Bellamy, H. D.; Weisgraber, K. H.; Rupp, B.

    2000-01-01

    An amino-terminal fragment of human apolipoprotein E3 (residues 1-165) has been expressed and crystallized in three different crystal forms under similar crystallization conditions. One crystal form has nearly identical cell dimensions to the previously reported orthorhombic (P2(1)2(1)2(1)) crystal form of the amino-terminal 22 kDa fragment of apolipoprotein E (residues 1-191). A second orthorhombic crystal form (P2(1)2(1)2(1) with cell dimensions differing from the first form) and a trigonal (P3(1)21) crystal form were also characterized. The structures of the first orthorhombic and the trigonal form were determined by seleno-methionine multiwavelength anomalous dispersion, and the structure of the second orthorhombic form was determined by molecular replacement using the structure from the trigonal form as a search model. A combination of modern experimental and computational techniques provided high-quality electron-density maps, which revealed new features of the apolipoprotein E structure, including an unambiguously traced loop connecting helices 2 and 3 in the four-helix bundle and a number of multiconformation side chains. The three crystal forms contain a common intermolecular, antiparallel packing arrangement. The electrostatic complimentarity observed in this antiparallel packing resembles the interaction of apolipoprotein E with the monoclonal antibody 2E8 and the low density lipoprotein receptor. Superposition of the model structures from all three crystal forms reveals flexibility and pronounced kinks in helices near one end of the four-helix bundle. This mobility at one end of the molecule provides new insights into the structural changes in apolipoprotein E that occur with lipid association. PMID:10850798

  15. Complete dissociation of the HIV-1 gp41 ectodomain and membrane proximal regions upon phospholipid binding

    PubMed Central

    Roche, Julien; Louis, John M.; Aniana, Annie; Ghirlando, Rodolfo; Bax, Ad

    2015-01-01

    The envelope glycoprotein gp41 mediates the process of membrane fusion that enables entry of the HIV-1 virus into the host cell. Strong lipid affinity of the ectodomain suggests that its heptad repeat regions play an active role in destabilizing membranes by directly binding to the lipid bilayers and thereby lowering the free-energy barrier for membrane fusion. In such a model, immediately following the shedding of gp120, the N-heptad and C-heptad helices dissociate and melt into the host cell and viral membranes, respectively, pulling the destabilized membranes into juxtaposition, ready for fusion. Post-fusion, reaching the final 6-helix bundle (6HB) conformation then involves competition between intermolecular interactions needed for formation of the symmetric 6HB trimer and the membrane affinity of gp41's ectodomain, including its membrane-proximal regions. Our solution NMR study of the structural and dynamic properties of three constructs containing the ectodomain of gp41 with and without its membrane-proximal regions suggests that these segments do not form inter-helical interactions until the very late steps of the fusion process. Interactions between the polar termini of the heptad regions, which are not associating with the lipid surface, therefore may constitute the main driving force initiating formation of the final post-fusion states. The absence of significant intermolecular ectodomain interactions in the presence of dodecyl phosphocholine highlights the importance of trimerization of gp41’s transmembrane helix to prevent complete dissociation of the trimer during the course of fusion. PMID:25631354

  16. A Conserved Motif in the Membrane Proximal C-Terminal Tail of Human Muscarinic M1 Acetylcholine Receptors Affects Plasma Membrane Expression

    PubMed Central

    Ehlert, Frederick J.; Shults, Crystal A.

    2010-01-01

    We investigated the functional role of a conserved motif, F(x)6LL, in the membrane proximal C-tail of the human muscarinic M1 (hM1) receptor. By use of site-directed mutagenesis, several different point mutations were introduced into the C-tail sequence 423FRDTFRLLL431. Wild-type and mutant hM1 receptors were transiently expressed in Chinese hamster ovary cells, and the amount of plasma membrane-expressed receptor was determined by use of intact, whole-cell [3H]N-methylscopolamine binding assays. The plasma membrane expression of hM1 receptors possessing either L430A or L431A or both point mutations was significantly reduced compared with the wild type. The hM1 receptor possessing a L430A/L431A double-point mutation was retained in the endoplasmic reticulum (ER), and atropine treatment caused the redistribution of the mutant receptor from the ER to the plasma membrane. Atropine treatment also caused an increase in the maximal response and potency of carbachol-stimulated phosphoinositide hydrolysis elicited by the L430A/L431A mutant. The effect of atropine on the L430A/L431A receptor mutant suggests that L430 and L431 play a role in folding hM1 receptors, which is necessary for exit from the ER. Using site-directed mutagenesis, we also identified amino acid residues at the base of transmembrane-spanning domain 1 (TM1), V46 and L47, that, when mutated, reduce the plasma membrane expression of hM1 receptors in an atropine-reversible manner. Overall, these mutagenesis data show that amino acid residues in the membrane-proximal C-tail and base of TM1 are necessary for hM1 receptors to achieve a transport-competent state. PMID:19841475

  17. The amino-terminal segment in the β-domain of δ-cadinene synthase is essential for catalysis.

    PubMed

    González, Verónica; Grundy, Daniel J; Faraldos, Juan A; Allemann, Rudolf K

    2016-08-21

    Despite its distance from the active site the flexible amino-terminal segment (NTS) in the β-domain of the plant sesquiterpene cyclase δ-cadinene synthase (DCS) is essential for active site closure and desolvation events during catalysis. PMID:27431578

  18. The amino-terminal domain of ORF149 of koi herpesvirus is preferentially targeted by IgM from carp populations surviving infection.

    PubMed

    Torrent, F; Villena, A; Lee, P A; Fuchs, W; Bergmann, S M; Coll, J M

    2016-10-01

    Recombinantly expressed fragments of the protein encoded by ORF149 (pORF149), a structural protein from the common- and koi-carp-infecting cyprinid herpesvirus-3 (CyHV-3) that was previously shown to be antigenic, were used to obtain evidence that its amino-terminal part contains immunodominant epitopes in fish populations that survived the infection. To obtain such evidence, nonspecific binding of carp serum tetrameric IgM had to be overcome by a novel ELISA protocol (rec2-ELISA). Rec2-ELISA involved pre-adsorption of carp sera with a heterologous recombinant fragment before incubation with pORF149 fragments and detection with anti-carp IgM monoclonal antibodies. Only in this way was it possible to distinguish between sera from uninfected and survivor carp populations. Although IgM from survivors recognised pORF149 fragments to a lesser degree than whole virus, specificity was confirmed by correlation of rec2- and CyHV-3-ELISAs, inhibition of rec2-ELISA by an excess of frgIIORF149, ELISA using IgM-capture, Western blotting, and reduction of reactivity in CyHV-3-ELISA by pre-adsorption of sera with frgIIORF149. The similarity of IgM-binding profiles between frgIORF149 (amino acid residues 42-629) and frgIIORF149 (42-159) and their reactivities with previously described anti-CyHV-3 monoclonal antibodies confirmed that most pORF149 epitopes were localised in its amino-terminal part. PMID:27383208

  19. Amino-terminated biphenylthiol self-assembled monolayers as highly reactive molecular templates

    SciTech Connect

    Meyerbroeker, N.; Waske, P.; Zharnikov, M.

    2015-03-14

    Self-assembled monolayers (SAMs) with amino tail groups are of interest due to their ability of coupling further compounds. Such groups can be, in particular, created by electron irradiation of nitro- or nitrile-substituted aromatic SAMs, which provide a basis for chemical nanolithography and the fabrication of functionalized nanomembranes. An estimate of reactivity of the created amino groups requires a reference system of homogeneous, amino-terminated aromatic SAMs, which can also be used as a highly reactive molecular template. Here, we describe the synthesis of 4′-aminobiphenyl-4-thiol (ABPT) and SAMs prepared from this precursor on Au(111). The monolayers were characterized by X-ray photoelectron spectroscopy and near edge X-ray absorption fine structure spectroscopy, which revealed that they are well defined, chemically uniform, densely packed, and highly ordered. To examine the influence of electron irradiation on the reactivity of the terminal amino groups, ABPT SAMs were exposed to low energy (50 eV) electrons up to a dose of 40 mC/cm{sup 2} and, subsequently, immersed in either trifluoroacetic, pentafluoropropionic, or heptafluorobutyric anhydride. Analysing the amount of the attached anhydride species made it possible to determine the percentage of reactive amino groups as well as the effect of steric hindrance upon the coupling reaction. The above results are compared with those obtained for the well-established nitro-substituted biphenylthiol monolayers.

  20. Production of functional small interfering RNAs by an amino-terminal deletion mutant of human Dicer

    PubMed Central

    Kennedy, Edward M.; Whisnant, Adam W.; Kornepati, Anand V. R.; Marshall, Joy B.; Bogerd, Hal P.; Cullen, Bryan R.

    2015-01-01

    Although RNA interference (RNAi) functions as a potent antiviral innate-immune response in plants and invertebrates, mammalian somatic cells appear incapable of mounting an RNAi response and few, if any, small interfering RNAs (siRNAs) can be detected. To examine why siRNA production is inefficient, we have generated double-knockout human cells lacking both Dicer and protein kinase RNA-activated. Using these cells, which tolerate double-stranded RNA expression, we show that a mutant form of human Dicer lacking the amino-terminal helicase domain can process double-stranded RNAs to produce high levels of siRNAs that are readily detectable by Northern blot, are loaded into RNA-induced silencing complexes, and can effectively and specifically inhibit the expression of cognate mRNAs. Remarkably, overexpression of this mutant Dicer, but not wild-type Dicer, also resulted in a partial inhibition of Influenza A virus—but not poliovirus—replication in human cells. PMID:26621737

  1. Introduced Amino Terminal Epitopes Can Reduce Surface Expression of Neuronal Nicotinic Receptors

    PubMed Central

    Bracamontes, John R.; Akk, Gustav; Steinbach, Joe Henry

    2016-01-01

    Epitopes accessible on the surface of intact cells are extremely valuable in studies of membrane proteins, allowing quantification and determination of the distribution of proteins as well as identification of cells expressing large numbers of proteins. However for many membrane proteins there are no suitable antibodies to native sequences, due to lack of availability, low affinity or lack of specificity. In these cases the use of an introduced epitope at specific sites in the protein of interest can often provide a suitable tool for studies. However, the introduction of the epitope sequence has the potential to affect protein expression, the assembly of multisubunit proteins or transport to the surface membrane. We find that surface expression of heteromeric neuronal nicotinic receptors containing the α4 and β4 subunits can be affected by introduced epitopes when inserted near the amino terminus of a subunit. The FLAG epitope greatly reduces surface expression when introduced into either α4 or β4 subunits, the V5 epitope has little effect when placed in either, while the Myc epitope reduces expression more when inserted into β4 than α4. These results indicate that the extreme amino terminal region is important for assembly of these receptors, and demonstrate that some widely used introduced epitopes may severely reduce surface expression. PMID:26963253

  2. Oncogenic transformation by vrel requires an amino-terminal activation domain

    SciTech Connect

    Kamens, J.; Brent, R. . Dept. of Molecular Biology); Richardson, P.; Gilmore, T. . Dept. of Biology); Mosialos, G. . Dept. of Chemistry)

    1990-06-01

    The mechanism by which the products of the v-{ital rel} oncogene, the corresponding c-{ital rel} proto-oncogene, and the related {ital dorsal} gene of {ital Drosophila melanogaster} exert their effects is not clear. The authors show that the v-{ital rel}, chicken c-{ital rel}, and {ital dorsal} proteins activated gene expression when fused to LexA sequences and bound to DNA upstream of target genes in {ital Saccharomyces cerevisiae}. They have defined two distinct activation regions in the c-{ital rel} protein. Region I, located in the amino-terminal half of {ital rel} and {ital dorsal} proteins, contains no stretches of glutamines, prolines, or acidic amino acids and therefore may be a novel activation domain. Lesions in the v-{ital rel} protein that diminished or abolished oncogenic transformation of avian spleen cells correspondingly affected transcription activation by region I. Region II, located in the carboxy terminus of the c-{ital rel} protein, is highly acidic. Region II is not present in the v-{ital rel} protein or in a transforming mutant derivative of the c-{ital rel} protein. The authors' results show that the oncogenicity of Rel proteins requires activation region I and suggest that the biological function of {ital rel} and {ital dorsal} proteins depends on transcription activation by this region.

  3. Interference of amino-terminal desmin fragments with desmin filament formation.

    PubMed

    Bär, Harald; Sharma, Sarika; Kleiner, Helga; Mücke, Norbert; Zentgraf, Hanswalter; Katus, Hugo A; Aebi, Ueli; Herrmann, Harald

    2009-11-01

    Short polypeptides from intermediate filament (IF) proteins containing one of the two IF-consensus motifs interfere severely with filament assembly in vitro. We now have systematically investigated a series of larger fragments of the muscle-specific IF protein desmin representing entire functional domains such as coil1 or coil 2. "Half molecules" comprising the amino-terminal portion of desmin, such as DesDeltaC240 and the "tagged" derivative Des(ESA)DeltaC244, assembled into large, roundish aggregates already at low ionic strength, DesDeltaC250 formed extended, relatively uniform filaments, whereas DesDeltaC265 and DesDeltaC300 were soluble under these conditions. Surprisingly, all mutant desmin fragments assembled very rapidly into long thick filaments or spacious aggregates when the ionic strength was raised to standard assembly conditions. In contrast, when these desmin mutants were assembled in the presence of wild-type (WT) desmin, their assembly properties were completely changed: The elongation of the two shorter desmin fragments was completely inhibited by WT desmin, whereas DesDeltaC250, DesDeltaC265 and DesDeltaC300 coassembled with desmin into filaments, but these mixed filaments were distinctly disturbed and exhibited a very different phenotype for each mutant. After transfection into fibroblasts and cardiomyocytes, the truncated mutant Des (ESA)DeltaC244 localized largely to the cytoplasm, as revealed by a tag-specific monoclonal antibody, and also partially colocalized there with the collapsed endogenous vimentin and desmin systems indicating its interference with IF-organizing processes. In contrast, in cells without an authentic cytoplasmic IF system such as line SW13, Des(ESA)DeltaC242 entered the nucleus and was deposited in small dot-like structures in chromatin-free spaces without any noticeable effect on nuclear morphology. PMID:19530175

  4. Insights into the Conformation of the Membrane Proximal Regions Critical to the Trimerization of the HIV-1 gp41 Ectodomain Bound to Dodecyl Phosphocholine Micelles

    PubMed Central

    Louis, John M.; Baber, James L.; Ghirlando, Rodolfo; Aniana, Annie; Bax, Ad; Roche, Julien

    2016-01-01

    The transitioning of the ectodomain of gp41 from a pre-hairpin to a six-helix bundle conformation is a crucial aspect of virus-cell fusion. To gain insight into the intermediary steps of the fusion process we have studied the pH and dodecyl phosphocholine (DPC) micelle dependent trimer association of gp41 by systematic deletion analysis of an optimized construct termed 17–172 (residues 528 to 683 of Env) that spans the fusion peptide proximal region (FPPR) to the membrane proximal external region (MPER) of gp41, by sedimentation velocity and double electron-electron resonance (DEER) EPR spectroscopy. Trimerization at pH 7 requires the presence of both the FPPR and MPER regions. However, at pH 4, the protein completely dissociates to monomers. DEER measurements reveal a partial fraying of the C-terminal MPER residues in the 17–172 trimer while the other regions, including the FPPR, remain compact. In accordance, truncating nine C-terminal MPER residues (675–683) in the 17–172 construct does not shift the trimer-monomer equilibrium significantly. Thus, in the context of the gp41 ectodomain spanning residues 17–172, trimerization is clearly dependent on FPPR and MPER regions even when the terminal residues of MPER unravel. The antibody Z13e1, which spans both the 2F5 and 4E10 epitopes in MPER, binds to 17–172 with a Kd of 1 ± 0.12 μM. Accordingly, individual antibodies 2F5 and 4E10 also recognize the 17–172 trimer/DPC complex. We propose that binding of the C-terminal residues of MPER to the surface of the DPC micelles models a correct positioning of the trimeric transmembrane domain anchored in the viral membrane. PMID:27513582

  5. Insights into the Conformation of the Membrane Proximal Regions Critical to the Trimerization of the HIV-1 gp41 Ectodomain Bound to Dodecyl Phosphocholine Micelles.

    PubMed

    Louis, John M; Baber, James L; Ghirlando, Rodolfo; Aniana, Annie; Bax, Ad; Roche, Julien

    2016-01-01

    The transitioning of the ectodomain of gp41 from a pre-hairpin to a six-helix bundle conformation is a crucial aspect of virus-cell fusion. To gain insight into the intermediary steps of the fusion process we have studied the pH and dodecyl phosphocholine (DPC) micelle dependent trimer association of gp41 by systematic deletion analysis of an optimized construct termed 17-172 (residues 528 to 683 of Env) that spans the fusion peptide proximal region (FPPR) to the membrane proximal external region (MPER) of gp41, by sedimentation velocity and double electron-electron resonance (DEER) EPR spectroscopy. Trimerization at pH 7 requires the presence of both the FPPR and MPER regions. However, at pH 4, the protein completely dissociates to monomers. DEER measurements reveal a partial fraying of the C-terminal MPER residues in the 17-172 trimer while the other regions, including the FPPR, remain compact. In accordance, truncating nine C-terminal MPER residues (675-683) in the 17-172 construct does not shift the trimer-monomer equilibrium significantly. Thus, in the context of the gp41 ectodomain spanning residues 17-172, trimerization is clearly dependent on FPPR and MPER regions even when the terminal residues of MPER unravel. The antibody Z13e1, which spans both the 2F5 and 4E10 epitopes in MPER, binds to 17-172 with a Kd of 1 ± 0.12 μM. Accordingly, individual antibodies 2F5 and 4E10 also recognize the 17-172 trimer/DPC complex. We propose that binding of the C-terminal residues of MPER to the surface of the DPC micelles models a correct positioning of the trimeric transmembrane domain anchored in the viral membrane. PMID:27513582

  6. Structural Characterization of HIV gp41 with the Membrane-proximal External Region

    SciTech Connect

    Shi, W.; Bohon, J; Han, D; Habte, H; Qin, Y; Cho, M; Chance, M

    2010-01-01

    Human immunodeficiency virus, type 1 (HIV-1) envelope glycoprotein (gp120/gp41) plays a critical role in virus infection and pathogenesis. Three of the six monoclonal antibodies considered to have broadly neutralizing activities (2F5, 4E10, and Z13e1) bind to the membrane-proximal external region (MPER) of gp41. This makes the MPER a desirable template for developing immunogens that can elicit antibodies with properties similar to these monoclonal antibodies, with a long term goal of developing antigens that could serve as novel HIV vaccines. In order to provide a structural basis for rational antigen design, an MPER construct, HR1-54Q, was generated for x-ray crystallographic and x-ray footprinting studies to provide both high resolution atomic coordinates and verification of the solution state of the antigen, respectively. The crystal structure of HR1-54Q reveals a trimeric, coiled-coil six-helical bundle, which probably represents a postfusion form of gp41. The MPER portion extends from HR2 in continuation of a slightly bent long helix and is relatively flexible. The structures observed for the 2F5 and 4E10 epitopes agree well with existing structural data, and enzyme-linked immunosorbent assays indicate that the antigen binds well to antibodies that recognize the above epitopes. Hydroxyl radical-mediated protein footprinting of the antigen in solution reveals specifically protected and accessible regions consistent with the predictions based on the trimeric structure from the crystallographic data. Overall, the HR1-54Q antigen, as characterized by crystallography and footprinting, represents a postfusion, trimeric form of HIV gp41, and its structure provides a rational basis for gp41 antigen design suitable for HIV vaccine development.

  7. Structural characterization of HIV gp41 with the membrane-proximal external region.

    PubMed

    Shi, Wuxian; Bohon, Jen; Han, Dong P; Habte, Habtom; Qin, Yali; Cho, Michael W; Chance, Mark R

    2010-07-30

    Human immunodeficiency virus, type 1 (HIV-1) envelope glycoprotein (gp120/gp41) plays a critical role in virus infection and pathogenesis. Three of the six monoclonal antibodies considered to have broadly neutralizing activities (2F5, 4E10, and Z13e1) bind to the membrane-proximal external region (MPER) of gp41. This makes the MPER a desirable template for developing immunogens that can elicit antibodies with properties similar to these monoclonal antibodies, with a long term goal of developing antigens that could serve as novel HIV vaccines. In order to provide a structural basis for rational antigen design, an MPER construct, HR1-54Q, was generated for x-ray crystallographic and x-ray footprinting studies to provide both high resolution atomic coordinates and verification of the solution state of the antigen, respectively. The crystal structure of HR1-54Q reveals a trimeric, coiled-coil six-helical bundle, which probably represents a postfusion form of gp41. The MPER portion extends from HR2 in continuation of a slightly bent long helix and is relatively flexible. The structures observed for the 2F5 and 4E10 epitopes agree well with existing structural data, and enzyme-linked immunosorbent assays indicate that the antigen binds well to antibodies that recognize the above epitopes. Hydroxyl radical-mediated protein footprinting of the antigen in solution reveals specifically protected and accessible regions consistent with the predictions based on the trimeric structure from the crystallographic data. Overall, the HR1-54Q antigen, as characterized by crystallography and footprinting, represents a postfusion, trimeric form of HIV gp41, and its structure provides a rational basis for gp41 antigen design suitable for HIV vaccine development. PMID:20525690

  8. Structural Characterization of HIV gp41 with the Membrane-proximal External Region*

    PubMed Central

    Shi, Wuxian; Bohon, Jen; Han, Dong P.; Habte, Habtom; Qin, Yali; Cho, Michael W.; Chance, Mark R.

    2010-01-01

    Human immunodeficiency virus, type 1 (HIV-1) envelope glycoprotein (gp120/gp41) plays a critical role in virus infection and pathogenesis. Three of the six monoclonal antibodies considered to have broadly neutralizing activities (2F5, 4E10, and Z13e1) bind to the membrane-proximal external region (MPER) of gp41. This makes the MPER a desirable template for developing immunogens that can elicit antibodies with properties similar to these monoclonal antibodies, with a long term goal of developing antigens that could serve as novel HIV vaccines. In order to provide a structural basis for rational antigen design, an MPER construct, HR1-54Q, was generated for x-ray crystallographic and x-ray footprinting studies to provide both high resolution atomic coordinates and verification of the solution state of the antigen, respectively. The crystal structure of HR1-54Q reveals a trimeric, coiled-coil six-helical bundle, which probably represents a postfusion form of gp41. The MPER portion extends from HR2 in continuation of a slightly bent long helix and is relatively flexible. The structures observed for the 2F5 and 4E10 epitopes agree well with existing structural data, and enzyme-linked immunosorbent assays indicate that the antigen binds well to antibodies that recognize the above epitopes. Hydroxyl radical-mediated protein footprinting of the antigen in solution reveals specifically protected and accessible regions consistent with the predictions based on the trimeric structure from the crystallographic data. Overall, the HR1-54Q antigen, as characterized by crystallography and footprinting, represents a postfusion, trimeric form of HIV gp41, and its structure provides a rational basis for gp41 antigen design suitable for HIV vaccine development. PMID:20525690

  9. Amino-terminal pro-brain natriuretic peptide in children with latent rheumatic heart disease

    PubMed Central

    Zachariah, Justin P; Aliku, Twalib; Scheel, Amy; Hasan, Babar S; Lwabi, Peter; Sable, Craig; Beaton, Andrea Z

    2016-01-01

    Background: Rheumatic heart disease (RHD) is a global cause of early heart failure. Early RHD is characterized by valvar regurgitation, leading to ventricular distention and possible elaboration of amino-terminal pro-brain natriuretic peptide (NT-proBNP). We investigated the ability of NT-proBNP to distinguish cases of latent RHD detected by echocardiographic screening from the controls. Materials and Methods: Ugandan children (N = 44, 36% males, mean age: 12 ± 2 years) with latent RHD (cases) and siblings (controls) by echocardiography were enrolled. Cases and controls were matched for age and sex, and they had normal hemoglobin (mean: 12.8 mg/dL). Children with congenital heart disease, pregnancy, left ventricular dilation or ejection fraction (EF) below 55%, or other acute or known chronic health conditions were excluded. RHD cases were defined by the World Heart Federation (WHF) 2012 consensus guideline criteria as definite. Controls had no echocardiography (echo) evidence for RHD. At the time of echo, venous blood samples were drawn and stored as serum. NT-proBNP levels were measured using sandwich immunoassay. Paired t-tests were used to compare NT-proBNP concentrations including sex-specific analyses. Results: The mean NT-proBNP concentration in the cases was 105.74 ± 67.21 pg/mL while in the controls, it was 86.63 ± 55.77 pg/mL. The cases did not differ from the controls (P = 0.3). In sex-specific analyses, male cases differed significantly from the controls (158.78 ± 68.82 versus 76 ± 42.43, P = 0.008). Female cases did not differ from the controls (75.44 ± 45.03 versus 92.30 ± 62.35 respectively, P = 0.4). Conclusion: Serum NT-proBNP did not distinguish between latent RHD cases and the controls. Sex and within-family exposures may confound this result. More investigation into biomarker-based RHD detection is warranted. PMID:27212845

  10. Mapping of the amino-terminal half of polyomavirus middle-T antigen indicates that this region is the binding domain for pp60c-src.

    PubMed Central

    Markland, W; Smith, A E

    1987-01-01

    The majority of the carboxy-terminal half of polyomavirus middle-T antigen has been variously mutated and, with the exception of the putative membrane-binding domain (amino acids 394 to 415), was found to be largely dispensible for the transforming activity of the protein. A comparison of the small-T antigen amino acid sequences (equivalent to the region of middle-T encoded by exon 1) of simian virus 40, BK virus, polyomavirus, and a recently described hamster papovavirus highlighted regions of potential interest in mapping functions to the amino-terminal half of polyomavirus middle-T antigen. The regions of interest include amino acids 168 to 191 (previously investigated by this group [S. H. Cheng, W. Markland, A. F. Markham, and A. E. Smith, EMBO J. 5:325-334, 1986]), two cysteine-rich clusters (amino acids 120 to 125 and 148 to 153), and amino acids 92 to 117 (within the limits of the previously described hr-t mutant, SD15). Point mutations, multiple point mutations, and deletions were made by site-specific and site-directed mutagenesis within the cysteine-rich clusters and residues 92 to 117. Studies of the transforming ability of the altered middle-T species demonstrated that this activity is highly sensitive to amino acid changes. All four regions (as defined above) within the amino-terminal half of middle-T have now been studied in detail. The phenotype of the mutants is predominantly transformation defective, and the corresponding variant middle-T species are characterized by being either totally or severely handicapped in the ability to associate actively with pp60c-src. Whether the mutations affect the regions of interaction between middle-T and pp60c-src or simply interfere with the overall conformation of this domain is not known. However, there would appear to be a conformational constraint on this portion of the molecule with regard to its interaction with pp60c-src and by extension to the ability of the middle-T species to transform. Images PMID

  11. Amino-terminal palmitate or polybasic domain can provide required second signal to myristate for membrane binding of p56lck.

    PubMed

    Kwong, J; Lublin, D M

    1995-02-15

    Recent work has shown that several members of the src family of protein tyrosine kinases (PTKs) are modified by palmitoylation, including p56lck and p59fyn but not p60src. Mapping of the sites of palmitoylation in p56lck identified cys3 as the major site and cys5 as a minor site of palmitoylation. A non-palmitoylated p56lck(cys3,5-->ser) mutant was localized exclusively in the cytoplasm despite the presence of amino-terminal myristoylation, thus indicating that palmitoylation of p56lck was necessary for membrane binding. The addition of a domain of six lysine residues to a non-palmitoylated p56lck mutant was sufficient to re-establish membrane binding but not to target the non-palmitoylated p56lck to caveolae. These results establish that two signals, myristoylation plus either palmitoylation or a polybasic domain, are necessary for membrane binding of src family PTKs. PMID:7864883

  12. A Membrane Proximal Helix in the Cytosolic Domain of the Human APP Interacting Protein LR11/SorLA Deforms Liposomes

    PubMed Central

    Gill, Richard L.; Wang, Xingsheng; Tian, Fang

    2014-01-01

    Over the last decade, compelling evidence has linked the development of Alzheimer’s disease (AD) to defective intracellular trafficking of the amyloid precursor protein (APP). Faulty APP trafficking results in an overproduction of Aβ peptides, which is generally agreed to be the primary cause of AD-related pathogenesis. LR11 (SorLA), a type I transmembrane sorting receptor, has emerged as a key regulator of APP trafficking and processing. It directly interacts with APP and diverts it away from amyloidogenic processing. The 54-residue cytosolic domain of LR11 is essential for its proper intracellular localization and trafficking which, in turn, determines the fate of APP. Here, we have found a surprising membrane-proximal amphipathic helix in the cytosolic domain of LR11. Moreover, a peptide corresponding to this region folds into an α-helical structure in the presence of liposomes and transforms liposomes to small vesicles and tubule-like particles. We postulate that this amphipathic helix may contribute to the dynamic remodeling of membrane structure and facilitate LR11 intracellular transport. PMID:24866012

  13. A membrane proximal helix in the cytosolic domain of the human APP interacting protein LR11/SorLA deforms liposomes.

    PubMed

    Gill, Richard L; Wang, Xingsheng; Tian, Fang

    2015-01-01

    Over the last decade, compelling evidence has linked the development of Alzheimer's disease (AD) to defective intracellular trafficking of the amyloid precursor protein (APP). Faulty APP trafficking results in an overproduction of Aβ peptides, which is generally agreed to be the primary cause of AD-related pathogenesis. LR11 (SorLA), a type I transmembrane sorting receptor, has emerged as a key regulator of APP trafficking and processing. It directly interacts with APP and diverts it away from amyloidogenic processing. The 54-residue cytosolic domain of LR11 is essential for its proper intracellular localization and trafficking which, in turn, determines the fate of APP. Here, we have found a surprising membrane-proximal amphipathic helix in the cytosolic domain of LR11. Moreover, a peptide corresponding to this region folds into an α-helical structure in the presence of liposomes and transforms liposomes to small vesicles and tubule-like particles. We postulate that this amphipathic helix may contribute to the dynamic remodeling of membrane structure and facilitate LR11 intracellular transport. PMID:24866012

  14. Chemical modification of silica-gel with hydroxyl- or amino-terminated polyamine for adsorption of Au(III)

    NASA Astrophysics Data System (ADS)

    Qu, Rongjun; Wang, Minghua; Sun, Changmei; Zhang, Ying; Ji, Chunnuan; Chen, Hou; Meng, Yanfeng; Yin, Ping

    2008-12-01

    Silica-gel chemically modified by γ-aminopropyltrimethoxysilane (APTS) reacted with methyl acrylate (MA) to form esterified silica-gel SiO 2-MA, and then SiO 2-MA reacted with ethanolamine (EA), diethanolamine (DEA), ethylenediamine (EDA), diethylenetriamine (DETA), triethylenetetramine (TETA) respectively to obtain five novel adsorbents, hydroxyl-terminated polyamine functionalized silica-gels (SiO 2-EA and SiO 2-DEA) and amino-terminated ones (SiO 2-EDA, SiO 2-DETA, and SiO 2-TETA). Their structures were characterized by FTIR, WAXD, thermal analysis, and elemental analysis. The investigation of adsorption kinetics of the five adsorbents for Au(III) under different temperatures showed that all the adsorption processes were endothermic in nature. The amino-terminated polyamine grafted silica-gels exhibited higher adsorption rates than the hydroxyl-terminated ones. The Langmuir model was better than Freundlich model to fit the adsorption isotherms of the five products for Au(III).

  15. A Simple Procedure for Constructing 5'-Amino-Terminated Oligodeoxynucleotides in Aqueous Solution

    NASA Technical Reports Server (NTRS)

    Bruick, Richard K.; Koppitz, Marcus; Joyce, Gerald F.; Orgel, Leslie E.

    1997-01-01

    A rapid method for the synthesis of oligodeoxynucleotides (ODNs) terminated by 5'-amino-5'-deoxythymidine is described. A 3'-phosphorylated ODN (the donor) is incubated in aqueous solution with 5'-amino- 5'-deoxythymidine in the presence of N-(3-dimethylaminopropyl)-)N'-ethylcarbodiimide hydrochloride (EDC), extending the donor by one residue via a phosphoramidate bond. Template- directed ligation of the extended donor and an acceptor ODN, followed by acid hydrolysis, yields the acceptor ODN extended by a single 5'-amino-5'-deoxythymidine residue at its 5'terminus.

  16. Modulation of Nonneutralizing HIV-1 gp41 Responses by an MHC-Restricted TH Epitope Overlapping Those of Membrane Proximal External Region Broadly Neutralizing Antibodies

    PubMed Central

    Zhang, Jinsong; Alam, S. Munir; Bouton-Verville, Hilary; Chen, Yao; Newman, Amanda; Stewart, Shelley; Jaeger, Frederick H.; Montefiori, David; Dennison, S. Moses; Haynes, Barton F.; Verkoczy, Laurent

    2014-01-01

    A goal of HIV-1 vaccine development is to elicit broadly neutralizing antibodies (BnAbs), but current immunization strategies fail to induce BnAbs, and for unknown reasons, often induce non-neutralizing Abs instead. To explore potential host genetic contributions controlling Ab responses to the HIV-1 Envelope (Env), we have used congenic strains to identify a critical role for MHC class II restriction in modulating Ab responses to the membrane proximal external region (MPER) of gp41, a key vaccine target. Immunized H-2d-congenic strains had more rapid, sustained, and elevated MPER+ Ab titers than those bearing other haplotypes, regardless of immunogen, adjuvant, or prime/boost regimen used, including formulations designed to provide T-cell help. H-2d restricted MPER+ serum Ab responses depended on CD4 TH interactions with Class II (as revealed in immunized intra-H-2d/b congenic or CD154-/- H-2d strains, and by selective abrogation of MPER re-stimulated, H-2d-restricted primed splenocytes by Class II-blocking Abs), and failed to neutralize HIV-1 in the TZM-b/l neutralization assay, coinciding with lack of specificity for an aspartate residue in the neutralization core of BnAb 2F5. Unexpectedly, H-2d restricted MPER+ responses functionally mapped to a core TH epitope partially overlapping the 2F5/z13/4E10 BnAb epitopes as well as non-neutralizing B-cell/Ab binding residues. We propose that Class II-restriction contributes to the general heterogeneity of non- neutralizing gp41 responses induced by Env. Moreover, the proximity of TH and B-cell epitopes in this restriction may have to be considered in re-designing minimal MPER immunogens aimed at exclusively binding BnAb epitopes and triggering MPER+ BnAbs. PMID:24465011

  17. Identification of an amino-terminal fragment of apolipoprotein E4 that localizes to neurofibrillary tangles of the Alzheimer's disease brain.

    PubMed

    Rohn, Troy T; Catlin, Lindsey W; Coonse, Kendra G; Habig, Jeffrey W

    2012-09-26

    Although the risk factor for harboring the apolipoprotein E4 (apoE4) allele in late-onset Alzheimer's disease (AD) is well known, the mechanism by which apoE4 contributes to AD pathogenesis has yet to be clarified. Preferential cleavage of the ApoE4 isoform relative to other polymorphic forms appears to be significant, as the resulting fragments are associated with hallmarks of AD. To examine the possible role of apoE4 proteolysis in AD, we designed a site-directed antibody directed at position D172, which would yield a predicted amino-terminal fragment previously identified in AD brain extracts. Western blot analysis utilizing this novel antibody, termed the amino-terminal apoE4 cleavage fragment (nApoE4CF) Ab, consistently identified the predicted amino-terminal fragment (∼18kDa) in several commercially available forms of human recombinant apoE4 purified from E. coli. Mass spectrometry confirmed the identity of this 18kDa fragment as being an amino-terminal fragment of apoE4. Immunohistochemical experiments indicated the nApoE4CF Ab specifically labeled neurofibrillary tangles (NFTs) in AD frontal cortex sections that colocalized with the mature tangle marker PHF-1. Taken together, these results suggest a novel cleavage event of apoE4, generating an amino-terminal fragment that localizes within NFTs of the AD brain. PMID:22902767

  18. Amino-terminal sequence of glycoprotein D of herpes simplex virus types 1 and 2

    SciTech Connect

    Eisenberg, R.J.; Long, D.; Hogue-Angeletti, R.; Cohen, G.H.

    1984-01-01

    Glycoprotein D (gD) of herpes simplex virus is a structural component of the virion envelope which stimulates production of high titers of herpes simplex virus type-common neutralizing antibody. The authors caried out automated N-terminal amino acid sequencing studies on radiolabeled preparations of gD-1 (gD of herpes simplex virus type 1) and gD-2 (gD of herpes simplex virus type 2). Although some differences were noted, particularly in the methionine and alanine profiles for gD-1 and gD-2, the amino acid sequence of a number of the first 30 residues of the amino terminus of gD-1 and gD-2 appears to be quite similar. For both proteins, the first residue is a lysine. When we compared out sequence data for gD-1 with those predicted by nucleic acid sequencing, the two sequences could be aligned (with one exception) starting at residue 26 (lysine) of the predicted sequence. Thus, the first 25 amino acids of the predicted sequence are absent from the polypeptides isolated from infected cells.

  19. Structure of the Zinc-Bound Amino-Terminal Domain of the NMDA Receptor NR2B Subunit

    SciTech Connect

    Karakas, E.; Simorowski, N; Furukawa, H

    2009-01-01

    N-methyl-D-aspartate (NMDA) receptors belong to the family of ionotropic glutamate receptors (iGluRs) that mediate the majority of fast excitatory synaptic transmission in the mammalian brain. One of the hallmarks for the function of NMDA receptors is that their ion channel activity is allosterically regulated by binding of modulator compounds to the extracellular amino-terminal domain (ATD) distinct from the L-glutamate-binding domain. The molecular basis for the ATD-mediated allosteric regulation has been enigmatic because of a complete lack of structural information on NMDA receptor ATDs. Here, we report the crystal structures of ATD from the NR2B NMDA receptor subunit in the zinc-free and zinc-bound states. The structures reveal the overall clamshell-like architecture distinct from the non-NMDA receptor ATDs and molecular determinants for the zinc-binding site, ion-binding sites, and the architecture of the putative phenylethanolamine-binding site.

  20. Terminal Interface Conformations Modulate Dimer Stability Prior to Amino Terminal Autoprocessing of HIV-1 Protease

    SciTech Connect

    Agniswamy, Johnson; Sayer, Jane M.; Weber, Irene T.; Louis, John M.

    2012-04-17

    The HIV-1 protease (PR) mediates its own release (autoprocessing) from the polyprotein precursor, Gag-Pol, flanked by the transframe region (TFR) and reverse transcriptase at its N- and C-termini, respectively. Autoprocessing at the N-terminus of PR mediates stable dimer formation essential for catalytic activity, leading to the formation of infectious virus. An antiparallel {beta}-sheet interface formed by the four N- and C-terminal residues of each subunit is important for dimer stability. Here, we present the first high-resolution crystal structures of model protease precursor-clinical inhibitor (PI darunavir or saquinavir) complexes, revealing varying conformations of the N-terminal flanking (S{sup -4}FNF{sup -1}) and interface residues (P{sup 1}QIT{sup 4}). A 180{sup o} rotation of the T{sup 4}-L{sup 5} peptide bond is accompanied by a new Q{sup 2}-L{sup 5} hydrogen bond and complete disengagement of PQIT from the {beta}-sheet dimer interface, which may be a feature for intramolecular autoprocessing. This result is consistent with drastically lower thermal stability by 14-20 C of PI complexes of precursors and the mature PR lacking its PQIT residues (by 18.3 C). Similar to the TFR-PR precursor, this deletion also results in a darunavir dissociation constant (2 x 10{sup 4})-fold higher and a markedly increased dimer dissociation constant relative to the mature PR. The terminal {beta}-sheet perturbations of the dimeric structure likely account for the drastically poorer inhibition of autoprocessing of TFR-PR relative to the mature PR, even though significant differences in active site-PI interactions in these structures were not observed. The novel conformations of the dimer interface may be exploited to target selectively the protease precursor prior to its N-terminal cleavage.

  1. Anti-NMDA Receptor Encephalitis Antibody Binding Is Dependent on Amino Acid Identity of a Small Region Within the GluN1 Amino Terminal Domain

    PubMed Central

    Gleichman, Amy J.; Spruce, Lynn A.; Dalmau, Josep; Seeholzer, Steven H.; Lynch, David R.

    2012-01-01

    Anti-NMDA receptor (NMDAR) encephalitis is a newly identified autoimmune disorder that targets NMDARs, causing severe neurological symptoms including hallucinations, psychosis, and seizures, and may result in death (Dalmau et al., 2008). However, the exact epitope to which these antibodies bind is unknown. A clearly defined antigenic region could provide more precise testing, allow for comparison of immunogenicity between patients to explore potential clinically relevant variations, elucidate the functional effects of antibodies, and make patients’ antibodies a more effective tool with which to study NMDAR function. Here, we use human cerebrospinal fluid to explore the antigenic region of the NMDAR. We created a series of mutants within the amino terminal domain of GluN1 that change patient antibody binding in transfected cells in stereotyped ways. These mutants demonstrate that the N368/G369 region of GluN1 is crucial for the creation of immunoreactivity. Mass spectrometry experiments show that N368 is glycosylated in transfected cells and rat brain regions; however, this glycosylation is not directly required for epitope formation. Mutations of residues N368/G369 change the closed time of the receptor in single channel recordings; more frequent channel openings correlates with the degree of antibody staining, and acute antibody exposure prolongs open time of the receptor. The staining pattern of mutant receptors is similar across subgroups of patients, indicating consistent immunogenicity, although we have identified one region that has a variable role in epitope formation. These findings provide tools for detailed comparison of antibodies across patients and suggest an interaction between antibody binding and channel function. PMID:22875940

  2. Human cell receptor CD46 is down regulated through recognition of a membrane-proximal region of the cytoplasmic domain in persistent measles virus infection.

    PubMed Central

    Hirano, A; Yant, S; Iwata, K; Korte-Sarfaty, J; Seya, T; Nagasawa, S; Wong, T C

    1996-01-01

    Monkey cells persistently infected by measles virus (MV) Biken strain (Biken-CV-1 cells) showed no cytopathic effects and lacked surface expression of a homolog of human cell receptor, membrane cofactor protein CD46. Transfection of a human CD46 gene into these cells induced extensive cell fusion, indicating that down regulation of the endogenous CD46 homolog was essential for the maintenance of a noncytopathic mode of infection. Surface expression of the exogenously introduced human CD46 was also drastically down regulated in the persistently infected cells compared with uninfected cells. The down regulation was specific for CD46 and did not affect surface expression of exogenously introduced CD4. Exogenous human CD46 was synthesized efficiently in the persistently infected cells, but it did not accumulate on the cell surface. Fusion of Biken-CV-1 cells required the extracellular hemagglutinin (H-protein)-binding domain but not the cytoplasmic domain. Replacing the transmembrane and cytoplasmic domains of CD46 with a glycosylphosphatidylinositol anchor did not prevent cell fusion but completely alleviated down regulation of the glycosylphosphatidylinositol-anchored CD46 in Biken-CV-1 cells. Deletion analyses revealed that the membrane-distal sequences of the CD46 cytoplasmic domain were not only unnecessary but also inhibitory for CD46 down regulation. By contrast, the six amino acid residues proximal to the membrane contained a sequence required for CD46 down regulation in the persistently infected cells. These results indicate that CD46 is down regulated in the persistently infected cells by a mechanism that recognizes a membrane-proximal sequence in the CD46 cytoplasmic domain. PMID:8794336

  3. Natural variation of the amino-terminal glutamine-rich domain in Drosophila argonaute2 is not associated with developmental defects.

    PubMed

    Hain, Daniel; Bettencourt, Brian R; Okamura, Katsutomo; Csorba, Tibor; Meyer, Wibke; Jin, Zhigang; Biggerstaff, Jason; Siomi, Haruhiko; Hutvagner, Gyorgy; Lai, Eric C; Welte, Michael; Müller, H-Arno J

    2010-01-01

    The Drosophila argonaute2 (ago2) gene plays a major role in siRNA mediated RNA silencing pathways. Unlike mammalian Argonaute proteins, the Drosophila protein has an unusual amino-terminal domain made up largely of multiple copies of glutamine-rich repeats (GRRs). We report here that the ago2 locus produces an alternative transcript that encodes a putative short isoform without this amino-terminal domain. Several ago2 mutations previously reported to be null alleles only abolish expression of the long, GRR-containing isoform. Analysis of drop out (dop) mutations had previously suggested that variations in GRR copy number result in defects in RNAi and embryonic development. However, we find that dop mutations genetically complement transcript-null alleles of ago2 and that ago2 alleles with variant GRR copy numbers support normal development. In addition, we show that the assembly of the central RNAi machinery, the RISC (RNA induced silencing complex), is unimpaired in embryos when GRR copy number is altered. In fact, we find that GRR copy number is highly variable in natural D. melanogaster populations as well as in laboratory strains. Finally, while many other insects share an extensive, glutamine-rich Ago2 amino-terminal domain, its primary sequence varies drastically between species. Our data indicate that GRR variation does not modulate an essential function of Ago2 and that the amino-terminal domain of Ago2 is subject to rapid evolution. PMID:21253006

  4. Natural Variation of the Amino-Terminal Glutamine-Rich Domain in Drosophila Argonaute2 Is Not Associated with Developmental Defects

    PubMed Central

    Hain, Daniel; Bettencourt, Brian R.; Okamura, Katsutomo; Csorba, Tibor; Meyer, Wibke; Jin, Zhigang; Biggerstaff, Jason; Siomi, Haruhiko; Hutvagner, Gyorgy; Lai, Eric C.

    2010-01-01

    The Drosophila argonaute2 (ago2) gene plays a major role in siRNA mediated RNA silencing pathways. Unlike mammalian Argonaute proteins, the Drosophila protein has an unusual amino-terminal domain made up largely of multiple copies of glutamine-rich repeats (GRRs). We report here that the ago2 locus produces an alternative transcript that encodes a putative short isoform without this amino-terminal domain. Several ago2 mutations previously reported to be null alleles only abolish expression of the long, GRR-containing isoform. Analysis of drop out (dop) mutations had previously suggested that variations in GRR copy number result in defects in RNAi and embryonic development. However, we find that dop mutations genetically complement transcript-null alleles of ago2 and that ago2 alleles with variant GRR copy numbers support normal development. In addition, we show that the assembly of the central RNAi machinery, the RISC (RNA induced silencing complex), is unimpaired in embryos when GRR copy number is altered. In fact, we find that GRR copy number is highly variable in natural D. melanogaster populations as well as in laboratory strains. Finally, while many other insects share an extensive, glutamine-rich Ago2 amino-terminal domain, its primary sequence varies drastically between species. Our data indicate that GRR variation does not modulate an essential function of Ago2 and that the amino-terminal domain of Ago2 is subject to rapid evolution. PMID:21253006

  5. Zinc phthalocyanine conjugated with the amino-terminal fragment of urokinase for tumor-targeting photodynamic therapy.

    PubMed

    Chen, Zhuo; Xu, Peng; Chen, Jincan; Chen, Hongwei; Hu, Ping; Chen, Xueyuan; Lin, Lin; Huang, Yunmei; Zheng, Ke; Zhou, Shanyong; Li, Rui; Chen, Song; Liu, Jianyong; Xue, Jinping; Huang, Mingdong

    2014-10-01

    Photodynamic therapy (PDT) has attracted much interest for the treatment of cancer due to the increased incidence of multidrug resistance and systemic toxicity in conventional chemotherapy. Phthalocyanine (Pc) is one of main classes of photosensitizers for PDT and possesses optimal photophysical and photochemical properties. A higher specificity can ideally be achieved when Pcs are targeted towards tumor-specific receptors, which may also facilitate specific drug delivery. Herein, we develop a simple and unique strategy to prepare a hydrophilic tumor-targeting photosensitizer ATF-ZnPc by covalently coupling zinc phthalocyanine (ZnPc) to the amino-terminal fragment (ATF) of urokinase-type plasminogen activator (uPA), a fragment responsible for uPA receptor (uPAR, a biomarker overexpressed in cancer cells), through the carboxyl groups of ATF. We demonstrate the high efficacy of this tumor-targeting PDT agent for the inhibition of tumor growth both in vitro and in vivo. Our in vivo optical imaging results using H22 tumor-bearing mice show clearly the selective accumulation of ATF-ZnPc in tumor region, thereby revealing the great potential of ATF-ZnPc for clinical applications such as cancer detection and guidance of tumor resection in addition to photodynamic treatment. PMID:24969665

  6. β1 integrins mediate resistance to ionizing radiation in vivo by inhibiting c-Jun amino terminal kinase 1

    PubMed Central

    Goel, Hira Lal; Sayeed, Aejaz; Breen, Michael; Zarif, Matthew J.; Garlick, David S.; Leav, Irwin; Davis, Roger J.; FitzGerald, Thomas J.; Morrione, Andrea; Hsieh, Chung-Cheng; Liu, Qin; Dicker, Adam P.; Altieri, Dario C.; Languino, Lucia R.

    2013-01-01

    This study was carried out to dissect the mechanism by which β1 integrins promote resistance to radiation. For this purpose, we conditionally ablated β1 integrins in the prostatic epithelium of transgenic adenocarcinoma of mouse prostate (TRAMP) mice. The ability of β1 to promote resistance to radiation was also analyzed by using an inhibitory antibody to β1, AIIB2, in a xenograft model. The role of β1 integrins and of a β1 downstream target, c-Jun amino-terminal kinase 1 (JNK1), in regulating radiation-induced apoptosis in vivo and in vitro was studied. We show that β1 integrins promote prostate cancer (PrCa) progression and resistance to radiation in vivo. Mechanistically, β1 integrins are shown here to suppress activation of JNK1 and, consequently apoptosis, in response to irradiation. Downregulation of JNK1 is necessary to preserve the effect of β1 on resistance to radiation in vitro and in vivo. Finally, given the established cross-talk between β1 integrins and type 1 insulin-like growth factor receptor (IGF-IR), we analyzed the ability of IGF-IR to modulate β1 integrin levels. We report that IGF-IR regulates the expression of β1 integrins, which in turn confer resistance to radiation in PrCa cells. In conclusion, this study demonstrates that β1 integrins mediate resistance to ionizing radiation through inhibition of JNK1 activation. PMID:23359252

  7. Increase in plasma concentrations of cardiodilatin (amino terminal pro-atrial natriuretic peptide) in cardiac failure and during recumbency.

    PubMed Central

    Meleagros, L; Gibbs, J S; Ghatei, M A; Bloom, S R

    1988-01-01

    Plasma concentrations of cardiodilatin, the peptide sequence at the amino terminal of the pro-atrial natriuretic peptide, in 17 normal subjects ranged from 59 to 202 (mean 118 (SEM) (9] pmol/l. Recumbency increased the mean (SEM) concentration to 160 (13) pmol/l. The plasma concentration of cardiodilatin in 24 patients with congestive cardiac failure was much higher (964 (175) pmol/l) than in the normal subjects. It was highest in those with heart failure in New York Heart Association functional classes III and IV and the concentration correlated both with atrial natriuretic peptide concentrations and left ventricular ejection fraction. Concentrations rose during induced tachycardia in three patients tested. Chromatography showed a single clean peak of plasma cardiodilatin immunoreactivity. It seems that cardiodilatin is a second circulating cardiac peptide that is jointly released with atrial natriuretic peptide by common stimuli. Other workers have reported that, like atrial natriuretic peptide, three partial cardiodilatin sequences can stimulate renal particulate guanylate cyclase and increase cyclic guanosine monophosphate. The simultaneous release of cardiodilatin in higher circulating concentrations than atrial natriuretic peptide may be relevant to the finding that appropriate concentrations of exogenous atrial natiuretic peptide alone do not produce the full renal effects associated with endogenous peptide release. PMID:2970269

  8. Use of amino terminal type III procollagen peptide (P3NP) assay in methotrexate therapy for psoriasis

    PubMed Central

    Khan, S; Subedi, D; Chowdhury, M M U

    2006-01-01

    Hepatic fibrosis continues to be a risk in patients receiving methotrexate for psoriasis. Measurement of amino terminal levels of type III procollagen (P3NP) has been advocated as an effective non‐invasive test for ongoing hepatic fibrogenesis that could avoid liver biopsies. An audit was conducted to assess the practice of P3NP monitoring using guidelines produced by Manchester and whether the agreed levels correlate with histological severity. Sixty five patients with 174 P3NP assays and 30 liver biopsies were reviewed between the years 1999 and 2003. Total number of patient‐methotrexate years was 278.9 and the mean cumulative dose of methotrexate received was 2000 (SD 1838) mg. A higher cumulative dose of methotrexate correlated significantly with high mean and maximum P3NP levels. Of the 30 liver biopsies, 26 (86.6%) showed normal histology or mild to moderate steatosis, three had focal fibrosis, and one had early cirrhosis. A median P3NP value of 5.8 μg/l or higher had a stronger correlation with histological severity. It is concluded that P3NP assay is a valuable adjunct to the clinical management of patients receiving long term methotrexate that can avoid or reduce unnecessary liver biopsies. PMID:16679477

  9. Membrane-Active Sequences within gp41 Membrane Proximal External Region (MPER) Modulate MPER-Containing Peptidyl Fusion Inhibitor Activity and the Biosynthesis of HIV-1 Structural Proteins

    PubMed Central

    Zhang, Si Min; Jejcic, Alenka; Tam, James P.; Vahlne, Anders

    2015-01-01

    The membrane proximal external region (MPER) is a highly conserved membrane-active region located at the juxtamembrane positions within class I viral fusion glycoproteins and essential for membrane fusion events during viral entry. The MPER in the human immunodeficiency virus type I (HIV-1) envelope protein (Env) interacts with the lipid bilayers through a cluster of tryptophan (Trp) residues and a C-terminal cholesterol-interacting motif. The inclusion of the MPER N-terminal sequence contributes to the membrane reactivity and anti-viral efficacy of the first two anti-HIV peptidyl fusion inhibitors T20 and T1249. As a type I transmembrane protein, Env also interacts with the cellular membranes during its biosynthesis and trafficking. Here we investigated the roles of MPER membrane-active sequences during both viral entry and assembly, specifically, their roles in the design of peptidyl fusion inhibitors and the biosynthesis of viral structural proteins. We found that elimination of the membrane-active elements in MPER peptides, namely, penta Trp→alanine (Ala) substitutions and the disruption of the C-terminal cholesterol-interacting motif through deletion inhibited the anti-viral effect against the pseudotyped HIV-1. Furthermore, as compared to C-terminal dimerization, N-terminal dimerization of MPER peptides and N-terminal extension with five helix-forming residues enhanced their anti-viral efficacy substantially. The secondary structure study revealed that the penta-Trp→Ala substitutions also increased the helical content in the MPER sequence, which prompted us to study the biological relevance of such mutations in pre-fusion Env. We observed that Ala mutations of Trp664, Trp668 and Trp670 in MPER moderately lowered the intracellular and intraviral contents of Env while significantly elevating the content of another viral structural protein, p55/Gag and its derivative p24/capsid. The data suggest a role of the gp41 MPER in the membrane-reactive events during

  10. Complexin induces a conformational change at the membrane-proximal C-terminal end of the SNARE complex

    PubMed Central

    Choi, Ucheor B; Zhao, Minglei; Zhang, Yunxiang; Lai, Ying; Brunger, Axel T

    2016-01-01

    Complexin regulates spontaneous and activates Ca2+-triggered neurotransmitter release, yet the molecular mechanisms are still unclear. Here we performed single molecule fluorescence resonance energy transfer experiments and uncovered two conformations of complexin-1 bound to the ternary SNARE complex. In the cis conformation, complexin-1 induces a conformational change at the membrane-proximal C-terminal end of the ternary SNARE complex that specifically depends on the N-terminal, accessory, and central domains of complexin-1. The complexin-1 induced conformation of the ternary SNARE complex may be related to a conformation that is juxtaposing the synaptic vesicle and plasma membranes. In the trans conformation, complexin-1 can simultaneously interact with a ternary SNARE complex via the central domain and a binary SNARE complex consisting of syntaxin-1A and SNAP-25A via the accessory domain. The cis conformation may be involved in activation of synchronous neurotransmitter release, whereas both conformations may be involved in regulating spontaneous release. DOI: http://dx.doi.org/10.7554/eLife.16886.001 PMID:27253060

  11. Complexin induces a conformational change at the membrane-proximal C-terminal end of the SNARE complex.

    PubMed

    Choi, Ucheor B; Zhao, Minglei; Zhang, Yunxiang; Lai, Ying; Brunger, Axel T

    2016-01-01

    Complexin regulates spontaneous and activates Ca(2+)-triggered neurotransmitter release, yet the molecular mechanisms are still unclear. Here we performed single molecule fluorescence resonance energy transfer experiments and uncovered two conformations of complexin-1 bound to the ternary SNARE complex. In the cis conformation, complexin-1 induces a conformational change at the membrane-proximal C-terminal end of the ternary SNARE complex that specifically depends on the N-terminal, accessory, and central domains of complexin-1. The complexin-1 induced conformation of the ternary SNARE complex may be related to a conformation that is juxtaposing the synaptic vesicle and plasma membranes. In the trans conformation, complexin-1 can simultaneously interact with a ternary SNARE complex via the central domain and a binary SNARE complex consisting of syntaxin-1A and SNAP-25A via the accessory domain. The cis conformation may be involved in activation of synchronous neurotransmitter release, whereas both conformations may be involved in regulating spontaneous release. PMID:27253060

  12. Modulating immunogenic properties of HIV-1 gp41 membrane-proximal external region by destabilizing six-helix bundle structure.

    PubMed

    Banerjee, Saikat; Shi, Heliang; Habte, Habtom H; Qin, Yali; Cho, Michael W

    2016-03-01

    The C-terminal alpha-helix of gp41 membrane-proximal external region (MPER; (671)NWFDITNWLWYIK(683)) encompassing 4E10/10E8 epitopes is an attractive target for HIV-1 vaccine development. We previously reported that gp41-HR1-54Q, a trimeric protein comprised of the MPER in the context of a stable six-helix bundle (6HB), induced strong immune responses against the helix, but antibodies were directed primarily against the non-neutralizing face of the helix. To better target 4E10/10E8 epitopes, we generated four putative fusion intermediates by introducing double point mutations or deletions in the heptad repeat region 1 (HR1) that destabilize 6HB in varying degrees. One variant, HR1-∆10-54K, elicited antibodies in rabbits that targeted W672, I675 and L679, which are critical for 4E10/10E8 recognition. Overall, the results demonstrated that altering structural parameters of 6HB can influence immunogenic properties of the MPER and antibody targeting. Further exploration of this strategy could allow development of immunogens that could lead to induction of 4E10/10E8-like antibodies. PMID:26803471

  13. A novel antimicrobial peptide derived from membrane-proximal external region of human immunodeficiency virus type 1.

    PubMed

    He, Xiaoqiu; Zhang, Huayan; Shi, Yuhua; Gong, Xin; Guan, Shanshan; Yin, He; Yang, Lan; Yu, Yongjiao; Kuai, Ziyu; Liu, Dongni; Hua, Rui; Wang, Song; Shan, Yaming

    2016-04-01

    With increasing microbial drug resistance worldwide, antimicrobial peptides (AMPs) are considered promising alternatives to addressing this problem. In this study, a series of synthetic peptides were designed based on the membrane-disrupting properties of the membrane-proximal external region (MPER) of human immunodeficiency virus type 1 (HIV-1) envelope protein. The peptide AP16-A was found to exhibit the most effective antimicrobial activities against both Gram-negative and Gram-positive bacteria. The minimal bactericidal concentration (MBC) of AP16-A ranged from 2 μg/ml to 16 μg/ml. AP16-A had no detectable cytotoxicity in various tissue cultures and a mouse model. Furthermore, results of confocal fluorescence microscopy and the SYTOX Green uptake assay indicated that AP16-A killed Gram-negative bacteria by the combined effects of relatively slow membrane permeabilization and interaction with an intracellular target, while it killed Gram-positive bacteria by a fast membrane permeabilization process, which achieved relatively more rapid bacterial killing kinetics. The results of this study support the potential use of AP16-A as an AMP. PMID:26875765

  14. Control of N-methyl-D-aspartate Receptor Function by the NR2 Subunit Amino-Terminal Domain

    PubMed Central

    Yuan, Hongjie; Hansen, Kasper B.; Vance, Katie M.; Ogden, Kevin K.; Traynelis, Stephen F.

    2009-01-01

    NMDA receptors comprised of different NR2 subunits exhibit strikingly unique biophysical and pharmacological properties. Here we report that the extracellular amino-terminal domain (ATD) of the NR2 subunit controls pharmacological and kinetic properties of recombinant NMDA receptors, such as agonist potency, deactivation time course, open probability (POPEN), and mean open/shut duration. Using ATD deletion mutants of NR2A, NR2B, NR2C, NR2D and chimeras of NR2A and NR2D with interchanged ATD (NR2A-(2D-ATD) and NR2D-(2A-ATD)), we show that the ATD contributes to the low glutamate potency of NR2A-containing NMDA receptors and the high glutamate potency of NR2D-containing receptors. The ATD influences the deactivation time courses of NMDA receptors, as removal of the ATD from NR2A slows the deactivation rate, while removal of the ATD from NR2B, NR2C and NR2D accelerates the deactivation rate. Open probability also is influenced by the ATD. Removal of the ATD from NR2A or replacement of the NR2A-ATD with that of NR2D decreases POPEN in single channel recordings from outside-out patches of HEK 293 cells. By contrast, deletion of the ATD from NR2D or replacement of the NR2D ATD with that of NR2A increases POPEN and mean open duration. These data demonstrate the modular nature of NMDA receptors and show that the ATD of the different NR2 subunits plays an important role in fine-tuning the functional properties of the individual NMDA receptor subtypes. PMID:19793963

  15. The Amino-Terminal Domain of Bovine Viral Diarrhea Virus Npro Protein Is Necessary for Alpha/Beta Interferon Antagonism

    PubMed Central

    Gil, Laura H. V. G.; Ansari, Israrul H.; Vassilev, Ventzislav; Liang, Delin; Lai, Vicky C. H.; Zhong, Weidong; Hong, Zhi; Dubovi, Edward J.; Donis, Ruben O.

    2006-01-01

    The alpha/beta interferon (IFN-α/β) system is the first line of defense against viral infection and a critical link between the innate and adaptive immune responses. IFN-α/β secretion is the hallmark of cellular responses to acute RNA virus infections. As part of their survival strategy, many viruses have evolved mechanisms to counteract the host IFN-α/β response. Bovine viral diarrhea virus (BVDV) (genus Pestivirus) was reported to trigger interferon production in infected cultured cells under certain circumstances or to suppress it under others. Our studies with various cultured fibroblasts and epithelial bovine cells indicated that cytopathic (cp) BVDV induces IFN-α/β very inefficiently. Using a set of engineered cp BVDVs expressing mutant Npro and appropriate controls, we found that the IFN-α/β response to infection was dependent on Npro expression and independent of viral replication efficiency. In order to investigate whether the protease activity of Npro is required for IFN-α/β antagonism, we engineered Npro mutants lacking protease activity by replacement of amino acid E22, H49, or C69. We found that E22 and H49 substitutions abolished the ability of Npro to suppress IFN, whereas C69 had no effect, suggesting that the structural integrity of the N terminus of Npro was more important than its catalytic activity for IFN-α/β suppression. A catalytically active mutant with a change at a conserved Npro region near the N terminus (L8P) in both BVDV biotypes did not antagonize IFN-α/β production, confirming its involvement in this process. Taken together, these results not only provide direct evidence for the role of Npro in blocking IFN-α/β induction, but also implicate the amino-terminal domain of the protein in this function. PMID:16378992

  16. Crystal structures of the glutamate receptor ion channel GluK3 and GluK5 amino terminal domains

    PubMed Central

    Kumar, Janesh; Mayer, Mark L.

    2010-01-01

    Ionotropic glutamate receptors (iGluRs) mediate the majority of fast excitatory synaptic neurotransmission in the central nervous system. The selective assembly of iGluRs into the AMPA, kainate and NMDA receptor subtypes is regulated by their extracellular amino terminal domains (ATD). Kainate receptors are further classified into low-affinity (GluK1-3) and high-affinity (GluK4-5) receptor families based on their affinity for the neurotoxin kainic acid. These two families share 42% sequence identity for the intact receptor but only 28% sequence identity at the level of ATD. We have determined for the first time high-resolution crystal structures for the GluK3 and GluK5 ATDs, both of which crystallize as dimers, but with a strikingly different dimer assembly at the R1 interface. By contrast, for both GluK3 and GluK5 the R2 domain dimer assembly is similar to that reported previously for other non-NMDA iGluRs. This observation is consistent with the reports that GluK4-5 cannot form functional homomeric ion channels and require obligate coassembly with GluK1-3. Our analysis also reveals that the relative orientation of domains R1 and R2 in individual non-NMDA receptor ATDs varies by up to 10°, in contrast to the 50° difference reported for the NMDA receptor GluN2B subunit. This restricted domain movement in non-NMDA receptor ATDs seems to result from both extensive intramolecular contacts between domains R1 and R2, and from their assembly as dimers which interact at both the R1 and R2 domains. Our results provide the first insights into the structure and function for GluK4-5, the least understood family of iGluRs. PMID:20951142

  17. Alteration of the mode of antibacterial action of a defensin by the amino-terminal loop substitution

    SciTech Connect

    Gao, Bin; Zhu, Shunyi

    2012-10-05

    Highlights: Black-Right-Pointing-Pointer Al-M is an engineered fungal defensin with the n-loop of an insect defensin. Black-Right-Pointing-Pointer Al-M adopts a native defensin-like structure with high antibacterial potency. Black-Right-Pointing-Pointer Al-M kills bacteria through a membrane disruptive mechanism. Black-Right-Pointing-Pointer This work sheds light on the functional evolution of CS{alpha}{beta}-type defensins. -- Abstract: Ancient invertebrate-type and classical insect-type defensins (AITDs and CITDs) are two groups of evolutionarily related antimicrobial peptides (AMPs) that adopt a conserved cysteine-stabilized {alpha}-helical and {beta}-sheet (CS{alpha}{beta}) fold with a different amino-terminal loop (n-loop) size and diverse modes of antibacterial action. Although they both are identified as inhibitors of cell wall biosynthesis, only CITDs evolved membrane disruptive ability by peptide oligomerization to form pores. To understand how this occurred, we modified micasin, a fungus-derived AITDs with a non-membrane disruptive mechanism, by substituting its n-loop with that of an insect-derived CITDs. After air oxidization, the synthetic hybrid defensin (termed Al-M) was structurally identified by circular dichroism (CD) and functionally evaluated by antibacterial and membrane permeability assays and electronic microscopic observation. Results showed that Al-M folded into a native-like defensin structure, as determined by its CD spectrum that is similar to that of micasin. Al-M was highly efficacious against the Gram-positive bacterium Bacillus megaterium with a lethal concentration of 1.76 {mu}M. As expected, in contrast to micasin, Al-M killed the bacteria through a membrane disruptive mechanism of action. The alteration in modes of action supports a key role of the n-loop extension in assembling functional surface of CITDs for membrane disruption. Our work provides mechanical evidence for evolutionary relationship between AITDs and CITDs.

  18. Autoantibodies Recognizing the Amino Terminal 1-17 Segment of CENP-A Display Unique Specificities in Systemic Sclerosis

    PubMed Central

    Favoino, Elvira; Digiglio, Liboria; Cuomo, Giovanna; Favia, Isabella E.; Racanelli, Vito; Valentini, Gabriele; Perosa, Federico

    2013-01-01

    Centromere-associated protein A (CENP-A), a common autoimmune target in a subset of systemic sclerosis patients, appears to have no role to explain why its corresponding auto-antibodies are more frequently found in the limited than the diffuse form of systemic sclerosis. Therefore, we investigated the fine specificity of anti-CENP-A antibodies as a first step to understanding their role in systemic sclerosis pathology. We focused on the amino-terminal portion of CENP-A spanning amino acids 1 to 17 (Ap1-17), which represents, along with Ap17-30, an immunodominant epitope of the protein. Peptide Ap1-17 was used to purify antibodies from 8 patients with systemic sclerosis. Anti-Ap1-17 antibodies specifically reacted with human CENP-A but did not cross-react with CENP-B or Ap17-30. Panning of a phage display peptide library with anti-Ap1-17 antibodies from 2 patients identified two novel, partially overlapping motifs, <5Rx(st)xKP10> and <9KPxxPxR15> as the result of the alignment of specific phage clone insert sequences. Anti-Ap1-17 IgG from the 8 patients had different reactivities to isolated phage clone insert sequences. Scanning the Swiss-Prot database revealed a large number of different types of proteins containing the two Ap1-17 antigenic motifs. These data show that anti-CENP-A1-17 antibodies are generated independently from anti-CENP-B antibodies and display great heterogeneity in their specificity by recognizing different motifs within that peptide sequence. This finding, along with the widespread interspecies and human tissue distribution of the two motifs, suggests that the number of motif-expressing proteins which can be the potential target of these antibodies is markedly higher than that estimated from the peptide-based epitope spreading model. PMID:23613856

  19. Amino-terminal p53 mutations lead to expression of apoptosis proficient p47 and prognosticate better survival, but predispose to tumorigenesis

    PubMed Central

    Phang, Beng Hooi; Othman, Rashidah; Bougeard, Gaelle; Chia, Ren Hui; Frebourg, Thierry; Tang, Choong Leong; Cheah, Peh Yean; Sabapathy, Kanaga

    2015-01-01

    Whereas most mutations in p53 occur in the DNA-binding domain and lead to its functional inactivation, their relevance in the amino-terminal transactivation domain is unclear. We show here that amino-terminal p53 (ATp53) mutations often result in the abrogation of full-length p53 expression, but concomitantly lead to the expression of the amino-terminally truncated p47 isoform. Using genetically modified cancer cells that only express p47, we demonstrate it to be up-regulated in response to various stimuli, and to contribute to cell death, through its ability to selectively activate a group of apoptotic target genes. Target gene selectivity is influenced by K382 acetylation, which depends on the amino terminus, and is required for recruitment of selective cofactors. Consistently, cancers capable of expressing p47 had a better overall survival. Nonetheless, retention of the apoptotic function appears insufficient for tumor suppression, because these mutations are also found in the germ line and lead to Li–Fraumeni syndrome. These data from ATp53 mutations collectively demonstrate that p53’s apoptosis proficiency is dispensable for tumor suppression, but could prognosticate better survival. PMID:26578795

  20. Recombinant expression, purification, and biophysical characterization of the transmembrane and membrane proximal domains of HIV-1 gp41

    PubMed Central

    Gong, Zhen; Kessans, Sarah A; Song, Lusheng; Dörner, Katerina; Lee, Ho-Hsien; Meador, Lydia R; LaBaer, Joshua; Hogue, Brenda G; Mor, Tsafrir S; Fromme, Petra

    2014-01-01

    The transmembrane subunit (gp41) of the envelope glycoprotein of HIV-1 associates noncovalently with the surface subunit (gp120) and together they play essential roles in viral mucosal transmission and infection of target cells. The membrane proximal region (MPR) of gp41 is highly conserved and contains epitopes of broadly neutralizing antibodies. The transmembrane (TM) domain of gp41 not only anchors the envelope glycoprotein complex in the viral membrane but also dynamically affects the interactions of the MPR with the membrane. While high-resolution X-ray structures of some segments of the MPR were solved in the past, they represent the post-fusion forms. Structural information on the TM domain of gp41 is scant and at low resolution. Here we describe the design, expression and purification of a protein construct that includes MPR and the transmembrane domain of gp41 (MPR-TMTEV-6His), which reacts with the broadly neutralizing antibodies 2F5 and 4E10 and thereby may represent an immunologically relevant conformation mimicking a prehairpin intermediate of gp41. The expression level of MPR-TMTEV-6His was improved by fusion to the C-terminus of Mistic protein, yielding ∼1 mg of pure protein per liter. The isolated MPR-TMTEV-6His protein was biophysically characterized and is a monodisperse candidate for crystallization. This work will enable further investigation into the structure of MPR-TMTEV-6His, which will be important for the structure-based design of a mucosal vaccine against HIV-1. PMID:25155369

  1. HIV-1 gp41 Core with Exposed Membrane-Proximal External Region Inducing Broad HIV-1 Neutralizing Antibodies

    PubMed Central

    Zhou, Leilei; Xu, Liling; Jiang, Shibo; Chen, Ying-hua

    2011-01-01

    The membrane-proximal external region (MPER) of the HIV-1 gp41 consists of epitopes for the broadly cross-neutralizing monoclonal antibodies 2F5 and 4E10. However, antigens containing the linear sequence of these epitopes are unable to elicit potent and broad neutralizing antibody responses in vaccinated hosts, possibly because of inappropriate conformation of these epitopes. Here we designed a recombinant antigen, designated NCM, which comprises the N- and C-terminal heptad repeats that can form a six-helix bundle (6HB) core and the MPER domain of gp41. Two mutations (T569A and I675V) previously reported to expose the neutralization epitopes were introduced into NCM to generate mutants named NCM(TA), NCM(IV), and NCM(TAIV). Our results showed that NCM and its mutants could react with antibodies specific for 6HB and MPER of gp41, suggesting that these antigens are in the form of a trimer of heterodimer (i.e., 6HB) with three exposed MPER tails. Antigen with double mutations, NCM(TAIV), elicited much stronger antibody response in rabbits than immunogens with single mutation, NCM(TA) and NCM(IV), or no mutation, NCM. The purified MPER-specific antibodies induced by NCM(TAIV) exhibited broad neutralizing activity, while the purified 6HB-specific antibodies showed no detectable neutralizing activity. Our recombinant antigen design supported by an investigation of its underlying molecular mechanisms provides a strong scientific platform for the discovery of a gp41 MPER-based AIDS vaccine. PMID:21483871

  2. Amino-Terminal Fragment of the Prohormone Brain-type Natriuretic Peptide (NT-proBNP) in Rheumatoid Arthritis

    PubMed Central

    Solus, Joseph; Chung, Cecilia P.; Oeser, Annette; Avalos, Ingrid; Gebretsadik, Tebeb; Shintani, Ayumi; Raggi, Paolo; Sokka, Tuulikki; Pincus, Theodore; Stein, C. Michael

    2008-01-01

    Objective Increased concentrations of amino-terminal prohormone brain-type natriuretic peptide (NT-proBNP) are associated with cardiovascular morbidity and mortality, but little is known about their relationship to chronic inflammation. Patients with rheumatoid arthritis (RA) have chronic inflammation, increased arterial stiffness and accelerated coronary atherosclerosis. We tested the hypothesis that NT-proBNP concentrations are elevated in patients with RA, and are associated with coronary artery calcification and markers of inflammation. Methods In 159 subjects with RA (90 patients with early RA and 69 patients with longstanding RA) without heart failure and 88 control subjects, we measured serum concentrations of NT-proBNP, interleukin (IL)-6, and tumor necrosis factor-α (TNF-α), and coronary calcification. Results NT-proBNP concentrations were elevated in patients with long-standing RA [median (IQR): 142.8 (54.8–270.5) pg/mL] and those with early RA [58.1 (19.4–157.6) pg/mL] compared to controls [18.1 (3.2–46.0) pg/mL, P<0.001]. In patients with RA, NT-proBNP concentrations were associated with age (ρ=0.35, P<0.001), IL-6 (ρ=0.33, P<0.001), TNF-α (ρ=0.23, P=0.003), CRP (ρ=0.21, P=0.01), coronary calcium score (ρ=0.30, P<0.001), systolic blood pressure (ρ=0.30, p<0.001), and disease activity (ρ=0.29, P<0.001). After adjustment for age, race and sex the associations between NT-proBNP concentrations and disease activity (P<0.001), TNF-α (P<0.001), IL-6 (P=0.04) and CRP concentrations (P=0.02) remained significant, but those with systolic blood pressure (P=0.10) and coronary calcium score (P=0.27) were attenuated. Conclusions NT-proBNP concentrations are increased in patients with RA without clinical heart failure and may indicate subclinical cardiovascular disease and a chronic inflammatory state. PMID:18759301

  3. Detection of synenkephalin, the amino-terminal portion of proenkephalin, by antisera directed against its carboxyl terminus.

    PubMed

    Stell, W K; Chaminade, M; Metters, K M; Rougeot, C; Dray, F; Rossier, J

    1990-02-01

    Synenkephalin (SYN), the nonopioid amino-terminal portion of proenkephalin (PRO), is stable and well conserved in mammals and therefore a promising marker for PRO systems. We immunized rabbits with synthetic [Tyr63]SYN(63-70)-octapeptide, coupled by glutaraldehyde to bovine serum albumin. In radioimmunoassay (RIA) using antiserum no. 681, [Tyr63]SYN(63-70)-octapeptide as standard, and 125I-[Tyr63]SYN(63-70)-octapeptide as tracer, the IC50 was approximately 51 fmol/100-microliters sample at equilibrium or 12 fmol/100 microliters in disequilibrium, and the sensitivity was approximately 3 fmol/100 microliters. Cross-reactivity of the assay was 100% with [Cys63]SYN(63-70)-octapeptide and with bovine adrenal 8.6-kilodalton peptide digested with trypsin and carboxypeptidase B, but less than 0.1% with transforming growth factor-alpha, less than or equal to 2 x 10(-6) with Leu-Leu-Ala [SYN(68-70)-tripeptide], and much less than 10(-6) with all other peptides tested. Therefore in RIA this antiserum is specific for the free carboxyl terminus of SYN. Because the peptide detected after enzyme digestion is the complete SYN(63-70)-octapeptide, we refer to the RIA as an assay for SYN(63-70). Tissue extracts were made in 1 M acetic acid, dried, reconstituted in Tris-CaCl2, and digested sequentially with trypsin plus carboxypeptidase B. Extracts from bovine corpus striatum gave SYN(63-70) RIA dilution curves parallel to the standard curve both before and after digestion. Digestion increased the amount of immunoreactive SYN(63-70) in striatum by a factor of 1.5-2.0. The ratio of total immunoreactive [Met5]enkephalin to total immunoreactive SYN(63-70) (after sequential digestion) was approximately 6:1. At least 90% of the immunoreactive SYN(63-70) in extracts of bovine caudate nucleus eluted from Sephadex G-100 with an apparent molecular weight equal to that of bovine PRO(1-77). Using the new RIA we were able to detect and characterize SYN processing for the first time in extracts of

  4. Engineering Recombinant Reoviruses To Display gp41 Membrane-Proximal External-Region Epitopes from HIV-1.

    PubMed

    Boehme, Karl W; Ikizler, Mine'; Iskarpatyoti, Jason A; Wetzel, J Denise; Willis, Jordan; Crowe, James E; LaBranche, Celia C; Montefiori, David C; Wilson, Gregory J; Dermody, Terence S

    2016-01-01

    The gp41 membrane-proximal external region (MPER) is a target for broadly neutralizing antibody responses against human immunodeficiency virus type 1 (HIV-1). However, replication-defective virus vaccines currently under evaluation in clinical trials do not efficiently elicit MPER-specific antibodies. Structural modeling suggests that the MPER forms an α-helical coiled coil that is required for function and immunogenicity. To maintain the native MPER conformation, we used reverse genetics to engineer replication-competent reovirus vectors that displayed MPER sequences in the α-helical coiled-coil tail domain of viral attachment protein σ1. Sequences in reovirus strain type 1 Lang (T1L) σ1 were exchanged with sequences encoding HIV-1 strain Ba-L MPER epitope 2F5 or the entire MPER. Individual 2F5 or MPER substitutions were introduced at virion-proximal or virion-distal sites in the σ1 tail. Recombinant reoviruses containing heterologous HIV-1 sequences were viable and produced progeny yields comparable to those with wild-type virus. HIV-1 sequences were retained following 10 serial passages in cell culture, indicating that the substitutions were genetically stable. Recombinant viruses engineered to display the 2F5 epitope or full-length MPER in σ1 were recognized by purified 2F5 antibody. Inoculation of mice with 2F5-containing vectors or rabbits with 2F5- or MPER-containing vectors elicited anti-reovirus antibodies, but HIV-1-specific antibodies were not detected. Together, these findings indicate that heterologous sequences that form α-helices can functionally replace native sequences in the α-helical tail domain of reovirus attachment protein σ1. However, although these vectors retain native antigenicity, they were not immunogenic, illustrating the difficulty of experimentally inducing immune responses to this essential region of HIV-1. IMPORTANCE Vaccines to protect against HIV-1, the causative agent of AIDS, are not approved for use. Antibodies that

  5. Engineering Recombinant Reoviruses To Display gp41 Membrane-Proximal External-Region Epitopes from HIV-1

    PubMed Central

    Boehme, Karl W.; Ikizler, Mine'; Iskarpatyoti, Jason A.; Wetzel, J. Denise; Willis, Jordan; Crowe, James E.; LaBranche, Celia C.; Montefiori, David C.

    2016-01-01

    ABSTRACT The gp41 membrane-proximal external region (MPER) is a target for broadly neutralizing antibody responses against human immunodeficiency virus type 1 (HIV-1). However, replication-defective virus vaccines currently under evaluation in clinical trials do not efficiently elicit MPER-specific antibodies. Structural modeling suggests that the MPER forms an α-helical coiled coil that is required for function and immunogenicity. To maintain the native MPER conformation, we used reverse genetics to engineer replication-competent reovirus vectors that displayed MPER sequences in the α-helical coiled-coil tail domain of viral attachment protein σ1. Sequences in reovirus strain type 1 Lang (T1L) σ1 were exchanged with sequences encoding HIV-1 strain Ba-L MPER epitope 2F5 or the entire MPER. Individual 2F5 or MPER substitutions were introduced at virion-proximal or virion-distal sites in the σ1 tail. Recombinant reoviruses containing heterologous HIV-1 sequences were viable and produced progeny yields comparable to those with wild-type virus. HIV-1 sequences were retained following 10 serial passages in cell culture, indicating that the substitutions were genetically stable. Recombinant viruses engineered to display the 2F5 epitope or full-length MPER in σ1 were recognized by purified 2F5 antibody. Inoculation of mice with 2F5-containing vectors or rabbits with 2F5- or MPER-containing vectors elicited anti-reovirus antibodies, but HIV-1-specific antibodies were not detected. Together, these findings indicate that heterologous sequences that form α-helices can functionally replace native sequences in the α-helical tail domain of reovirus attachment protein σ1. However, although these vectors retain native antigenicity, they were not immunogenic, illustrating the difficulty of experimentally inducing immune responses to this essential region of HIV-1. IMPORTANCE Vaccines to protect against HIV-1, the causative agent of AIDS, are not approved for use

  6. The amino-terminal 200 amino acids of the plasma membrane Na+,K+-ATPase alpha subunit confer ouabain sensitivity on the sarcoplasmic reticulum Ca(2+)-ATPase.

    PubMed Central

    Ishii, T; Takeyasu, K

    1993-01-01

    Cardiac glycosides such as G-strophanthin (ouabain) bind to and inhibit the plasma membrane Na+,K(+)-ATPase but not the sarcoplasmic reticulum (SR) Ca(2+)-ATPase, whereas thapsigargin specifically blocks the SR Ca(2+)-ATPase. The chimera [n/c]CC, in which the amino-terminal amino acids Met1 to Asp162 of the SR Ca(2+)-ATPase (SERCA1) were replaced with the corresponding portion of the Na+,K(+)-ATPase alpha 1 subunit (Met1 to Asp200), retained thapsigargin- and Ca(2+)-sensitive ATPase activity, although the activity was lower than that of the wild-type SR Ca(2+)-ATPase. Moreover, this Ca(2+)-sensitive ATPase activity was inhibited by ouabain. The chimera NCC, in which Met1-Gly354 of the SR Ca(2+)-ATPase were replaced with the corresponding portion of the Na+,K(+)-ATPase, lost the thapsigargin-sensitive Ca(2+)-ATPase activity seen in CCC and [n/c]CC. [3H]Ouabain binding to [n/c]CC and NCC demonstrated that the affinity for this inhibitor seen in the wild-type chicken Na+,K(+)-ATPase was restored in these chimeric molecules. Thus, the ouabain-binding domains are distinct from the thapsigargin sites; ouabain binds to the amino-terminal portion (Met1 to Asp200) of the Na+,K(+)-ATPase alpha 1 subunit, whereas thapsigargin interacts with the regions after Asp162 of the Ca(2+)-ATPase. Moreover, the amino-terminal 200 amino acids of the Na+,K(+)-ATPase alpha 1 subunit are sufficient to exert ouabain-dependent inhibition even after incorporation into the corresponding portion of the Ca(2+)-ATPase, and the segment Ile163 to Gly354 of the SR Ca(2+)-ATPase is critical for thapsigargin- and Ca(2+)-sensitive ATPase activity. Images Fig. 5 PMID:8415625

  7. Protein kinase and phosphoprotein phosphatase activities of nitrogen regulatory proteins NTRB and NTRC of enteric bacteria: roles of the conserved amino-terminal domain of NTRC.

    PubMed Central

    Keener, J; Kustu, S

    1988-01-01

    The NTRC protein (ntrC product) of enteric bacteria activates transcription of nitrogen-regulated genes by a holoenzyme form of RNA polymerase that contains the ntrA product (sigma 54) as sigma factor. Although unmodified NTRC will bind to DNA, it must be phosphorylated to activate transcription. Both phosphorylation and dephosphorylation of NTRC occur in the presence of the NTRB protein (ntrB product). We here demonstrate rigorously that it is the NTRB protein that is a protein kinase by showing that NTRB can phosphorylate itself, whereas NTRC cannot. Phosphorylated NTRC (NTRC-P) is capable of autodephosphorylation with a first-order rate constant of 0.14-0.19 min-1 (t 1/2 of 5.0-3.6 min) at 37 degrees C. In addition, there is regulated dephosphorylation of NTRC-P. By contrast to the autophosphatase activity, regulated dephosphorylation requires three components in addition to NTRC-P: the PII regulatory protein, NTRB, and ATP. NTRC is phosphorylated within its amino-terminal domain, which is conserved in one partner of a number of two-component regulatory systems in a wide variety of eubacteria. A purified amino-terminal fragment of NTRC (approximately equal to 12.5 kDa) is sufficient for recognition by NTRB and is autodephosphorylated at the same rate as the native protein. Images PMID:2839825

  8. The Arabidopsis Chloroplast Stromal N-Terminome: Complexities of Amino-Terminal Protein Maturation and Stability1[OPEN

    PubMed Central

    Rowland, Elden; Kim, Jitae; Bhuiyan, Nazmul H.; van Wijk, Klaas J.

    2015-01-01

    Protein amino (N) termini are prone to modifications and are major determinants of protein stability in bacteria, eukaryotes, and perhaps also in chloroplasts. Most chloroplast proteins undergo N-terminal maturation, but this is poorly understood due to insufficient experimental information. Consequently, N termini of mature chloroplast proteins cannot be accurately predicted. This motivated an extensive characterization of chloroplast protein N termini in Arabidopsis (Arabidopsis thaliana) using terminal amine isotopic labeling of substrates and mass spectrometry, generating nearly 14,000 tandem mass spectrometry spectra matching to protein N termini. Many nucleus-encoded plastid proteins accumulated with two or three different N termini; we evaluated the significance of these different proteoforms. Alanine, valine, threonine (often in N-α-acetylated form), and serine were by far the most observed N-terminal residues, even after normalization for their frequency in the plastid proteome, while other residues were absent or highly underrepresented. Plastid-encoded proteins showed a comparable distribution of N-terminal residues, but with a higher frequency of methionine. Infrequent residues (e.g. isoleucine, arginine, cysteine, proline, aspartate, and glutamate) were observed for several abundant proteins (e.g. heat shock proteins 70 and 90, Rubisco large subunit, and ferredoxin-glutamate synthase), likely reflecting functional regulation through their N termini. In contrast, the thylakoid lumenal proteome showed a wide diversity of N-terminal residues, including those typically associated with instability (aspartate, glutamate, leucine, and phenylalanine). We propose that, after cleavage of the chloroplast transit peptide by stromal processing peptidase, additional processing by unidentified peptidases occurs to avoid unstable or otherwise unfavorable N-terminal residues. The possibility of a chloroplast N-end rule is discussed. PMID:26371235

  9. Immunoreactive prohormone atrial natriuretic peptides 1-30 and 31-67 - Existence of a single circulating amino-terminal peptide

    NASA Technical Reports Server (NTRS)

    Chen, Yu-Ming; Whitson, Peggy A.; Cintron, Nitza M.

    1990-01-01

    Sep-Pak C18 extraction of human plasma and radioimmunoassay using antibodies which recognize atrial natriuretic peptide (99-128) and the prohormone sequences 1-30 and 31-67 resulted in mean values from 20 normal subjects of 26.2 (+/- 9.2), 362 (+/- 173) and 368 (+/- 160) pg/ml, respectively. A high correlation coefficient between values obtained using antibodies recognizing prohormone sequences 1-30 and 31-67 was observed (R = 0.84). Extracted plasma immunoreactivity of 1-30 and 31-67 both eluted at 46 percent acetonitrile. In contrast, chromatographic elution of synthetic peptides 1-30 and 31-67 was observed at 48 and 39 percent acetonitrile, respectively. Data suggest that the radioimmunoassay of plasma using antibodies recognizing prohormone sequences 1-30 and 31-67 may represent the measurement of a unique larger amino-terminal peptide fragment containing antigenic sites recognized by both antisera.

  10. Neutralization-resistant variants of a neurotropic coronavirus are generated by deletions within the amino-terminal half of the spike glycoprotein.

    PubMed Central

    Gallagher, T M; Parker, S E; Buchmeier, M J

    1990-01-01

    Neuroattenuated variants of mouse hepatitis virus type 4 (MHV-4) selected for resistance to neutralizing monoclonal antibodies (R.G. Dalziel, P.W. Lampert, P. J. Talbot, and M. J. Buchmeier, J. Virol. 59:463-471, 1986) were found to harbor large deletions in both mRNA 3 and its protein product, the 180-kilodalton viron spike (S) glycoprotein. By using antipeptide antibodies directed against selected portions of the chain, deletions were mapped to the middle of the amino-terminal S1 fragment, one of the two posttranslational cleavage products of S, and involved omission of 15 kilodaltons of protein. Deletion mutants could be selected only after multiple passage of virus through cultured cell lines; minimally passaged MHV-4 stocks contained putative point mutants selectable by neutralizing monoclonal antibodies but no deletions. Enhanced growth of deletion mutants relative to wild-type virus was observed in four cell lines used for virus propagation and was attributed to delayed and diminished cytopathic effects that allowed cultures to support virus production for prolonged periods. This hypothesis was reinforced by the finding that no selective advantage for the deletion mutants was observed in two cell lines resistant to virus-induced cytopathic effects. These results indicate that the passaging of MHV-4 in culture generates heterogeneity in S structure and eventually selects for rare neutralization-resistant deletion mutants with decreased virulence properties. Images PMID:1688627

  11. Improving solubility of NR2B amino-terminal domain of N-methyl-d-aspartate receptor expressed in Escherichia coli.

    PubMed

    Ng, Fui-Mee; Soh, Wanqin; Geballe, Matthew T; Low, Chian-Ming

    2007-10-12

    The amino-terminal domains (ATDs) of N-methyl-d-aspartate (NMDA) receptors contain binding sites for modulators and may serve as potential drug targets in neurological diseases. Here, three fusion tags (6xHis-, GST-, and MBP-) were fused to the ATD of NMDA receptor NR2B subunit (ATD2B) and expressed in Escherichia coli. Each tag's ability to confer enhanced solubility to ATD2B was assessed. Soluble ATD2B was successfully obtained as a MBP fusion protein. Dynamic light scattering revealed the protein (1mg/ml) exists as monodispersed species at 25 degrees C. Functional studies using circular dichroism showed that the soluble MBP-ATD2B bound ifenprodil in a dose-dependent manner. The dissociation constants obtained for ifenprodil were similar in the absence (64nM) and presence (116nM) of saturating concentration of maltose. Moreover, the yield of soluble MBP-ATD2B is 18 times higher than the refolded 6xHis-ATD2B. We have reported a systematic comparison of three different affinity tagging strategies and identified a rapid and efficient method to obtain large amount of ATD2B recombinant protein for biochemical and structural studies. PMID:17706601

  12. First Membrane Proximal External Region-Specific Anti-HIV1 Broadly Neutralizing Monoclonal IgA1 Presenting Short CDRH3 and Low Somatic Mutations.

    PubMed

    Benjelloun, Fahd; Oruc, Zeliha; Thielens, Nicole; Verrier, Bernard; Champier, Gael; Vincent, Nadine; Rochereau, Nicolas; Girard, Alexandre; Jospin, Fabienne; Chanut, Blandine; Genin, Christian; Cogné, Michel; Paul, Stephane

    2016-09-01

    Mucosal HIV-1-specific IgA have been described as being able to neutralize HIV-1 and to block viral transcytosis. In serum and saliva, the anti-HIV IgA response is predominantly raised against the envelope of HIV-1. In this work, we describe the in vivo generation of gp41-specific IgA1 in humanized α1KI mice to produce chimeric IgA1. Mice were immunized with a conformational immunogenic gp41-transfected cell line. Among 2300 clones screened by immunofluorescence microscopy, six different gp41-specific IgA with strong recognition of gp41 were identified. Two of them have strong neutralizing activity against primary HIV-1 tier 1, 2, and 3 strains and present a low rate of somatic mutations and autoreactivity, unlike what was described for classical gp41-specific IgG. Epitopes were identified and located in the hepted repeat 2/membrane proximal external region. These Abs could be of interest in prophylactic treatment to block HIV-1 penetration in mucosa or in chronically infected patients in combination with antiretroviral therapy to reduce viral load and reservoir. PMID:27481846

  13. Eliciting neutralizing antibodies against the membrane proximal external region of HIV-1 Env by chimeric live attenuated influenza A virus vaccines.

    PubMed

    Zang, Yang; Du, Dongchuan; Li, Na; Su, Weiheng; Liu, Xintao; Zhang, Yan; Nie, Jianhui; Wang, Youchun; Kong, Wei; Jiang, Chunlai

    2015-07-31

    Despite significant efforts directed toward research on HIV-1 vaccines, a truly effective immunogen has not been achieved. However, the broadly neutralizing antibodies (BnAbs) 2F5 and 4E10, targeting the highly conserved membrane proximal external region (MPER) of HIV-1, are two promising tools for vaccine development. Here we engrafted the MPER into the linker domain between the trimeric core structure and the transmembrane domain of influenza A virus HA2 to investigate the potential of such chimeric viruses to elicit HIV-1 neutralizing antibodies. In the context of proliferating attenuated influenza A viruses, these HIV-1 neutralizing antibody epitopes could be continuously expressed and mimicked their native conformation to induce humoral immune responses. While MPER-specific antibodies could be detected in serum of guinea pigs vaccinated with the chimeric viruses, they exhibited only weakly neutralizing activities. These antisera from vaccinated animals neutralized viruses of clades B and BC (tier 1), but not of clades AE (tier 1) and C (tier 2). These results suggest that influenza A virus can be used as a vehicle for displaying MPER and inducing BnAbs, but it provides limited protection against HIV-1 infection. In the future development of HIV-1 vaccines by rational design, a more effective live virus vector or multiple antigens should be chosen to facilitate the process of neutralizing antibody maturation. PMID:26126669

  14. Membrane-proximal TRAIL species are incapable of inducing short circuit apoptosis signaling: Implications for drug development and basic cytokine biology

    PubMed Central

    Tatzel, Katharina; Kuroki, Lindsay; Dmitriev, Igor; Kashentseva, Elena; Curiel, David T.; Goedegebuure, S. Peter; Powell, Matthew A.; Mutch, David G.; Hawkins, William G.; Spitzer, Dirk

    2016-01-01

    TRAIL continues to garner substantial interest as a recombinant cancer therapeutic while the native cytokine itself serves important tumor surveillance functions when expressed in membrane-anchored form on activated immune effector cells. We have recently developed the genetically stabilized TRAIL platform TR3 in efforts to improve the limitations associated with currently available drug variants. While in the process of characterizing mesothelin-targeted TR3 variants using a single chain antibody (scFv) delivery format (SS-TR3), we discovered that the membrane-tethered cytokine had a substantially increased activity profile compared to non-targeted TR3. However, cell death proceeded exclusively via a bystander mechanism and protected the mesothelin-positive targets from apoptosis rather than leading to their elimination. Incorporation of a spacer-into the mesothelin surface antigen or the cancer drug itself-converted SS-TR3 into a cis-acting phenotype. Further experiments with membrane-anchored TR3 variants and the native cytokine confirmed our hypothesis that membrane-proximal TRAIL species lack the capacity to physically engage their cognate receptors coexpressed on the same cell membrane. Our findings not only provide an explanation for the “peaceful” coexistence of ligand and receptor of a representative member of the TNF superfamily but give us vital clues for the design of activity-enhanced TR3-based cancer therapeutics. PMID:26935795

  15. Monoclonal antibody to the amino-terminal L sequence of murine leukemia virus glycosylated gag polyproteins demonstrates their unusual orientation in the cell membrane.

    PubMed Central

    Pillemer, E A; Kooistra, D A; Witte, O N; Weissman, I L

    1986-01-01

    To analyze cell surface murine leukemia virus gag protein expression, we have prepared monoclonal antibodies against the spontaneous AKR T lymphoma KKT-2. One of these antibodies, 43-13, detects an AKR-specific viral p12 determinant. A second monoclonal antibody, 43-17, detects a novel murine leukemia virus-related antigen found on glycosylated gag polyproteins (gp95gag, gp85gag, and gp55gag) on the surface of cells infected with and producing ecotropic endogenous viruses, but does not detect antigens within these virions. The 43-17 antibody immunoprecipitates the precursor of the cell surface gag protein whether in its glycosylated or unglycosylated state, but does not detect the cytoplasmic precursor of the virion gag proteins (Pr65gag). Based on these findings, we have localized the 43-17 determinant to the unique amino-terminal part of the glycosylated gag polyprotein (the L domain). We have determined that gp95gag contains L-p15-p12-p30-p10 determinants, whereas gp85gag lacks the carboxyterminal p10 determinant, and gp55gag lacks both p30 and p10 carboxy terminal determinants. Analysis of cell surface gag expression with the 43-17 antibody leads us to propose that the L domain plays a crucial role in (i) the insertion and orientation of murine leukemia virus gag polyproteins in the cell membrane and (ii) the relative abundance of expression of AKR leukemia virus versus Moloney murine leukemia virus glycosylated gag polyproteins in infected cells. Images PMID:2418213

  16. Amino-Terminal Pro-B-Type Natriuretic Peptide Improves Discrimination for Incident Atherosclerotic Cardiovascular Disease Beyond Ambulatory Blood Pressure in Elderly Men.

    PubMed

    Skoglund, Per H; Höijer, Jonas; Ärnlöv, Johan; Zethelius, Björn; Svensson, Per

    2015-09-01

    Improvement of risk prediction for atherosclerotic cardiovascular disease (ASCVD) is needed. Both ambulatory blood pressure (ABP) and biomarkers amino-terminal pro-B-type natriuretic peptide (NT-proBNP), high-sensitivity C-reactive protein and cystatin C improve risk prediction but they have not been evaluated in relation to each other. We analyzed whether NT-proBNP, high-sensitivity C-reactive protein, or cystatin C improved risk prediction beyond traditional ASCVD risk factors combined with 24-hour systolic BP (SBP). Secondary aim was to evaluate whether ABP improved risk prediction when compared with models with the biomarkers. We followed up 907 70-year-old men, free of baseline disease, for incident ASCVD defined as fatal or nonfatal myocardial infarction or fatal or nonfatal stroke for a median of 10 years. Cox regression was used to estimate the association between variables in the models and incident ASCVD. Biomarkers were added to a model containing both traditional risk factors and ABP and the models were compared on C-statistics and net reclassification improvement. Twenty-four hour SBP improved discrimination for incident ASCVD when compared with office SBP in a traditional risk factor model (area under the receiver-operating characteristic curve, +2.4%). NT-proBNP further improved reclassification (+18.7%-19.9%; P<0.01) when added to ABP models, whereas high-sensitivity C-reactive protein and cystatin C did not. Twenty-four hour SBP significantly improved net reclassification when added to a traditional risk factor model that included NT-proBNP. The combination of 24-hour SBP and NT-proBNP improved discrimination and net reclassification for incident ASCVD when compared with office SBP in elderly men. NT-proBNP, but not high-sensitivity C-reactive protein or cystatin C, improved risk prediction and discrimination when added to a model that included ABP. PMID:26150437

  17. The acidic amino-terminal region of herpes simplex virus type 1 alpha protein ICP27 is required for an essential lytic function.

    PubMed Central

    Rice, S A; Lam, V; Knipe, D M

    1993-01-01

    The herpes simplex virus type 1 (HSV-1) alpha protein ICP27 regulates the transition between the delayed-early and late phases of the viral infection. Previous genetic analyses have suggested that the important functional domains of ICP27 map to its carboxyl-terminal half. One striking feature of the primary sequence of ICP27, however, is an extremely acidic region near its amino terminus. To determine whether this region is required for ICP27 function, we deleted the sequences in the ICP27 gene which encode it (codons 12 through 63). In transient expression assays, the deletion mutant was unable to efficiently repress the expression of a cotransfected reporter gene or to efficiently complement the growth of d27-1, an HSV-1 ICP27 null mutant. These results suggested that the acidic region of ICP27 is involved in a regulatory function required for lytic growth. To test this possibility further, we introduced the mutant allele into the HSV-1 genome by marker transfer. Two independently derived isolates of the mutant virus, designated d1-2a and d1-2b, were recovered and analyzed. Both isolates were defective for growth in Vero cells, exhibiting a 100-fold reduction in virus yield compared with the wild-type infection. Vero cells infected with the d1-2 isolates showed a three- to eightfold reduction in viral DNA replication, a moderate reduction in the expression of viral gamma genes, and a delay in the repression of beta genes. The phenotype of the d1-2 isolates differs substantially from the phenotypes of previously isolated ICP27 mutants, which show much more severe defects in viral gene expression. Our results demonstrate that the amino-terminal half of ICP27 participates in its regulatory activities in both infected and transfected cells. Images PMID:8383210

  18. The amino-terminal GAF domain of Azotobacter vinelandii NifA binds 2-oxoglutarate to resist inhibition by NifL under nitrogen-limiting conditions.

    PubMed

    Little, Richard; Dixon, Ray

    2003-08-01

    The expression of genes required for the synthesis of molybdenum nitrogenase in Azotobacter vinelandii is controlled by the NifL-NifA transcriptional regulatory complex in response to nitrogen, carbon, and redox status. Activation of nif gene expression by the transcriptional activator NifA is inhibited by direct protein-protein interaction with NifL under conditions unfavorable for nitrogen fixation. We have recently shown that the NifL-NifA system responds directly to physiological concentrations of 2-oxoglutarate, resulting in relief of NifA activity from inhibition by NifL under conditions when fixed nitrogen is limiting. The inhibitory activity of NifL is restored under conditions of excess combined nitrogen through the binding of the signal transduction protein Av GlnK to the carboxyl-terminal domain of NifL. The amino-terminal domain of NifA comprises a GAF domain implicated in the regulatory response to NifL. A truncated form of NifA lacking this domain is not responsive to 2-oxoglutarate in the presence of NifL, suggesting that the GAF domain is required for the response to this ligand. Using isothermal titration calorimetry, we demonstrate stoichiometric binding of 2-oxoglutarate to both the isolated GAF domain and the full-length A. vinelandii NifA protein with a dissociation constant of approximately 60 microm. Limited proteolysis experiments indicate that the binding of 2-oxoglutarate increases the susceptibility of the GAF domain to trypsin digestion and also prevents NifL from protecting these cleavage sites. However, protection by NifL is restored when the non-modified (non-uridylylated) form of Av GlnK is also present. Our results suggest that the binding of 2-oxoglutarate to the GAF domain of NifA may induce a conformational change that prevents inhibition by NifL under conditions when fixed nitrogen is limiting. PMID:12759352

  19. High-Sensitivity Troponin I and Amino-Terminal Pro–B-Type Natriuretic Peptide Predict Heart Failure and Mortality in the General Population

    PubMed Central

    McKie, Paul M.; AbouEzzeddine, Omar F.; Scott, Christopher G.; Mehta, Ramila; Rodeheffer, Richard J.; Redfield, Margaret M.; Burnett, John C.; Jaffe, Allan S.

    2015-01-01

    INTRODUCTION High-sensitivity cardiac troponin assays have potent prognostic value in stable cardiovascular disease cohorts. Our objective was to assess the prognostic utility of a novel cardiac troponin I (cTnI) high-sensitivity assay, independently and in combination with amino-terminal pro–B-type natriuretic peptide (NT-proBNP), for the future development of heart failure and mortality in the general community. METHODS A well-characterized community-based cohort of 2042 participants underwent clinical assessment and echocardiographic evaluation. Baseline measurements of cTnI with a high-sensitivity assay and NT-proBNP were obtained in 1843 individuals. Participants were followed for new-onset heart failure and mortality with median (25th, 75th percentile) follow-up of 10.7 (7.9, 11.6) and 12.1 (10.4, 13.0) years, respectively. RESULTS When measured with a high-sensitivity assay, cTnI greater than the sex-specific 80th percentile was independently predictive of heart failure [hazard ratio 2.56 (95% confidence interval 1.88 – 3.50), P < 0.001] and mortality [1.91(1.49 – 2.46), P < 0.001] beyond conventional risk factors in this community-based cohort, with significant increases in the net reclassification improvement for heart failure. The prognostic utility of cTnI measured with a high-sensitivity assay goes beyond NT-proBNP, yet our data suggest that these 2 assays are complementary and most beneficial when evaluated together in identifying at-risk individuals in the community. CONCLUSIONS Our findings lay the foundation for prospective studies aimed at identification of individuals at high risk by use of a multimarker approach, followed by aggressive prevention strategies to prevent subsequent heart failure. PMID:24987112

  20. NMR structure of the amino-terminal domain from the Tfb1 subunit of TFIIH and characterization of its phosphoinositide and VP16 binding sites.

    PubMed

    Di Lello, Paola; Nguyen, Bao D; Jones, Tamara N; Potempa, Krzysztof; Kobor, Michael S; Legault, Pascale; Omichinski, James G

    2005-05-31

    General transcription factor IIH (TFIIH) is recruited to the preinitiation complex (PIC) through direct interactions between its p62 (Tfb1) subunit and the carboxyl-terminal domain of TFIIEalpha. TFIIH has also been shown to interact with a number of transcriptional activator proteins through interactions with the same p62 (Tfb1) subunit. We have determined the NMR solution structure of the amino-terminal domain from the Tfb1 subunit of yeast TFIIH (Tfb1(1-115)). Like the corresponding domain from the human p62 protein, Tfb1(1-115) contains a PH domain fold despite a low level of sequence identity between the two functionally homologous proteins. In addition, we have performed in vitro binding studies that demonstrate that the PH domains of Tfb1 and p62 specifically bind to monophosphorylated inositides [PtdIns(5)P and PtdIns(3)P]. NMR chemical shift mapping demonstrated that the PtdIns(5)P binding site on Tfb1 (p62) is located in the basic pocket formed by beta-strands beta5-beta7 of the PH domain fold. Interestingly, the structural composition of the PtdIns(5)P binding site is different from the composition of the binding sites for phosphoinositides on prototypic PH domains. We have also determined that the PH domains from Tfb1 and p62 are sufficient for binding to the activation domain of VP16. NMR chemical shift mapping demonstrated that the VP16 binding site within the PH domain of Tfb1 (p62) overlaps with the PtdIns(5)P binding site on Tfb1 (p62). These results provide new information about the recognition of phosphoinositides by PH domains, and point to a potential role for phosphoinositides in VP16 regulation. PMID:15909982

  1. Transaminase B from Escherichia coli: quaternary structure, amino-terminal sequence, substrate specificity, and absence of a separate valine-alpha-ketoglutarate activity.

    PubMed

    Lee-Peng, F C; Hermodson, M A; Kohlhaw, G B

    1979-08-01

    Transaminase B (branched-chain amino acid aminotransferase, EC 2.6.1.42), the ilvE gene product, was purified to apparent homogeneity from an Escherichia coli K-12 strain which carries the ilvE gene both on the host chromosome and on a plasmid. The oligomeric structure of the enzyme, as determined by analytical ultracentrifugation and sodium dodecyl sulfate-polyacrylamide gel electrophoresis, was confirmed to be that of a hexamer with a molecular weight of about 182,000 and apparently identical subunits. Cross-linking with dimethylsuberimidate yielded trimers, dimers, and monomers, but essentially no species of higher molecular weight. These results are consistent with a double-trimer arrangement of the subunits in native enzyme. The amino-terminal sequence was found to be: Gly Thr Lys Lys Ala Asp Tyr Ile (Trp) Phe Asn Gly (Thr) (Met) Val. Purified transaminase B catalyzed transamination between alpha-ketoglutarate and l-isoleucine, l-leucine, l-valine, and, to a lesser extent, l-phenylalanine and l-tyrosine, the latter reacting very sluggishly. The enzyme was free of aspartate transaminase and of transaminase C. The apparent K(m) values for the branched-chain alpha-ketoacids were smaller than those for the corresponding amino acids. The lowest K(m) was recorded for dl-alpha-keto-beta-methyl-n-valerate, and the highest was recorded for l-valine. The ratio of the valine- and isoleucine-alpha-ketoglutarate activities did not change significantly during purification, and both activities were quantitatively removed from crude extract by antibody raised against purified transaminase B. These observations argue against the existence of a separate valine-alpha-ketoglutarate transaminase. Anti-E. coli transaminase B antibody cross-reacted with crude extract from Salmonella typhimurium, but not with extract obtained from Pseudomonas aeruginosa. PMID:378964

  2. Liposomal vaccines incorporating molecular adjuvants and intrastructural T-cell help promote the immunogenicity of HIV membrane-proximal external region peptides

    PubMed Central

    Hanson, Melissa C.; Abraham, Wuhbet; Crespo, Monica P.; Chen, Stephanie H.; Liu, Haipeng; Szeto, Greg Lee; Kim, Mikyung; Reinherz, Ellis L.; Irvine, Darrell J.

    2015-01-01

    An HIV vaccine capable of inducing high and durable levels of broadly neutralizing antibodies has thus far proven elusive. A promising antigen is the membrane-proximal external region (MPER) from gp41, a segment of the viral envelope recognized by a number of broadly neutralizing antibodies. Though an attractive vaccine target due to the linear nature of the epitope and its highly conserved sequence, MPER peptides are poorly immunogenic and may require display on membranes to achieve a physiological conformation matching the native virus. Here we systematically explored how the structure and composition of liposomes displaying MPER peptides impacts the strength and durability of humoral responses to this antigen as well as helper T-cell responses in mice. Administration of MPER peptides anchored to the surface of liposomes induced MPER-specific antibodies whereas MPER administered in oil-based emulsion adjuvants or alum did not, even when combined with Toll like receptor agonists. High-titer IgG responses to liposomal MPER required the inclusion of molecular adjuvants such as monophosphoryl lipid A. Anti-MPER humoral responses were further enhanced by incorporating high-Tm lipids in the vesicle bilayer and optimizing the MPER density to a mean distance of ~10–15 nm between peptides on the liposomes' surfaces. Encapsulation of helper epitopes within the vesicles allowed efficient “intrastructural” T-cell help, which promoted IgG responses to MPER while minimizing competing B-cell responses against the helper sequence. These results define several key properties of liposome formulations that promote durable, high-titer antibody responses against MPER peptides, which will be a prerequisite for a successful MPER-targeting vaccine. PMID:25559188

  3. Differential killing of CD56-expressing cells by drug-conjugated human antibodies targeting membrane-distal and membrane-proximal non-overlapping epitopes.

    PubMed

    Feng, Yang; Wang, Yanping; Zhu, Zhongyu; Li, Wei; Sussman, Robyn T; Randall, Michael; Bosse, Kristopher R; Maris, John M; Dimitrov, Dimiter S

    2016-01-01

    CD56 (NCAM, neural cell adhesion molecule) is over-expressed in many tumor types, including neuroblastoma, multiple myeloma, small cell lung cancer, ovarian cancer, acute myeloid leukemia, NK-T lymphoma, neuroendocrine cancer and pancreatic cancer. Using phage display, we identified 2 high-affinity anti-CD56 human monoclonal antibodies (mAbs), m900 and m906, which bound to spatially separated non-overlapping epitopes with similar affinity (equilibrium dissociation constant 2.9 and 4.5 nM, respectively). m900 bound to the membrane proximal fibronectin type III-like domains, whereas m906 bound to the N-terminal IgG-like domains. m906 induced significant down-regulation of CD56 in 4 neuroblastoma cell lines tested, while m900-induced downregulation of CD56 was much lower. Antibody-drug conjugates (ADCs) made by conjugation with a highly potent pyrrolobenzodiazepine dimer (PBD) exhibited killing activity that correlated with CD56 down-regulation, and to some extent with in vivo binding ability of the antibodies. The m906PBD ADC was much more potent than m900PBD, likely due to higher CD56-mediated downregulation and stronger binding to cells. Treatment with m906PBD ADC resulted in very potent cytotoxicity (IC50: 0.05-1.7 pM). These results suggest a novel approach for targeting CD56-expressing neuroblastoma cells. Further studies in animal models and in humans are needed to find whether these antibodies and their drug conjugates are promising candidate therapeutics. PMID:26910291

  4. Receptor-Targeted Nipah Virus Glycoproteins Improve Cell-Type Selective Gene Delivery and Reveal a Preference for Membrane-Proximal Cell Attachment

    PubMed Central

    Bender, Ruben R.; Muth, Anke; Schneider, Irene C.; Friedel, Thorsten; Hartmann, Jessica; Plückthun, Andreas; Maisner, Andrea; Buchholz, Christian J.

    2016-01-01

    Receptor-targeted lentiviral vectors (LVs) can be an effective tool for selective transfer of genes into distinct cell types of choice. Moreover, they can be used to determine the molecular properties that cell surface proteins must fulfill to act as receptors for viral glycoproteins. Here we show that LVs pseudotyped with receptor-targeted Nipah virus (NiV) glycoproteins effectively enter into cells when they use cell surface proteins as receptors that bring them closely enough to the cell membrane (less than 100 Å distance). Then, they were flexible in receptor usage as demonstrated by successful targeting of EpCAM, CD20, and CD8, and as selective as LVs pseudotyped with receptor-targeted measles virus (MV) glycoproteins, the current standard for cell-type specific gene delivery. Remarkably, NiV-LVs could be produced at up to two orders of magnitude higher titers compared to their MV-based counterparts and were at least 10,000-fold less effectively neutralized than MV glycoprotein pseudotyped LVs by pooled human intravenous immunoglobulin. An important finding for NiV-LVs targeted to Her2/neu was an about 100-fold higher gene transfer activity when particles were targeted to membrane-proximal regions as compared to particles binding to a more membrane-distal epitope. Likewise, the low gene transfer activity mediated by NiV-LV particles bound to the membrane distal domains of CD117 or the glutamate receptor subunit 4 (GluA4) was substantially enhanced by reducing receptor size to below 100 Å. Overall, the data suggest that the NiV glycoproteins are optimally suited for cell-type specific gene delivery with LVs and, in addition, for the first time define which parts of a cell surface protein should be targeted to achieve optimal gene transfer rates with receptor-targeted LVs. PMID:27281338

  5. The Atomic Structure of the HIV-1 gp41 Transmembrane Domain and Its Connection to the Immunogenic Membrane-proximal External Region*♦

    PubMed Central

    Apellániz, Beatriz; Rujas, Edurne; Serrano, Soraya; Morante, Koldo; Tsumoto, Kouhei; Caaveiro, Jose M. M.; Jiménez, M. Ángeles; Nieva, José L.

    2015-01-01

    The membrane-proximal external region (MPER) C-terminal segment and the transmembrane domain (TMD) of gp41 are involved in HIV-1 envelope glycoprotein-mediated fusion and modulation of immune responses during viral infection. However, the atomic structure of this functional region remains unsolved. Here, based on the high resolution NMR data obtained for peptides spanning the C-terminal segment of MPER and the TMD, we report two main findings: (i) the conformational variability of the TMD helix at a membrane-buried position; and (ii) the existence of an uninterrupted α-helix spanning MPER and the N-terminal region of the TMD. Thus, our structural data provide evidence for the bipartite organization of TMD predicted by previous molecular dynamics simulations and functional studies, but they do not support the breaking of the helix at Lys-683, as was suggested by some models to mark the initiation of the TMD anchor. Antibody binding energetics examined with isothermal titration calorimetry and humoral responses elicited in rabbits by peptide-based vaccines further support the relevance of a continuous MPER-TMD helix for immune recognition. We conclude that the transmembrane anchor of HIV-1 envelope is composed of two distinct subdomains: 1) an immunogenic helix at the N terminus also involved in promoting membrane fusion; and 2) an immunosuppressive helix at the C terminus, which might also contribute to the late stages of the fusion process. The unprecedented high resolution structural data reported here may guide future vaccine and inhibitor developments. PMID:25787074

  6. Receptor-Targeted Nipah Virus Glycoproteins Improve Cell-Type Selective Gene Delivery and Reveal a Preference for Membrane-Proximal Cell Attachment.

    PubMed

    Bender, Ruben R; Muth, Anke; Schneider, Irene C; Friedel, Thorsten; Hartmann, Jessica; Plückthun, Andreas; Maisner, Andrea; Buchholz, Christian J

    2016-06-01

    Receptor-targeted lentiviral vectors (LVs) can be an effective tool for selective transfer of genes into distinct cell types of choice. Moreover, they can be used to determine the molecular properties that cell surface proteins must fulfill to act as receptors for viral glycoproteins. Here we show that LVs pseudotyped with receptor-targeted Nipah virus (NiV) glycoproteins effectively enter into cells when they use cell surface proteins as receptors that bring them closely enough to the cell membrane (less than 100 Å distance). Then, they were flexible in receptor usage as demonstrated by successful targeting of EpCAM, CD20, and CD8, and as selective as LVs pseudotyped with receptor-targeted measles virus (MV) glycoproteins, the current standard for cell-type specific gene delivery. Remarkably, NiV-LVs could be produced at up to two orders of magnitude higher titers compared to their MV-based counterparts and were at least 10,000-fold less effectively neutralized than MV glycoprotein pseudotyped LVs by pooled human intravenous immunoglobulin. An important finding for NiV-LVs targeted to Her2/neu was an about 100-fold higher gene transfer activity when particles were targeted to membrane-proximal regions as compared to particles binding to a more membrane-distal epitope. Likewise, the low gene transfer activity mediated by NiV-LV particles bound to the membrane distal domains of CD117 or the glutamate receptor subunit 4 (GluA4) was substantially enhanced by reducing receptor size to below 100 Å. Overall, the data suggest that the NiV glycoproteins are optimally suited for cell-type specific gene delivery with LVs and, in addition, for the first time define which parts of a cell surface protein should be targeted to achieve optimal gene transfer rates with receptor-targeted LVs. PMID:27281338

  7. Expression and T cell recognition of hybrid antigens with amino-terminal domains encoded by Qa-2 region of major histocompatibility complex and carboxyl termini of transplantation antigens.

    PubMed

    Stroynowski, I; Forman, J; Goodenow, R S; Schiffer, S G; McMillan, M; Sharrow, S O; Sachs, D H; Hood, L

    1985-05-01

    Coding potential of the Q6 gene from the Qa-2a region of BALB/c Crgl mice was analyzed by a combination of hybrid class I gene construction and DNA-mediated gene transfer. Recombinant genes were created by exon shuffling of the 5' coding region of the Q6 gene and the 3' coding region of a gene encoding a transplantation antigen (Kd, Dd, or Ld), or the inverse. Some of these hybrid class I genes were expressed in the transfected mouse fibroblasts (L cells). The hybrid class I molecules encoded by the 5' end of the Q6 gene and the 3' end of the Ld gene precipitated as 45,000 mol wt molecules associated with beta 2-microglobulin. The expression of the hybrid proteins indicates that 926 basepairs of the 5' flanking region upstream of the structural Q6 gene contain a promoter that functions as a transcription initiation site in L cells. The 3' portion of the Q6 gene appears to be responsible for the lack of cell surface expression of the intact Q6 and the hybrid Ld/Q6 genes in mouse fibroblasts. Accordingly, this portion of the Q6 class I gene may play a regulatory role in tissue-specific expression. Serological analyses of hybrid Q6 proteins suggested that Q6 may be a structural gene for CR (H-2 crossreactive) antigen found normally on subpopulations of lymphocytes. If this identification is correct, Q6 gene will define a new category of class I genes encoding approximately 40,000 mol wt molecules and carrying a characteristic truncated cytoplasmic tail. Analysis of L cells transfected with Q6 hybrid genes demonstrated also that the cytotoxic T cells specific for Qa-2a region-coded antigens recognize the amino-terminal alpha 1-alpha 2 domain of Q6 fusion products. This recognition can be blocked by anti-Qa-2a alloantiserum and monoclonal antibodies reactive with the alpha 3-beta 2-microglobulin portion of the Q6 hybrids. We propose that the structural requirements for the anti-Qa-2a cytotoxic T lymphocyte-specific epitopes on target molecules are the same as for anti

  8. B-type natriuretic peptide and amino-terminal pro-B-type natriuretic peptide in pediatric patients with pulmonary arterial hypertension

    PubMed Central

    Takatsuki, Shinichi; Wagner, Brandie D; Ivy, David Dunbar

    2011-01-01

    Objectives B-type natriuretic peptide (BNP) and the amino-terminal fragment (NTproBNP) correlate with clinical variables, but have not been simultaneously studied in a large number of pediatric patients with pulmonary arterial hypertension (PAH). The purpose of our investigation was to compare BNP and NTproBNP with clinical indicators of disease in a pediatric PAH population for which biomarkers are much needed. Design We retrospectively compared BNP and NTproBNP levels with exercise capacity, echocardiographic data, and hemodynamics in PAH patients under 21 years-old. Two hundred sixty three blood samples from 88 pediatric PAH patients were obtained, with BNP and NTproBNP drawn at the same time. Results There was a correlation between BNP and NTproBNP with mean pulmonary arterial pressure/mean arterial pressure (mPAP/mSAP) ratio (r=0.40 p<0.01, r=0.45 p<0.01, respectively), mean right atrial pressure (mRAP) (r=0.48 p<0.01, r=0.48 p<0.01), and tricuspid regurgitant (TR) velocity (r=0.36 p<0.01, r=0.41 p<0.01). BNP and NTproBNP are associated with 6 minute walking distance, mPAP, mPAP/mSAP ratio, mRAP, pulmonary vascular resistance index (PVRI), and TR velocity when investigated longitudinally. On the average, a 1 unit increase in log BNP or NTproBNP was associated with 4.5 unitsxm2 or 3.4 unitsxm2 increase in PVRI, respectively. There was a strong correlation between log BNP and log NTproBNP measurements (r= 0.87, p<0.01). Conclusion In pediatric PAH, BNP and NTProBNP are strongly correlated and predict changes in clinical variables and hemodynamics. In a cross-sectional analysis, NTproBNP correlated with echocardiographic and exercise data better than BNP; NTproBNP showed less within patient variability over time, therefore NTproBNP can add additional information towards predicting these clinical measurements. PMID:22325151

  9. Crystal Structures of the Glutamate Receptor Ion Channel GluK3 and GluK5 Amino-Terminal Domains

    SciTech Connect

    Kumar, Janesh; Mayer, Mark L.

    2010-11-30

    Ionotropic glutamate receptors (iGluRs) mediate the majority of fast excitatory synaptic neurotransmission in the central nervous system. The selective assembly of iGluRs into AMPA, kainate, and N-methyl-d-aspartic acid (NMDA) receptor subtypes is regulated by their extracellular amino-terminal domains (ATDs). Kainate receptors are further classified into low-affinity receptor families (GluK1-GluK3) and high-affinity receptor families (GluK4-GluK5) based on their affinity for the neurotoxin kainic acid. These two families share a 42% sequence identity for the intact receptor but only a 27% sequence identity at the level of ATD. We have determined for the first time the high-resolution crystal structures of GluK3 and GluK5 ATDs, both of which crystallize as dimers but with a strikingly different dimer assembly at the R1 interface. By contrast, for both GluK3 and GluK5, the R2 domain dimer assembly is similar to those reported previously for other non-NMDA iGluRs. This observation is consistent with the reports that GluK4-GluK5 cannot form functional homomeric ion channels and require obligate coassembly with GluK1-GluK3. Our analysis also reveals that the relative orientation of domains R1 and R2 in individual non-NMDA receptor ATDs varies by up to 10{sup o}, in contrast to the 50{sup o} difference reported for the NMDA receptor GluN2B subunit. This restricted domain movement in non-NMDA receptor ATDs seems to result both from extensive intramolecular contacts between domain R1 and domain R2 and from their assembly as dimers, which interact at both R1 and R2 domains. Our results provide the first insights into the structure and function of GluK4-GluK5, the least understood family of iGluRs.

  10. The Serine Protease Plasmin Cleaves the Amino-terminal Domain of the NR2A Subunit to Relieve Zinc Inhibition of the N-Methyl-d-aspartate Receptors*S⃞

    PubMed Central

    Yuan, Hongjie; Vance, Katie M.; Junge, Candice E.; Geballe, Matthew T.; Snyder, James P.; Hepler, John R.; Yepes, Manuel; Low, Chian-Ming; Traynelis, Stephen F.

    2009-01-01

    Zinc is hypothesized to be co-released with glutamate at synapses of the central nervous system. Zinc binds to NR1/NR2A N-methyl-d-aspartate (NMDA) receptors with high affinity and inhibits NMDAR function in a voltage-independent manner. The serine protease plasmin can cleave a number of substrates, including protease-activated receptors, and may play an important role in several disorders of the central nervous system, including ischemia and spinal cord injury. Here, we demonstrate that plasmin can cleave the native NR2A amino-terminal domain (NR2AATD), removing the functional high affinity Zn2+ binding site. Plasmin also cleaves recombinant NR2AATD at lysine 317 (Lys317), thereby producing a ∼40-kDa fragment, consistent with plasmin-induced NR2A cleavage fragments observed in rat brain membrane preparations. A homology model of the NR2AATD predicts that Lys317 is near the surface of the protein and is accessible to plasmin. Recombinant expression of NR2A with an amino-terminal deletion at Lys317 is functional and Zn2+ insensitive. Whole cell voltage-clamp recordings show that Zn2+ inhibition of agonist-evoked NMDA receptor currents of NR1/NR2A-transfected HEK 293 cells and cultured cortical neurons is significantly reduced by plasmin treatment. Mutating the plasmin cleavage site Lys317 on NR2A to alanine blocks the effect of plasmin on Zn2+ inhibition. The relief of Zn2+ inhibition by plasmin occurs in PAR1-/- cortical neurons and thus is independent of interaction with protease-activated receptors. These results suggest that plasmin can directly interact with NMDA receptors, and plasmin may increase NMDA receptor responses through disruption or removal of the amino-terminal domain and relief of Zn2+ inhibition. PMID:19240037

  11. Substitution of conserved cysteine residues in Wheat streak mosaic virus HC-Pro abolishes virus transmission by the wheat curl mite

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Substitutions in the amino-terminal region of Wheat streak mosaic virus (WSMV) HC-Pro were evaluated for effects on transmission by the wheat curl mite (Aceria tosichella Keifer). Alanine substitution at cysteine residues 16, 46 and 49 abolished vector transmission. Although alanine substitution a...

  12. In vitro gene fusions that join an enzymatically active beta-galactosidase segment to amino-terminal fragments of exogenous proteins: Escherichia coli plasmid vectors for the detection and cloning of translational initiation signals.

    PubMed Central

    Casadaban, M J; Chou, J; Cohen, S N

    1980-01-01

    We report the construction and use of a series of plasmid vectors suitable for the detection and cloning of translational control signals and 5' coding sequences of exogenously derived genes. In these plasmids, the first eight codons of the amino-terminal end of the lactose operon beta-galactosidase gene, lacZ, were removed, and unique BamHI, EcoRI, and SmaI (XmaI) endonuclease cleavage sites were incorporated adjacent to the eighth codon of lacZ. Introduction of deoxyribonucleic acid fragments containing appropriate regulatory signals and 5' coding sequences into such lac fusion plasmids led to the production of hybrid proteins consisting of the carboxyl-terminal segment of a beta-galactosidase remnant plus a peptide fragment that contained the amino-terminal amino acids encoded by the exogenous deoxyribonucleic acid sequence. These hybrid peptides retained beta-galactosidase enzymatic activity and yielded a Lac+ phenotype. Such hybrid proteins are useful for purifying peptide sequences encoded by exogenous deoxyribonucleic acid fragments and for studies relating the structure and function of specific peptide segments. Images PMID:6162838

  13. A Residue Quartet in the Extracellular Domain of the Prolactin Receptor Selectively Controls Mitogen-activated Protein Kinase Signaling*

    PubMed Central

    Zhang, Chi; Nygaard, Mads; Haxholm, Gitte W.; Boutillon, Florence; Bernadet, Marie; Hoos, Sylviane; England, Patrick; Broutin, Isabelle; Kragelund, Birthe B.; Goffin, Vincent

    2015-01-01

    Cytokine receptors elicit several signaling pathways, but it is poorly understood how they select and discriminate between them. We have scrutinized the prolactin receptor as an archetype model of homodimeric cytokine receptors to address the role of the extracellular membrane proximal domain in signal transfer and pathway selection. Structure-guided manipulation of residues involved in the receptor dimerization interface identified one residue (position 170) that in cell-based assays profoundly altered pathway selectivity and species-specific bio-characteristics. Subsequent in vitro spectroscopic and nuclear magnetic resonance analyses revealed that this residue was part of a residue quartet responsible for specific local structural changes underlying these effects. This included alteration of a novel aromatic T-stack within the membrane proximal domain, which promoted selective signaling affecting primarily the MAPK (ERK1/2) pathway. Importantly, activation of the MAPK pathway correlated with in vitro stabilities of ternary ligand·receptor complexes, suggesting a threshold mean lifetime of the complex necessary to achieve maximal activation. No such dependence was observed for STAT5 signaling. Thus, this study establishes a residue quartet in the extracellular membrane proximal domain of homodimeric cytokine receptors as a key regulator of intracellular signaling discrimination. PMID:25784554

  14. Amino-terminal processing of proteins: hemoglobin South Florida, a variant with retention of initiator methionine and N alpha-acetylation.

    PubMed Central

    Boissel, J P; Kasper, T J; Shah, S C; Malone, J I; Bunn, H F

    1985-01-01

    The hemoglobin variant South Florida has been shown by protein sequencing and fast-atom-bombardment mass spectroscopy to have a substitution of methionine for the NH2-terminal valine of the beta-globin chain. In addition, there was complete retention of the initiator methionine on the mutant polypeptide. Approximately 20% of the protein was acetylated at the NH2 terminus of the beta chain. A search of a comprehensive data bank of protein and gene sequences revealed 84 unrelated vertebrate proteins that have not undergone cleavage of leader sequences. A highly nonrandom distribution of residues at the NH2 termini of these proteins predicts removal of the initiator methionine as well as NH2-terminal acetylation. Proteins that undergo removal commonly have serine, alanine, glycine, or valine, as the NH2-terminal residues. The first three residues favor N alpha-acetylation. Proteins that retain the initiator methionine commonly have a charged residue or methionine at the second position. Information on Hb South Florida and other hemoglobins coupled with this survey of primary sequence provides insights into the NH2-terminal processing of proteins. PMID:3866233

  15. Potentiation of Neuronal Nicotinic Receptors by 17β-Estradiol: Roles of the Carboxy-Terminal and the Amino-Terminal Extracellular Domains

    PubMed Central

    Jin, Xiaochun; Steinbach, Joe Henry

    2015-01-01

    The endogenous steroid 17β-estradiol (βEST) potentiates activation of neuronal nicotinic receptors containing α4 subunits. Previous work has shown that the final 4 residues of the α4 subunit are required for potentiation. However, receptors containing the α2 subunit are not potentiated although it has these 4 residues, and only one amino acid difference in the C-terminal tail (FLAGMI vs. WLAGMI). Previous work had indicated that the tryptophan residue was involved in binding an analog of βEST, but not in potentiation by βEST. To determine the structural basis for the loss of potentiation we analyzed data from chimeric subunits, which indicated that the major factor underlying the difference between α2 and α4 is the tryptophan/phenylalanine difference, while the N-terminal extracellular domain is a less significant factor. When the tryptophan in α4 was mutated, both phenylalanine and tyrosine conferred lower potentiation while lysine and leucine did not. The reduction reflected a reduced maximal magnitude of potentiation, indicating that the tryptophan is involved in transduction of steroid effects. The regions of the α4 N-terminal extracellular domain involved in potentiation lie near the agonist-binding pocket, rather than close to the membrane or the C-terminal tail, and appear to be involved in transduction rather than binding. These observations indicate that the C-terminal region is involved in both steroid binding (AGMI residues) and transduction (W). The role of the N-terminus appears to be independent of the C-terminal tryptophan and likely reflects an influence on conformational changes caused during channel activation by agonist and potentiation by estradiol. PMID:26684647

  16. Posttranslational Modifications in the Amino- Terminal Region of the Large Subunit of Ribulose- 1,5-Bisphosphate Carboxylase/Oxygenase from Several Plant Species 1

    PubMed Central

    Houtz, Robert L.; Poneleit, Loelle; Jones, Samantha B.; Royer, Malcolm; Stults, John T.

    1992-01-01

    A combination of limited tryptic proteolysis, reverse phasehigh performance liquid chromatography, Edman degradative sequencing, amino acid analysis, and fast-atom bombardment mass-spectrometry was used to remove and identify the first 14 to 18 N-terminal amino acid residues of the large subunit of higher plant-type ribulose-1,5-bisphosphate carboxylase/oxygenase (Rubisco) from Chlamydomonas reinhardtii, Marchantia polymorpha, pea (Pisum sativum), tomato (Lycopersicon esculentum), potato (Solanum tuberosum), pepper (Capsicum annuum), soybean (Glycine max), petunia (Petunia x hybrida), cowpea (Vigna sinensis), and cucumber (Cucumis sativus) plants. The N-terminal tryptic peptide from acetylated Pro-3 to Lys-8 of the large subunit of Rubisco was identical in all species, but the amino acid sequence of the penultimate N-terminal tryptic peptide varied. Eight of the 10 species examined contained a trimethyllysyl residue at position 14 in the large subunit of Rubisco, whereas Chlamydomonas and Marchantia contained an unmodified lysyl residue at this position. ImagesFigure 1 PMID:16668742

  17. Amino-terminal amino acid sequence of the major structural polypeptides of avian retroviruses: sequence homology between reticuloendotheliosis virus p30 and p30s of mammalian retroviruses.

    PubMed Central

    Hunter, E; Bhown, A S; Bennett, J C

    1978-01-01

    The major structural polypeptides, p30 of reticuloendotheliosis virus (REV) (strain T) and p27 of avian sarcoma virus B77, have been compared with regard to amino acid composition. NH2-terminal amino acid sequence, and immunological crossreactions. The amino acid composition of the two polypeptides is distinct, and a comparison of the first 30 NH2-terminal amino acids of REV p30 with that for the first 25 of B77 p27 yields only three homologous residues. In competition radioimmunoassays the polypeptides show no crossreactivity. A comparison of the amino acid composition and NH2-terminal amino acid sequence of REV p30 with those reported for several mammalian retrovirus p30s shows remarkable similarities. Both REV and mammalian p30s contain a large number of polar residues in their amino acid composition and show approximately 40% homology in the first 30 NH2-terminal amino acids. No crossreactivity could be observed, however, in competition radioimmunoassays between Rauscher murine leukemia virus p30 and that of REV. The observations reported here suggest a close evolutionary relationship between REV and the mammalian retroviruses. Images PMID:208072

  18. The Molecular Basis for Histone H4- and H2A-Specific Amino-Terminal Acetylation by NatD

    PubMed Central

    Magin, Robert S.; Liszczak, Glen P.; Marmorstein, Ronen

    2014-01-01

    SUMMARY N-terminal acetylation is among the most common protein modifications in eukaryotes and is mediated by evolutionarily conserved N-terminal acetyltransferases (NATs). NatD is among the most selective NATs; its only known substrates are histones H4 and H2A, containing the N-terminal sequence SGRGK in humans. Here we characterize the molecular basis for substrate-specific acetylation by NatD by reporting its crystal structure bound to cognate substrates and performing related biochemical studies. A novel N-terminal segment wraps around the catalytic core domain to make stabilizing interactions, and the α1-α2 and β6-β7 loops adopt novel conformations to properly orient the histone N termini in the binding site. Ser1 and Arg3 of the histone make extensive contacts to highly conserved NatD residues in the substrate binding pocket, and flanking glycine residues also appear to contribute to substrate-specific binding by NatD, together defining a Ser-Gly-Arg-Gly recognition sequence. These studies have implications for understanding substrate-specific acetylation by NAT enzymes. PMID:25619998

  19. Isolation of L-3-phenyllactyl-Leu-Arg-Asn-NH sub 2 (Antho-RNamide), a sea anemone neuropeptide containing an unusual amino-terminal blocking group

    SciTech Connect

    Grimmelikhuijzen, C.J.P.; Jacob, E.; Graff, D.; Reinscheid, R.K.; Nothacker, H.P. ); Rinehart, K.L.; Staley, A.L. )

    1990-07-01

    Using a radioimmunoassay for the carboxyl-terminal sequence Arg-Asn-NH{sub 2}, the authors have purified a peptide from acetic acid extracts of the sea anemone Anthopleura elegantissima. By classical amino acid analyses, mass spectrometry, and {sup 1}H NMR spectroscopy, the structure of this peptide was determined as 3-phenyllactyl-Leu-Arg-Asn-NH{sub 2}. By using reversed-phase HPLC and a chiral mobile phase, it was shown that the 3-phenyllactyl group had the L configuration. Immunocytochemical staining with antiserum against Arg-Asn-NH{sub 2} showed that L-3-phenyllactyl-Leu-Arg-Asn-NH{sub 2} (Antho-RNamide) was localized in neutrons of sea anemones. The L-3-phenyllactyl group has not been found earlier in neuropeptides of vertebrates or higher invertebrates. They propose that this residue renders Antho-RNamide resistant to nonspecific aminopeptidases, thereby increasing the stability of the peptide after neuronal release.

  20. Hybridoma antibodies to the lipid-binding site(s) in the amino-terminal region of fibronectin inhibits binding of streptococcal lipoteichoic acid.

    PubMed

    Stanislawski, L; Courtney, H S; Simpson, W A; Hasty, D L; Beachey, E H; Robert, L; Ofek, I

    1987-08-01

    In this report, we present evidence to suggest that streptococci and lipoteichoic acid (LTA) interact with a fatty acid binding site located near the NH2-terminus of fibronectin. The evidence is based on the following observations. Antibodies directed against a synthetic peptide (residues 1-30 of the amino-terminus of fibronectin) reacted with the two thermolysin-generated peptides (24 and 28 kilodaltons [kDa]) that were adsorbed by and eluted from streptococci. The adsorption of the 24- and 28-kDa peptides to streptococci was inhibited by LTA. The two monoclonal antibodies that inhibited the binding of LTA to fibronectin reacted only with the 24- and 28-kDa fragments of fibronectin. Conversely, LTA, as well as lauric acid and oleic acid, blocked the binding of the same monoclonal antibodies to fibronectin. LTA had no effect on the binding of hybridoma antibodies directed against the collagen or cell-binding domain. PMID:3298457

  1. Biophysical characterization of the MerP-like amino-terminal extension of the mercuric reductase from Ralstonia metallidurans CH34.

    PubMed

    Rossy, Emmanuel; Champier, Ludovic; Bersch, Beate; Brutscher, Bernhard; Blackledge, Martin; Covès, Jacques

    2004-01-01

    The purified native mercuric reductase (MerA) from Ralstonia metallidurans CH34 contains an N-terminal sequence of 68 amino acids predicted to be homologous to MerP, the periplasmic mercury-binding protein. This MerP-like protein has now been expressed independently. The protein was named MerAa by homology with Ccc2a, the first soluble domain of the copper-transporting ATPase from yeast. Deltaa has been characterized using a set of biophysical techniques. The binding of mercury was followed using circular dichroism spectroscopy and electrospray mass spectrometry. The two cysteine residues contained in the consensus sequence GMTC XXC are involved in the binding of one mercury atom, with an apparent affinity comparable to that of MerP for the same metal. The metal-binding site is confirmed by NMR chemical shift changes observed between apo- and metal-bound MerAa in solution. NMR shift and NOE data also indicate that only minor structural changes occur upon metal binding. Further NMR investigation of the fold of MerAa using long-range methyl-methyl NOE and backbone residual dipolar coupling data confirm the expected close structural homology with MerP. (15)N relaxation data show that MerAa is a globally rigid molecule. An increased backbone mobility was observed for the loop region connecting the first beta-strand and the first alpha-helix and comprising the metal-binding domain. Although significantly reduced, this loop region keeps some conformational flexibility upon metal binding. Altogether, our data suggest a role of MerAa in mercury trafficking. PMID:14624351

  2. Enhanced activation of an amino-terminally truncated isoform of the voltage-gated proton channel HVCN1 enriched in malignant B cells

    PubMed Central

    Hondares, Elayne; Brown, Mark Adrian; Musset, Boris; Morgan, Deri; Cherny, Vladimir V.; Taubert, Christina; Bhamrah, Mandeep K.; Coe, David; Marelli-Berg, Federica; Gribben, John G.; Dyer, Martin J. S.; DeCoursey, Thomas E.; Capasso, Melania

    2014-01-01

    HVCN1 (Hydrogen voltage-gated channel 1) is the only mammalian voltage-gated proton channel. In human B lymphocytes, HVCN1 associates with the B-cell receptor (BCR) and is required for optimal BCR signaling and redox control. HVCN1 is expressed in malignant B cells that rely on BCR signaling, such as chronic lymphocytic leukemia (CLL) cells. However, little is known about its regulation in these cells. We found that HVCN1 was expressed in B cells as two protein isoforms. The shorter isoform (HVCN1S) was enriched in B cells from a cohort of 76 CLL patients. When overexpressed in a B-cell lymphoma line, HVCN1S responded more profoundly to protein kinase C-dependent phosphorylation. This more potent enhanced gating response was mediated by increased phosphorylation of the same residue responsible for enhanced gating in HVCN1L, Thr29. Furthermore, the association of HVCN1S with the BCR was weaker, which resulted in its diminished internalization upon BCR stimulation. Finally, HVCN1S conferred a proliferative and migratory advantage as well as enhanced BCR-dependent signaling. Overall, our data show for the first time, to our knowledge, the existence of a shorter isoform of HVCN1 with enhanced gating that is specifically enriched in malignant B cells. The properties of HVCN1S suggest that it may contribute to the pathogenesis of BCR-dependent B-cell malignancies. PMID:25425665

  3. The amino-terminal conserved domain of 4-hydroxy-3-methylbut-2-enyl diphosphate reductase is critical for its function in oxygen-evolving photosynthetic organisms.

    PubMed

    Hsieh, Wei-Yu; Hsieh, Ming-Hsiun

    2015-01-01

    4-hydroxy-3-methylbut-2-enyl diphosphate reductase (HDR), also known as isoprenoid synthesis H (IspH) or lysis-tolerant B (LytB), catalyzes the last step of the methylerythritol phosphate pathway to synthesize isopentenyl diphosphate and dimethylallyl diphosphate. The structure and reaction mechanism of IspH have been actively investigated in Escherichia coli but little is known in plants. Compared with the bacterial IspH, cyanobacterial and plant HDRs all contain an extra N-terminal conserved domain (NCD) that is essential for their function. Tyr72 in the NCD and several plant-specific residues around the central active site are critical for Arabidopsis HDR function. These results suggest that the structure and reaction mechanism of HDR/IspH may be different between plants and bacteria. The E. coli IspH is an iron-sulfur protein that is sensitive to oxygen. It is possible that the cyanobacterial HDR may independently evolve from the common ancestor of prokaryotes to obtain the NCD, which may protect the enzyme from high concentration of oxygen during photosynthesis. PMID:25723575

  4. Crystal structure of type I ryanodine receptor amino-terminal beta-trefoil domain reveals a disease-associated mutation "hot spot" loop.

    PubMed

    Amador, Fernando J; Liu, Shuang; Ishiyama, Noboru; Plevin, Michael J; Wilson, Aaron; MacLennan, David H; Ikura, Mitsuhiko

    2009-07-01

    Muscle contraction and relaxation is regulated by transient elevations of myoplasmic Ca(2+). Ca(2+) is released from stores in the lumen of the sarco(endo)plasmic reticulum (SER) to initiate formation of the Ca(2+) transient by activation of a class of Ca(2+) release channels referred to as ryanodine receptors (RyRs) and is pumped back into the SER lumen by Ca(2+)-ATPases (SERCAs) to terminate the Ca(2+) transient. Mutations in the type 1 ryanodine receptor gene, RYR1, are associated with 2 skeletal muscle disorders, malignant hyperthermia (MH), and central core disease (CCD). The evaluation of proposed mechanisms by which RyR1 mutations cause MH and CCD is hindered by the lack of high-resolution structural information. Here, we report the crystal structure of the N-terminal 210 residues of RyR1 (RyR(NTD)) at 2.5 A. The RyR(NTD) structure is similar to that of the suppressor domain of type 1 inositol 1,4,5-trisphosphate receptor (IP(3)Rsup), but lacks most of the long helix-turn-helix segment of the "arm" domain in IP(3)Rsup. The N-terminal beta-trefoil fold, found in both RyR and IP(3)R, is likely to play a critical role in regulatory mechanisms in this channel family. A disease-associated mutation "hot spot" loop was identified between strands 8 and 9 in a highly basic region of RyR1. Biophysical studies showed that 3 MH-associated mutations (C36R, R164C, and R178C) do not adversely affect the global stability or fold of RyR(NTD), supporting previously described mechanisms whereby mutations perturb protein-protein interactions. PMID:19541610

  5. Crystal structure of type I ryanodine receptor amino-terminal [beta]-trefoil domain reveals a disease-associated mutation 'hot spot' loop

    SciTech Connect

    Amador, Fernando J.; Liu, Shuang; Ishiyama, Noboru; Plevin, Michael J.; Wilson, Aaron; MacLennan, David H.; Ikura, Mitsuhiko

    2009-12-01

    Muscle contraction and relaxation is regulated by transient elevations of myoplasmic Ca{sup 2+}. Ca{sup 2+} is released from stores in the lumen of the sarco(endo)plasmic reticulum (SER) to initiate formation of the Ca{sup 2+} transient by activation of a class of Ca{sup 2+} release channels referred to as ryanodine receptors (RyRs) and is pumped back into the SER lumen by Ca{sup 2+}-ATPases (SERCAs) to terminate the Ca{sup 2+} transient. Mutations in the type 1 ryanodine receptor gene, RYR1, are associated with 2 skeletal muscle disorders, malignant hyperthermia (MH), and central core disease (CCD). The evaluation of proposed mechanisms by which RyR1 mutations cause MH and CCD is hindered by the lack of high-resolution structural information. Here, we report the crystal structure of the N-terminal 210 residues of RyR1 (RyR{sub NTD}) at 2.5 {angstrom}. The RyR{sub NTD} structure is similar to that of the suppressor domain of type 1 inositol 1,4,5-trisphosphate receptor (IP3Rsup), but lacks most of the long helix-turn-helix segment of the 'arm' domain in IP3Rsup. The N-terminal {beta}-trefoil fold, found in both RyR and IP{sub 3}R, is likely to play a critical role in regulatory mechanisms in this channel family. A disease-associated mutation 'hot spot' loop was identified between strands 8 and 9 in a highly basic region of RyR1. Biophysical studies showed that 3 MH-associated mutations (C36R, R164C, and R178C) do not adversely affect the global stability or fold of RyRNTD, supporting previously described mechanisms whereby mutations perturb protein-protein interactions.

  6. Uniform {sup 15}N- and {sup 15}N/{sup 13}C-labeling of proteins in mammalian cells and solution structure of the amino terminal fragment of u-PA

    SciTech Connect

    Hansen, A.P.; Petros, A.M.; Meadows, R.P.; Mazar, A.P.; Nettesheim, D.G.; Pederson, T.M.; Fesik, S.W.

    1994-12-01

    Urokinase-type plasminogen activator (u-PA) is a 54-kDa glycoprotein that catalyzes the conversion of plasminogen to plasmin, a broad-specificity protease responsible for the degradation of fibrin clots and extracellular matrix components. The u-PA protein consists of three individual modules: a growth factor domain (GFD), a kringle, and a serine protease domain. The amino terminal fragment (ATF) includes the GFD-responsible for u-PA binding to its receptor-and the kringle domains. This protein was expressed and uniformly {sup 15}N-and {sup 15}N/{sup 13}C-labeled in mammalian cells by methods that will be described. In addition, we present the three-dimensional structure of ATF that was derived from 1299 NOE-derived distance restraints along with the {phi} angle and hydrogen bonding restraints. Although the individual domains in the structures were highly converged, the two domains are structurally independent. The overall structures of the individual domains are very similar to the structures of homologous proteins. However, important structural differences between the growth factor domain of u-PA and other homologous proteins were observed in the region that has been implicated in binding the urokinase receptor. These results may explain, in part, why other growth factors show no appreciable affinity for the urokinase receptor.

  7. Negatively-charged residues in the polar carboxy-terminal region in FSP27 are indispensable for expanding lipid droplets.

    PubMed

    Tamori, Yoshikazu; Tateya, Sanshiro; Ijuin, Takeshi; Nishimoto, Yuki; Nakajima, Shinsuke; Ogawa, Wataru

    2016-03-01

    FSP27 has an important role in large lipid droplet (LD) formation because it exchanges lipids at the contact site between LDs. In the present study, we clarify that the amino-terminal domain of FSP27 (amino acids 1-130) is dispensable for LD enlargement, although it accelerates LD growth. LD expansion depends on the carboxy-terminal domain of FSP27 (amino acids 131-239). Especially, the negative charge of the acidic residues (D215, E218, E219 and E220) in the polar carboxy-terminal region (amino acids 202-239) is essential for the enlargement of LD. We propose that the carboxy-terminal domain of FSP27 has a crucial role in LD expansion, whereas the amino-terminal domain only has a supportive role. PMID:26921608

  8. The development of decision limits for the GH-2000 detection methodology using additional insulin-like growth factor-I and amino-terminal pro-peptide of type III collagen assays.

    PubMed

    Holt, Richard I G; Böhning, Walailuck; Guha, Nishan; Bartlett, Christiaan; Cowan, David A; Giraud, Sylvain; Bassett, E Eryl; Sönksen, Peter H; Böhning, Dankmar

    2015-09-01

    The GH-2000 and GH-2004 projects have developed a method for detecting GH misuse based on measuring insulin-like growth factor-I (IGF-I) and the amino-terminal pro-peptide of type III collagen (P-III-NP). The objectives were to analyze more samples from elite athletes to improve the reliability of the decision limit estimates, to evaluate whether the existing decision limits needed revision, and to validate further non-radioisotopic assays for these markers. The study included 998 male and 931 female elite athletes. Blood samples were collected according to World Anti-Doping Agency (WADA) guidelines at various sporting events including the 2011 International Association of Athletics Federations (IAAF) World Athletics Championships in Daegu, South Korea. IGF-I was measured by the Immunotech A15729 IGF-I IRMA, the Immunodiagnostic Systems iSYS IGF-I assay and a recently developed mass spectrometry (LC-MS/MS) method. P-III-NP was measured by the Cisbio RIA-gnost P-III-P, Orion UniQ™ PIIINP RIA and Siemens ADVIA Centaur P-III-NP assays. The GH-2000 score decision limits were developed using existing statistical techniques. Decision limits were determined using a specificity of 99.99% and an allowance for uncertainty because of the finite sample size. The revised Immunotech IGF-I - Orion P-III-NP assay combination decision limit did not change significantly following the addition of the new samples. The new decision limits are applied to currently available non-radioisotopic assays to measure IGF-I and P-III-NP in elite athletes, which should allow wider flexibility to implement the GH-2000 marker test for GH misuse while providing some resilience against manufacturer withdrawal or change of assays. PMID:25645199

  9. Plasmodium falciparum: an epitope within a highly conserved region of the 47-kDa amino-terminal domain of the serine repeat antigen is a target of parasite-inhibitory antibodies.

    PubMed

    Fox, B A; Xing-Li, P; Suzue, K; Horii, T; Bzik, D J

    1997-02-01

    Previously, the Plasmodium falciparum serine repeat antigen has been shown to be protective in primate models of malaria immunity and also to be a target of in vitro parasite-inhibitory antibodies. To further define parasite-inhibitory epitopes a series of deletions from the amino-terminal 47-kDa domain of the serine repeat antigen (SERA) were constructed as glutathione-S-transferase fusion proteins. Several GST-SERA fusion proteins were used to vaccinate mice with Freund's adjuvant and the resulting immune sera were used to assay for the inhibition of P. falciparum invasion of erythrocytes in vitro. The minimal epitope shown to be the target of invasion-blocking antibodies was SERA amino acids 17-165. Additional GST-SERA deletion constructs of the 47-kDa domain were developed and evaluated for reactivity, by Western immunoblot analysis, with a parasite-inhibitory murine monoclonal antibody (mAb 43E5), a parasite-inhibitory pooled goat polyclonal sera, and a pooled human Nigerian immune serum. The parasite-inhibitory epitope defined by mAb 43E5 was mapped to SERA amino acids 17-110 and, at least, part of the epitope was defined to include amino acids in the region of amino acids 59-72. The parasite-inhibitory epitope recognized by mAb 43E5 appears to be well conserved between diverse geographical isolates of P. falciparum. The results have relevance for malaria vaccine development and suggest that an appropriately designed recombinant SERA antigen produced from a synthetic gene in Escherichia coli may be an effective component of a candidate malaria vaccine. PMID:9030663

  10. Role of endotoxin in acute inflammation induced by gram-negative bacteria: specific inhibition of lipopolysaccharide-mediated responses with an amino-terminal fragment of bactericidal/permeability-increasing protein.

    PubMed Central

    Kohn, F R; Kung, A H

    1995-01-01

    A recombinant 23-kDa amino-terminal fragment of human bactericidal/permeability-increasing protein (rBPI23), a potent lipopolysaccharide (LPS)-binding/neutralizing protein, was used as a probe to assess the role of endotoxin in the acute inflammatory responses elicited by gram-negative bacteria in rat subcutaneous air pouches. In initial experiments, rBPI23 prevented the Escherichia coli O111:B4 LPS-induced accumulation of polymorphonuclear leukocytes (PMN), tumor necrosis factor alpha (TNF-alpha), and nitrite (a stable end product of nitric oxide formation) in exudate fluids. Significant inhibition of TNF-alpha production was still evident when rBPI23 treatment was delayed for 30 min after LPS instillation. In subsequent experiments, rBPI23 also prevented the nitrite and early (2-h) TNF-alpha accumulation induced by three different strains of formaldehyde-killed gram-negative bacteria (E. coli O7:K1, E. coli O111:B4, and Pseudomonas aeruginosa 12.4.4) but did not inhibit the PMN or late (6-h) TNF-alpha accumulation induced by these bacteria. As with LPS challenge, a significant inhibition of early TNF-alpha production was still evident when rBPI23 treatment was delayed for 30 to 60 min after instillation of killed bacteria. The results indicate that in this experimental model the NO and early TNF-alpha responses to gram-negative bacterial challenge are mediated predominantly by endotoxin, whereas the PMN and late TNF-alpha responses may be mediated by other bacterial components. Moreover, the results indicate that rBPI23 can inhibit the bacterially induced production of certain potentially harmful mediators (TNF-alpha and NO) without entirely blocking the host defense, i.e., PMN response, against the bacteria. PMID:7806373

  11. Amino-terminal domain of the v-fms oncogene product includes a functional signal peptide that directs synthesis of a transforming glycoprotein in the absence of feline leukemia virus gag sequences

    SciTech Connect

    Wheeler, E.F.; Roussel, M.F.; Hampe, A.; Walker, M.H.; Fried, V.A.; Look, A.T.; Rettenmier, C.W.; Sherr, C.J.

    1986-08-01

    The nucleotide sequence of a 5' segment of the human genomic c-fms proto-oncogene suggested that recombination between feline leukemia virus and feline c-fms sequences might have occurred in a region encoding the 5' untranslated portion of c-fms mRNA. The polyprotein precursor gP180/sup gag-fms/ encoded by the McDonough strain of feline sarcoma virus was therefore predicted to contain 34 v-fms-coded amino acids derived from sequences of the c-fms gene that are not ordinarily translated from the proto-oncogene mRNA. The (gP180/sup gag-fms/) polyprotein was cotranslationally cleaved near the gag-fms junction to remove its gag gene-coded portion. Determination of the amino-terminal sequence of the resulting v-fms-coded glycoprotein, gp120/sup v-fms/, showed that the site of proteolysis corresponded to a predicted signal peptidase cleavage site within the c-fms gene product. Together, these analyses suggested that the linked gag sequences may not be necessary for expression of a biologically active v-fms gene product. The gag-fms sequences of feline sarcoma virus strain McDonough and the v-fms sequences alone were inserted into a murine retroviral vector containing a neomycin resistance gene. The authors conclude that a cryptic hydrophobic signal peptide sequence in v-fms was unmasked by gag deletion, thereby allowing the correct orientation and transport of the v-fms was unmasked by gag deletion, thereby allowing the correct orientation and transport of the v-fms gene product within membranous organelles. It seems likely that the proteolytic cleavage of gP180/gag-fms/ is mediated by signal peptidase and that the amino termini of gp140/sup v-fms/ and the c-fms gene product are identical.

  12. The 52 000 MW Ro/SS-A autoantigen in Sjögren's syndrome/systemic lupus erythematosus (Ro52) is an interferon-gamma inducible tripartite motif protein associated with membrane proximal structures.

    PubMed

    Rhodes, Davd A; Ihrke, Gudrun; Reinicke, Anna T; Malcherek, Georg; Towey, Michael; Isenberg, David A; Trowsdale, John

    2002-06-01

    The 52 000 MW Ro/SS-A (Ro52) protein is a major target of autoantibodies in autoimmune conditions such as systemic lupus erythematosus and Sjögren's syndrome. Recent genomic and bioinformatic studies have shown that Ro52 belongs to a large family of related RING/Bbox/coiled-coil (RBCC) tripartite motif proteins sharing overall domain structure and 40-50% identity at the amino acid level. Ro52 also has a B30.2 domain at the C-terminus. Using the human genome draft sequence, the genomic organization of the Ro52 gene on human chromosome 11p15.5 has been deduced and related to the protein domain structure. We show that the steady-state levels of Ro52 mRNA are normally very low but are induced by cell activation with interferon-gamma. In transient transfection of HeLa cells, epitope-tagged Ro52 protein was localized to unidentified membrane proximal rod-like structures. Using in vitro coupled transcription/translation followed by immunoprecipitation, the autoimmune response to Ro52 protein was investigated and two distinct interactions were resolved. The Ro52 C-terminal B30.2 domain interacts with human immunoglobulin independently of antibody specificities. Sera derived from patients with Sjögren's syndrome and systemic lupus erythematosus, in addition, contained specific autoantibodies directed towards the rest of the Ro52 molecule. The majority of these autoimmune sera also immunoprecipitated the Ro52-related molecule RNF15. A possible role for Ro52 protein in alterations of plasma membranes during cellular activation or apoptosis is discussed. PMID:12047754

  13. Extracellular membrane-proximal domain of HAb18G/CD147 binds to metal ion-dependent adhesion site (MIDAS) motif of integrin β1 to modulate malignant properties of hepatoma cells.

    PubMed

    Li, Yong; Wu, Jiao; Song, Fei; Tang, Juan; Wang, Shi-Jie; Yu, Xiao-Ling; Chen, Zhi-Nan; Jiang, Jian-Li

    2012-02-10

    Several lines of evidence suggest that HAb18G/CD147 interacts with the integrin variants α3β1 and α6β1. However, the mechanism of the interaction remains largely unknown. In this study, mammalian protein-protein interaction trap (MAPPIT), a mammalian two-hybrid method, was used to study the CD147-integrin β1 subunit interaction. CD147 in human hepatocellular carcinoma (HCC) cells was interfered with by small hairpin RNA. Nude mouse xenograft model and metastatic model of HCC were used to detect the role of CD147 in carcinogenesis and metastasis. We found that the extracellular membrane-proximal domain of HAb18G/CD147 (I-type domain) binds at the metal ion-dependent adhesion site in the βA domain of the integrin β1 subunit, and Asp(179) in the I-type domain of HAb18G/CD147 plays an important role in the interaction. The levels of the proteins that act downstream of integrin, including focal adhesion kinase (FAK) and phospho-FAK, were decreased, and the cytoskeletal structures of HCC cells were rearranged bearing the HAb18G/CD147 deletion. Simultaneously, the migration and invasion capacities, secretion of matrix metalloproteinases, colony formation rate in vitro, and tumor growth and metastatic potential in vivo were decreased. These results indicate that the interaction of HAb18G/CD147 extracellular I-type domain with the integrin β1 metal ion-dependent adhesion site motif activates the downstream FAK signaling pathway, subsequently enhancing the malignant properties of HCC cells. PMID:22130661

  14. Extracellular Membrane-proximal Domain of HAb18G/CD147 Binds to Metal Ion-dependent Adhesion Site (MIDAS) Motif of Integrin β1 to Modulate Malignant Properties of Hepatoma Cells*

    PubMed Central

    Li, Yong; Wu, Jiao; Song, Fei; Tang, Juan; Wang, Shi-Jie; Yu, Xiao-Ling; Chen, Zhi-Nan; Jiang, Jian-Li

    2012-01-01

    Several lines of evidence suggest that HAb18G/CD147 interacts with the integrin variants α3β1 and α6β1. However, the mechanism of the interaction remains largely unknown. In this study, mammalian protein-protein interaction trap (MAPPIT), a mammalian two-hybrid method, was used to study the CD147-integrin β1 subunit interaction. CD147 in human hepatocellular carcinoma (HCC) cells was interfered with by small hairpin RNA. Nude mouse xenograft model and metastatic model of HCC were used to detect the role of CD147 in carcinogenesis and metastasis. We found that the extracellular membrane-proximal domain of HAb18G/CD147 (I-type domain) binds at the metal ion-dependent adhesion site in the βA domain of the integrin β1 subunit, and Asp179 in the I-type domain of HAb18G/CD147 plays an important role in the interaction. The levels of the proteins that act downstream of integrin, including focal adhesion kinase (FAK) and phospho-FAK, were decreased, and the cytoskeletal structures of HCC cells were rearranged bearing the HAb18G/CD147 deletion. Simultaneously, the migration and invasion capacities, secretion of matrix metalloproteinases, colony formation rate in vitro, and tumor growth and metastatic potential in vivo were decreased. These results indicate that the interaction of HAb18G/CD147 extracellular I-type domain with the integrin β1 metal ion-dependent adhesion site motif activates the downstream FAK signaling pathway, subsequently enhancing the malignant properties of HCC cells. PMID:22130661

  15. Carboxy-terminal telopeptide (CTX) and amino-terminal propeptide (PINP) of type I collagen as markers of bone metastases in patients with non-small cell lung cancer.

    PubMed

    Lumachi, Franco; Santeufemia, Davide A; Del Conte, Alessandro; Mazza, Francesco; Tozzoli, Renato; Chiara, Giordano B; Basso, Stefano M M

    2013-06-01

    The early diagnosis of non-small cell lung carcinoma (NSCLC) is difficult, and 30-40% of patients with NSCLC develop bone metastases (BMs) during the course of their disease. Because the delayed demonstration of skeletal involvement may seriously affect survival, there is a need for early diagnosis of BMs. Unfortunately, the sensitivity of common serum tumor markers is low and they are used mainly for monitoring the efficacy of therapy and detection of recurrence. The aim of this study was to evaluate the utility of a panel of serum biomarkers in patients with NSCLC and BMs. Sixteen patients (11 males, 5 females; median age=64 years, range 54-68 years) with NSCLC and BMs (cases), and 18 age- and stage-matched patients without BMs (controls) underwent measurement of serum carboxy-terminal telopeptide of type I collagen (CTX), tartrate-resistant acid phosphatase isoform type 5b (TRAP5b) and amino-terminal propeptide of type I collagen (PINP), carcinoembryonic antigen (CEA) and fragments of cytokeratin 19 (CYFRA 21-1. CTX (443.7 ± 945.1 vs. 402.7 ± 28.4 pg/ml, p=0.003) and PINP (75.9 ± 11.4 vs. 64.1 ± 7.5 μg/l, p=0.001) were significantly higher in patients with BMs, while the mean value of the other markers did not differ (p=NS) between cases and controls. The sensitivity, specificity and accuracy were 73.3%, 86.7% and 79.4% for CTX; 55.5%, 62.5% and 58.8% for CEA; 65.0%, 78.6% and 70.6% for CYFRA; 30.4%, 76.2% and 67.6% for TRAP5b; and 72.2%, 81.2% and 76.5% for PINP, respectively. The area under the receiver operating characteristic curve (AUC) for CTX was 0.68. In conclusion, CTX and PINP measurement can be useful in monitoring patients with NSCLC during follow-up, with the aim of detecting BMs early. PMID:23749913

  16. The amino-terminal portion of CD1 of the adenovirus E1A proteins is required to induce susceptibility to tumor necrosis factor cytolysis in adenovirus-infected mouse cells.

    PubMed

    Duerksen-Hughes, P J; Hermiston, T W; Wold, W S; Gooding, L R

    1991-03-01

    Previous work by our laboratory and others has shown that mouse cells normally resistant to tumor necrosis factor can be made sensitive to the cytokine by the expression of adenovirus E1A. The E1A gene can be introduced by either infection or transfection, and either of the two major E1A proteins, 289R or 243R, can induce this sensitivity. The E1A proteins are multifunctional and modular, with specific domains associated with specific functions. Here, we report that the CD1 domain of E1A is required to induce susceptibility to tumor necrosis factor cytolysis in adenovirus-infected mouse C3HA fibroblasts. Amino acids C terminal to residue 60 and N terminal to residue 36 are not necessary for this function. This conclusion is based on 51Cr-release assays for cytolysis in cells infected with adenovirus mutants with deletions in various portions of E1A. These E1A mutants are all in an H5dl309 background and therefore they lack the tumor necrosis factor protection function provided by the 14.7-kilodalton (14.7K) protein encoded by region E3. Western blot (immunoblot) analysis indicated that most of the mutant E1A proteins were stable in infected C3HA cells, although with certain large deletions the E1A proteins were unstable. The region between residues 36 and 60 is included within but does not precisely correlate with domains in E1A that have been implicated in nuclear localization, enhancer repression, cellular immortalization, cell transformation in cooperation with ras, induction of cellular DNA synthesis and proliferation, induction of DNA degradation, and binding to the 300K protein and the 105K retinoblastoma protein. PMID:1825340

  17. Lysyl Hydroxylase 3 Modifies Lysine Residues to Facilitate Oligomerization of Mannan-Binding Lectin

    PubMed Central

    Risteli, Maija; Ruotsalainen, Heli; Bergmann, Ulrich; Venkatraman Girija, Umakhanth; Wallis, Russell; Myllylä, Raili

    2014-01-01

    Lysyl hydroxylase 3 (LH3) is a multifunctional protein with lysyl hydroxylase, galactosyltransferase and glucosyltransferase activities. The LH3 has been shown to modify the lysine residues both in collagens and also in some collagenous proteins. In this study we show for the first time that LH3 is essential for catalyzing formation of the glucosylgalactosylhydroxylysines of mannan-binding lectin (MBL), the first component of the lectin pathway of complement activation. Furthermore, loss of the terminal glucose units on the derivatized lysine residues in mouse embryonic fibroblasts lacking the LH3 protein leads to defective disulphide bonding and oligomerization of rat MBL-A, with a decrease in the proportion of the larger functional MBL oligomers. The oligomerization could be completely restored with the full length LH3 or the amino-terminal fragment of LH3 that possesses the glycosyltransferase activities. Our results confirm that LH3 is the only enzyme capable of glucosylating the galactosylhydroxylysine residues in proteins with a collagenous domain. In mice lacking the lysyl hydroxylase activity of LH3, but with untouched galactosyltransferase and glucosyltransferase activities, reduced circulating MBL-A levels were observed. Oligomerization was normal, however and residual lysyl hydroxylation was compensated in part by other lysyl hydroxylase isoenzymes. Our data suggest that LH3 is commonly involved in biosynthesis of collagenous proteins and the glucosylation of galactosylhydroxylysines residues by LH3 is crucial for the formation of the functional high-molecular weight MBL oligomers. PMID:25419660

  18. Crop residues

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Crop residues [e.g., corn (Zea mays) stover and small grain straw] are sometimes excluded when discussing cellulosic energy crops per se, but because of the vast area upon which they are grown and their current role in the development of cellulosic energy systems. This chapter focuses on current cor...

  19. Early region 1B of adenovirus 2 encodes two coterminal proteins of 495 and 155 amino acid residues.

    PubMed Central

    Anderson, C W; Schmitt, R C; Smart, J E; Lewis, J B

    1984-01-01

    Partial sequence analysis of tryptic peptides has identified the E1B-495R (E1b-57K) (early transcription region 1B of 495 amino acid residues, with an approximate molecular weight of 57,000) protein of adenovirus 2 as encoded by the 495 amino acid open reading frame located in the adenovirus 2 DNA sequence between nucleotides 2016 and 3500. Additional proteins of 16,000 Mr and 18,000 Mr that are related to the E1B-495R protein were identified by cell-free translation of hybridization-selected mRNA. Analysis of [35S]methionine-containing amino terminal tryptic peptides by thin-layer chromatography showed that the E1B-495R, E1B-18K, and E1B-16K proteins all begin at the same initiation codon. The E1B-495R protein from 293 cells also has the same initial tryptic peptide, acetyl-methionyl-glutamyl-arginine. Sequence analysis of E1B-18K tryptic peptides indicated that this protein also has the same carboxy terminus as the E1B-495R protein and that it is derived from an mRNA that is spliced to remove sequences between nucleotides 2250 and 3269, resulting in a protein product of 155 amino acid residues. Analysis of E1B-16K tryptic peptides has not yet revealed the carboxy terminal structure of this protein. Both the E1B-495R and the E1B-155R (E1B-18K) proteins, as well as the E1B-16K protein, were precipitated from cell-free translations and from extracts of infected cells by antiserum against an amino terminal nonapeptide common to these proteins. Images PMID:6323739

  20. Optimal Replication Activity of Vesicular Stomatitis Virus RNA Polymerase Requires Phosphorylation of a Residue(s) at Carboxy-Terminal Domain II of Its Accessory Subunit, Phosphoprotein P

    PubMed Central

    Hwang, Leroy N.; Englund, Nathan; Das, Tapas; Banerjee, Amiya K.; Pattnaik, Asit K.

    1999-01-01

    The phosphoprotein, P, of vesicular stomatitis virus (VSV) is a key subunit of the viral RNA-dependent RNA polymerase complex. The protein is phosphorylated at multiple sites in two different domains. We recently showed that specific serine and threonine residues within the amino-terminal acidic domain I of P protein must be phosphorylated for in vivo transcription activity, but not for replication activity, of the polymerase complex. To examine the role of phosphorylation of the carboxy-terminal domain II residues of the P protein in transcription and replication, we have used a panel of mutant P proteins in which the phosphate acceptor sites (Ser-226, Ser-227, and Ser-233) were altered to alanines either individually or in various combinations. Analyses of the mutant proteins for their ability to support replication of a VSV minigenomic RNA suggest that phosphorylation of either Ser-226 or Ser-227 is necessary for optimal replication activity of the protein. The mutant protein (P226/227) in which both of these residues were altered to alanines was only about 8% active in replication compared to the wild-type (wt) protein. Substitution of alanine for Ser-233 did not have any adverse effect on replication activity of the protein. In contrast, all the mutant proteins showed activities similar to that of the wt protein in transcription. These results indicate that phosphorylation of the carboxy-terminal domain II residues of P protein are required for optimal replication activity but not for transcription activity. Furthermore, substitution of glutamic acid residues for Ser-226 and Ser-227 resulted in a protein that was only 14% active in replication but almost fully active in transcription. Taken together, these results, along with our earlier studies, suggest that phosphorylation of residues at two different domains in the P protein regulates its activity in transcription and replication of the VSV genome. PMID:10364310

  1. Residual Cap

    NASA Technical Reports Server (NTRS)

    2006-01-01

    10 May 2006 This Mars Global Surveyor (MGS) Mars Orbiter Camera (MOC) image shows a summertime view of the south polar residual cap of Mars. In this image, mesas composed largely of solid carbon dioxide are separated from one another by irregularly-shaped depressions. The variation in brightness across this scene is a function of several factors including, but not limited to, varying proportions of dust and solid carbon dioxide, undulating topography, and differences in the roughness of the slopes versus the flat surfaces.

    Location near: 86.7oS, 343.3oW Image width: 3 km (1.9 mi) Illumination from: upper left Season: Southern Summer

  2. Molybdenum cofactor properties and [Fe-S] cluster coordination in Escherichia coli nitrate reductase A: investigation by site-directed mutagenesis of the conserved his-50 residue in the NarG subunit.

    PubMed

    Magalon, A; Asso, M; Guigliarelli, B; Rothery, R A; Bertrand, P; Giordano, G; Blasco, F

    1998-05-19

    Most of the molybdoenzymes contain, in the amino-terminal region of their catalytic subunits, a conserved Cys group that in some cases binds an [Fe-S] cluster. In dissimilatory nitrate reductases, the first Cys residue of this motif is replaced by a conserved His residue. Site-directed mutagenesis of this residue (His-50) was performed on the NarG subunit from Escherichia coli nitrate reductase A. The results obtained by EPR spectroscopy enable us to exclude the implication of this residue in [Fe-S] binding. Additionally, we showed that the His-50 residue does not coordinate the molybdenum atom, but its substitution by Cys or Ser introduces a perturbation of the hydrogen bonding network around the molybdenum cofactor. From potentiometric studies, it is proposed that the high-pH and the low-pH forms of the Mo(V) are both involved during the redox turnover of the enzyme. Perturbation of the Mo(V) pKV value might be responsible for the low activity reported in the His-50-Cys mutant enzyme. A catalytic model is proposed in which the protonation/deprotonation of the Mo(V) species is an essential step. Thus, one of the two protons involved in the catalytic cycle could be the one coupled to the molybdenum atom in the dissimilatory nitrate reductase of E. coli. PMID:9585550

  3. Spatial Approximation between Secretin Residue Five and the Third Extracellular Loop of Its Receptor Provides New Insight into the Molecular Basis of Natural Agonist Binding

    PubMed Central

    Dong, Maoqing; Lam, Polo C.-H.; Pinon, Delia I.; Sexton, Patrick M.; Abagyan, Ruben; Miller, Laurence J.

    2013-01-01

    The amino terminus of class II G protein-coupled receptors plays an important role in ligand binding and receptor activation. Understanding of the conformation of the amino-terminal domain of these receptors has been substantially advanced with the solution of nuclear magnetic resonance and crystal structures of this region of receptors for corticotrophin-releasing factor, pituitary adenylate cyclase-activating polypeptide, and gastric inhibitory polypeptide. However, the orientation of the amino terminus relative to the receptor core and how the receptor gets activated upon ligand binding remain unclear. In this work, we have used photoaffinity labeling to identify a critical spatial approximation between residue five of secretin and a residue within the proposed third extracellular loop of the secretin receptor. This was achieved by purification, deglycosylation, cyanogen bromide cleavage, and sequencing of labeled wild-type and mutant secretin receptors. This constraint has been used to refine our evolving molecular model of secretin docked at the intact receptor, which for the first time includes refined helical bundle and loop regions and reflects a peptide-binding groove within the receptor amino terminus that directs the amino terminus of the peptide toward the receptor body. This model is fully consistent with the endogenous agonist mechanism for class II G protein-coupled receptor activation, where ligand binding promotes the interaction of a portion of the receptor amino terminus with the receptor body to activate it. PMID:18467541

  4. Interfacial residual thermal strain

    NASA Astrophysics Data System (ADS)

    Kasen, M.; Santoyo, R.

    A method has been developed for assessing the influence of polymer chemical composition and of processing parameters on the magnitude of residual stress developed in glass-fibre-reinforced composites subjected to various cure cycles and subsequently cooled to cryogenic temperatures. The test method was applied to nine resin types, including epoxy, vinyl ester, polyester, cyanate ester and phenolic formulations. Results suggest that polyester resin develops substantially less overall residual strain than do the other resin systems.

  5. Close proximity gunshot residues.

    PubMed

    Thornton, J I

    1986-04-01

    Intuitively, a hand held in close proximity to a firearm at the instant of discharge will intercept a significant amount of gunshot residue, even though the hand did not actually come into contact with the weapon. There is, however, little information specifically described in the forensic science literature concerning the residue levels which might be encountered in such an instance. The present work confirms that antimony levels consistent with an individual having fired or handled a firearm may be intercepted by a hand held in close proximity. PMID:3711843

  6. From start to finish: amino-terminal protein modifications as degradation signals in plants.

    PubMed

    Gibbs, Daniel J; Bailey, Mark; Tedds, Hannah M; Holdsworth, Michael J

    2016-09-01

    Contents 1188 I. 1188 II. 1189 III. 1190 IV. 1191 V. 1192 1192 References 1192 SUMMARY: The amino- (N-) terminus (Nt) of a protein can undergo a diverse array of co- and posttranslational modifications. Many of these create degradation signals (N-degrons) that mediate protein destruction via the N-end rule pathway of ubiquitin-mediated proteolysis. In plants, the N-end rule pathway has emerged as a major system for regulated control of protein stability. Nt-arginylation-dependent degradation regulates multiple growth, development and stress responses, and recently identified functions of Nt-acetylation can also be linked to effects on the in vivo half-lives of Nt-acetylated proteins. There is also increasing evidence that N-termini could act as important protein stability determinants in plastids. Here we review recent advances in our understanding of the relationship between the nature of protein N-termini, Nt-processing events and proteolysis in plants. PMID:27439310

  7. The amino-terminal domain of glutamate receptor {delta}2 triggers presynaptic differentiation

    SciTech Connect

    Uemura, Takeshi; Mishina, Masayoshi

    2008-12-26

    Glutamate receptor (GluR) {delta}2 selectively expressed in cerebellar Purkinje cells plays key roles in synapse formation, long-term depression and motor learning. We propose that GluR{delta}2 regulates synapse formation by making a physical linkage between the active zone and postsynaptic density. To examine the issue, GluR{delta}2-transfected 293T cells were cultured with cerebellar neurons. We found numerous punctate signals for presynaptic markers on the surface of 293T cells expressing GluR{delta}2. The presynaptic specializations induced by GluR{delta}2 were capable of exo- and endocytosis as indicated by FM1-43 dye labeling. Replacement of the extracellular N-terminal domain (NTD) of GluR{delta}2 with that of the AMPA receptor GluR{alpha}1 abolished the inducing activity. The NTD of GluR{delta}2 fused to the immunoglobulin constant region successfully induced the accumulation of presynaptic specializations on the surface of beads bearing the fusion protein. These results suggest that GluR{delta}2 triggers presynaptic differentiation by direct interaction with presynaptic components through the NTD.

  8. The biological functions of Naa10 — From amino-terminal acetylation to human disease

    PubMed Central

    Dörfel, Max J.; Lyon, Gholson J.

    2015-01-01

    N-terminal acetylation (NTA) is one of the most abundant protein modifications known, and the N-terminal acetyltransferase (NAT) machinery is conserved throughout all Eukarya. Over the past 50 years, the function of NTA has begun to be slowly elucidated, and this includes the modulation of protein–protein interaction, protein-stability, protein function, and protein targeting to specific cellular compartments. Many of these functions have been studied in the context of Naa10/NatA; however, we are only starting to really understand the full complexity of this picture. Roughly, about 40% of all human proteins are substrates of Naa10 and the impact of this modification has only been studied for a few of them. Besides acting as a NAT in the NatA complex, recently other functions have been linked to Naa10, including post-translational NTA, lysine acetylation, and NAT/KAT-independent functions. Also, recent publications have linked mutations in Naa10 to various diseases, emphasizing the importance of Naa10 research in humans. The recent design and synthesis of the first bisubstrate inhibitors that potently and selectively inhibit the NatA/Naa10 complex, monomeric Naa10, and hNaa50 further increases the toolset to analyze Naa10 function. PMID:25987439

  9. Amino terminal region of Phytophthora sojae cel12 endoglucanase confers tissue collapse function in Nicotiana

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Phytophthora encodes an unusually large number of glycosyl hydrolases (GH), with many large gene families resulting from duplication events. There are ten copies of GH 12 (cel12) present in Phytophthora sojae. This is the only pathogen endoglucanase family to which plants produce an inhibitory pr...

  10. CROP-RESIDUE MANAGEMENT

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Our agricultural production system is under increasing pressure to provide low cost, high quality food, fiber and biofuels while maintaining and preserving the environment. Increased interest in crop residues for production system sustainability is related to the recognition that the soil, water and...

  11. An immunogen containing four tandem 10E8 epitope repeats with exposed key residues induces antibodies that neutralize HIV-1 and activates an ADCC reporter gene.

    PubMed

    Sun, Zhiwu; Zhu, Yun; Wang, Qian; Ye, Ling; Dai, Yanyan; Su, Shan; Yu, Fei; Ying, Tianlei; Yang, Chinglai; Jiang, Shibo; Lu, Lu

    2016-01-01

    After three decades of intensive research efforts, an effective vaccine against HIV-1 remains to be developed. Several broadly neutralizing antibodies to HIV-1, such as 10E8, recognize the membrane proximal external region (MPER) of the HIV-1 gp41 protein. Thus, the MPER is considered to be a very important target for vaccine design. However, the MPER segment has very weak immunogenicity and tends to insert its epitope residues into the cell membrane, thereby avoiding antibody binding. To address this complication in vaccine development, we herein designed a peptide, designated 10E8-4P, containing four copies of the 10E8 epitope as an immunogen. As predicted by structural simulation, 10E8-4P exhibits a well-arranged tandem helical conformation, with the key residues in the 10E8 epitope oriented at different angles, thus suggesting that some of these key residues may be exposed outside of the lipid membrane. Compared with a peptide containing a single 10E8 epitope (10E8-1P), 10E8-4P not only exhibited better antigenicity but also elicited neutralizing antibody response against HIV-1 pseudoviruses, whereas 10E8-1P could not induce detectable neutralizing antibody response. Importantly, antibodies elicited by 10E8-4P also possessed a strong ability to activate an antibody-dependent cell-mediated cytotoxicity (ADCC) reporter gene, thus suggesting that they may have ADCC activity. Therefore, this strategy shows promise for further optimization and application in future HIV-1 vaccine design. PMID:27329850

  12. An immunogen containing four tandem 10E8 epitope repeats with exposed key residues induces antibodies that neutralize HIV-1 and activates an ADCC reporter gene

    PubMed Central

    Sun, Zhiwu; Zhu, Yun; Wang, Qian; Ye, Ling; Dai, Yanyan; Su, Shan; Yu, Fei; Ying, Tianlei; Yang, Chinglai; Jiang, Shibo; Lu, Lu

    2016-01-01

    After three decades of intensive research efforts, an effective vaccine against HIV-1 remains to be developed. Several broadly neutralizing antibodies to HIV-1, such as 10E8, recognize the membrane proximal external region (MPER) of the HIV-1 gp41 protein. Thus, the MPER is considered to be a very important target for vaccine design. However, the MPER segment has very weak immunogenicity and tends to insert its epitope residues into the cell membrane, thereby avoiding antibody binding. To address this complication in vaccine development, we herein designed a peptide, designated 10E8-4P, containing four copies of the 10E8 epitope as an immunogen. As predicted by structural simulation, 10E8-4P exhibits a well-arranged tandem helical conformation, with the key residues in the 10E8 epitope oriented at different angles, thus suggesting that some of these key residues may be exposed outside of the lipid membrane. Compared with a peptide containing a single 10E8 epitope (10E8-1P), 10E8-4P not only exhibited better antigenicity but also elicited neutralizing antibody response against HIV-1 pseudoviruses, whereas 10E8-1P could not induce detectable neutralizing antibody response. Importantly, antibodies elicited by 10E8-4P also possessed a strong ability to activate an antibody-dependent cell-mediated cytotoxicity (ADCC) reporter gene, thus suggesting that they may have ADCC activity. Therefore, this strategy shows promise for further optimization and application in future HIV-1 vaccine design. PMID:27329850

  13. Enhanced stability of Cu(2+)-ATCUN complexes under physiologically relevant conditions by insertion of structurally bulky and hydrophobic amino acid residues into the ATCUN motif.

    PubMed

    Miyamoto, Takaaki; Fukino, Yuta; Kamino, Shinichiro; Ueda, Masashi; Enomoto, Shuichi

    2016-06-21

    Copper complexes formed by an amino terminal Cu(2+)- and Ni(2+)-binding (ATCUN) motif have attracted attention as metallodrug candidates that cleave DNA or RNA and inactivate enzymes. Although the stability of the Cu(2+)-ATCUN complex under physiologically relevant conditions is a key factor for medical applications, it has remained unclear. Here we prepared a series of ATCUN peptides by inserting various amino acid residues into positions 1 and 2, and investigated the stability of the Cu(2+)-ATCUN complexes in aqueous solution, blood plasma, and living animals. Systematic pH titration showed that the low basicity of the N-terminal amine of the peptide stabilized the Cu(2+)-ATCUN complex in aqueous solution. Interestingly, the stability of (64)Cu-labeled ATCUN complexes in blood plasma was significantly enhanced by the structural bulkiness and hydrophobicity of the amino acid residues at positions 1 and 2. To validate the in vivo stability, six ATCUN motifs (YYH, VVH, NNH, TTH, GGH, and DDH) were conjugated to a tumor-targeting peptide, octreotide (Oct). The stability of the (64)Cu-ATCUN-Oct complexes in blood plasma showed a similar trend to that of the (64)Cu-ATCUN complexes. The (64)Cu-YYH-Oct complex exhibited the highest stability in blood plasma. According to the positron emission tomography and competitive blocking studies of a tumor-bearing mouse model, (64)Cu-YYH-Oct specifically accumulated in tumors, suggesting that the complex was sufficiently stable to reach its target in vivo. The results show that the structural bulkiness and hydrophobicity of the residues at positions 1 and 2 are key parameters for designing metallodrugs on the basis of the Cu(2+)-ATCUN complex. PMID:27184978

  14. Residual stresses in material processing

    SciTech Connect

    Kozaczek, K.J.; Watkins, T.R.; Hubbard, C.R.; Wang, Xun-Li; Spooner, S.

    1994-09-01

    Material manufacturing processes often introduce residual stresses into the product. The residual stresses affect the properties of the material and often are detrimental. Therefore, the distribution and magnitude of residual stresses in the final product are usually an important factor in manufacturing process optimization or component life prediction. The present paper briefly discusses the causes of residual stresses. It then adresses the direct, nondestructive methods of residual stress measurement by X-ray and neutron diffraction. Examples are presented to demonstrate the importance of residual stress measurement in machining and joining operations.

  15. Complexin splits the membrane-proximal region of a single SNAREpin.

    PubMed

    Yin, Linxiang; Kim, Jaewook; Shin, Yeon-Kyun

    2016-07-15

    Complexin (Cpx) is thought to be a major regulator of soluble N-ethylmaleimide-sensitive factor-attachment protein receptor (SNARE)-dependent membrane fusion. Although the inhibition of membrane fusion by Cpx has been frequently reported, its structural basis has been elusive and an anticipated disruption of the SNARE core has never been observed. In the present study, to mimic the natural environment, we assembled a single SNAREpin between two nanodisc membrane patches. Single-molecule FRET (smFRET) detects a large conformational change, specifically at the C-terminal half, whereas no conformational change is observed at the N-terminal half. Our results suggest that Cpx splits the C-terminal half of the SNARE core at least 10 Å (1 Å=0.1 nm), whereby inhibiting further progression of SNARE zippering and membrane fusion. PMID:27222590

  16. SRC Residual fuel oils

    DOEpatents

    Tewari, Krishna C.; Foster, Edward P.

    1985-01-01

    Coal solids (SRC) and distillate oils are combined to afford single-phase blends of residual oils which have utility as fuel oils substitutes. The components are combined on the basis of their respective polarities, that is, on the basis of their heteroatom content, to assure complete solubilization of SRC. The resulting composition is a fuel oil blend which retains its stability and homogeneity over the long term.

  17. Residual Neuromuscular Blockade.

    PubMed

    Plummer-Roberts, Anna L; Trost, Christina; Collins, Shawn; Hewer, Ian

    2016-02-01

    This article provides an update on residual neuromuscular blockade for nurse anesthetists. The neuromuscular junction, pharmacology for producing and reversing neuromuscular blockade, monitoring sites and methods, and patient implications relating to incomplete reversal of neuromuscular blockade are reviewed. Overall recommendations include using multiple settings when employing a peripheral nerve stimulator for monitoring return of neuromuscular function and administering pharmacologic reversal when the train-of-four ratio is below 0.9. PMID:26939390

  18. Energy from rice residues

    SciTech Connect

    Mahin, D.B.

    1990-03-01

    Developing countries produce millions of tons of rice husks and straw as a byproduct of harvesting rice. Although some of these rice residues are used for fuel or other purposes, most are burned for disposal or just dumped. However, since the mid- 1980's, industrial plants for rice residue utilization have been installed in several countries and are planned in a number of others. The report provides information on systems to produce energy from rice residues that are commercially available in the United States, Europe, and various developing countries, with an emphasis on those currently used or sold on an international level. Specifically reviewed are the use of rice husks to produce: (1) industrial process heat either directly from furnaces or by generating low pressure steam in boilers; (2) mechanical and electrical power for rice milling via steam engine systems, steam turbine/generator systems, and gasifier/engine systems; and (3) electric power for the grid. The outlook for producing energy from rice straw is also assessed. In addition, the prospects for the use of energy from husks or straw in the processing of rice bran are reviewed.

  19. The residual caries dilemma.

    PubMed

    Weerheijm, K L; Groen, H J

    1999-12-01

    Restorative dentistry is based on the assumption that bacterial infection of demineralized dentine should prompt operative intervention. One of the concepts of practical dentistry is to create a favourable environment for caries arrest with minimal operative intervention. The progress of remaining primary caries is key to any discussion of this concept. This discussion is important for the atraumatic restorative treatment (ART) approach, since the removal of all carious dentine is sometimes difficult using hand instruments only. In this paper the results of possible measures to guard against the effects of residual carious and its consequences are reviewed, in order to obtain an impression of the justification for (in)complete excavation of occlusal dentinal caries. Three types of measure are considered: isolating the caries process from the oral environment, excavating the carious dentine, and using a cariostatic filling material. Each of these measures contributes to the arrest of the caries process. However, none of these measures can arrest this process by itself. A combination of all three seems necessary. It is concluded that although residual caries does not seem to be the criterion for rerestoration, one has to strive for as complete caries removal as possible. If this cannot be fulfilled the sealing capacities of the filling material seem to be more important than its cariostatic properties. PMID:10600078

  20. Residual gas analyzer calibration

    NASA Technical Reports Server (NTRS)

    Lilienkamp, R. H.

    1972-01-01

    A technique which employs known gas mixtures to calibrate the residual gas analyzer (RGA) is described. The mass spectra from the RGA are recorded for each gas mixture. This mass spectra data and the mixture composition data each form a matrix. From the two matrices the calibration matrix may be computed. The matrix mathematics requires the number of calibration gas mixtures be equal to or greater than the number of gases included in the calibration. This technique was evaluated using a mathematical model of an RGA to generate the mass spectra. This model included shot noise errors in the mass spectra. Errors in the gas concentrations were also included in the valuation. The effects of these errors was studied by varying their magnitudes and comparing the resulting calibrations. Several methods of evaluating an actual calibration are presented. The effects of the number of gases in then, the composition of the calibration mixture, and the number of mixtures used are discussed.

  1. Materials recovery from shredder residues

    SciTech Connect

    Daniels, E. J.; Jody, B. J.; Pomykala, J., Jr.

    2000-07-24

    Each year, about five (5) million ton of shredder residues are landfilled in the US. Similar quantities are landfilled in Europe and the Pacific Rim. Landfilling of these residues results in a cost to the existing recycling industry and also represents a loss of material resources that are otherwise recyclable. In this paper, the authors outline the resources recoverable from typical shredder residues and describe technology that they have developed to recover these resources.

  2. Microwave emission and crop residues

    NASA Technical Reports Server (NTRS)

    Jackson, Thomas J.; O'Neill, Peggy E.

    1991-01-01

    A series of controlled experiments were conducted to determine the significance of crop residues or stubble in estimating the emission of the underlying soil. Observations using truck-mounted L and C band passive microwave radiometers showed that for dry wheat and soybeans the dry residue caused negligible attenuation of the background emission. Green residues, with water contents typical of standing crops, did have a significant effect on the background emission. Results for these green residues also indicated that extremes in plant structure, as created using parallel and perpendicular stalk orientations, can cause very large differences in the degree of attenuation.

  3. On tide-induced lagrangian residual current and residual transport: 1. Lagrangian residual current

    USGS Publications Warehouse

    Feng, Shizuo; Cheng, Ralph T.; Pangen, Xi

    1986-01-01

    Residual currents in tidal estuaries and coastal embayments have been recognized as fundamental factors which affect the long-term transport processes. It has been pointed out by previous studies that it is more relevant to use a Lagrangian mean velocity than an Eulerian mean velocity to determine the movements of water masses. Under weakly nonlinear approximation, the parameter k, which is the ratio of the net displacement of a labeled water mass in one tidal cycle to the tidal excursion, is assumed to be small. Solutions for tides, tidal current, and residual current have been considered for two-dimensional, barotropic estuaries and coastal seas. Particular attention has been paid to the distinction between the Lagrangian and Eulerian residual currents. When k is small, the first-order Lagrangian residual is shown to be the sum of the Eulerian residual current and the Stokes drift. The Lagrangian residual drift velocity or the second-order Lagrangian residual current has been shown to be dependent on the phase of tidal current. The Lagrangian drift velocity is induced by nonlinear interactions between tides, tidal currents, and the first-order residual currents, and it takes the form of an ellipse on a hodograph plane. Several examples are given to further demonstrate the unique properties of the Lagrangian residual current.

  4. Universality in Protein Residue Networks

    PubMed Central

    Estrada, Ernesto

    2010-01-01

    Abstract Residue networks representing 595 nonhomologous proteins are studied. These networks exhibit universal topological characteristics as they belong to the topological class of modular networks formed by several highly interconnected clusters separated by topological cavities. There are some networks that tend to deviate from this universality. These networks represent small-size proteins having <200 residues. This article explains such differences in terms of the domain structure of these proteins. On the other hand, the topological cavities characterizing proteins residue networks match very well with protein binding sites. This study investigates the effect of the cutoff value used in building the residue network. For small cutoff values, <5 Å, the cavities found are very large corresponding almost to the whole protein surface. On the contrary, for large cutoff value, >10.0 Å, only very large cavities are detected and the networks look very homogeneous. These findings are useful for practical purposes as well as for identifying protein-like complex networks. Finally, this article shows that the main topological class of residue networks is not reproduced by random networks growing according to Erdös-Rényi model or the preferential attachment method of Barabási-Albert. However, the Watts-Strogatz model reproduces very well the topological class as well as other topological properties of residue network. A more biologically appealing modification of the Watts-Strogatz model to describe residue networks is proposed. PMID:20197043

  5. Safety assessment of drug residues

    SciTech Connect

    Jackson, B.A.

    1980-05-15

    The safety assessment of drug residues is part of the process for defining the conditions for the safe use of drugs in food-producing animals. The information needed to assess the safety of drug residues is provided by chemical and toxicity tests. Toxicity tests are conducted to identify the type of effect produced and to determine the exposure concentrations that would be expected not to produce the effect. These tests include acute, subacute, and chronic toxicity tests, as well as reproduction studies and other special tests. The results are used to find an acceptable daily intake for drug residues that can be used to set a tolerance.

  6. Americium recovery from reduction residues

    DOEpatents

    Conner, W.V.; Proctor, S.G.

    1973-12-25

    A process for separation and recovery of americium values from container or bomb'' reduction residues comprising dissolving the residues in a suitable acid, adjusting the hydrogen ion concentration to a desired level by adding a base, precipitating the americium as americium oxalate by adding oxalic acid, digesting the solution, separating the precipitate, and thereafter calcining the americium oxalate precipitate to form americium oxide. (Official Gazette)

  7. DISSOLUTION OF NEPTUNIUM OXIDE RESIDUES

    SciTech Connect

    Kyser, E

    2009-01-12

    This report describes the development of a dissolution flowsheet for neptunium (Np) oxide (NpO{sub 2}) residues (i.e., various NpO{sub 2} sources, HB-Line glovebox sweepings, and Savannah River National Laboratory (SRNL) thermogravimetric analysis samples). Samples of each type of materials proposed for processing were dissolved in a closed laboratory apparatus and the rate and total quantity of off-gas were measured. Samples of the off-gas were also analyzed. The quantity and type of solids remaining (when visible) were determined after post-dissolution filtration of the solution. Recommended conditions for dissolution of the NpO{sub 2} residues are: Solution Matrix and Loading: {approx}50 g Np/L (750 g Np in 15 L of dissolver solution), using 8 M nitric acid (HNO{sub 3}), 0.025 M potassium fluoride (KF) at greater than 100 C for at least 3 hours. Off-gas: Analysis of the off-gas indicated nitric oxide (NO), nitrogen dioxide (NO{sub 2}) and nitrous oxide (N{sub 2}O) as the only identified components. No hydrogen (H{sub 2}) was detected. The molar ratio of off-gas produced per mole of Np dissolved ranged from 0.25 to 0.4 moles of gas per mole of Np dissolved. A peak off-gas rate of {approx}0.1 scfm/kg bulk oxide was observed. Residual Solids: Pure NpO{sub 2} dissolved with little or no residue with the proposed flowsheet but the NpCo and both sweepings samples left visible solid residue after dissolution. For the NpCo and Part II Sweepings samples the residue amounted to {approx}1% of the initial material, but for the Part I Sweepings sample, the residue amounted to {approx}8 % of the initial material. These residues contained primarily aluminum (Al) and silicon (Si) compounds that did not completely dissolve under the flowsheet conditions. The residues from both sweepings samples contained minor amounts of plutonium (Pu) particles. Overall, the undissolved Np and Pu particles in the residues were a very small fraction of the total solids.

  8. Residual stresses in welded plates

    NASA Technical Reports Server (NTRS)

    Bernstein, Edward L.

    1994-01-01

    The purpose of this project was to develop a simple model which could be used to study residual stress. The mechanism that results in residual stresses in the welding process starts with the deposition of molten weld metal which heats the immediately adjacent material. After solidification of weld material, normal thermal shrinkage is resisted by the adjacent, cooler material. When the thermal strain exceeds the elastic strain corresponding to the yield point stress, the stress level is limited by this value, which decreases with increasing temperature. Cooling then causes elastic unloading which is restrained by the adjoining material. Permanent plastic strain occurs, and tension is caused in the region immediately adjacent to the weld material. Compression arises in the metal farther from the weld in order to maintain overall static equilibrium. Subsequent repair welds may add to the level of residual stresses. The level of residual stress is related to the onset of fracture during welding. Thus, it is of great importance to be able to predict the level of residual stresses remaining after a weld procedure, and to determine the factors, such as weld speed, temperature, direction, and number of passes, which may affect the magnitude of remaining residual stress. It was hoped to use traditional analytical modeling techniques so that it would be easier to comprehend the effect of these variables on the resulting stress. This approach was chosen in place of finite element methods so as to facilitate the understanding of the physical processes. The accuracy of the results was checked with some existing experimental studies giving residual stress levels found from x-ray diffraction measurements.

  9. Residual deformations in ocular tissues

    PubMed Central

    Wang, Ruoya; Raykin, Julia; Gleason, Rudolph L.; Ethier, C. Ross

    2015-01-01

    Residual deformations strongly influence the local biomechanical environment in a number of connective tissues. The sclera is known to be biomechanically important in healthy and diseased eyes, such as in glaucoma. Here, we study the residual deformations of the sclera, as well as the adjacent choroid and retina. Using freshly harvested porcine eyes, we developed two approaches of quantifying residual deformations in the spherically shaped tissues of interest. The first consisted of punching discs from the posterior wall of the eye and quantifying the changes in the area and eccentricity of these samples. The second consisted of cutting a ring from the equatorial sclera and making stress-relieving cuts in it. Measurements of curvature were made before and after the stress-relieving cuts. Using the first approach, we observed a 42% areal contraction of the choroid, but only modest contractions of the sclera and retina. The observed contractions were asymmetric. In the second approach, we observed an opening of the scleral rings (approx. 10% decrease in curvature). We conclude that residual bending deformations are present in the sclera, which we speculate may be due to radially heterogeneous growth and remodelling of the tissue during normal development. Further, residual areal deformations present in the choroid may be due to the network of elastic fibres in this tissue and residual deformations in the constituent vascular bed. Future studies of ocular biomechanics should attempt to include effects of these residual deformations into mechanical models in order to gain a better understanding of the biomechanics of the ocular wall. PMID:25740853

  10. Dry fermentation of agricultural residues

    NASA Astrophysics Data System (ADS)

    Jewell, W. J.; Chandler, J. A.; Dellorto, S.; Fanfoni, K. J.; Fast, S.; Jackson, D.; Kabrick, R. M.

    1981-09-01

    A dry fermentation process is discussed which converts agricultural residues to methane, using the residues in their as produced state. The process appears to simplify and enhance the possibilities for using crop residues as an energy source. The major process variables investigated include temperature, the amount and type of inoculum, buffer requirements, compaction, and pretreatment to control the initial available organic components that create pH problems. A pilot-scale reactor operation on corn stover at a temperature of 550 C, with 25 percent initial total solids, a seed-to-feed ratio of 2.5 percent, and a buffer-to-feed ratio of 8 percent achieved 33 percent total volatile solids destruction in 60 days. Volumetric biogas yields from this unit were greater than 1 vol/vol day for 12 days, and greater than 0.5 vol/vol day for 32 days, at a substrate density of 169 kg/m (3).

  11. Chemistry of combined residual chlorination

    SciTech Connect

    Leao, S.F.; Selleck, R.E.

    1982-01-01

    The decay of the combined chlorine residual was investigated in this work. Recent concerns about the formation of undesirable compounds such as chloroform with free residual chlorination have focused attention on the alternative use of combined residual chlorination. This work investigates the applicability of reactions proposed to describe the transformations and decay of the combined residual with time. Sodium hypochlorite was added to buffered solutions of ammonia with the chlorine residual being monitored over periods extending up to 10 days. The reaction was studied at four initial concentrations of hypochlorite of 100, 50, 25 and 10 mg/L as Cl/sub 2/ with molar application ratios of chlorine to ammonia, defined herein as M ratios, of 0.90, 0.50, 0.25 and 0.05 at each hypochlorite dose. Sixty-eight experiments were conducted at the pH of 6.6 and 7.2. The conclusions are: (1) in the absence of free chlorine, the concentration of NH/sub 3/ does not seem to affect the rate of disappearance of the residual other than through the formation of NHCl/sub 2/ by NH/sub 2/Cl hydrolysis; (2) the reaction between NHCl/sub 2/ and NH/sub 4//sup +/ to form NH/sub 2/Cl is either much slower than reported by Gray et. al. or the mechanism is different with a rate limiting step not involving NH/sub 3/ or NH/sub 4//sup +/; (3) a redox reaction in addition to the first-order decomposition of NHCl/sub 2/ appears necessary. Model simulation results indicated that a reaction of the type NH/sub 2/Cl + NHCl/sub 2/ ..-->.. P added to the first-order NHCl/sub 2/ decomposition can explain the results observed except at the higher chlorine doses.

  12. 40 CFR 1065.705 - Residual and intermediate residual fuel.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... specifications for fuels meeting the definition of residual fuel in 40 CFR 80.2, including fuels marketed as... 991.0 1010.0 ISO 3675 or ISO 12185 (see also ISO 8217). Kinematic viscosity at 50 °C, max cSt 30.0...

  13. Collection of sugarcane crop residue for energy

    SciTech Connect

    Eiland, B.R.; Clayton, J.E.

    1982-12-01

    Crop residue left after sugarcane harvesting was recovered using a forage harvester and a large round baler. The quantity, bulk density and moisture content of the crop residue was determined in four fields. Crop residue from 7 ha was burned in boilers at a sugar mill. Samples of this residue were tested by a laboratory and compared to sugarcane bagasse.

  14. Residual Structures in Latent Growth Curve Modeling

    ERIC Educational Resources Information Center

    Grimm, Kevin J.; Widaman, Keith F.

    2010-01-01

    Several alternatives are available for specifying the residual structure in latent growth curve modeling. Two specifications involve uncorrelated residuals and represent the most commonly used residual structures. The first, building on repeated measures analysis of variance and common specifications in multilevel models, forces residual variances…

  15. IMPROVED TECHNIQUES FOR RESIDUAL OZONE

    EPA Science Inventory

    Eight analytical methods for the determination of residual ozone in water are evaluated. Four are iodometric methods based on the reduction of ozone by iodide ion: the iodometric method, the amperometric method, the arsenic (III) back titration method, and the N, N-diethyl-p-phen...

  16. Leptogenesis and residual CP symmetry

    NASA Astrophysics Data System (ADS)

    Chen, Peng; Ding, Gui-Jun; King, Stephen F.

    2016-03-01

    We discuss flavour dependent leptogenesis in the framework of lepton flavour models based on discrete flavour and CP symmetries applied to the type-I seesaw model. Working in the flavour basis, we analyse the case of two general residual CP symmetries in the neutrino sector, which corresponds to all possible semi-direct models based on a preserved Z 2 in the neutrino sector, together with a CP symmetry, which constrains the PMNS matrix up to a single free parameter which may be fixed by the reactor angle. We systematically study and classify this case for all possible residual CP symmetries, and show that the R-matrix is tightly constrained up to a single free parameter, with only certain forms being consistent with successful leptogenesis, leading to possible connections between leptogenesis and PMNS parameters. The formalism is completely general in the sense that the two residual CP symmetries could result from any high energy discrete flavour theory which respects any CP symmetry. As a simple example, we apply the formalism to a high energy S 4 flavour symmetry with a generalized CP symmetry, broken to two residual CP symmetries in the neutrino sector, recovering familiar results for PMNS predictions, together with new results for flavour dependent leptogenesis.

  17. Pyrotechnic reaction residue particle analysis.

    PubMed

    Kosanke, Kenneth L; Dujay, Richard C; Kosanke, Bonnie J

    2006-03-01

    Pyrotechnic reaction residue particle (PRRP) production, sampling and analysis are all very similar to that for primer gunshot residue. In both cases, the preferred method of analysis uses scanning electron microscopy to locate suspect particles and then uses energy dispersive x-ray spectroscopy to characterize the particle's constituent chemical elements. There are relatively few times when standard micro-analytical chemistry performed on pyrotechnic residues may not provide sufficient information for forensic investigators. However, on those occasions, PRRP analysis provides a greatly improved ability to discriminate between materials of pyrotechnic origin and other unrelated substances also present. The greater specificity of PRRP analysis is the result of its analyzing a large number of individual micron-sized particles, rather than producing only a single integrated result such as produced using standard micro-analytical chemistry. For example, PRRP analyses are used to demonstrate its ability to successfully (1) discriminate between pyrotechnic residues and unrelated background contamination, (2) identify that two different pyrotechnic compositions had previously been exploded within the same device, and (3) establish the chronology of an incident involving two separate and closely occurring explosions. PMID:16566762

  18. Amino acid substitutions of cysteine residues near the amino terminus of Wheat streak mosaic virus HC-Pro abolishes virus transmission by the wheat curl mite

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The amino-terminal half of HC-Pro of Wheat streak mosaic virus (WSMV) is required for semi-persistent transmission by the wheat curl mite (Aceria tosichella Keifer). The amino-proximal region of WSMV HC-Pro is cysteine-rich with a zinc finger-like motif. Amino acid substitutions were made in this re...

  19. Residual Resistivity of Dilute Alloys

    NASA Astrophysics Data System (ADS)

    Vora, Aditya M.

    The residual resistivity for 156 dilute alloys of 19 hosts of different groups of the periodic table has been studied on the basis of the single parametric model potential formalism. Ashcroft's empty core model (EMC) potential is explored for the first time with five different local field correction functions, viz, Hartree (H), Taylor (T), Ichimaru-Utsumi (IU), Farid et al. (F), and Sarkar et al. (S) to investigate the effect of the exchange and correlation on the aforesaid properties. The comparison of the presently computed outcomes with the available theoretical and experimental data is highly encouraging. The investigation of residual resistivity is found to be quite sensitive to the selection of local field correction function, showing a significant variation with the change in the function.

  20. Primer residues deposited by handguns.

    PubMed

    Cooper, R; Guileyardo, J M; Stone, I C; Hall, V; Fletcher, L

    1994-12-01

    There is much anecdotal information being disseminated, even offered in expert witness testimony, concerning the deposit of primer residues on the hands of persons in front of the muzzle of handguns. We present data for 9 mm and 380 Auto pistols and for a 38 caliber revolver depicting the procedure for obtaining wipings taken from targets representing the hands of a gunshot victim. These wipings from pork tissue were then analyzed for the primer residue metals antimony, barium, and lead. The data show that the two primary metals, antimony and barium, are deposited on the targets out to 4 feet for the pistols and out to three feet for the 38-caliber revolver. Testing will continue in actual cases with the gun and ammunition involved in the shooting. PMID:7879775

  1. Catalytic combustion of residual fuels

    NASA Technical Reports Server (NTRS)

    Bulzan, D. L.; Tacina, R. R.

    1981-01-01

    A noble metal catalytic reactor was tested using two grades of petroleum derived residual fuels at specified inlet air temperatures, pressures, and reference velocities. Combustion efficiencies greater than 99.5 percent were obtained. Steady state operation of the catalytic reactor required inlet air temperatures of at least 800 K. At lower inlet air temperatures, upstream burning in the premixing zone occurred which was probably caused by fuel deposition and accumulation on the premixing zone walls. Increasing the inlet air temperature prevented this occurrence. Both residual fuels contained about 0.5 percent nitrogen by weight. NO sub x emissions ranged from 50 to 110 ppm by volume at 15 percent excess O2. Conversion of fuel-bound nitrogen to NO sub x ranged from 25 to 50 percent.

  2. Limits of adaptation, residual interferences

    NASA Technical Reports Server (NTRS)

    Mokry, Miroslav (Editor); Erickson, J. C., Jr.; Goodyer, Michael J.; Mignosi, Andre; Russo, Giuseppe P.; Smith, J.; Wedemeyer, Erich H.; Newman, Perry A.

    1990-01-01

    Methods of determining linear residual wall interference appear to be well established theoretically; however they need to be validated, for example by comparative studies of test data on the same model in different adaptive-wall wind tunnels as well as in passive, ventilated-wall tunnels. The GARTEur CAST 7 and the CAST 10/DOA 2 investigations are excellent examples of such comparative studies. Results to date in both one-variable and two-variable methods for nonlinear wall interference indicate that a great deal more research and validation are required. The status in 2D flow is advanced over that in 3D flow as is the case generally with adaptive-wall development. Nevertheless, it is now well established that for transonic testing with extensive supercritical flow present, significant wall interference is likely to exist in conventional ventilated test sections. Consequently, residual correction procedures require further development hand-in-hand with further adaptive-wall development.

  3. Separation of polyethylene glycols and amino-terminated polyethylene glycols by high-performance liquid chromatography under near critical conditions.

    PubMed

    Wei, Y-Z; Zhuo, R-X; Jiang, X-L

    2016-05-20

    The separation and characterization of polyethylene glycols (PEGs) and amino-substituted derivatives on common silica-based reversed-phase packing columns using isocratic elution is described. This separation is achieved by liquid chromatography under the near critical conditions (LCCC), based on the number of amino functional end groups without obvious effect of molar mass for PEGs. The mobile phase is acetonitrile in water with an optimal ammonium acetate buffer. The separation mechanism of PEG and amino-substituted PEG under the near LCCC on silica-based packing columns is confirmed to be ion-exchange interaction. Under the LCCC of PEG backbone, with fine tune of buffer concentration, the retention factor ratios for benzylamine and phenol in buffered mobile phases, α(benzylamine/phenol)-values, were used to assess the ion-exchange capacity on silica-based reversed-phase packing columns. To the best of our knowledge, this is the first report on separation of amino-functional PEGs independent of the molar mass by isocratic elution using common C18 or phenyl reversed-phase packing columns. PMID:27102303

  4. Amino-terminal domains of c-myc and N-myc proteins mediate binding to the retinoblastoma gene product

    NASA Astrophysics Data System (ADS)

    Rustgi, Anil K.; Dyson, Nicholas; Bernards, Rene

    1991-08-01

    THE proteins encoded by the myc gene family are involved in the control of cell proliferation and differentiation, and aberrant expression of myc proteins has been implicated in the genesis of a variety of neoplasms1. In the carboxyl terminus, myc proteins have two domains that encode a basic domain/helix-loop-helix and a leucine zipper motif, respectively. These motifs are involved both in DNA binding and in protein dimerization2-5. In addition, myc protein family members share several regions of highly conserved amino acids in their amino termini that are essential for transformation6,7. We report here that an N-terminal domain present in both the c-myc and N-myc proteins mediates binding to the retinoblastoma gene product, pRb. We show that the human papilloma virus E7 protein competes with c-myc for binding to pRb, indicating that these proteins share overlapping binding sites on pRb. Furthermore, a mutant Rb protein from a human tumour cell line that carried a 35-amino-acid deletion in its C terminus failed to bind to c-myc. Our results suggest that c-myc and pRb cooperate through direct binding to control cell proliferation.

  5. Structural changes and metal binding by proalbumins and other amino-terminal genetic variants of human serum albumin.

    PubMed Central

    Takahashi, N; Takahashi, Y; Putnam, F W

    1987-01-01

    Proalbumins are rare genetic variants of human serum albumin containing a basic propeptide that is not removed during post-transcriptional processing because of a mutation in the site of excision, an Arg-Arg sequence. We have identified the amino acid substitutions in three different types of proalbumins designated Gainesville, Taipei, and Takefu. The first two proalbumins are identical to previously described proalbumins of the Christchurch and Lille types, respectively, and exhibit the characteristic properties of susceptibility to tryptic cleavage and of lower metal-binding affinity. Takefu is a third type of proalbumin and resists tryptic cleavage because of the substitution Arg-1----Pro. Each of the first two types of proalbumins has been identified in geographically separate, ethnically diverse populations and therefore must have arisen by independent mutations. There is some tendency for mutations in albumin to cluster in the propeptide sequence. Although the substitution His3----Gln in the genetic variant albumin Nagasaki-3 decreases metal-binding affinity, mutations further down the polypeptide chain have no such effect, nor is there any reduction of copper-binding affinity in albumin from patients with Wilson disease. Images PMID:3478700

  6. The amino-terminal structure of human fragile X mental retardation protein obtained using precipitant-immobilized imprinted polymers

    NASA Astrophysics Data System (ADS)

    Hu, Yufeng; Chen, Zhenhang; Fu, Yanjun; He, Qingzhong; Jiang, Lun; Zheng, Jiangge; Gao, Yina; Mei, Pinchao; Chen, Zhongzhou; Ren, Xueqin

    2015-03-01

    Flexibility is an intrinsic property of proteins and essential for their biological functions. However, because of structural flexibility, obtaining high-quality crystals of proteins with heterogeneous conformations remain challenging. Here, we show a novel approach to immobilize traditional precipitants onto molecularly imprinted polymers (MIPs) to facilitate protein crystallization, especially for flexible proteins. By applying this method, high-quality crystals of the flexible N-terminus of human fragile X mental retardation protein are obtained, whose absence causes the most common inherited mental retardation. A novel KH domain and an intermolecular disulfide bond are discovered, and several types of dimers are found in solution, thus providing insights into the function of this protein. Furthermore, the precipitant-immobilized MIPs (piMIPs) successfully facilitate flexible protein crystal formation for five model proteins with increased diffraction resolution. This highlights the potential of piMIPs for the crystallization of flexible proteins.

  7. Impaired surface membrane insertion of homo- and heterodimeric human muscle chloride channels carrying amino-terminal myotonia-causing mutations

    PubMed Central

    Ronstedt, Katharina; Sternberg, Damien; Detro-Dassen, Silvia; Gramkow, Thomas; Begemann, Birgit; Becher, Toni; Kilian, Petra; Grieschat, Matthias; Machtens, Jan-Philipp; Schmalzing, Günther; Fischer, Martin; Fahlke, Christoph

    2015-01-01

    Mutations in the muscle chloride channel gene (CLCN1) cause myotonia congenita, an inherited condition characterized by muscle stiffness upon sudden forceful movement. We here studied the functional consequences of four disease-causing mutations that predict amino acid substitutions Q43R, S70L, Y137D and Q160H. Wild-type (WT) and mutant hClC-1 channels were heterologously expressed as YFP or CFP fusion protein in HEK293T cells and analyzed by whole-cell patch clamp and fluorescence recordings on individual cells. Q43R, Y137D and Q160H, but not S70L reduced macroscopic current amplitudes, but left channel gating and unitary current amplitudes unaffected. We developed a novel assay combining electrophysiological and fluorescence measurements at the single-cell level in order to measure the probability of ion channel surface membrane insertion. With the exception of S70L, all tested mutations significantly reduced the relative number of homodimeric hClC-1 channels in the surface membrane. The strongest effect was seen for Q43R that reduced the surface insertion probability by more than 99% in Q43R homodimeric channels and by 92 ± 3% in heterodimeric WT/Q43R channels compared to homodimeric WT channels. The new method offers a sensitive approach to investigate mutations that were reported to cause channelopathies, but display only minor changes in ion channel function. PMID:26502825

  8. Natural disordered sequences in the amino terminal domain of nuclear receptors: lessons from the androgen and glucocorticoid receptors.

    PubMed

    McEwan, Iain J; Lavery, Derek; Fischer, Katharina; Watt, Kate

    2007-01-01

    Steroid hormones are a diverse class of structurally related molecules, derived from cholesterol, that include androgens, estrogens, progesterone and corticosteroids. They represent an important group of physiologically active signalling molecules that bind intracellular receptor proteins and regulate genes involved in developmental, reproductive and metabolic processes. The receptor proteins share structurally and functionally related ligand binding and DNA-binding domains, but possess distinct N-terminal domains (NTD) of unique length and amino acids sequence. The NTD contains sequences important for gene regulation, exhibit structure plasticity and are likely to contribute to the specificity of the steroid hormone/receptor response. PMID:17464357

  9. Natural disordered sequences in the amino terminal domain of nuclear receptors: lessons from the androgen and glucocorticoid receptors

    PubMed Central

    McEwan, Iain J.; Lavery, Derek; Fischer, Katharina; Watt, Kate

    2007-01-01

    Steroid hormones are a diverse class of structurally related molecules, derived from cholesterol, that include androgens, estrogens, progesterone and corticosteroids. They represent an important group of physiologically active signalling molecules that bind intracellular receptor proteins and regulate genes involved in developmental, reproductive and metabolic processes. The receptor proteins share structurally and functionally related ligand binding and DNA-binding domains, but possess distinct N-terminal domains (NTD) of unique length and amino acids sequence. The NTD contains sequences important for gene regulation, exhibit structure plasticity and are likely to contribute to the specificity of the steroid hormone/receptor response. PMID:17464357

  10. Vitrification of NAC process residue

    SciTech Connect

    Merrill, R.A.; Whittington, K.F.; Peters, R.D.

    1995-12-31

    Vitrification tests have been performed with simulated waste compositions formulated to represent the residue which would be obtained from the treatment of low-level, nitrate wastes from Hanford and Oak Ridge by the nitrate to ammonia and ceramic (NAC) process. The tests were designed to demonstrate the feasibility of vitrifying NAC residue and to quantify the impact of the NAC process on the volume of vitrified waste. The residue from NAC treatment of low-level nitrate wastes consists primarily of oxides of aluminum and sodium. High alumina glasses were formulated to maximize the waste loading of the NAC product. Transparent glasses with up to 35 wt% alumina, and even higher contents in opaque glasses, were obtained at melting temperatures of 1,200 C to 1,400 C. A modified TCLP leach test showed the high alumina glasses to have good chemical durability, leaching significantly less than either the ARM-1 or the DWPF-EA high-level waste reference glasses. A significant increase in the final waste volume would be a major result of the NAC process on LLW vitrification. For Hanford wastes, NAC-treatment of nitrate wastes followed by vitrification of the residue will increase the final volume of vitrified waste by 50% to 90%; for Melton Valley waste from Oak Ridge, the increase in final glass volume will be 260% to 280%. The increase in volume is relative to direct vitrification of the waste in a 20 wt% Na{sub 2}O glass formulation. The increase in waste volume directly affects not only disposal costs, but also operating and/or capital costs. Larger plant size, longer operating time, and additional energy and additive costs are direct results of increases in waste volume. Such increases may be balanced by beneficial impacts on the vitrification process; however, those effects are outside the scope of this report.

  11. Vitrification of NAC process residue

    SciTech Connect

    Merrill, R.A.; Whittington, K.F.; Peters, R.D.

    1995-09-01

    Vitrification tests have been performed with simulated waste compositions formulated to represent the residue which would be obtained from the treatment of low-level, nitrate wastes from Hanford and Oak Ridge by the nitrate to ammonia and ceramic (NAC) process. The tests were designed to demonstrate the feasibility of vitrifying NAC residue and to quantify the impact of the NAC process on the volume of vitrified waste. The residue from NAC treatment of low-level nitrate wastes consists primarily of oxides of aluminum and sodium. High alumina glasses were formulated to maximize the waste loading of the NAC product. Transparent glasses with up to 35 wt% alumina, and even higher contents in opaque glasses, were obtained at melting temperatures of 1200{degrees}C to 1400{degrees}C. A modified TCLP leach test showed the high alumina glasses to have good chemical durability, leaching significantly less than either the ARM-1 or the DWPF-EA high-level waste reference glasses. A significant increase in the final waste volume would be a major result of the NAC process on LLW vitrification. For Hanford wastes, NAC-treatment of nitrate wastes followed by vitrification of the residue will increase the final volume of vitrified waste by 50% to 90%; for Melton Valley waste from Oak Ridge, the increase in final glass volume will be 260% to 280%. The increase in volume is relative to direct vitrification of the waste in a 20 wt% Na{sub 2}O glass formulation. The increase in waste volume directly affects not only disposal costs, but also operating and/or capital costs. Larger plant size, longer operating time, and additional energy and additive costs are direct results of increases in waste volume. Such increases may be balanced by beneficial impacts on the vitrification process; however, those effects are outside the scope of this report.

  12. Residue management at Rocky Flats

    SciTech Connect

    Olencz, J.

    1995-12-31

    Past plutonium production and manufacturing operations conducted at the Rocky Flats Environmental Technology Site (RFETS) produced a variety of plutonium-contaminated by-product materials. Residues are a category of these materials and were categorized as {open_quotes}materials in-process{close_quotes} to be recovered due to their inherent plutonium concentrations. In 1989 all RFETS plutonium production and manufacturing operations were curtailed. This report describes the management of plutonium bearing liquid and solid wastes.

  13. Evaluation of residue drum storage safety risks

    SciTech Connect

    Conner, W.V.

    1994-06-17

    A study was conducted to determine if any potential safety problems exist in the residue drum backlog at the Rocky Flats Plant. Plutonium residues stored in 55-gallon drums were packaged for short-term storage until the residues could be processed for plutonium recovery. These residues have now been determined by the Department of Energy to be waste materials, and the residues will remain in storage until plans for disposal of the material can be developed. The packaging configurations which were safe for short-term storage may not be safe for long-term storage. Interviews with Rocky Flats personnel involved with packaging the residues reveal that more than one packaging configuration was used for some of the residues. A tabulation of packaging configurations was developed based on the information obtained from the interviews. A number of potential safety problems were identified during this study, including hydrogen generation from some residues and residue packaging materials, contamination containment loss, metal residue packaging container corrosion, and pyrophoric plutonium compound formation. Risk factors were developed for evaluating the risk potential of the various residue categories, and the residues in storage at Rocky Flats were ranked by risk potential. Preliminary drum head space gas sampling studies have demonstrated the potential for formation of flammable hydrogen-oxygen mixtures in some residue drums.

  14. PESTICIDE RESIDUE RECOVERIES FROM SURFACE WIPES

    EPA Science Inventory

    Human exposure is a consequence of pesticide use indoors with a primary source resulting from residue deposition on household surfaces. Accurate measurements of surface residues is essential for estimating exposure from different routes. Various procedures have been developed ...

  15. 48 CFR 250.104 - Residual powers.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 48 Federal Acquisition Regulations System 3 2014-10-01 2014-10-01 false Residual powers. 250.104 Section 250.104 Federal Acquisition Regulations System DEFENSE ACQUISITION REGULATIONS SYSTEM, DEPARTMENT... Contractual Actions 250.104 Residual powers....

  16. 48 CFR 1850.104 - Residual powers.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 48 Federal Acquisition Regulations System 6 2014-10-01 2014-10-01 false Residual powers. 1850.104 Section 1850.104 Federal Acquisition Regulations System NATIONAL AERONAUTICS AND SPACE ADMINISTRATION... 1850.104 Residual powers....

  17. 48 CFR 250.104 - Residual powers.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 48 Federal Acquisition Regulations System 3 2011-10-01 2011-10-01 false Residual powers. 250.104 Section 250.104 Federal Acquisition Regulations System DEFENSE ACQUISITION REGULATIONS SYSTEM, DEPARTMENT... Contractual Actions 250.104 Residual powers....

  18. 48 CFR 1850.104 - Residual powers.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 48 Federal Acquisition Regulations System 6 2012-10-01 2012-10-01 false Residual powers. 1850.104 Section 1850.104 Federal Acquisition Regulations System NATIONAL AERONAUTICS AND SPACE ADMINISTRATION... 1850.104 Residual powers....

  19. 48 CFR 970.5001 - Residual powers.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 48 Federal Acquisition Regulations System 5 2012-10-01 2012-10-01 false Residual powers. 970.5001 Section 970.5001 Federal Acquisition Regulations System DEPARTMENT OF ENERGY AGENCY SUPPLEMENTARY....5001 Residual powers....

  20. 48 CFR 250.104 - Residual powers.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 48 Federal Acquisition Regulations System 3 2013-10-01 2013-10-01 false Residual powers. 250.104 Section 250.104 Federal Acquisition Regulations System DEFENSE ACQUISITION REGULATIONS SYSTEM, DEPARTMENT... Contractual Actions 250.104 Residual powers....

  1. 48 CFR 970.5001 - Residual powers.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 48 Federal Acquisition Regulations System 5 2013-10-01 2013-10-01 false Residual powers. 970.5001 Section 970.5001 Federal Acquisition Regulations System DEPARTMENT OF ENERGY AGENCY SUPPLEMENTARY....5001 Residual powers....

  2. 48 CFR 970.5001 - Residual powers.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 48 Federal Acquisition Regulations System 5 2010-10-01 2010-10-01 false Residual powers. 970.5001 Section 970.5001 Federal Acquisition Regulations System DEPARTMENT OF ENERGY AGENCY SUPPLEMENTARY....5001 Residual powers....

  3. 48 CFR 970.5001 - Residual powers.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 48 Federal Acquisition Regulations System 5 2014-10-01 2014-10-01 false Residual powers. 970.5001 Section 970.5001 Federal Acquisition Regulations System DEPARTMENT OF ENERGY AGENCY SUPPLEMENTARY....5001 Residual powers....

  4. 48 CFR 1850.104 - Residual powers.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 48 Federal Acquisition Regulations System 6 2013-10-01 2013-10-01 false Residual powers. 1850.104 Section 1850.104 Federal Acquisition Regulations System NATIONAL AERONAUTICS AND SPACE ADMINISTRATION... 1850.104 Residual powers....

  5. 48 CFR 250.104 - Residual powers.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 48 Federal Acquisition Regulations System 3 2012-10-01 2012-10-01 false Residual powers. 250.104 Section 250.104 Federal Acquisition Regulations System DEFENSE ACQUISITION REGULATIONS SYSTEM, DEPARTMENT... Contractual Actions 250.104 Residual powers....

  6. 48 CFR 250.104 - Residual powers.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 48 Federal Acquisition Regulations System 3 2010-10-01 2010-10-01 false Residual powers. 250.104 Section 250.104 Federal Acquisition Regulations System DEFENSE ACQUISITION REGULATIONS SYSTEM, DEPARTMENT... Contractual Actions 250.104 Residual powers....

  7. 48 CFR 970.5001 - Residual powers.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 48 Federal Acquisition Regulations System 5 2011-10-01 2011-10-01 false Residual powers. 970.5001 Section 970.5001 Federal Acquisition Regulations System DEPARTMENT OF ENERGY AGENCY SUPPLEMENTARY....5001 Residual powers....

  8. 40 CFR 1065.705 - Residual and intermediate residual fuel.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... specifications for fuels meeting the definition of residual fuel in 40 CFR 80.2, including fuels marketed as...). Kinematic viscosity at 50 °C, max cSt 30.0 80.0 180.0 380.0 700.0 ISO 3104:1994/Cor 1:1997. Flash point, min... ISO 6245. Water, max (m3/m3)% 0.5 0.5 0.5 0.5 0.5 ISO 3733. Sulfur, max (kg/kg)% 3.50 4.00 4.50 4.50...

  9. 40 CFR 1065.705 - Residual and intermediate residual fuel.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... specifications for fuels meeting the definition of residual fuel in 40 CFR 80.2, including fuels marketed as...). Kinematic viscosity at 50 °C, max cSt 30.0 80.0 180.0 380.0 700.0 ISO 3104:1994/Cor 1:1997. Flash point, min... ISO 6245. Water, max (m3/m3)% 0.5 0.5 0.5 0.5 0.5 ISO 3733. Sulfur, max (kg/kg)% 3.50 4.00 4.50 4.50...

  10. 40 CFR 1065.705 - Residual and intermediate residual fuel.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... specifications for fuels meeting the definition of residual fuel in 40 CFR 80.2, including fuels marketed as...). Kinematic viscosity at 50 °C, max cSt 30.0 80.0 180.0 380.0 700.0 ISO 3104:1994/Cor 1:1997. Flash point, min... ISO 6245. Water, max (m3/m3)% 0.5 0.5 0.5 0.5 0.5 ISO 3733. Sulfur, max (kg/kg)% 3.50 4.00 4.50 4.50...

  11. 40 CFR 1065.705 - Residual and intermediate residual fuel.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... specifications for fuels meeting the definition of residual fuel in 40 CFR 80.2, including fuels marketed as...). Kinematic viscosity at 50 °C, max cSt 30.0 80.0 180.0 380.0 700.0 ISO 3104:1994/Cor 1:1997. Flash point, min... ISO 6245. Water, max (m3/m3)% 0.5 0.5 0.5 0.5 0.5 ISO 3733. Sulfur, max (kg/kg)% 3.50 4.00 4.50 4.50...

  12. SPECIATION OF ELEMENTS IN INCINERATION RESIDUES

    EPA Science Inventory

    Knowledge as to the speciation of elements in incineration residues is important for the successful management and utilization of the residues and for modelling and predicting their leaching behavior. s part of a larger research effort on speciation in combustion residues, ESP as...

  13. COMPOSITION AND DECOMPOSITION OF PEANUT RESIDUES

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Limited information exists on the mineralizable nitrogen (N) content of peanut (Arachis hypogaea L.) residue. The objective of this study was to determine the N contribution of pre- and post harvest peanut residue on two soil types. Aboveground peanut residue (cv. Georgia Green) was collected prio...

  14. 9 CFR 311.39 - Biological residues.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 9 Animals and Animal Products 2 2014-01-01 2014-01-01 false Biological residues. 311.39 Section... Biological residues. Carcasses, organs, or other parts of carcasses of livestock shall be condemned if it is determined that they are adulterated because of the presence of any biological residues....

  15. 9 CFR 311.39 - Biological residues.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 9 Animals and Animal Products 2 2012-01-01 2012-01-01 false Biological residues. 311.39 Section... Biological residues. Carcasses, organs, or other parts of carcasses of livestock shall be condemned if it is determined that they are adulterated because of the presence of any biological residues....

  16. 9 CFR 311.39 - Biological residues.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 9 Animals and Animal Products 2 2013-01-01 2013-01-01 false Biological residues. 311.39 Section... Biological residues. Carcasses, organs, or other parts of carcasses of livestock shall be condemned if it is determined that they are adulterated because of the presence of any biological residues....

  17. 9 CFR 311.39 - Biological residues.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 9 Animals and Animal Products 2 2011-01-01 2011-01-01 false Biological residues. 311.39 Section... Biological residues. Carcasses, organs, or other parts of carcasses of livestock shall be condemned if it is determined that they are adulterated because of the presence of any biological residues....

  18. 9 CFR 311.39 - Biological residues.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 9 Animals and Animal Products 2 2010-01-01 2010-01-01 false Biological residues. 311.39 Section... Biological residues. Carcasses, organs, or other parts of carcasses of livestock shall be condemned if it is determined that they are adulterated because of the presence of any biological residues....

  19. Management of post-harvest residue blanket

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Timely and effective residue management is essential for maximum sugar yields. Several studies were implemented in 2003 and harvested in 2004 in an effort to increase the effectiveness of residue management practices. Six studies were conducted to determine the effect of residue removal timing a...

  20. 48 CFR 50.104 - Residual powers.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 48 Federal Acquisition Regulations System 1 2013-10-01 2013-10-01 false Residual powers. 50.104... EXTRAORDINARY CONTRACTUAL ACTIONS AND THE SAFETY ACT Extraordinary Contractual Actions 50.104 Residual powers. This section prescribes standards and procedures for exercising residual powers under Pub. L....

  1. 48 CFR 50.104 - Residual powers.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 48 Federal Acquisition Regulations System 1 2011-10-01 2011-10-01 false Residual powers. 50.104... EXTRAORDINARY CONTRACTUAL ACTIONS AND THE SAFETY ACT Extraordinary Contractual Actions 50.104 Residual powers. This section prescribes standards and procedures for exercising residual powers under Pub. L....

  2. 48 CFR 50.104 - Residual powers.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 48 Federal Acquisition Regulations System 1 2010-10-01 2010-10-01 false Residual powers. 50.104... EXTRAORDINARY CONTRACTUAL ACTIONS AND THE SAFETY ACT Extraordinary Contractual Actions 50.104 Residual powers. This section prescribes standards and procedures for exercising residual powers under Pub. L....

  3. 48 CFR 50.104 - Residual powers.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 48 Federal Acquisition Regulations System 1 2012-10-01 2012-10-01 false Residual powers. 50.104... EXTRAORDINARY CONTRACTUAL ACTIONS AND THE SAFETY ACT Extraordinary Contractual Actions 50.104 Residual powers. This section prescribes standards and procedures for exercising residual powers under Pub. L....

  4. 48 CFR 50.104 - Residual powers.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 48 Federal Acquisition Regulations System 1 2014-10-01 2014-10-01 false Residual powers. 50.104... EXTRAORDINARY CONTRACTUAL ACTIONS AND THE SAFETY ACT Extraordinary Contractual Actions 50.104 Residual powers. This section prescribes standards and procedures for exercising residual powers under Pub. L....

  5. Microbial degradation of post-harvest residues

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Management of post-harvest residues, produced during the green cane harvesting of sugarcane in Louisiana, has become an increasingly important issue for producers, particularly in areas where burning of the residues is banned or restricted. If the residues, which range from 4-8 tonnes per hectare, ...

  6. Structure of the Membrane Proximal Oxioreductase Domain of Human Steap3, the Dominant Ferrireductase of the Erythroid Transferrin Cycle

    SciTech Connect

    Sendamarai, A.K.; Ohgami, R.S.; Fleming, M.D.; Lawrence, C.M.

    2009-05-27

    The daily production of 200 billion erythrocytes requires 20 mg of iron, accounting for nearly 80% of the iron demand in humans. Thus, erythroid precursor cells possess an efficient mechanism for iron uptake in which iron loaded transferrin (Tf) binds to the transferrin receptor (TfR) at the cell surface. The Tf:TfR complex then enters the endosome via receptor-mediated endocytosis. Upon endosomal acidification, iron is released from Tf, reduced to Fe{sup 2+} by Steap3, and transported across the endosomal membrane by divalent metal iron transporter 1. Steap3, the major ferrireductase in erythrocyte endosomes, is a member of a unique family of reductases. Steap3 is comprised of an N-terminal cytosolic oxidoreductase domain and a C-terminal heme-containing transmembrane domain. Cytosolic NADPH and a flavin are predicted cofactors, but the NADPH/flavin binding domain differs significantly from those in other eukaryotic reductases. Instead, Steap3 shows remarkable, although limited homology to FNO, an archaeal oxidoreductase. We have determined the crystal structure of the human Steap3 oxidoreductase domain in the absence and presence of NADPH. The structure reveals an FNO-like domain with an unexpected dimer interface and substrate binding sites that are well positioned to direct electron transfer from the cytosol to a heme moiety predicted to be fixed within the transmembrane domain. Here, we discuss possible gating mechanisms for electron transfer across the endosomal membrane.

  7. The Sec7 N-terminal regulatory domains facilitate membrane-proximal activation of the Arf1 GTPase

    PubMed Central

    Richardson, Brian C; Halaby, Steve L; Gustafson, Margaret A; Fromme, J Christopher

    2016-01-01

    The Golgi complex is the central sorting compartment of eukaryotic cells. Arf guanine nucleotide exchange factors (Arf-GEFs) regulate virtually all traffic through the Golgi by activating Arf GTPase trafficking pathways. The Golgi Arf-GEFs contain multiple autoregulatory domains, but the precise mechanisms underlying their function remain largely undefined. We report a crystal structure revealing that the N-terminal DCB and HUS regulatory domains of the Arf-GEF Sec7 form a single structural unit. We demonstrate that the established role of the N-terminal region in dimerization is not conserved; instead, a C-terminal autoinhibitory domain is responsible for dimerization of Sec7. We find that the DCB/HUS domain amplifies the ability of Sec7 to activate Arf1 on the membrane surface by facilitating membrane insertion of the Arf1 amphipathic helix. This enhancing function of the Sec7 N-terminal domains is consistent with the high rate of Arf1-dependent trafficking to the plasma membrane necessary for maximal cell growth. DOI: http://dx.doi.org/10.7554/eLife.12411.001 PMID:26765562

  8. Structure of the membrane proximal oxidoreductase domain of human Steap3, the dominant ferrireductase of the erythroid transferrin cycle

    PubMed Central

    Sendamarai, Anoop K.; Ohgami, Robert S.; Fleming, Mark D.; Lawrence, C. Martin

    2008-01-01

    The daily production of 200 billion erythrocytes requires 20 mg of iron, accounting for nearly 80% of the iron demand in humans. Thus, erythroid precursor cells possess an efficient mechanism for iron uptake in which iron loaded transferrin (Tf) binds to the transferrin receptor (TfR) at the cell surface. The Tf:TfR complex then enters the endosome via receptor-mediated endocytosis. Upon endosomal acidification, iron is released from Tf, reduced to Fe2+ by Steap3, and transported across the endosomal membrane by divalent metal iron transporter 1. Steap3, the major ferrireductase in erythrocyte endosomes, is a member of a unique family of reductases. Steap3 is comprised of an N-terminal cytosolic oxidoreductase domain and a C-terminal heme-containing transmembrane domain. Cytosolic NADPH and a flavin are predicted cofactors, but the NADPH/flavin binding domain differs significantly from those in other eukaryotic reductases. Instead, Steap3 shows remarkable, although limited homology to FNO, an archaeal oxidoreductase. We have determined the crystal structure of the human Steap3 oxidoreductase domain in the absence and presence of NADPH. The structure reveals an FNO-like domain with an unexpected dimer interface and substrate binding sites that are well positioned to direct electron transfer from the cytosol to a heme moiety predicted to be fixed within the transmembrane domain. Here, we discuss possible gating mechanisms for electron transfer across the endosomal membrane. PMID:18495927

  9. Wood residues: trash or treasure

    SciTech Connect

    Bolgiano, C.

    1983-12-01

    Forest residues have acquired new economic value since the growth of the wood-energy markets has prompted private woodlot owners to begin managing and harvesting their forests after nearly a century of neglect. Estimates place half the commercial forests as overstocked, with poor-quality trees and unmarketable varieties, as well as standing dead or fallen trees and slash which are aesthetically bad. Overzealous cleansing of the forest floor, however, will deplete forests soils of nutrients and expose them to erosion in addition to destroying wildlife habitat. A compromise is needed to balance the ecological and economic benefits. (DCK)

  10. Process to recycle shredder residue

    DOEpatents

    Jody, Bassam J.; Daniels, Edward J.; Bonsignore, Patrick V.

    2001-01-01

    A system and process for recycling shredder residue, in which separating any polyurethane foam materials are first separated. Then separate a fines fraction of less than about 1/4 inch leaving a plastics-rich fraction. Thereafter, the plastics rich fraction is sequentially contacted with a series of solvents beginning with one or more of hexane or an alcohol to remove automotive fluids; acetone to remove ABS; one or more of EDC, THF or a ketone having a boiling point of not greater than about 125.degree. C. to remove PVC; and one or more of xylene or toluene to remove polypropylene and polyethylene. The solvents are recovered and recycled.

  11. Organochlorine residues in starlings, 1972.

    PubMed

    Nickerson, P R; Barbehenn, K R

    1975-03-01

    During the fall of 1972 starlings were collected from 130 sites in conjunction with the National Pesticide Monitoring Program. They were analyzed for DDT and its metabolites, dieldrin, heptachlor epoxide, benzene hexachloride, polychlorinated biphenyls and, for the first time in the series, oxychlordane and HCB. Mean DDT and dieldrin residue levels have declined significantly since 1967 and a regression analysis suggests that levels of DDT and its metabolites should fall below a mean of 0.1 ppm for the 1974 starling collection. PMID:1161450

  12. 40 CFR 180.519 - Bromide ion and residual bromine; tolerances for residues.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 25 2013-07-01 2013-07-01 false Bromide ion and residual bromine... Tolerances § 180.519 Bromide ion and residual bromine; tolerances for residues. (a) General. The food additives, bromide ion and residual bromine, may be present in water, potable in accordance with...

  13. 40 CFR 180.519 - Bromide ion and residual bromine; tolerances for residues.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 40 Protection of Environment 24 2011-07-01 2011-07-01 false Bromide ion and residual bromine... Tolerances § 180.519 Bromide ion and residual bromine; tolerances for residues. (a) General. The food additives, bromide ion and residual bromine, may be present in water, potable in accordance with...

  14. 40 CFR 180.519 - Bromide ion and residual bromine; tolerances for residues.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 40 Protection of Environment 25 2012-07-01 2012-07-01 false Bromide ion and residual bromine... Tolerances § 180.519 Bromide ion and residual bromine; tolerances for residues. (a) General. The food additives, bromide ion and residual bromine, may be present in water, potable in accordance with...

  15. 40 CFR 180.519 - Bromide ion and residual bromine; tolerances for residues.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 23 2010-07-01 2010-07-01 false Bromide ion and residual bromine... Tolerances § 180.519 Bromide ion and residual bromine; tolerances for residues. (a) General. The food additives, bromide ion and residual bromine, may be present in water, potable in accordance with...

  16. 40 CFR 180.519 - Bromide ion and residual bromine; tolerances for residues.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 24 2014-07-01 2014-07-01 false Bromide ion and residual bromine... Tolerances § 180.519 Bromide ion and residual bromine; tolerances for residues. (a) General. The food additives, bromide ion and residual bromine, may be present in water, potable in accordance with...

  17. Managing residual limb hyperhidrosis in wounded warriors.

    PubMed

    Pace, Sarah; Kentosh, Joshua

    2016-06-01

    Residual limb dermatologic problems are a common concern among young active traumatic amputee patients who strive to maintain an active lifestyle. Hyperhidrosis of residual limbs is a recognized inciting factor that often contributes to residual limb dermatoses and is driven by the design of the prosthetic liner covering the residual limb. Treatment of hyperhidrosis in this population presents a unique challenge. Several accepted treatments of hyperhidrosis can offer some relief but have been limited by lack of results or side-effect profiles. Microwave thermal ablation has presented an enticing potential for residual limb hyperhidrosis. PMID:27416083

  18. Fiber-optic polymer residue monitor

    SciTech Connect

    Pfeifer, K.B.; Jarecki, R.L. Jr.; Dalton, T.J.

    1998-10-01

    Semiconductor processing tools that use a plasma to etch polysilicon or oxides produce residue polymers that build up on the exposed surfaces of the processing chamber. These residues are generally stressed and with time can cause flaking onto wafers resulting in yield loss. Currently, residue buildup is not monitored, and chambers are cleaned at regular intervals resulting in excess downtime for the tool. In addition, knowledge of the residue buildup rate and index of refraction is useful in determining the state of health of the chamber process. The authors have developed a novel optical fiber-based robust sensor that allows measurement of the residue polymer buildup while not affecting the plasma process.

  19. 40 CFR 180.432 - Lactofen; tolerances for residues.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... Lactofen; tolerances for residues. (a) General. Tolerances are established for residues of the herbicide... for residues of the herbicide lactofen, including its metabolites and degradates, in or on...

  20. 40 CFR 180.432 - Lactofen; tolerances for residues.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... Lactofen; tolerances for residues. (a) General. Tolerances are established for residues of the herbicide... for residues of the herbicide lactofen, including its metabolites and degradates, in or on...

  1. 40 CFR 180.432 - Lactofen; tolerances for residues.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... Lactofen; tolerances for residues. (a) General. Tolerances are established for residues of the herbicide... for residues of the herbicide lactofen, including its metabolites and degradates, in or on...

  2. 40 CFR 180.432 - Lactofen; tolerances for residues.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... Lactofen; tolerances for residues. (a) General. Tolerances are established for residues of the herbicide... for residues of the herbicide lactofen, including its metabolites and degradates, in or on...

  3. RESIDUAL STRESSES IN 3013 CONTAINERS

    SciTech Connect

    Mickalonis, J.; Dunn, K.

    2009-11-10

    The DOE Complex is packaging plutonium-bearing materials for storage and eventual disposition or disposal. The materials are handled according to the DOE-STD-3013 which outlines general requirements for stabilization, packaging and long-term storage. The storage vessels for the plutonium-bearing materials are termed 3013 containers. Stress corrosion cracking has been identified as a potential container degradation mode and this work determined that the residual stresses in the containers are sufficient to support such cracking. Sections of the 3013 outer, inner, and convenience containers, in both the as-fabricated condition and the closure welded condition, were evaluated per ASTM standard G-36. The standard requires exposure to a boiling magnesium chloride solution, which is an aggressive testing solution. Tests in a less aggressive 40% calcium chloride solution were also conducted. These tests were used to reveal the relative stress corrosion cracking susceptibility of the as fabricated 3013 containers. Significant cracking was observed in all containers in areas near welds and transitions in the container diameter. Stress corrosion cracks developed in both the lid and the body of gas tungsten arc welded and laser closure welded containers. The development of stress corrosion cracks in the as-fabricated and in the closure welded container samples demonstrates that the residual stresses in the 3013 containers are sufficient to support stress corrosion cracking if the environmental conditions inside the containers do not preclude the cracking process.

  4. Residual number processing in dyscalculia.

    PubMed

    Cappelletti, Marinella; Price, Cathy J

    2014-01-01

    Developmental dyscalculia - a congenital learning disability in understanding numerical concepts - is typically associated with parietal lobe abnormality. However, people with dyscalculia often retain some residual numerical abilities, reported in studies that otherwise focused on abnormalities in the dyscalculic brain. Here we took a different perspective by focusing on brain regions that support residual number processing in dyscalculia. All participants accurately performed semantic and categorical colour-decision tasks with numerical and non-numerical stimuli, with adults with dyscalculia performing slower than controls in the number semantic tasks only. Structural imaging showed less grey-matter volume in the right parietal cortex in people with dyscalculia relative to controls. Functional MRI showed that accurate number semantic judgements were maintained by parietal and inferior frontal activations that were common to adults with dyscalculia and controls, with higher activation for participants with dyscalculia than controls in the right superior frontal cortex and the left inferior frontal sulcus. Enhanced activation in these frontal areas was driven by people with dyscalculia who made faster rather than slower numerical decisions; however, activation could not be accounted for by response times per se, because it was greater for fast relative to slow dyscalculics but not greater for fast controls relative to slow dyscalculics. In conclusion, our results reveal two frontal brain regions that support efficient number processing in dyscalculia. PMID:24266008

  5. Residual stress patterns in steel welds

    SciTech Connect

    Spooner, S.; Hubbard, C.R.; Wang, X.L.; David, S.A.; Holden, T.M.; Root, J.H.; Swainson, I.

    1994-12-31

    Neutron strain scanning of residual stress is a valuable nondestructive tool for evaluation of residual stress in welds. The penetrating characteristic of neutrons permits mapping of strain patterns with a spatial resolution approaching 1mm at depths of 20mm in steels. While the overall patterns of the residual stress tensor in a weld are understood, the detailed patterns depend on welding process parameters and the effects of solid state transformation. The residual strain profiles in two multi-pass austenitic welds and a ferritic steel weld are presented. The stress-free lattice parameters within the fusion zone and the adjacent heat affected zone in the two austenitic welds show that the interpretation of residual stress from strains are affected by welding parameters. An interpretation of the residual strain pattern in the ferritic steel plate can be made using the strain measurements of a Gleeble test bar which has undergone the solid state austenite decomposition.

  6. Optical systolic array processor using residue arithmetic

    NASA Technical Reports Server (NTRS)

    Jackson, J.; Casasent, D.

    1983-01-01

    The use of residue arithmetic to increase the accuracy and reduce the dynamic range requirements of optical matrix-vector processors is evaluated. It is determined that matrix-vector operations and iterative algorithms can be performed totally in residue notation. A new parallel residue quantizer circuit is developed which significantly improves the performance of the systolic array feedback processor. Results are presented of a computer simulation of this system used to solve a set of three simultaneous equations.

  7. Identification of kinetically hot residues in proteins.

    PubMed Central

    Demirel, M. C.; Atilgan, A. R.; Jernigan, R. L.; Erman, B.; Bahar, I.

    1998-01-01

    A number of recent studies called attention to the presence of kinetically important residues underlying the formation and stabilization of folding nuclei in proteins, and to the possible existence of a correlation between conserved residues and those participating in the folding nuclei. Here, we use the Gaussian network model (GNM), which recently proved useful in describing the dynamic characteristics of proteins for identifying the kinetically hot residues in folded structures. These are the residues involved in the highest frequency fluctuations near the native state coordinates. Their high frequency is a manifestation of the steepness of the energy landscape near their native state positions. The theory is applied to a series of proteins whose kinetically important residues have been extensively explored: chymotrypsin inhibitor 2, cytochrome c, and related C2 proteins. Most of the residues previously pointed out to underlie the folding process of these proteins, and to be critically important for the stabilization of the tertiary fold, are correctly identified, indicating a correlation between the kinetic hot spots and the early forming structural elements in proteins. Additionally, a strong correlation between kinetically hot residues and loci of conserved residues is observed. Finally, residues that may be important for the stability of the tertiary structure of CheY are proposed. PMID:9865946

  8. Particulate residue separators for harvesting devices

    DOEpatents

    Hoskinson, Reed L.; Kenney, Kevin L.; Wright, Christopher T.; Hess, John R.

    2010-06-29

    A particulate residue separator and a method for separating a particulate residue stream may include a plenum borne by a harvesting device, and have a first, intake end and a second, exhaust end; first and second particulate residue air streams which are formed by the harvesting device and which travel, at least in part, along the plenum and in a direction of the second, exhaust end; and a baffle assembly which is located in partially occluding relation relative to the plenum, and which substantially separates the first and second particulate residue air streams.

  9. Methods of separating particulate residue streams

    DOEpatents

    Hoskinson, Reed L.; Kenney, Kevin L.; Wright, Christopher T.; Hess, J. Richard

    2011-04-05

    A particulate residue separator and a method for separating a particulate residue stream may include an air plenum borne by a harvesting device, and have a first, intake end and a second, exhaust end; first and second particulate residue air streams that are formed by the harvesting device and that travel, at least in part, along the air plenum and in a direction of the second, exhaust end; and a baffle assembly that is located in partially occluding relation relative to the air plenum and that substantially separates the first and second particulate residue air streams.

  10. Partitioning Residue-derived and Residue-induced Emissions of N2O Using 15N-labelled Crop Residues

    NASA Astrophysics Data System (ADS)

    Farrell, R. E.; Carverhill, J.; Lemke, R.; Knight, J. D.

    2014-12-01

    Estimates of N2O emissions in Canada indicate that 17% of all agriculture-based emissions are associated with the decomposition of crop residues. However, research specific to the western Canadian prairies (including Saskatchewan) has shown that the N2O emission factor for N sources in this region typically ranges between 0.2 and 0.6%, which is well below the current IPCC default emission factor of 1.0%. Thus, it stands to reason that emissions from crop residues should also be lower than those calculated using the current IPCC emission factor. Current data indicates that residue decomposition, N mineralization and N2O production are affected by a number of factors such as C:N ratio and chemical composition of the residue, soil type, and soil water content; thus, a bench-scale incubation study was conducted to examine the effects of soil type and water content on N2O emissions associated with the decomposition of different crop residues. The study was carried out using soils from the Black, Dark Brown, Brown, and Gray soil zones and was conducted at both 50% and 70% water-filled pore space (WFPS); the soils were amended with 15N-labeled residues of wheat, pea, canola, and flax, or with an equivalent amount of 15N-labeled urea; 15N2O production was monitored using a Picarro G5101-i isotopic N2O analyzer. Crop residue additions to the soils resulted in both direct and indirect emissions of N2O, with residue derived emissions (RDE; measured as 15N2O) generally exceeding residue-induced emissions (RIE) at 50% WFPS—with RDEs ranging from 42% to 88% (mean = 58%) of the total N2O. Conversely, at 70% WFPS, RDEs were generally lower than RIEs—ranging from 21% to 83% (mean = 48%). Whereas both water content and soil type had an impact on N2O production, there was a clear and consistent trend in the emission factors for the residues; i.e., emissions were always greatest for the canola residue and lowest for the wheat residue and urea fertilizer; and intermediate for pea

  11. Assessment of secondary crop residues. Final report

    SciTech Connect

    Ashare, E.; Leuschner, A.P.; West, C.E.; Langton, B.

    1981-03-01

    This report is the first of three reports assessing the feasibility of converting secondary agricultural residues to energy in the form of either methane gas or ethyl alcohol. Secondary agricultural residues are defined in this study as those residues resulting from biomass processing to produce primary products; e.g., whey from cheese processing, vegetable processing wastes, residues from paper pulping, etc. This report summarizes the first two phases of this study, data compilation, and evaluation. Subsequent reports will analyze the technical and economic feasibility of converting these residues to energy and the implementability of this technology. The industries for which data has been compiled in this report include vegetable, fruit, seafood, meat, poultry, and dairy processing and the pulp, paper, and paperboard industry. The data collected include raw product input, final processed product output, residue types, and quantity, residue concentration, biodegradability, seasonality of production, and geographic distribution of processing facilities. In general, these industries produce a relatively solid residue ranging in total solids concentration from 10 to 50% and a dilute liquid residue with an organic content (measured as COD or BOD) ranging from a few hundred to a few thousand mg/l. Due to the significant quantities of residues generated in each of the industries, it appears that the potential exists for generating a substantial quantity of energy. For a particular industry this quantity of energy can range from only one percent upwards to nearly thirty-five percent of the total processing energy required. The total processing energy required for the industries included in this study is approximately 2.5 quads per year. The potential energy which can be generated from these industrial residues will be 0.05 to 0.10 quads per year or approximately 2 to 4 percent of the total demand.

  12. A Benchmark Study on Casting Residual Stress

    SciTech Connect

    Johnson, Eric M.; Watkins, Thomas R; Schmidlin, Joshua E; Dutler, S. A.

    2012-01-01

    Stringent regulatory requirements, such as Tier IV norms, have pushed the cast iron for automotive applications to its limit. The castings need to be designed with closer tolerances by incorporating hitherto unknowns, such as residual stresses arising due to thermal gradients, phase and microstructural changes during solidification phenomenon. Residual stresses were earlier neglected in the casting designs by incorporating large factors of safety. Experimental measurement of residual stress in a casting through neutron or X-ray diffraction, sectioning or hole drilling, magnetic, electric or photoelastic measurements is very difficult and time consuming exercise. A detailed multi-physics model, incorporating thermo-mechanical and phase transformation phenomenon, provides an attractive alternative to assess the residual stresses generated during casting. However, before relying on the simulation methodology, it is important to rigorously validate the prediction capability by comparing it to experimental measurements. In the present work, a benchmark study was undertaken for casting residual stress measurements through neutron diffraction, which was subsequently used to validate the accuracy of simulation prediction. The stress lattice specimen geometry was designed such that subsequent castings would generate adequate residual stresses during solidification and cooling, without any cracks. The residual stresses in the cast specimen were measured using neutron diffraction. Considering the difficulty in accessing the neutron diffraction facility, these measurements can be considered as benchmark for casting simulation validations. Simulations were performed using the identical specimen geometry and casting conditions for predictions of residual stresses. The simulation predictions were found to agree well with the experimentally measured residual stresses. The experimentally validated model can be subsequently used to predict residual stresses in different cast

  13. Characterization Report on Sand, Slag, and Crucible Residues and on Fluoride Residues

    SciTech Connect

    Murray, A.M.

    1999-02-10

    This paper reports on the chemical characterization of the sand, slag, and crucible (SS and C) residues and the fluoride residues that may be shipped from the Rocky Flats Environmental Technology Site (RFETS) to Savannah River Site (SRS).

  14. 46 CFR 153.1608 - Calculation of total NLS residue and clingage NLS residue.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... MATERIALS Test and Calculation Procedures for Determining Stripping Quantity, Clingage NLS Residue, and... NLS residue for each tank is calculated by adding the stripping quantity and the clingage NLS...

  15. 46 CFR 153.1608 - Calculation of total NLS residue and clingage NLS residue.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... MATERIALS Test and Calculation Procedures for Determining Stripping Quantity, Clingage NLS Residue, and... NLS residue for each tank is calculated by adding the stripping quantity and the clingage NLS...

  16. 46 CFR 153.1608 - Calculation of total NLS residue and clingage NLS residue.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... MATERIALS Test and Calculation Procedures for Determining Stripping Quantity, Clingage NLS Residue, and... NLS residue for each tank is calculated by adding the stripping quantity and the clingage NLS...

  17. 46 CFR 153.1608 - Calculation of total NLS residue and clingage NLS residue.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... MATERIALS Test and Calculation Procedures for Determining Stripping Quantity, Clingage NLS Residue, and... NLS residue for each tank is calculated by adding the stripping quantity and the clingage NLS...

  18. Gunshot residue, ten years later.

    PubMed

    Wilber, C G; Lantz, R K; Sulik, P L

    1991-09-01

    Gunshot residues may be central to a competent reconstruction of a shooting incident. When a young boy was shot in the neck by a playmate using a .22-caliber single-action revolver, permanent paralysis from mid-thorax downward ensued. Ten years later the victim sued the importer, the vendor, the German manufacturer, and the shooter's family. Investigative reports indicated "horseplay" and questionable emergency medical team care. Depositions were contradictory. The entry wound, removed at surgery, was fixed and processed for slides. The histopathologist referred to "black pigment granules" in the wound track. The 10-year-old slides and block were retrieved. The coverslip was removed from a representative slide that was examined under the scanning, x-ray dispersive microscope. The black granules contained amounts of lead, barium, and antimony far beyond any normal range. The firing range had to have been no greater than 6-12 in (15.24-30.48 cm). The case was promptly settled out of court. PMID:1750390

  19. The Gatekeeper Residue and Beyond

    PubMed Central

    Choi, Ryan; Song, Yifan; Fox, Anna M.W.; Hillesland, Heidi K.; Zhang, Zhongsheng; Vidadala, RamaSubbaRao; Merritt, Ethan A.; Lau, Audrey O.T.; Maly, Dustin J.; Fan, Erkang; Barrett, Lynn K.; Van Voorhis, Wesley C.; Ojo, Kayode K.

    2015-01-01

    SUMMARY Specific roles of individual CDPKs vary, but in general, they mediate essential biological functions necessary for parasite's survival. A comparative analysis of the structural-activity relationships (SAR) of Neospora caninum, Eimeria tenella and Babesia bovis Calcium-dependent Protein kinases (CDPKs) together with those of Plasmodium falciparum, Cryptosporidium parvum, and Toxoplasma gondii was performed by screening against 333 Bumped kinase inhibitors (BKIs). Structural modeling and experimental data revealed that residues other than the gatekeeper influence compound-protein interactions resulting in distinct sensitivity profiles. We subsequently defined potential amino-acid structural influences within the ATP binding cavity for each orthologue necessary for consideration in the development of broad-spectrum apicomplexan CDPK inhibitors. Although the BKI library was developed for specific inhibition of glycine gatekeeper CDPKs combined with low inhibition of threonine gatekeeper human SRC kinase; some library compounds exhibit activity against serine or threonine containing CDPKs. Divergent BKI sensitivity of CDPK homologs could be explained on the basis of differences in the size and orientation of the hydrophobic pocket and specific variation at other amino-acid positions within the ATP binding cavity. In particular, BbCDPK4 and PfCDPK1 are sensitive to a larger fraction of compounds than EtCDPK1 despite the presence of threonine gatekeeper in all the three CDPKs. PMID:24927073

  20. Thermal Insulation from Hardwood Residues

    NASA Astrophysics Data System (ADS)

    Sable, I.; Grinfelds, U.; Vikele, L.; Rozenberga, L.; Zeps, M.; Luguza, S.

    2015-11-01

    Adequate heat is one of the prerequisites for human wellbeing; therefore, building insulation is required in places where the outside temperature is not suitable for living. The climate change, with its rising temperatures and longer dry periods, promotes enlargement of the regions with conditions more convenient for hardwood species than for softwood species. Birch (Betula pendula) is the most common hardwood species in Latvia. The aim of this work was to obtain birch fibres from wood residues of plywood production and to form low-density thermal insulation boards. Board formation and production was done in the presence of water; natural binder, fire retardant and fungicide were added in different concentrations. Board properties such as density, transportability or resistance to particulate loss, thermal conductivity and reaction to fire were investigated. This study included thermal insulation boards with the density of 102-120 kg/m3; a strong correlation between density and the binder amount was found. Transportability also improved with the addition of a binder, and 0.1-0.5% of the binder was the most appropriate amount for this purpose. The measured thermal conductivity was in the range of 0.040-0.043 W/(m·K). Fire resistance increased with adding the fire retardant. We concluded that birch fibres are applicable for thermal insulation board production, and it is possible to diversify board properties, changing the amount of different additives.

  1. Tank 12H residuals sample analysis report

    SciTech Connect

    Oji, L. N.; Shine, E. P.; Diprete, D. P.; Coleman, C. J.; Hay, M. S.

    2015-06-11

    The Savannah River National Laboratory (SRNL) was requested by Savannah River Remediation (SRR) to provide sample preparation and analysis of the Tank 12H final characterization samples to determine the residual tank inventory prior to grouting. Eleven Tank 12H floor and mound residual material samples and three cooling coil scrape samples were collected and delivered to SRNL between May and August of 2014.

  2. Photoelastic measurements of residual stresses for NDE

    NASA Technical Reports Server (NTRS)

    Redner, Alex S.

    1988-01-01

    Photoelastic measurements of residual strains are used extensively in the QC and inspection of transparent materials. A new method of measurements, based on Spectral Contents Analysis, is described in this paper. The method uses a personal computer for photoelastic data acquisition, eliminating personal skill and subjectivity. the new tool should make the measurements of residual strains for QC simpler and more reliable.

  3. Crop Residues: The Rest of the Story

    Technology Transfer Automated Retrieval System (TEKTRAN)

    A recent scientific publication stated that to remove CO2 from the atmosphere, the most permanent and rapid solution would be to sink crop residues to the ocean floor where they would be buried in deep ocean sediments. However, mitigating rising atmospheric CO2 concentrations by removing crop residu...

  4. Soil water evaporation and crop residues

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Crop residues have value when left in the field and also when removed from the field and sold as a commodity. Reducing soil water evaporation (E) is one of the benefits of leaving crop residues in place. E was measured beneath a corn canopy at the soil suface with nearly full coverage by corn stover...

  5. BOOSTER CHLORINATION FOR MANAGING DISINFECTANT RESIDUALS

    EPA Science Inventory

    Booster chlorination is an approach to residual maintenance in which chlorine is applied at strategic locations within the distribution system. Situations in which booster chlorination may be most effective for maintaining a residual are explained informally in the context of a ...

  6. 40 CFR 240.208 - Residue.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 26 2013-07-01 2013-07-01 false Residue. 240.208 Section 240.208 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) SOLID WASTES GUIDELINES FOR THE THERMAL PROCESSING OF SOLID WASTES Requirements and Recommended Procedures § 240.208 Residue....

  7. 40 CFR 240.208 - Residue.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 25 2014-07-01 2014-07-01 false Residue. 240.208 Section 240.208 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) SOLID WASTES GUIDELINES FOR THE THERMAL PROCESSING OF SOLID WASTES Requirements and Recommended Procedures § 240.208 Residue....

  8. 40 CFR 240.208 - Residue.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 40 Protection of Environment 26 2012-07-01 2011-07-01 true Residue. 240.208 Section 240.208 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) SOLID WASTES GUIDELINES FOR THE THERMAL PROCESSING OF SOLID WASTES Requirements and Recommended Procedures § 240.208 Residue....

  9. 40 CFR 240.208 - Residue.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 40 Protection of Environment 25 2011-07-01 2011-07-01 false Residue. 240.208 Section 240.208 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) SOLID WASTES GUIDELINES FOR THE THERMAL PROCESSING OF SOLID WASTES Requirements and Recommended Procedures § 240.208 Residue....

  10. RECOVERY OF URANIUM VALUES FROM RESIDUES

    DOEpatents

    Schaap, W.B.

    1959-08-18

    A process is described for the recovery of uranium from insoluble oxide residues resistant to repeated leaching with mineral acids. The residue is treated with gaseous hydrogen fluoride, then with hydrogen and again with hydrogen fluoride, preferably at 500 to 700 deg C, prior to the mineral acid leaching.

  11. 40 CFR 158.2290 - Residue chemistry.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... Health Administration in 29 CFR 1910.1200 must accompany analytical standards. 3. Data are required if a... 40 Protection of Environment 25 2013-07-01 2013-07-01 false Residue chemistry. 158.2290 Section... REQUIREMENTS FOR PESTICIDES Antimicrobial Pesticide Data Requirements § 158.2290 Residue chemistry. (a)...

  12. 40 CFR 158.2290 - Residue chemistry.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... Health Administration in 29 CFR 1910.1200 must accompany analytical standards. 3. Data are required if a... 40 Protection of Environment 24 2014-07-01 2014-07-01 false Residue chemistry. 158.2290 Section... REQUIREMENTS FOR PESTICIDES Antimicrobial Pesticide Data Requirements § 158.2290 Residue chemistry. (a)...

  13. CHARACTERISTICS AND TREATABILITY OF URBAN RUNOFF RESIDUALS

    EPA Science Inventory

    This study was undertaken to determine the character of urban stormwater runoff (UR) residuals as well as handling and disposal techniques. Samples of UR residuals for this study were obtained from a field-assembled sedimentation basin in Racine, WI, swirl and helical bend solids...

  14. 40 CFR 240.208 - Residue.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 24 2010-07-01 2010-07-01 false Residue. 240.208 Section 240.208 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) SOLID WASTES GUIDELINES FOR THE THERMAL PROCESSING OF SOLID WASTES Requirements and Recommended Procedures § 240.208 Residue....

  15. Does Bt Corn Really Produce Tougher Residues

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Bt corn hybrids produce insecticidal proteins that are derived from a bacterium, Bacillus thuringiensis. There have been concerns that Bt corn hybrids produce residues that are relatively resistant to decomposition. We conducted four experiments that examined the decomposition of corn residues und...

  16. Distribution of veterinary drug residues among muscles

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The U.S. Food and Drug Administration sets tolerances for veterinary drug residues in muscle, but does not specify which muscle should be sampled for analysis. The goal of this research was to determine if antibiotic residue levels are dependent on muscle type. In this study, penicillin G (Pen G) d...

  17. Measurment Of Residual Stress In Ferromagnetic Materials

    NASA Technical Reports Server (NTRS)

    Namkung, Min; Yost, William T.; Kushnick, Peter W.; Grainger, John L.

    1992-01-01

    Magnetoacoustic (MAC) and magnetoacoustic emission (MAE) techniques combined to provide complete characterization of residual stresses in ferromagnetic structural materials. Combination of MAC and MAE techniques makes it possible to characterize residual tension and compression without being limited by surface conditions and unavailability of calibration standards. Significant in field of characterization of materials as well as detection of fatigue failure.

  18. Unicystic ameloblastoma arising from a residual cyst

    PubMed Central

    Mahajan, Amit D; Manjunatha, Bhari Sharanesha; Khurana, Neha M; Shah, Navin

    2014-01-01

    Intraoral swellings involving alveolar ridges in edentulous patients are clinically diagnosed as residual cysts, traumatic bone cysts, Stafne's jaw bone cavity, ameloblastoma and metastatic tumours of the jaw. This case report describes a residual cyst in a 68-year-old edentulous male patient which was enucleated and histopathologically confirmed as a unicystic ameloblastoma. PMID:25199192

  19. Should the Functional Residual Capacity be Ignored?

    PubMed Central

    Selvi E, Chandra; K.V Rao, Kuppu; Malathi

    2013-01-01

    Aim and Objectives: The functional residual capacity was given the least importance than the other lung volume parameters. Studies have revealed the restrictive pattern of lung disease in patients with liver cirrhosis. We aimed to analyze the importance of the functional residual capacity and other lung volumes of cirrhotic patients. Subjects and Methods: Forty (40) patients with cirrhosis (Child’s-B) were enrolled in this study. The vital capacity was measured by an instrument called V02 Max 22. The other lung volumes which were measured were derived parameters. The functional residual capacity was measured by the nitrogen wash-out method. Results: The measured value of the functional residual capacity was below normal as compared to the reference value. The total lung capacity and the vital capacity were positively correlated with the functional residual capacity. The residual volume was found to be increased in twelve out of forty cirrhotic patients. Conclusion: The functional residual capacity can be determined by the compliance of the lung and the chest wall. The patients with a reduced functional residual capacity may be suffering from dyspnoea, probably due to the restrictive pattern of the lung disease. Hence, the reduced lung volumes of the subjects may be due to the abnormalities in the mechanics of ventilation. PMID:23450122

  20. Crop residues: a resource for whom?

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Crop residues represent an important on-farm resource, which are now being considered a harvestable commodity contributing to bio-fuel production. This review of literature looks at how crop residues contribute to soil properties and processes, water conservation and quality, on-farm forage availab...

  1. Nationwide residues of organochlorines in starlings, 1974

    USGS Publications Warehouse

    White, D.H.

    1976-01-01

    Organochlorine residues in starlings (Sturnus vulgaris) from 126 collection sites were monitored during the fall of 1974. DDE, DDT, polychlorinated biphenyls (PCB's), and benzene hexachloride were present in all samples. Dieldrin, heptachlor expoxide, hexachlorobenzene, and oxychlordane were present in approximately 97% of the samples. DDE, dieldrin, and PCB residues in starlings were significantly lower than they had been in 1972.

  2. 48 CFR 1450.104 - Residual powers.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 48 Federal Acquisition Regulations System 5 2013-10-01 2013-10-01 false Residual powers. 1450.104 Section 1450.104 Federal Acquisition Regulations System DEPARTMENT OF THE INTERIOR CONTRACT MANAGEMENT EXTRAORDINARY CONTRACTUAL ACTIONS AND THE SAFETY ACT Extraordinary Contractual Actions 1450.104 Residual powers....

  3. 48 CFR 1450.104 - Residual powers.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 48 Federal Acquisition Regulations System 5 2014-10-01 2014-10-01 false Residual powers. 1450.104 Section 1450.104 Federal Acquisition Regulations System DEPARTMENT OF THE INTERIOR CONTRACT MANAGEMENT EXTRAORDINARY CONTRACTUAL ACTIONS AND THE SAFETY ACT Extraordinary Contractual Actions 1450.104 Residual powers....

  4. 48 CFR 1450.104 - Residual powers.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 48 Federal Acquisition Regulations System 5 2011-10-01 2011-10-01 false Residual powers. 1450.104 Section 1450.104 Federal Acquisition Regulations System DEPARTMENT OF THE INTERIOR CONTRACT MANAGEMENT EXTRAORDINARY CONTRACTUAL ACTIONS AND THE SAFETY ACT Extraordinary Contractual Actions 1450.104 Residual powers....

  5. 48 CFR 1450.104 - Residual powers.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 48 Federal Acquisition Regulations System 5 2012-10-01 2012-10-01 false Residual powers. 1450.104 Section 1450.104 Federal Acquisition Regulations System DEPARTMENT OF THE INTERIOR CONTRACT MANAGEMENT EXTRAORDINARY CONTRACTUAL ACTIONS AND THE SAFETY ACT Extraordinary Contractual Actions 1450.104 Residual powers....

  6. 48 CFR 1450.104 - Residual powers.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 48 Federal Acquisition Regulations System 5 2010-10-01 2010-10-01 false Residual powers. 1450.104 Section 1450.104 Federal Acquisition Regulations System DEPARTMENT OF THE INTERIOR CONTRACT MANAGEMENT EXTRAORDINARY CONTRACTUAL ACTIONS AND THE SAFETY ACT Extraordinary Contractual Actions 1450.104 Residual powers....

  7. Residue management: Back to the roots

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Addressing the issues of climate change and sustainable biomass feedstocks have soil as a common theme. Managing crop residues is directly related to soil management. Understanding how soil and crop residue management interact provides insight on how to assure agricultural soil can serve as a carbon...

  8. Nationwide residues of organochlorines in starlings, 1974.

    PubMed

    White, D H

    1976-06-01

    Organochlorine residues in starlings (Sturnus vulgaris) from 126 collection sites were monitored during the fall of 1974. DDE, DDT, polychlorinated biphenyls (PCB's), and benzene hexachloride were present in all samples. Dieldrin, heptachlor expoxide, hexachlorobenzene, and oxychlordane were present in approximately 97% of the samples. DDE, dieldrin, and PCB residues in starlings were significantly lower than they had been in 1972. PMID:940731

  9. Residuals Management and Water Pollution Control Planning.

    ERIC Educational Resources Information Center

    Environmental Protection Agency, Washington, DC. Office of Public Affairs.

    This pamphlet addresses the problems associated with residuals and water quality especially as it relates to the National Water Pollution Control Program. The types of residuals and appropriate management systems are discussed. Additionally, one section is devoted to the role of citizen participation in developing management programs. (CS)

  10. 46 CFR 153.1608 - Calculation of total NLS residue and clingage NLS residue.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 46 Shipping 5 2010-10-01 2010-10-01 false Calculation of total NLS residue and clingage NLS residue. 153.1608 Section 153.1608 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED... MATERIALS Test and Calculation Procedures for Determining Stripping Quantity, Clingage NLS Residue,...

  11. Residuals and the Residual-Based Statistic for Testing Goodness of Fit of Structural Equation Models

    ERIC Educational Resources Information Center

    Foldnes, Njal; Foss, Tron; Olsson, Ulf Henning

    2012-01-01

    The residuals obtained from fitting a structural equation model are crucial ingredients in obtaining chi-square goodness-of-fit statistics for the model. The authors present a didactic discussion of the residuals, obtaining a geometrical interpretation by recognizing the residuals as the result of oblique projections. This sheds light on the…

  12. Process for treatment of residual gas

    SciTech Connect

    Nolden, K.

    1980-01-01

    A process is disclosed for the treatment of the residual gases which are produced when hydrogen sulfide is reduced, by combustion, to elementary sulfur by the Claus process. The residual gases are fed through a heated conduit and gas scrubber, wherein the temperature of those residual gases are maintained above the melting point of sulfur. A portion of the raw coke oven gas condensate is admitted to the gas scrubber to be returned to the coke oven battery main from the flushing liquid separator as flushing liquor. The residual gases are then conducted through the coke oven gas purification process equipment along with the raw coke oven gas where the residual gases are intermixed with the raw coke oven gas prior to tar separation.

  13. Residual stress measurement in YBCO thin films.

    SciTech Connect

    Cheon, J. H.; Singh, J. P.

    2002-05-13

    Residual stress in YBCO films on Ag and Hastelloy C substrates was determined by using 3-D optical interferometry and laser scanning to measure the change in curvature radius before and after film deposition. The residual stress was obtained by appropriate analysis of curvature measurements. Consistent with residual thermal stress calculations based on the thermal expansion coefficient mismatch between the substrates and YBCO film, the measured residual stress in the YBCO film on Hastelloy C substrate was tensile, while it was compressive on the Ag substrate. The stress values measured by the two techniques were generally in good agreement, suggesting that optical interferometry and laser scanning have promise for measuring residual stresses in thin films.

  14. Gunshot residue preservation in seawater.

    PubMed

    Lindström, Anne-Christine; Hoogewerff, Jurian; Athens, Josie; Obertova, Zuzana; Duncan, Warwick; Waddell, Neil; Kieser, Jules

    2015-08-01

    Little is known about the persistence of gunshot residue (GSR) in soft tissue and bones during decomposition in marine environments. For a better understanding, qualitative and quantitative data were obtained on GSR retention on soft tissue and bony gunshot wounds (GSWs). A quantity of 36 fleshed and 36 defleshed bovine ribs were shot at contact range with 0.22 calibre hollow point ammunition using a Stirling 0.22 calibre long rifle. Bone specimens in triplicate were placed in three environments: submerged, intertidal and in supralittoral zone. Sets of triplicates were recovered on day 3, 10, 24 and 38, and analysed with scanning electron microscopy with energy dispersive X-ray spectrometry (SEM-EDX), and inductive coupled plasma mass spectrometry (ICP-MS). The SEM-EDX recorded GSR-indicative particles surrounding the bullet entrance on all bone types (fleshed and defleshed) in all environments throughout the study. GSR-unique particles were only detected on the supralittoral bones. The ICP-MS analysis showed faster GSR loss on submerged than intertidal and supralittoral defleshed specimens. Fleshed specimens showed a faster GSR loss on intertidal than submerged and supralittoral specimens. In conclusion, the GSR disappeared faster from submerged and intertidal than non-submerged specimens. The difference of detection of GSR between analysed specimens (defleshed versus fleshed) disappeared upon defleshing. This study highlights the potential of finding evidence of GSR in a submerged body and the potential of microscopic and analytical methods for examining suspected GSW in highly decomposed bodies in marine habitats. PMID:26115226

  15. Recycling of auto shredder residue.

    PubMed

    Nourreddine, Menad

    2007-01-31

    Currently, about 75% of end-of-life vehicle's (ELV) total weight is recycled in EU countries. The remaining 25%, which is called auto shredder residues (ASR) or auto fluff, is disposed of as landfill because of its complexity. It is a major challenge to reduce this percentage of obsolete cars. The European draft directive states that by the year 2006, only 15% of the vehicle's weight can be disposed of at landfill sites and by 2015, this will be reduced to 5%. The draft directive states that a further 10% can be incinerated. The quantities of shredder fluff are likely to increase in the coming years. This is because of the growing number of cars being scrapped, coupled with the increase in the amount of plastics used in cars. In Sweden, some current projects are focusing on recycling of ASR material. In this paper some different alternatives for using this material are reported. The hypothetical injection of ASR into a blast furnace concentrating on ASR's effect to some blast furnace (BF) parameters has been completed using a blast furnace mass balance model. As a result, in principle, ASR can be used as reducing agent in the BF process if certain conditions are met. The particle size of ASR material must be controlled to ensure optimal gasification of the material in the raceway. Regarding the chemical composition of ASR, the non-ferrous content can affect the pig iron quality, which is difficult to rectify at a later point. The most attractive recycling alternative is to use the products obtained from pyrolysis of ASR in appropriate metallurgical processes. PMID:16600493

  16. Structure-based identification of catalytic residues

    PubMed Central

    Yahalom, Ran; Reshef, Dan; Wiener, Ayana; Frankel, Sagiv; Kalisman, Nir; Lerner, Boaz; Keasar, Chen

    2011-01-01

    The identification of catalytic residues is an essential step in functional characterization of enzymes. We present a purely structural approach to this problem, which is motivated by the difficulty of evolution-based methods to annotate structural genomics targets that have few or no homologs in the databases. Our approach combines a state-of-the-art support vector machine (SVM) classifier with novel structural features that augment structural clues by spatial averaging and Z-scoring. Special attention is paid to the class imbalance problem that stems from the overwhelming number of non-catalytic residues in enzymes compared to catalytic residues. This problem is tackled by: 1) optimizing the classifier to maximize a performance criterion that considers both type I and type II errors in the classification of catalytic and non-catalytic residues; 2) under-sampling non-catalytic residues before SVM training; and 3) during SVM training, penalizing errors in learning catalytic residues more than errors in learning non-catalytic residues. Tested on four enzyme datasets – one specifically designed by us to mimic the structural genomics scenario and three previously-evaluated datasets – our structure-based classifier is never inferior to similar structure-based classifiers and comparable to classifiers that use both structural and evolutionary features. In addition to evaluation of the performance of catalytic residue identification, we also present detailed case studies on three proteins. This analysis suggests that many false positive predictions may correspond to binding sites and other functional residues. A web server that implements the method, our own-designed database, and the source code of the programs are publicly available at http://www.cs.bgu.ac.il/~meshi/functionPrediction. PMID:21491495

  17. Structure-based identification of catalytic residues.

    PubMed

    Yahalom, Ran; Reshef, Dan; Wiener, Ayana; Frankel, Sagiv; Kalisman, Nir; Lerner, Boaz; Keasar, Chen

    2011-06-01

    The identification of catalytic residues is an essential step in functional characterization of enzymes. We present a purely structural approach to this problem, which is motivated by the difficulty of evolution-based methods to annotate structural genomics targets that have few or no homologs in the databases. Our approach combines a state-of-the-art support vector machine (SVM) classifier with novel structural features that augment structural clues by spatial averaging and Z scoring. Special attention is paid to the class imbalance problem that stems from the overwhelming number of non-catalytic residues in enzymes compared to catalytic residues. This problem is tackled by: (1) optimizing the classifier to maximize a performance criterion that considers both Type I and Type II errors in the classification of catalytic and non-catalytic residues; (2) under-sampling non-catalytic residues before SVM training; and (3) during SVM training, penalizing errors in learning catalytic residues more than errors in learning non-catalytic residues. Tested on four enzyme datasets, one specifically designed by us to mimic the structural genomics scenario and three previously evaluated datasets, our structure-based classifier is never inferior to similar structure-based classifiers and comparable to classifiers that use both structural and evolutionary features. In addition to the evaluation of the performance of catalytic residue identification, we also present detailed case studies on three proteins. This analysis suggests that many false positive predictions may correspond to binding sites and other functional residues. A web server that implements the method, our own-designed database, and the source code of the programs are publicly available at http://www.cs.bgu.ac.il/∼meshi/functionPrediction. PMID:21491495

  18. [Occurrence of pesticide residues in raspberries in 2000-2005].

    PubMed

    Sadło, Stanisław; Szpyrka, Ewa; Rogozińska, Krystyna; Rupar, Julian; Kuźmenko, Arletta

    2007-01-01

    The aim of this paper was to present occurrence of pesticide residues in raspberries in 2000-2005. Gas chromatographic and spectroscopy methods were used. The most frequently found were tolylfluanid residues (43% of the analysed samples), procymidone residues (33%), pyrimethanil residues (15%), ethylenebisdithiocarbamates (EBDC) residues (8%) and iprodione residues (5%), while insecticides (mainly synthetic pyrethroids) cypermethrin residues (6%) and bifenthrin (4%). In 8 % of analysed samples EBDC residues exceeded the national Maximum Residue Level established for raspberries. On relatively the highest level EBDC occurred. PMID:18246655

  19. Residual stresses in injection molded products

    NASA Astrophysics Data System (ADS)

    Jansen, K. M. B.

    2015-12-01

    During the molding process residual stresses are formed due to thermal contraction during cooling as well as the local pressure history during solidification. In this paper a simple analytical model is reviewed which relates residual stresses, product shrinkage as well as warpage to the temperature and pressure histories during molding. Precise excimer laser layer removal measurements were performed to verify the predicted residual stress distributions. In addition, detailed shrinkage and warpage measurements on a large series of polymers and for different molding conditions were performed and are shown to compare well with the model predictions.

  20. Simple approach for ranking structure determining residues

    PubMed Central

    Luna-Martínez, Oscar D.; Vidal-Limón, Abraham; Villalba-Velázquez, Miryam I.; Sánchez-Alcalá, Rosalba; Garduño-Juárez, Ramón; Uversky, Vladimir N.

    2016-01-01

    Mutating residues has been a common task in order to study structural properties of the protein of interest. Here, we propose and validate a simple method that allows the identification of structural determinants; i.e., residues essential for preservation of the stability of global structure, regardless of the protein topology. This method evaluates all of the residues in a 3D structure of a given globular protein by ranking them according to their connectivity and movement restrictions without topology constraints. Our results matched up with sequence-based predictors that look up for intrinsically disordered segments, suggesting that protein disorder can also be described with the proposed methodology. PMID:27366642

  1. Diazinon residues in insects from sprayed tobacco

    USGS Publications Warehouse

    Stromborg, K.L.; Beyer, W.N.; Kolbe, E.

    1982-01-01

    Pooled samples of tobacco hornworms collected from a field sprayed with 0.84 kg/ha of diazinon were analyzed for residues at various intervals after application. No residues of the toxic metabolite diazoxon were detected (sensitivity 0.5 ppm) in any sample. Only one sample exceeded 1.0 ppm of the parent compound and was collected 4 hours after spraying. Residues declined over time (P<0.01) and none were detected (sensitivity 0.1 ppm) 18 days after spraying. the potential hazard to birds eating these insects appeared to be minimal.

  2. Identification of residues by infrared spectroscopy

    SciTech Connect

    Barber, T.E.; Ayala, N.L.; Jin, Hong; Drumheller, C.T.

    1997-12-31

    Mid-infrared spectroscopy of surfaces can be a very powerful technique for the qualitative and quantitative analysis of surface residues. The goal of this work was to study the application of diffuse reflectance mid-infrared spectroscopy to the identification of pesticide, herbicide, and explosive residues on surfaces. A field portable diffuse reflectance spectrometer was used to collect the mid-infrared spectra of clean surfaces and contaminated surfaces. These spectra were used as calibration sets to develop automated data analysis to classify or to identify residues on samples. In this presentation, the instrumentation and data process algorithms will be discussed.

  3. Simple approach for ranking structure determining residues.

    PubMed

    Luna-Martínez, Oscar D; Vidal-Limón, Abraham; Villalba-Velázquez, Miryam I; Sánchez-Alcalá, Rosalba; Garduño-Juárez, Ramón; Uversky, Vladimir N; Becerril, Baltazar

    2016-01-01

    Mutating residues has been a common task in order to study structural properties of the protein of interest. Here, we propose and validate a simple method that allows the identification of structural determinants; i.e., residues essential for preservation of the stability of global structure, regardless of the protein topology. This method evaluates all of the residues in a 3D structure of a given globular protein by ranking them according to their connectivity and movement restrictions without topology constraints. Our results matched up with sequence-based predictors that look up for intrinsically disordered segments, suggesting that protein disorder can also be described with the proposed methodology. PMID:27366642

  4. Ultrasonics used to measure residual stress

    NASA Technical Reports Server (NTRS)

    1967-01-01

    Ultrasonic method is used to measure residual stress in metal structures. By using this method, various forms of wave propagation in metals are possible, and more thorough analysis of complex geometric structures may be had.

  5. Recovery of transuranics from process residues

    SciTech Connect

    Gray, J.H.; Gray, L.W.

    1987-01-01

    Process residues are generated at both the Rocky Flats Plant (RFP) and the Savannah River Plant (SRP) during aqueous chemical and pyrochemical operations. Frequently, process operations will result in either impure products or produce residues sufficiently contaminated with transuranics to be nondiscardable as waste. Purification and recovery flowsheets for process residues have been developed to generate solutions compatible with subsequent Purex operations and either solid or liquid waste suitable for disposal. The ''scrub alloy'' and the ''anode heel alloy'' are examples of materials generated at RFP which have been processed at SRP using the developed recovery flowsheets. Examples of process residues being generated at SRP for which flowsheets are under development include LECO crucibles and alpha-contaminated hydraulic oil.

  6. Quantifying logging residue - before the fact

    SciTech Connect

    Bones, J.T.

    1982-06-01

    Tree biomass estimation, which is being integrated into the U.S. Forest Service Renewable Resources Evaluation Program, will give foresters the ability to estimate the amount of logging residues they might expect from harvested treetops and branches and residual rough, rotten, and small trees before the actual harvest. With planning, and increased demand for such timber products as pulpwood and fuelwood, product recovery could be increased by up to 43 percent in softwood stands and 99% in hardwoods. Recovery levels affect gross product receipts and site preparation costs. An example of product recovery and residue generation is presented for three harvesting options in Pennsylvania hardwood stands. Under the whole-tree harvesting option, 46% more product was recovered than in single product harvesting, and logging residue levels were reduced by 58%.

  7. Ceramic colorant from untreated iron ore residue.

    PubMed

    Pereira, Oscar Costa; Bernardin, Adriano Michael

    2012-09-30

    This work deals with the development of a ceramic colorant for glazes from an untreated iron ore residue. 6 mass% of the residue was added in suspensions (1.80 g/cm(3) density and 30s viscosity) of white, transparent and matte glazes, which were applied as thin layers (0.5mm) on engobeb and not fired ceramic tiles. The tiles were fired in laboratory roller kiln in a cycle of 35 min and maximum temperatures between 1050 and 1180°C. The residue and glazes were characterized by chemical (XRF) and thermal (DTA and optical dilatometry) analyses, and the glazed tiles by colorimetric and XRD analyses. The results showed that the colorant embedded in the transparent glaze results in a reddish glaze (like pine nut) suitable for the ceramic roof tile industry. For the matte and white glazes, the residue has changed the color of the tiles with temperature. PMID:22795839

  8. SAR impulse response with residual chirps.

    SciTech Connect

    Doerry, Armin Walter

    2009-06-01

    A Linear Frequency-Modulated (LFM) chirp is a function with unit amplitude and quadratic phase characteristic. In a focused Synthetic Aperture Radar (SAR) image, a residual chirp is undesired for targets of interest, as it coarsens the manifested resolution. However, for undesired spurious signals, a residual chirp is often advantageous because it spreads the energy and thereby diminishes its peak value. In either case, a good understanding of the effects of a residual LFM chirp on a SAR Impulse Response (IPR) is required to facilitate system analysis and design. This report presents an analysis of the effects of a residual chirp on the IPR. As reference, there is a rich body of publications on various aspects of LFM chirps. A quick search reveals a plethora of articles, going back to the early 1950s. We mention here purely as trivia one of the earlier analysis papers on this waveform by Klauder, et al.

  9. Differential Spectroscopic Imaging of Particulate Explosives Residue

    SciTech Connect

    Bernacki, Bruce E.; Ho, Nicolas

    2008-04-01

    We present experimental results showing transmission and reflection imaging of approximately 100 microgram quantities of particulate explosives residue using a commercial uncooled microbolometer infrared camera and CO2 laser differential wavelength illumination.

  10. Detecting Residues On Grit-Blasted Surfaces

    NASA Technical Reports Server (NTRS)

    Novak, H. L.; Zook, L. M.

    1989-01-01

    Addition of fluorescent or iridescent material to plastic grit particles proposed for detection of grit residues after grit-blast cleaning. Residual films visible by observing grit-blasted surfaces under infrared or ultraviolet light. Plastic grit contains fluorescent or iridescent additive in core and coating. Wherever grit material becomes embedded, additive makes it visible under infrared or ultraviolet light. Applicable to other grit materials, for example fluorescent or iridescent materials added to particles of glass, silicon carbide, aluminum oxide, or zirconium silicate.

  11. Bayesian nonparametric regression with varying residual density.

    PubMed

    Pati, Debdeep; Dunson, David B

    2014-02-01

    We consider the problem of robust Bayesian inference on the mean regression function allowing the residual density to change flexibly with predictors. The proposed class of models is based on a Gaussian process prior for the mean regression function and mixtures of Gaussians for the collection of residual densities indexed by predictors. Initially considering the homoscedastic case, we propose priors for the residual density based on probit stick-breaking (PSB) scale mixtures and symmetrized PSB (sPSB) location-scale mixtures. Both priors restrict the residual density to be symmetric about zero, with the sPSB prior more flexible in allowing multimodal densities. We provide sufficient conditions to ensure strong posterior consistency in estimating the regression function under the sPSB prior, generalizing existing theory focused on parametric residual distributions. The PSB and sPSB priors are generalized to allow residual densities to change nonparametrically with predictors through incorporating Gaussian processes in the stick-breaking components. This leads to a robust Bayesian regression procedure that automatically down-weights outliers and influential observations in a locally-adaptive manner. Posterior computation relies on an efficient data augmentation exact block Gibbs sampler. The methods are illustrated using simulated and real data applications. PMID:24465053

  12. Fluorescence imaging to quantify crop residue cover

    NASA Technical Reports Server (NTRS)

    Daughtry, C. S. T.; Mcmurtrey, J. E., III; Chappelle, E. W.

    1994-01-01

    Crop residues, the portion of the crop left in the field after harvest, can be an important management factor in controlling soil erosion. Methods to quantify residue cover are needed that are rapid, accurate, and objective. Scenes with known amounts of crop residue were illuminated with long wave ultraviolet (UV) radiation and fluorescence images were recorded with an intensified video camera fitted with a 453 to 488 nm band pass filter. A light colored soil and a dark colored soil were used as background for the weathered soybean stems. Residue cover was determined by counting the proportion of the pixels in the image with fluorescence values greater than a threshold. Soil pixels had the lowest gray levels in the images. The values of the soybean residue pixels spanned nearly the full range of the 8-bit video data. Classification accuracies typically were within 3(absolute units) of measured cover values. Video imaging can provide an intuitive understanding of the fraction of the soil covered by residue.

  13. Resist residue removal using UV ozone treatment

    NASA Astrophysics Data System (ADS)

    Chen, Shu-Fang; Chang, Ching-Yu; Ku, Yao-Ching

    2010-04-01

    In a conventional lithography process, the resist pattern is removed by dry strip or wet chemical etch. The wet chemical etch includes sulfuric peroxide etch and solvent etch. The wet chemical etch process is always combined with the dry strip process to meet the residue process spec. However, in some applications, only the wet-etch process can be used to avoid substrate damage during the plasma step. However, organic residue can be found from particle surface scan and TGA/DSC after normal solvent strip. In this paper, we investigate polymer residue stripping using only solvent as well as solvent in combination with UV treatment. For solvents only, some solvents different from the conventional PGMEA/PGME mixture in polarity, also exhibited stripping ability but the efficiency is not as good as PGME/PGMEA mixture. When supplemented with UV treatment, the organic residue can be further decomposed and removed completely. The UV we used contains 185nm and 254nm wavelengths. Ozone is generated during UV exposure and acts as oxidant. The organic residue is thus decomposed and removed. It has been proven as an effective method to cleave the C-C bond without damaging the wafer substrate. The organic residue on the wafer surface can be easily stripped away under UV-ozone exposure. Its defect performance is also discussed in this paper.

  14. RESIDUAL ENERGY SPECTRUM OF SOLAR WIND TURBULENCE

    SciTech Connect

    Chen, C. H. K.; Bale, S. D.; Salem, C. S.; Maruca, B. A.

    2013-06-20

    It has long been known that the energy in velocity and magnetic field fluctuations in the solar wind is not in equipartition. In this paper, we present an analysis of 5 yr of Wind data at 1 AU to investigate the reason for this. The residual energy (difference between energy in velocity and magnetic field fluctuations) was calculated using both the standard magnetohydrodynamic (MHD) normalization for the magnetic field and a kinetic version, which includes temperature anisotropies and drifts between particle species. It was found that with the kinetic normalization, the fluctuations are closer to equipartition, with a mean normalized residual energy of {sigma}{sub r} = -0.19 and mean Alfven ratio of r{sub A} = 0.71. The spectrum of residual energy, in the kinetic normalization, was found to be steeper than both the velocity and magnetic field spectra, consistent with some recent MHD turbulence predictions and numerical simulations, having a spectral index close to -1.9. The local properties of residual energy and cross helicity were also investigated, showing that globally balanced intervals with small residual energy contain local patches of larger imbalance and larger residual energy at all scales, as expected for nonlinear turbulent interactions.

  15. Pyrethroid insecticide residues on vegetable crops.

    PubMed

    Ripley, B D; Ritcey, G M; Harris, C R; Denommé, M A; Brown, P D

    2001-08-01

    Pyrethroid insecticides were applied on various vegetable crops as foliar treatments to determine dissipation rates. On Chinese broccoli (Guy Lon), Chinese mustard (Pak Choi) and Chinese cabbage (Kasumi, napa), fenvalerate was persistent with residues of 0.10, 0.14 and 0.11 mg kg-1, respectively, by day 21. Cypermethrin residues on head lettuce were below 0.1 mg kg-1 by day 10 but on the leafier romaine and endive varieties it was more persistent and required 14-19 days to dissipate below this concentration. After three applications, residues of cypermethrin in harvested carrots and of permethrin in eggplant were not detected on the day of application. On asparagus, deltamethrin and cypermethrin residues declined to less than 0.1 mg kg-1 by days 1 and 2, respectively; permethrin was more persistent, requiring more than 2 days to decline to less than 0.1 mg kg-1. Deltamethrin on dry (cooking) and Spanish onions was not detected on the day of application. On tomatoes, the concentration of permethrin was 0.093 mg kg-1 on the day of application and declined to about 0.05 mg kg-1 after 2-4 days. In general, permethrin, cypermethrin and deltamethrin residues declined to acceptable concentrations within an acceptable pre-harvest interval. Fenvalerate may be too persistent on these speciality crops unless a maximum residue limit > 0.1 mg kg-1 is permitted. PMID:11517721

  16. Axial residual stresses in boron fibers

    NASA Technical Reports Server (NTRS)

    Behrendt, D. R.

    1978-01-01

    The axial residual stress distribution as a function of radius was determined from the fiber surface to the core including the average residual stress in the core. Such measurements on boron on tungsten (B/W) fibers show that the residual stresses for 102, 142, 203, and 366 micron diameter fibers were similar, being compressive at the surface and changing monotonically to a region of tensile within the boron. At approximately 25 percent of the original radius, the stress reaches a maximum tensile stress of about 860 mn/sq.m and then decreases to a compressive stress near the tungsten boride core. Data were presented for 203 micron diameter B/W fibers that show annealing above 900 C reduces the residual stresses. A comparison between 102 micron diameter B/W and boron on carbon (b/C) shows that the residual stresses were similar in the outer regions of the fibers, but that large differences near and in the core were observed. The effects of these residual stresses on the fracture of boron fibers were discussed.

  17. Method for residual household waste composition studies.

    PubMed

    Sahimaa, Olli; Hupponen, Mari; Horttanainen, Mika; Sorvari, Jaana

    2015-12-01

    The rising awareness of decreasing natural resources has brought forward the idea of a circular economy and resource efficiency in Europe. As a part of this movement, European countries have identified the need to monitor residual waste flows in order to make recycling more efficient. In Finland, studies on the composition of residual household waste have mostly been conducted using different methods, which makes the comparison of the results difficult. The aim of this study was to develop a reliable method for residual household waste composition studies. First, a literature review on European study methods was performed. Also, 19 Finnish waste composition studies were compared in order to identify the shortcomings of the current Finnish residual household waste composition data. Moreover, the information needs of different waste management authorities concerning residual household waste were studied through a survey and personal interviews. Stratification, sampling, the classification of fractions and statistical analysis were identified as the key factors in a residual household waste composition study. The area studied should be divided into non-overlapping strata in order to decrease the heterogeneity of waste and enable comparisons between different waste producers. A minimum of six subsamples, each 100 kg, from each stratum should be sorted. Confidence intervals for each waste category should be determined in order to evaluate the applicability of the results. A new three-level classification system was created based on Finnish stakeholders' information needs and compared to four other European waste composition study classifications. PMID:26337965

  18. 40 CFR 180.339 - MCPA; tolerances for residues.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ...; tolerances for residues. (a) General. (1) Tolerances are established for residues of the herbicide MCPA ((4... for residues of the herbicide MCPA ((4-chloro-2-methylphenoxy)acetic acid) resulting from the...

  19. 40 CFR 180.339 - MCPA; tolerances for residues.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ...; tolerances for residues. (a) General. (1) Tolerances are established for residues of the herbicide MCPA ((4... for residues of the herbicide MCPA ((4-chloro-2-methylphenoxy)acetic acid) resulting from the...

  20. 40 CFR 180.432 - Lactofen; tolerances for residues.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... Lactofen; tolerances for residues. (a) Tolerances are established for residues of the herbicide lactofen, 1... residues of the herbicide, lactofen, 1-(carboethoxy)ethyl 5- -2- nitrobenzoate, in or on the following...

  1. 40 CFR 180.339 - MCPA; tolerances for residues.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ...; tolerances for residues. (a) General. (1) Tolerances are established for residues of the herbicide MCPA ((4... for residues of the herbicide MCPA ((4-chloro-2-methylphenoxy)acetic acid) resulting from the...

  2. 40 CFR 180.339 - MCPA; tolerances for residues.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ...; tolerances for residues. (a) General. (1) Tolerances are established for residues of the herbicide MCPA ((4... for residues of the herbicide MCPA ((4-chloro-2-methylphenoxy)acetic acid) resulting from the...

  3. 40 CFR 180.339 - MCPA; tolerances for residues.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ...; tolerances for residues. (a) General. (1) Tolerances are established for residues of the herbicide MCPA ((4... for residues of the herbicide MCPA ((4-chloro-2-methylphenoxy)acetic acid) resulting from the...

  4. 40 CFR 180.659 - Pyroxasulfone; tolerances for residues.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... residues of the herbicide pyroxasulfone, including its metabolites and degradates, in or on the commodities....015 (2) Tolerances are established for residues of the herbicide pyroxasulfone, including...

  5. 40 CFR 180.600 - Propoxycarbazone; tolerances for residues

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... combined residues of the herbicide propoxycarbazone methyl 2- amino]sulfonyl]benzoate and its metabolite....05 (2) Tolerances are established for residues of the herbicide propoxycarbazone methyl 2-...

  6. 40 CFR 180.600 - Propoxycarbazone; tolerances for residues.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... combined residues of the herbicide propoxycarbazone methyl 2- amino]sulfonyl]benzoate and its metabolite....05 (2) Tolerances are established for residues of the herbicide propoxycarbazone methyl 2-...

  7. 40 CFR 180.600 - Propoxycarbazone; tolerances for residues

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... combined residues of the herbicide propoxycarbazone methyl 2- amino]sulfonyl]benzoate and its metabolite....05 (2) Tolerances are established for residues of the herbicide propoxycarbazone methyl 2-...

  8. 40 CFR 180.600 - Propoxycarbazone; tolerances for residues

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... combined residues of the herbicide propoxycarbazone methyl 2- amino]sulfonyl]benzoate and its metabolite....05 (2) Tolerances are established for residues of the herbicide propoxycarbazone methyl 2-...

  9. 40 CFR 180.600 - Propoxycarbazone; tolerances for residues.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... combined residues of the herbicide propoxycarbazone methyl 2- amino]sulfonyl]benzoate and its metabolite....05 (2) Tolerances are established for residues of the herbicide propoxycarbazone methyl 2-...

  10. A survey of residual analysis and a new test of residual trend.

    PubMed

    McDowell, J J; Calvin, Olivia L; Klapes, Bryan

    2016-05-01

    A survey of residual analysis in behavior-analytic research reveals that existing methods are problematic in one way or another. A new test for residual trends is proposed that avoids the problematic features of the existing methods. It entails fitting cubic polynomials to sets of residuals and comparing their effect sizes to those that would be expected if the sets of residuals were random. To this end, sampling distributions of effect sizes for fits of a cubic polynomial to random data were obtained by generating sets of random standardized residuals of various sizes, n. A cubic polynomial was then fitted to each set of residuals and its effect size was calculated. This yielded a sampling distribution of effect sizes for each n. To test for a residual trend in experimental data, the median effect size of cubic-polynomial fits to sets of experimental residuals can be compared to the median of the corresponding sampling distribution of effect sizes for random residuals using a sign test. An example from the literature, which entailed comparing mathematical and computational models of continuous choice, is used to illustrate the utility of the test. PMID:27193244

  11. Sustainable System for Residual Hazards Management

    SciTech Connect

    Kevin M. Kostelnik; James H. Clarke; Jerry L. Harbour

    2004-06-01

    Hazardous, radioactive and other toxic substances have routinely been generated and subsequently disposed of in the shallow subsurface throughout the world. Many of today’s waste management techniques do not eliminate the problem, but rather only concentrate or contain the hazardous contaminants. Residual hazards result from the presence of hazardous and/or contaminated material that remains on-site following active operations or the completion of remedial actions. Residual hazards pose continued risk to humans and the environment and represent a significant and chronic problem that require continuous longterm management (i.e. >1000 years). To protect human health and safeguard the natural environment, a sustainable system is required for the proper management of residual hazards. A sustainable system for the management of residual hazards will require the integration of engineered, institutional and land-use controls to isolate residual contaminants and thus minimize the associated hazards. Engineered controls are physical modifications to the natural setting and ecosystem, including the site, facility, and/or the residual materials themselves, in order to reduce or eliminate the potential for exposure to contaminants of concern (COCs). Institutional controls are processes, instruments, and mechanisms designed to influence human behavior and activity. System failure can involve hazardous material escaping from the confinement because of system degradation (i.e., chronic or acute degradation) or by externalintrusion of the biosphere into the contaminated material because of the loss of institutional control. An ongoing analysis of contemporary and historic sites suggests that the significance of the loss of institutional controls is a critical pathway because decisions made during the operations/remedial action phase, as well as decisions made throughout the residual hazards management period, are key to the longterm success of the prescribed system. In fact

  12. Crop Residue Coverage Estimation Using ASTER Imagery

    NASA Astrophysics Data System (ADS)

    Lewis, D.; Yao, H.; Kincaid, R.

    2006-12-01

    Soil erosion and its related runoff is a serious problem in U.S. agriculture. USDA has classified 33 percent of U.S. agricultural land as being highly erodible. It is well recognized that residue coverage on the soil surface can reduce soil erosion. The National Food Security Act of 1985 requires that agricultural producers protect all highly erodible cropland from excessive erosion. The 2002 Farm Bill gave U.S. Department of Agriculture's (USDA) Natural Resource Conservation Service (NRCS) the authority to make a determination of compliance. NRCS is currently running several programs to implement conservation practices and to monitor compliance. To be in compliance, growers must keep crop residue cover more than 30 percent of the field. This requires field-level assessment. The NRCS does not have the resources to regularly survey every field. One potential approach for compliance decision making is using data from the Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER) sensor onboard NASA's Terra satellite. ASTER data provides 15 bands of 15 meter visible/NIR (VNIR) and 30 meter SWIR resolution data. Both the spatial resolution and spectral wavelength range and resolution are suitable for field level residue cover estimation. The objective of this study was to explore the potential of using ASTER data for crop residue cover estimation. The results indicate that ASTER imagery has good capability to identify residue within the corn fields and moderate capability in soybean residue estimation. SWIR bands have the most promise in separating crop residue when compared to the VNIR bands. Satellite based remote sensing imagery could be a potential rapid decision making tool for NRCS's compliance programs.

  13. Treatment of vacuum residues in hydroconversion conditions

    NASA Astrophysics Data System (ADS)

    León, A. Y.; Mendoza, D. L.; Espinosa, J. O.; Laverde, D.

    2016-02-01

    In this paper the use of a liquid homogeneous catalyst has been studied in reactivity vacuum residues by hydroconversion under different conditions. To cover a wide range of compositions, six (6) vacuum residues were selected from crude mixtures. Hydroconversion test were performed in batch reactor with hydrogen atmosphere at about 2000psi in a temperature range between 430 and 480°C. The results allowed to establish that the reactivity hydroconversion conditions about coke formation is higher in vacuum residues with higher content of resins and asphaltenes. The reaction conditions promote distillate formation, however, with increasing stringency conditions, the distillate yield decreases due to distillate transformation into temperature range 430 and 460°C compared to the tests performed without catalyst demonstrating that the use of homogeneous catalyst is an alternative to treating vacuum residues and results are satisfactory in the conversion processes. Finally, predictive expressions have been developed in the formation of products depending on the conditions of temperature and physicochemical properties of processed vacuum residue.

  14. [Migrants from disposable gloves and residual acrylonitrile].

    PubMed

    Wakui, C; Kawamura, Y; Maitani, T

    2001-10-01

    Disposable gloves made from polyvinyl chloride with and without di(2-ethylhexyl) phthalate (PVC-DEHP, PVC-NP), polyethylene (PE), natural rubber (NR) and nitrile-butadiene rubber (NBR) were investigated with respect to evaporation residue, migrated metals, migrants and residual acrylonitrile. The evaporation residue found in n-heptane was 870-1,300 ppm from PVC-DEHP and PVC-NP, which was due to the plasticizers. Most of the PE gloves had low evaporation residue levels and migrants, except for the glove designated as antibacterial, which released copper and zinc into 4% acetic acid. For the NR and NBR gloves, the evaporation residue found in 4% acetic acid was 29-180 ppm. They also released over 10 ppm of calcium and 6 ppm of zinc into 4% acetic acid, and 1.68-8.37 ppm of zinc di-ethyldithiocarbamate and zinc di-n-butyldithiocarbamate used as vulcanization accelerators into n-heptane. The acrylonitrile content was 0.40-0.94 ppm in NBR gloves. PMID:11775358

  15. Analytical electron microscopy of LDEF impactor residues

    NASA Technical Reports Server (NTRS)

    Bernhard, Ronald P.; Barrett, Ruth A.; Zolensky, Michael E.

    1995-01-01

    The LDEF contained 57 individual experiment trays or tray portions specifically designed to characterize critical aspects of meteoroid and debris environment in low-Earth orbit (LEO). However, it was realized from the beginning that the most efficient use of the satellite would be to characterize impact features from the entire surface of the LDEF. With this in mind particular interest has focused on common materials facing in all 26 LDEF facing directions; among the most important of these materials has been the tray clamps. Therefore, in an effort to better understand the nature and flux of particulates in LEO, and their effects on spacecraft hardware, we are analyzing residues found in impact features on LDEF tray clamp surfaces. This paper summarizes all data from 79 clamps located on Bay A & B of the LDEF. We also describe current efforts to characterize impactor residues recovered from the impact craters, and we have found that a low, but significant, fraction of these residues have survived in a largely unmelted state. These residues can be characterized sufficiently to permit resolution of the impactor origin. We have concentrated on the residue from chondritic interplanetary dust particles (micrometeoroids), as these represent the harshest test of our analytical capabilities.

  16. Disposal of Rocky Flats residues as waste

    SciTech Connect

    Dustin, D.F.; Sendelweck, V.S.; Rivera, M.A.

    1993-03-01

    Work is underway at the Rocky Flats Plant to evaluate alternatives for the removal of a large inventory of plutonium-contaminated residues from the plant. One alternative under consideration is to package the residues as transuranic wastes for ultimate shipment to the Waste Isolation Pilot Plant. Current waste acceptance criteria and transportation regulations require that approximately 1000 cubic yards of residues be repackaged to produce over 20,000 cubic yards of WIPP certified waste. The major regulatory drivers leading to this increase in waste volume are the fissile gram equivalent, surface radiation dose rate, and thermal power limits. In the interest of waste minimization, analyses have been conducted to determine, for each residue type, the controlling criterion leading to the volume increase, the impact of relaxing that criterion on subsequent waste volume, and the means by which rules changes may be implemented. The results of this study have identified the most appropriate changes to be proposed in regulatory requirements in order to minimize the costs of disposing of Rocky Flats residues as transuranic wastes.

  17. Disposal of Rocky Flats residues as waste

    SciTech Connect

    Dustin, D.F.; Sendelweck, V.S. . Rocky Flats Plant); Rivera, M.A. )

    1993-01-01

    Work is underway at the Rocky Flats Plant to evaluate alternatives for the removal of a large inventory of plutonium-contaminated residues from the plant. One alternative under consideration is to package the residues as transuranic wastes for ultimate shipment to the Waste Isolation Pilot Plant. Current waste acceptance criteria and transportation regulations require that approximately 1000 cubic yards of residues be repackaged to produce over 20,000 cubic yards of WIPP certified waste. The major regulatory drivers leading to this increase in waste volume are the fissile gram equivalent, surface radiation dose rate, and thermal power limits. In the interest of waste minimization, analyses have been conducted to determine, for each residue type, the controlling criterion leading to the volume increase, the impact of relaxing that criterion on subsequent waste volume, and the means by which rules changes may be implemented. The results of this study have identified the most appropriate changes to be proposed in regulatory requirements in order to minimize the costs of disposing of Rocky Flats residues as transuranic wastes.

  18. Mobility of organic carbon from incineration residues

    SciTech Connect

    Ecke, Holger Svensson, Malin

    2008-07-01

    Dissolved organic carbon (DOC) may affect the transport of pollutants from incineration residues when landfilled or used in geotechnical construction. The leaching of dissolved organic carbon (DOC) from municipal solid waste incineration (MSWI) bottom ash and air pollution control residue (APC) from the incineration of waste wood was investigated. Factors affecting the mobility of DOC were studied in a reduced 2{sup 6-1} experimental design. Controlled factors were treatment with ultrasonic radiation, full carbonation (addition of CO{sub 2} until the pH was stable for 2.5 h), liquid-to-solid (L/S) ratio, pH, leaching temperature and time. Full carbonation, pH and the L/S ratio were the main factors controlling the mobility of DOC in the bottom ash. Approximately 60 weight-% of the total organic carbon (TOC) in the bottom ash was available for leaching in aqueous solutions. The L/S ratio and pH mainly controlled the mobilization of DOC from the APC residue. About 93 weight-% of TOC in the APC residue was, however, not mobilized at all, which might be due to a high content of elemental carbon. Using the European standard EN 13 137 for determination of total organic carbon (TOC) in MSWI residues is inappropriate. The results might be biased due to elemental carbon. It is recommended to develop a TOC method distinguishing between organic and elemental carbon.

  19. Quantifying Significance of MHC II Residues.

    PubMed

    Fan, Ying; Lu, Ruoshui; Wang, Lusheng; Andreatta, Massimo; Li, Shuai Cheng

    2014-01-01

    The major histocompatibility complex (MHC), a cell-surface protein mediating immune recognition, plays important roles in the immune response system of all higher vertebrates. MHC molecules are highly polymorphic and they are grouped into serotypes according to the specificity of the response. It is a common belief that a protein sequence determines its three dimensional structure and function. Hence, the protein sequence determines the serotype. Residues play different levels of importance. In this paper, we quantify the residue significance with the available serotype information. Knowing the significance of the residues will deepen our understanding of the MHC molecules and yield us a concise representation of the molecules. In this paper we propose a linear programming-based approach to find significant residue positions as well as quantifying their significance in MHC II DR molecules. Among all the residues in MHC II DR molecules, 18 positions are of particular significance, which is consistent with the literature on MHC binding sites, and succinct pseudo-sequences appear to be adequate to capture the whole sequence features. When the result is used for classification of MHC molecules with serotype assigned by WHO, a 98.4 percent prediction performance is achieved. The methods have been implemented in java (http://code.google.com/p/quassi/). PMID:26355503

  20. Modeling residual hydrologic errors with Bayesian inference

    NASA Astrophysics Data System (ADS)

    Smith, Tyler; Marshall, Lucy; Sharma, Ashish

    2015-09-01

    Hydrologic modelers are confronted with the challenge of producing estimates of the uncertainty associated with model predictions across an array of catchments and hydrologic flow regimes. Formal Bayesian approaches are commonly employed for parameter calibration and uncertainty analysis, but are often criticized for making strong assumptions about the nature of model residuals via the likelihood function that may not be well satisfied (or even checked). This technical note outlines a residual error model (likelihood function) specification framework that aims to provide guidance for the application of more appropriate residual error models through a nested approach that is both flexible and extendible. The framework synthesizes many previously employed residual error models and has been applied to four synthetic datasets (of differing error structure) and a real dataset from the Black River catchment in Queensland, Australia. Each residual error model was investigated and assessed under a top-down approach focused on its ability to properly characterize the errors. The results of these test applications indicate that a multifaceted assessment strategy is necessary to determine the adequacy of an individual likelihood function.

  1. 77 FR 24671 - Compliance Guide for Residue Prevention and Agency Testing Policy for Residues

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-04-25

    ... increased testing animals from producers who are under an injunction obtained by the Food and Drug... addition, FSIS intends to increase its testing for residues in animals from producers who are under an... Food Safety and Inspection Service Compliance Guide for Residue Prevention and Agency Testing...

  2. Distribution of Penicillin G Residues in Culled Dairy Cow Muscles: Implications for Residue Monitoring

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The U.S. Food and Drug Administration sets tolerances for veterinary drug residues in muscle, but does not specify which type of muscle should be analyzed. In order to determine if antibiotic residue levels are dependent on muscle type, 7 culled dairy cows were dosed with Penicillin G (Pen G) from ...

  3. Crop residue and residue management effects on Armadillidium vulgare (Isopoda: Armadillidiidae) populations and soybean stand densities.

    PubMed

    Johnson, W A; Alfaress, S; Whitworth, R J; McCornack, B P

    2012-10-01

    In general, Armadillidium vulgare (Latreille) are considered nonpests of soybean [Glycine max (L.) Merrill], but changes in soil conservation practices have shifted the pest status of this organism from an opportunistic to a perennial, early-season pest in parts of central Kansas. As a result, soybean producers that rotate with corn (Zea mays L.) under conservation tillage practices have resorted to removing excess corn residue by using controlled burns. In a 2-yr field study (2009-2010), we demonstrated that residue removal in burned compared with unburned plots (measured as previous crop residue weights) had minimal impact on numbers of live and dead A. vulgare, soybean seedling emergence, and isopod feeding damage over time. Specifically, removal of residue by burning did not result in higher emergence rates for soybean stands or less feeding damage by A. vulgare. In a separate study, we found that number of live A. vulgare and residue weights had no consistent relationship with seedling emergence or feeding damage. Furthermore, seedling emergence was not impacted by higher numbers ofA. vulgare in unburned plots, indicating that emergence in this study may have been influenced by factors other than A. vulgare densities. These studies demonstrate that removing residue through controlled burning did not impact seedling emergence in presence of A. vulgare and that residue and feeding damage to seedlings did not consistently relate to A. vulgare densities. Other factors that may have influenced a relationship between residue and live isopod numbers, such as variable moisture levels, are discussed. PMID:23156159

  4. 40 CFR 721.4500 - Isopropylamine distillation residues and ethylamine distillation residues.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 30 2010-07-01 2010-07-01 false Isopropylamine distillation residues and ethylamine distillation residues. 721.4500 Section 721.4500 Protection of Environment... SUBSTANCES Significant New Uses for Specific Chemical Substances § 721.4500 Isopropylamine...

  5. 40 CFR 721.4500 - Isopropylamine distillation residues and ethylamine distillation residues.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 40 Protection of Environment 31 2011-07-01 2011-07-01 false Isopropylamine distillation residues and ethylamine distillation residues. 721.4500 Section 721.4500 Protection of Environment... SUBSTANCES Significant New Uses for Specific Chemical Substances § 721.4500 Isopropylamine...

  6. 40 CFR 721.4500 - Isopropylamine distillation residues and ethylamine distillation residues.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 32 2013-07-01 2013-07-01 false Isopropylamine distillation residues and ethylamine distillation residues. 721.4500 Section 721.4500 Protection of Environment... SUBSTANCES Significant New Uses for Specific Chemical Substances § 721.4500 Isopropylamine...

  7. 40 CFR 721.4500 - Isopropylamine distillation residues and ethylamine distillation residues.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 40 Protection of Environment 32 2012-07-01 2012-07-01 false Isopropylamine distillation residues and ethylamine distillation residues. 721.4500 Section 721.4500 Protection of Environment... SUBSTANCES Significant New Uses for Specific Chemical Substances § 721.4500 Isopropylamine...

  8. 40 CFR 721.4500 - Isopropylamine distillation residues and ethylamine distillation residues.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 31 2014-07-01 2014-07-01 false Isopropylamine distillation residues and ethylamine distillation residues. 721.4500 Section 721.4500 Protection of Environment... SUBSTANCES Significant New Uses for Specific Chemical Substances § 721.4500 Isopropylamine...

  9. Predicted residue-residue contacts can help the scoring of 3D models.

    PubMed

    Tress, Michael L; Valencia, Alfonso

    2010-06-01

    During the 7th Critical Assessment of Protein Structure Prediction (CASP7) experiment, it was suggested that the real value of predicted residue-residue contacts might lie in the scoring of 3D model structures. Here, we have carried out a detailed reassessment of the contact predictions made during the recent CASP8 experiment to determine whether predicted contacts might aid in the selection of close-to-native structures or be a useful tool for scoring 3D structural models. We used the contacts predicted by the CASP8 residue-residue contact prediction groups to select models for each target domain submitted to the experiment. We found that the information contained in the predicted residue-residue contacts would probably have helped in the selection of 3D models in the free modeling regime and over the harder comparative modeling targets. Indeed, in many cases, the models selected using just the predicted contacts had better GDT-TS scores than all but the best 3D prediction groups. Despite the well-known low accuracy of residue-residue contact predictions, it is clear that the predictive power of contacts can be useful in 3D model prediction strategies. PMID:20408174

  10. Use of imiquimod for residual acral melanoma.

    PubMed

    Sue, Gloria R; Hanlon, Allison; Lazova, Rossitza; Narayan, Deepak

    2014-01-01

    Recent reports suggest that topical imiquimod cream is an effective treatment option for certain types of melanomas. No reports exist on the efficacy of using imiquimod cream to treat melanoma located on the plantar surface of the foot. We present two patients with a melanoma of the foot who had residual melanoma following surgical excision with acceptable margins. The patients were then treated with topical imiquimod for 8 weeks after which a repeat biopsy of the affected region showed no evidence of residual melanoma in situ. The use of topical imiquimod cream should be considered in the management of residual melanoma in situ of the plantar surface of the foot. PMID:25188932

  11. Residual Stress Analysis in Thick Uranium Films

    SciTech Connect

    Hodge, A M; Foreman, R J; Gallegos, G F

    2004-12-06

    Residual stress analysis was performed on thick, 1.0 to 25 {micro}m, depleted Uranium (DU) films deposited on an Al substrate by magnetron sputtering. Two distinct characterization techniques were used to measure substrate curvature before and after deposition. Stress evaluation was performed using the Benabdi/Roche equation, which is based on beam theory of a bi-layer material. The residual stress evolution was studied as a function of coating thickness and applied negative bias voltage (0-300V). The stresses developed were always compressive; however, increasing the coating thickness and applying a bias voltage presented a trend towards more tensile stresses and thus an overall reduction of residual stresses.

  12. Field Test Kit for Gun Residue Detection

    SciTech Connect

    WALKER, PAMELA K.; RODACY, PHILIP J.

    2002-01-01

    One of the major needs of the law enforcement field is a product that quickly, accurately, and inexpensively identifies whether a person has recently fired a gun--even if the suspect has attempted to wash the traces of gunpowder off. The Field Test Kit for Gunshot Residue Identification based on Sandia National Laboratories technology works with a wide variety of handguns and other weaponry using gunpowder. There are several organic chemicals in small arms propellants such as nitrocellulose, nitroglycerine, dinitrotoluene, and nitrites left behind after the firing of a gun that result from the incomplete combustion of the gunpowder. Sandia has developed a colorimetric shooter identification kit for in situ detection of gunshot residue (GSR) from a suspect. The test kit is the first of its kind and is small, inexpensive, and easily transported by individual law enforcement personnel requiring minimal training for effective use. It will provide immediate information identifying gunshot residue.

  13. Residual Stress Predictions in Polycrystalline Alumina

    SciTech Connect

    VEDULA,VENKATA R.; GLASS,S. JILL; SAYLOR,DAVID M.; ROHRER,GREGORY S.; CARTER,W. CRAIG; LANGER,STEPHEN A.

    1999-12-13

    Microstructure-level residual stresses arise in polycrystalline ceramics during processing as a result of thermal expansion anisotropy and crystallographic disorientation across the grain boundaries. Depending upon the grain size, the magnitude of these stresses can be sufficiently high to cause spontaneous microcracking during the processing of these materials. They are also likely to affect where cracks initiate and propagate under macroscopic loading. The magnitudes of residual stresses in untextured and textured alumina samples were predicted using object oriented finite (OOF) element analysis and experimentally determined grain orientations. The crystallographic orientations were obtained by electron-backscattered diffraction (EBSD). The residual stresses were lower and the stress distributions were narrower in the textured samples compared to those in the untextured samples. Crack initiation and propagation were also simulated using the Griffith fracture criterion. The grain boundary to surface energy ratios required for computations were estimated using AFM groove measurements.

  14. Initial deactivation of residue hydrometallation catalysts

    SciTech Connect

    Gualda, G.; Kasztelan, S.

    1995-12-31

    A strong deactivation of residue hydrodemetallization catalysts is usually observed in the first days of a run. We report in this work a comparative study of the deactivation of a NiMo/alumina catalyst with a special pore structure so-called {open_quotes}chestnut burr{close_quotes} by coke and metal+coke deposits. The former set of samples were prepared in batch reactor by varying operating conditions and the latter set of samples were prepared in continuous flow reactor in both cases using a Safaniya atmospheric residue. Various methods were employed to characterize the deposits (TEM, XPS, EPMA, Surface area measurements, porosimetry, etc...) including catalytic tests of the used catalyst with various model reactants, it has been found that metal deposits are responsible for the initial deactivation of the residue hydrodametallation catalyst used in this work.

  15. Longitudinal residual stresses in boron fibers

    NASA Technical Reports Server (NTRS)

    Behrendt, D. R.

    1976-01-01

    A method of measuring the longitudinal residual stress distribution in boron fibers is presented. The residual stresses in commercial CVD boron on tungsten fibers of 102, 142, and 203 microns (4, 5.6, and 8 mil) diameters were determined. Results for the three sizes show a compressive stress at the surface 800 to -1400 MN/sq m 120 to -200 ksi), changing monotonically to a region of tensile stress within the boron. At approximately 25 percent of the original radius, the stress reaches a maximum tensile 600 to 1000 MN/sq m(90 to 150 ksi) and then decreases to compressive near the tungsten boride core. The core itself is under a compressive stress of approximately -1300 MN/sq m (-190 ksi). The effects of surface removal on core residual stress and core-initiated fracture are discussed.

  16. System and method for measuring residual stress

    DOEpatents

    Prime, Michael B.

    2002-01-01

    The present invention is a method and system for determining the residual stress within an elastic object. In the method, an elastic object is cut along a path having a known configuration. The cut creates a portion of the object having a new free surface. The free surface then deforms to a contour which is different from the path. Next, the contour is measured to determine how much deformation has occurred across the new free surface. Points defining the contour are collected in an empirical data set. The portion of the object is then modeled in a computer simulator. The points in the empirical data set are entered into the computer simulator. The computer simulator then calculates the residual stress along the path which caused the points within the object to move to the positions measured in the empirical data set. The calculated residual stress is then presented in a useful format to an analyst.

  17. Firearms discharge residue sample collection techniques.

    PubMed

    Goleb, J A; Midkiff, C R

    1975-10-01

    Critical comparisons of Ba and Sb in firearms discharge residue were made on samples collected by three independent collection technqiues. Collection materials studied were transparent adhesive tape, (Scotch Brand), a solution of cellulose acetate in acetone ("Film Lift"), and plastic-shafted cotton swabs wetted with dilute nitric acid. Flameless atomic absorption analyses were performed with a Jarrell-Ash Model 810 instrument equipped with a tantalum strip atomizer. Tape and cotton swabs gave comparable positive indications of residue, with frequencies of 90 and 80%, respectively. The plastic Film Lift gave fewer positives, with a frequency of 50%. With the transparent tape lift, gunshot residue particles are discernible, making nondestructive microscopic identification possible prior to destructive elemental analysis. PMID:1176924

  18. Determination of pesticide residues in cannabis smoke.

    PubMed

    Sullivan, Nicholas; Elzinga, Sytze; Raber, Jeffrey C

    2013-01-01

    The present study was conducted in order to quantify to what extent cannabis consumers may be exposed to pesticide and other chemical residues through inhaled mainstream cannabis smoke. Three different smoking devices were evaluated in order to provide a generalized data set representative of pesticide exposures possible for medical cannabis users. Three different pesticides, bifenthrin, diazinon, and permethrin, along with the plant growth regulator paclobutrazol, which are readily available to cultivators in commercial products, were investigated in the experiment. Smoke generated from the smoking devices was condensed in tandem chilled gas traps and analyzed with gas chromatography-mass spectrometry (GC-MS). Recoveries of residues were as high as 69.5% depending on the device used and the component investigated, suggesting that the potential of pesticide and chemical residue exposures to cannabis users is substantial and may pose a significant toxicological threat in the absence of adequate regulatory frameworks. PMID:23737769

  19. Residual Defect Density in Random Disks Deposits

    PubMed Central

    Topic, Nikola; Pöschel, Thorsten; Gallas, Jason A. C.

    2015-01-01

    We investigate the residual distribution of structural defects in very tall packings of disks deposited randomly in large channels. By performing simulations involving the sedimentation of up to 50 × 109 particles we find all deposits to consistently show a non-zero residual density of defects obeying a characteristic power-law as a function of the channel width. This remarkable finding corrects the widespread belief that the density of defects should vanish algebraically with growing height. A non-zero residual density of defects implies a type of long-range spatial order in the packing, as opposed to only local ordering. In addition, we find deposits of particles to involve considerably less randomness than generally presumed. PMID:26235809

  20. [Determination of residual organic solvents and macroporous resin residues in Akebia saponin D].

    PubMed

    Wang, Qiao-han; Yang, Xiao-lin; Xiao, Wei; Wang, Zhen-zhong; Ding, Gang; Huang, Wen-zhe; Yang, Zhong-lin

    2015-05-01

    According to ICH, Chinese Pharmacopoeia and supplementary requirements on the separation and purification of herbal extract with macroporous adsorption resin by SFDA, hexane, acetidine, ethanol, benzene, methyl-benzene, o-xylene, m-xylene, p-xylene, styrene, diethyl-benzene and divinyl-benzene of residual organic solvents and macroporous resin residues in Akebia saponin D were determined by headspace capillary GC. Eleven residues in Akebia saponin D were completely separated on DB-wax column, with FID detector, high purity nitrogen as the carry gases. The calibration curves were in good linearity (0.999 2-0.999 7). The reproducibility was good (RSD < 10%). The average recoveries were 80.0% -110%. The detection limit of each component was far lower than the limit concentration. The method is simple, reproducible, and can be used to determine the residual organic solvents and macroporous resin residues in Akebia saponin D. PMID:26390656

  1. Residue variability and sampling--practical problems and consequences for residues monitoring.

    PubMed

    Hill, A R

    2000-07-01

    Data generated in the UK have indicated that pesticide residue levels can be highly variable between the individual fruit or vegetables from the same crop or lot in trade. Statistical experiments with these data showed that residues in composite samples, taken according to Codex recommendations, are unlikely to differ by more than a factor of 3-4 from the mean level in the lot. This was corroborated by results obtained from real composite samples. Many fruit or vegetables in trade are mixed after harvest to form combined lots. Analysis of composite samples provides a good indication of average residues but, where the lot has been mixed, such average values are potentially misleading. Residues monitoring is the best means available for general control of pesticide use and consumer exposure, but new strategies for sampling and analysis are required to address the combined effects of residues variability and mixing of lots. PMID:10983575

  2. Genomic Prediction Accounting for Residual Heteroskedasticity

    PubMed Central

    Ou, Zhining; Tempelman, Robert J.; Steibel, Juan P.; Ernst, Catherine W.; Bates, Ronald O.; Bello, Nora M.

    2015-01-01

    Whole-genome prediction (WGP) models that use single-nucleotide polymorphism marker information to predict genetic merit of animals and plants typically assume homogeneous residual variance. However, variability is often heterogeneous across agricultural production systems and may subsequently bias WGP-based inferences. This study extends classical WGP models based on normality, heavy-tailed specifications and variable selection to explicitly account for environmentally-driven residual heteroskedasticity under a hierarchical Bayesian mixed-models framework. WGP models assuming homogeneous or heterogeneous residual variances were fitted to training data generated under simulation scenarios reflecting a gradient of increasing heteroskedasticity. Model fit was based on pseudo-Bayes factors and also on prediction accuracy of genomic breeding values computed on a validation data subset one generation removed from the simulated training dataset. Homogeneous vs. heterogeneous residual variance WGP models were also fitted to two quantitative traits, namely 45-min postmortem carcass temperature and loin muscle pH, recorded in a swine resource population dataset prescreened for high and mild residual heteroskedasticity, respectively. Fit of competing WGP models was compared using pseudo-Bayes factors. Predictive ability, defined as the correlation between predicted and observed phenotypes in validation sets of a five-fold cross-validation was also computed. Heteroskedastic error WGP models showed improved model fit and enhanced prediction accuracy compared to homoskedastic error WGP models although the magnitude of the improvement was small (less than two percentage points net gain in prediction accuracy). Nevertheless, accounting for residual heteroskedasticity did improve accuracy of selection, especially on individuals of extreme genetic merit. PMID:26564950

  3. Persistent organochlorine pesticide residues in animal feed.

    PubMed

    Nag, Subir Kumar; Raikwar, Mukesh K

    2011-03-01

    Animal products like milk and meat are often found to be contaminated with residues of persistent pesticides and other toxic substances. The major source of entry of these compounds to animal body is the contaminated feed and fodder. So, unless the residues are managed at this stage, it is very difficult to prevent contamination in milk and meat. Therefore, the status of residue level of most persistent organochlorinated pesticides (OCP) in feed and fodder should be monitored regularly. The frequency of occurrence and contamination levels of OCP residues in different kinds of animal concentrate feed and straw samples collected from Bundelkhand region of India were determined. Out of 533 total samples, 301 i.e. 56.47% samples were positive containing residues of different OCPs like hexachlorocyclohexane (HCH) isomers, dichlorodiphenyltrichloroethane (DDT) complex, endosulfan and dicofol. Among different HCH isomers, the mean concentration of β-HCH was highest, and total HCH varied from 0.01 to 0.306 mg kg(-1). In case of DDT complex, i.e. DDD, DDE and DDT, the concentration ranged between 0.016 and 0.118 mg kg(-1) and the pp(|) isomers were more frequently encountered than their op(|) counterparts. Endosulfan was also found in some samples in concentration ranging from 0.009 to 0.237 mg/kg, but dicofol could be recorded in very few samples. Although feed samples were found to contain OC residues, after comparing their levels in positive samples with the limiting values of respective pesticides, only very few were found to exceed the threshold level. Otherwise, they were mostly within safe limits. PMID:20443138

  4. Rigid Residue Scan Simulations Systematically Reveal Residue Entropic Roles in Protein Allostery.

    PubMed

    Kalescky, Robert; Zhou, Hongyu; Liu, Jin; Tao, Peng

    2016-04-01

    Intra-protein information is transmitted over distances via allosteric processes. This ubiquitous protein process allows for protein function changes due to ligand binding events. Understanding protein allostery is essential to understanding protein functions. In this study, allostery in the second PDZ domain (PDZ2) in the human PTP1E protein is examined as model system to advance a recently developed rigid residue scan method combining with configurational entropy calculation and principal component analysis. The contributions from individual residues to whole-protein dynamics and allostery were systematically assessed via rigid body simulations of both unbound and ligand-bound states of the protein. The entropic contributions of individual residues to whole-protein dynamics were evaluated based on covariance-based correlation analysis of all simulations. The changes of overall protein entropy when individual residues being held rigid support that the rigidity/flexibility equilibrium in protein structure is governed by the La Châtelier's principle of chemical equilibrium. Key residues of PDZ2 allostery were identified with good agreement with NMR studies of the same protein bound to the same peptide. On the other hand, the change of entropic contribution from each residue upon perturbation revealed intrinsic differences among all the residues. The quasi-harmonic and principal component analyses of simulations without rigid residue perturbation showed a coherent allosteric mode from unbound and bound states, respectively. The projection of simulations with rigid residue perturbation onto coherent allosteric modes demonstrated the intrinsic shifting of ensemble distributions supporting the population-shift theory of protein allostery. Overall, the study presented here provides a robust and systematic approach to estimate the contribution of individual residue internal motion to overall protein dynamics and allostery. PMID:27115535

  5. Rigid Residue Scan Simulations Systematically Reveal Residue Entropic Roles in Protein Allostery

    PubMed Central

    Liu, Jin

    2016-01-01

    Intra-protein information is transmitted over distances via allosteric processes. This ubiquitous protein process allows for protein function changes due to ligand binding events. Understanding protein allostery is essential to understanding protein functions. In this study, allostery in the second PDZ domain (PDZ2) in the human PTP1E protein is examined as model system to advance a recently developed rigid residue scan method combining with configurational entropy calculation and principal component analysis. The contributions from individual residues to whole-protein dynamics and allostery were systematically assessed via rigid body simulations of both unbound and ligand-bound states of the protein. The entropic contributions of individual residues to whole-protein dynamics were evaluated based on covariance-based correlation analysis of all simulations. The changes of overall protein entropy when individual residues being held rigid support that the rigidity/flexibility equilibrium in protein structure is governed by the La Châtelier’s principle of chemical equilibrium. Key residues of PDZ2 allostery were identified with good agreement with NMR studies of the same protein bound to the same peptide. On the other hand, the change of entropic contribution from each residue upon perturbation revealed intrinsic differences among all the residues. The quasi-harmonic and principal component analyses of simulations without rigid residue perturbation showed a coherent allosteric mode from unbound and bound states, respectively. The projection of simulations with rigid residue perturbation onto coherent allosteric modes demonstrated the intrinsic shifting of ensemble distributions supporting the population-shift theory of protein allostery. Overall, the study presented here provides a robust and systematic approach to estimate the contribution of individual residue internal motion to overall protein dynamics and allostery. PMID:27115535

  6. Minimal residual disease in hypopigmented mycosis fungoides.

    PubMed

    Hsiao, Pa-Fan; Hsiao, Cheng-Hsiang; Tsai, Tsen-Fang; Jee, Shiou-Hwa

    2006-05-01

    We describe the case of a 13-year-old boy with stage I hypopigmented mycosis fungoides in whom minimal residual disease was detected with T-cell receptor gamma-polymerase chain reaction after the disease was in complete clinical remission. We further cloned and sequenced the T-cell receptor gamma-polymerase chain reaction product of the lesion in remission and found that the original T-cell clone still existed in decreased amounts. The patient was followed up for 3 1/2 years without any new lesions developing. The clinical significance of this residual malignant T-cell clone in mycosis fungoides remains to be elucidated. PMID:16631939

  7. 51st North American Chemical Residue Workshop.

    PubMed

    Yang, Paul; Martos, Perry; Barrett, Brad

    2015-06-01

    Manuscripts collected in this 51st North American Chemical Residue Workshop (NACRW) Symposium issue of the Journal of Agricultural and Food Chemistry (JAFC) were originally presented at the 51st NACRW meeting. The 2014 NACRW JAFC symposium collects 14 publications representing the broad range of topics in chemical analyses presented at the 2014 meeting. These include the analysis of chemical residues and contaminants in food, environment, feed, botanical, and bee samples as well as the application of quality control/quality assurance protocols in routine and method development. PMID:25682880

  8. Continuous Removal of Coal-Gasification Residue

    NASA Technical Reports Server (NTRS)

    Collins, Earl R., Jr.; Suitor, J.; Dubis, D.

    1986-01-01

    Continuous-flow hopper processes solid residue from coal gasification, converting it from ashes, cinders, and clinkers to particles size of sand granules. Unit does not require repeated depressurization of lockhopper to admit and release materials. Therefore consumes less energy. Because unit has no airlock valves opened and closed repeatedly on hot, abrasive particles, subjected to lesser wear. Coal-gasification residue flows slowly through pressure-letdown device. Material enters and leaves continuously. Cleanout door on each pressure-letdown chamber allows access for maintenance and emergencies.

  9. Finesky -- removing higher order sky residuals

    NASA Astrophysics Data System (ADS)

    Dahlen, Tomas; Grumm, David

    2010-07-01

    We report on a new IRAF task called finesky that removes higher order sky residuals in NICMOS images by creating a masked median image of the observed sky. This median sky image is thereafter subtracted from the science images. A residual signal after image processing using the calibration software calnica may be present due to reference files that do not sufficiently match the conditions of the observations. This includes a slight mismatch in the dark current or the flat-field corrections. The task described here can also used to create sky flat-field images.

  10. Residual dust charges in discharge afterglow

    SciTech Connect

    Coueedel, L.; Mikikian, M.; Boufendi, L.; Samarian, A. A.

    2006-08-15

    An on-ground measurement of dust-particle residual charges in the afterglow of a dusty plasma was performed in a rf discharge. An upward thermophoretic force was used to balance the gravitational force. It was found that positively charged, negatively charged, and neutral dust particles coexisted for more than 1 min after the discharge was switched off. The mean residual charge for 200-nm-radius particles was measured. The dust particle mean charge is about -5e at a pressure of 1.2 mbar and about -3e at a pressure of 0.4 mbar.

  11. Catalytic combustion with incompletely vaporized residual fuel

    NASA Technical Reports Server (NTRS)

    Rosfjord, T. J.

    1981-01-01

    Catalytic combustion of fuel lean mixtures of incompletely vaporized residual fuel and air was investigated. The 7.6 cm diameter, graded cell reactor was constructed from zirconia spinel substrate and catalyzed with a noble metal catalyst. Streams of luminous particles exited the rector as a result of fuel deposition and carbonization on the substrate. Similar results were obtained with blends of No. 6 and No. 2 oil. Blends of shale residual oil and No. 2 oil resulted in stable operation. In shale oil blends the combustor performance degraded with a reduced degree of fuel vaporization. In tests performed with No. 2 oil a similar effect was observed.

  12. 21 CFR 500.86 - Marker residue and target tissue.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... measure the depletion of the residue of carcinogenic concern until its concentration is at or below Sm. (b... marker residues until the concentration of the residue of carcinogenic concern is at or below Sm. (c... taken as confirmation that the residue of carcinogenic concern does not exceed Sm in each of the...

  13. 21 CFR 500.86 - Marker residue and target tissue.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... measure the depletion of the residue of carcinogenic concern until its concentration is at or below Sm. (b... marker residues until the concentration of the residue of carcinogenic concern is at or below Sm. (c... taken as confirmation that the residue of carcinogenic concern does not exceed Sm in each of the...

  14. 21 CFR 500.86 - Marker residue and target tissue.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... measure the depletion of the residue of carcinogenic concern until its concentration is at or below Sm. (b... marker residues until the concentration of the residue of carcinogenic concern is at or below Sm. (c... taken as confirmation that the residue of carcinogenic concern does not exceed Sm in each of the...

  15. 40 CFR 180.210 - Bromacil; tolerances for residues.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 23 2010-07-01 2010-07-01 false Bromacil; tolerances for residues. 180... PROGRAMS TOLERANCES AND EXEMPTIONS FOR PESTICIDE CHEMICAL RESIDUES IN FOOD Specific Tolerances § 180.210 Bromacil; tolerances for residues. (a) General. Tolerances are established for residues of the...

  16. 40 CFR 180.315 - Methamidophos; tolerances for residues.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 23 2010-07-01 2010-07-01 false Methamidophos; tolerances for residues...) PESTICIDE PROGRAMS TOLERANCES AND EXEMPTIONS FOR PESTICIDE CHEMICAL RESIDUES IN FOOD Specific Tolerances § 180.315 Methamidophos; tolerances for residues. (a) Tolerances are established for residues of...

  17. 40 CFR 180.299 - Dicrotophos; tolerances for residues.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 23 2010-07-01 2010-07-01 false Dicrotophos; tolerances for residues...) PESTICIDE PROGRAMS TOLERANCES AND EXEMPTIONS FOR PESTICIDE CHEMICAL RESIDUES IN FOOD Specific Tolerances § 180.299 Dicrotophos; tolerances for residues. (a) General. Tolerances are established for residues...

  18. 40 CFR 180.132 - Thiram; tolerances for residues.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 23 2010-07-01 2010-07-01 false Thiram; tolerances for residues. 180... PROGRAMS TOLERANCES AND EXEMPTIONS FOR PESTICIDE CHEMICAL RESIDUES IN FOOD Specific Tolerances § 180.132 Thiram; tolerances for residues. (a) General. Tolerances are established for residues of the...

  19. 40 CFR 279.67 - Management of residues.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 26 2010-07-01 2010-07-01 false Management of residues. 279.67 Section... for Energy Recovery § 279.67 Management of residues. Burners who generate residues from the storage or burning of used oil must manage the residues as specified in § 279.10(e)....

  20. 40 CFR 180.243 - Propazine; tolerances for residues.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 23 2010-07-01 2010-07-01 false Propazine; tolerances for residues...) PESTICIDE PROGRAMS TOLERANCES AND EXEMPTIONS FOR PESTICIDE CHEMICAL RESIDUES IN FOOD Specific Tolerances § 180.243 Propazine; tolerances for residues. Tolerances are established for negligible residues (N)...

  1. 40 CFR 180.198 - Trichlorfon; tolerances for residues.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 23 2010-07-01 2010-07-01 false Trichlorfon; tolerances for residues...) PESTICIDE PROGRAMS TOLERANCES AND EXEMPTIONS FOR PESTICIDE CHEMICAL RESIDUES IN FOOD Specific Tolerances § 180.198 Trichlorfon; tolerances for residues. (a) General. Tolerances are established for residues...

  2. 40 CFR 180.114 - Ferbam; tolerances for residues.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 23 2010-07-01 2010-07-01 false Ferbam; tolerances for residues. 180... PROGRAMS TOLERANCES AND EXEMPTIONS FOR PESTICIDE CHEMICAL RESIDUES IN FOOD Specific Tolerances § 180.114 Ferbam; tolerances for residues. (a) General. Tolerances are established for residues of the...

  3. 40 CFR 180.116 - Ziram; tolerances for residues.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 23 2010-07-01 2010-07-01 false Ziram; tolerances for residues. 180... PROGRAMS TOLERANCES AND EXEMPTIONS FOR PESTICIDE CHEMICAL RESIDUES IN FOOD Specific Tolerances § 180.116 Ziram; tolerances for residues. (a) General. Tolerances are established for residues of the...

  4. 40 CFR 279.47 - Management of residues.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 26 2010-07-01 2010-07-01 false Management of residues. 279.47 Section... Management of residues. Transporters who generate residues from the storage or transport of used oil must manage the residues as specified in § 279.10(e)....

  5. 40 CFR 180.263 - Phosalone; tolerances for residues.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 23 2010-07-01 2010-07-01 false Phosalone; tolerances for residues...) PESTICIDE PROGRAMS TOLERANCES AND EXEMPTIONS FOR PESTICIDE CHEMICAL RESIDUES IN FOOD Specific Tolerances § 180.263 Phosalone; tolerances for residues. (a) General. Tolerances are established for residues...

  6. 40 CFR 180.178 - Ethoxyquin; tolerances for residues.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 23 2010-07-01 2010-07-01 false Ethoxyquin; tolerances for residues...) PESTICIDE PROGRAMS TOLERANCES AND EXEMPTIONS FOR PESTICIDE CHEMICAL RESIDUES IN FOOD Specific Tolerances § 180.178 Ethoxyquin; tolerances for residues. (a) General. A tolerance is established for residues...

  7. 40 CFR 180.304 - Oryzalin; tolerances for residues.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 23 2010-07-01 2010-07-01 false Oryzalin; tolerances for residues. 180... PROGRAMS TOLERANCES AND EXEMPTIONS FOR PESTICIDE CHEMICAL RESIDUES IN FOOD Specific Tolerances § 180.304 Oryzalin; tolerances for residues. (a) General. Tolerances are established for residues of the...

  8. Assessment of secondary residues. Engineering and economic analysis. Final report

    SciTech Connect

    Leuschner, A.P.; West, C.E.; Ashare, E.

    1981-08-01

    Secondary agricultural residues are defined as those residues resulting from biomass processing to produce primary products; e.g., whey from cheese processing, vegetable processing wastes, and residues from pulp and paper processing. The analyses consist of specific case studies investigating the costs of converting liquid and/or solid residue streams to methane and/or ethanol. Several economically feasible examples were found: methane production from potato processing liquid residues, ethanol from potato processing solid residues, methane from cheese processing wastes, and methane from poultry processing liquid wastes. In facilities which operate year round, energy recovery is often feasible, whereas in seasonal operations, economic feasibility is not possible. Economic feasibility of energy production from secondary residues is strongly dependent on the current use of the solid and liquid residue. If the solid residue is sold as an animal feed, energy production is usually not economical. High solid and liquid residue disposal costs often make energy conversion economically feasible.

  9. Using Water To Analyze Greasy Residues

    NASA Technical Reports Server (NTRS)

    Hoppesch, Charles W.

    1994-01-01

    Water found useful as substitute for chlorofluorocarbon (CFC) solvents in tests to measure amounts of nonvolatile residues of contaminants (e.g., hydrocarbon greases) on equipment after it has been cleaned. Water does not harm environment and much cheaper than CFCs.

  10. Nonparametric inference on median residual life function.

    PubMed

    Jeong, Jong-Hyeon; Jung, Sin-Ho; Costantino, Joseph P

    2008-03-01

    A simple approach to the estimation of the median residual lifetime is proposed for a single group by inverting a function of the Kaplan-Meier estimators. A test statistic is proposed to compare two median residual lifetimes at any fixed time point. The test statistic does not involve estimation of the underlying probability density function of failure times under censoring. Extensive simulation studies are performed to validate the proposed test statistic in terms of type I error probabilities and powers at various time points. One of the oldest data sets from the National Surgical Adjuvant Breast and Bowel Project (NSABP), which has more than a quarter century of follow-up, is used to illustrate the method. The analysis results indicate that, without systematic post-operative therapy, a significant difference in median residual lifetimes between node-negative and node-positive breast cancer patients persists for about 10 years after surgery. The new estimates of the median residual lifetime could serve as a baseline for physicians to explain any incremental effects of post-operative treatments in terms of delaying breast cancer recurrence or prolonging remaining lifetimes of breast cancer patients. PMID:17501936

  11. NICKEL SPECIATION OF RESIDUAL OIL ASH

    EPA Science Inventory

    EPA GRANT NUMBER: R827649C002
    Title: Nickel Speciation Of Residual Oil Ash
    Investigators: Kevin C. Galbreath, John Won, Frank E. Huggins, Gerald P. Huffman, Christopher J. Zygarlicke, Donald L. Toman
    Institution: University of North Dakota<...

  12. Residual Stress Testing of Outer 3013 Containers

    SciTech Connect

    Dunn, K.

    2004-02-12

    A Gas Tungsten Arc Welded (GTAW) outer 3013 container and a laser welded outer 3013 container have been tested for residual stresses according to the American Society for Testing Materials (ASTM) Standard G-36-94 [1]. This ASTM standard describes a procedure for conducting stress-corrosion cracking tests in boiling magnesium chloride (MgCl2) solution. Container sections in both the as-fabricated condition as well as the closure welded condition were evaluated. Significantly large residual stresses were observed in the bottom half of the as-fabricated container, a result of the base to can fabrication weld because through wall cracks were observed perpendicular to the weld. This observation indicates that regardless of the closure weld technique, sufficient residual stresses exist in the as-fabricated container to provide the stress necessary for stress corrosion cracking of the container, at the base fabrication weld. Additionally, sufficiently high residual stresses were observed in both the lid and the body of the GTAW as well as the laser closure welded containers. The stresses are oriented perpendicular to the closure weld in both the container lid and the container body. Although the boiling MgCl2 test is not a quantitative test, a comparison of the test results from the closure welds shows that there are noticeably more through wall cracks in the laser closure welded container than in the GTAW closure welded container.

  13. DISPOSAL OF RESIDUES FROM BUILDING DECONTAMINATION ACTIVITIES

    EPA Science Inventory

    After a building has gone through decontamination activities from a chemical attack there will be a significant amount of building decontamination residue that will need to undergo disposal. This project consists of a fundamental study to investigate the desorption of simulated c...

  14. Fuel ethanol production from agricultural residues

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Ethanol is a renewable oxygenated fuel. In 2012, about 13.3 billion gallons of fuel ethanol was produced from corn in the USA which makes up 10% of gasoline supply. Various agricultural residues such as corn stover, wheat straw, rice straw and barley straw can serve as low-cost lignocellulosic fee...

  15. WORKSHOP ON EMERGING PATHOGENS IN RESIDUALS

    EPA Science Inventory

    There is considerable concern among regulatory authorities, the agricultural community and the public as a whole about the scientific community's ability to measure the level(s) of known pathogens in residuals. There is also concern for whether we are aware of all the pathogens t...

  16. AQUEOUS ELECTROCHEMICAL MECHANISMS IN ACTINIDE RESIDUE PROCESSING

    EPA Science Inventory

    The United States Department of Energy is faced with the stabilization and disposition of hundreds of metric tons of plutonium - and uranium-bearing residue materials resulting from 50+ years of nuclear weapons production activities. These materials are presently in storage at si...

  17. Permethylation Linkage Analysis Techniques for Residual Carbohydrates

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Permethylation analysis is the classic approach to establishing the position of glycosidic linkages between sugar residues. Typically, the carbohydrate is derivatized to form acid-stable methyl ethers, hydrolyzed, peracetylated, and analyzed by gas chromatography-mass spectrometry (GC-MS). The pos...

  18. Gastric Residual Volume: Rethinking the Threshold.

    PubMed

    Emami Zeydi, Amir; Sharafkhani, Mohammad; Armat, Mohammad Reza

    2016-01-01

    There are many challenges related to enteral feedings of the mechanically ventilated patient. Among the most often debated issues is the threshold for gastric residual volume before further feeding. This brief article considers the factors to be considered and reviews current thinking on the topic. PMID:27575801

  19. Organochlorine residues in northeaster Alberta otters

    SciTech Connect

    Somers, J.D.; Goski, B.C.; Barrett, M.W.

    1987-11-01

    The use of organochlorine pesticides in North America has for the most part been legislatively curtailed during the last decade, and North American production of polychlorinated biphenyls (PCS's) was stopped in the 1970's. However, monitoring of chemical residues in fish and wildlife indicates that these persistent compound are still much in evidence throughout North America. Data on chemical residues in Alberta wildlife, particularly non-migratory species, is for the most part unknown. Otters (Lutra canadensis) are consumers of fish, invertebrates, amphibians and small mammals cohabiting their aquatic habitat. As carnivores at the terminus of their respective food chains, semi-aquatic mammals such as otter and mink (Mustela vison) may be expected to accumulate pesticides, PCBs and heavy metals. Otters are relatively sedentary and monitoring of chemical residues in their tissues might yield a diverse contaminant profile unique to the specific environs from which the animals are collected. The purpose of this report is to present chemical residue data for otters collected from aquatic habitats in northeastern Alberta.

  20. 14C-carbaryl residues in hazelnut.

    PubMed

    Yücel, Ulkü; Ilim, Murat; Aslan, Nazife

    2006-01-01

    A hazelnut ocak (shrub growing form) in the field in Black Sea region of Turkey was treated with commercial carbaryl insecticide spiked with 14C-carbaryl. Three months later, the harvested hazelnuts were separated into husk, shell, and kernel components, then homogenized and analyzed. The total and unextractable (bound) 14C-residues were determined by combustion and the extractable 14C-residues were obtained by extracting the samples with methanol. Concentrated extracts were first analyzed by thin layer chromatography (TLC). The extracts were also subjected to a series of liquid-liquid extraction procedures for clean-up and the final extracts were analyzed by high performance liquid chromatography (HPLC). Crude hazelnut oil was also extracted with hexane and analyzed for total 14C-residue. A total of 1.3% of applied radioactivity was recovered from the total nut harvested, with 0.04%, 0.06%, and 1.2% present in shell, kernel, and husk, respectively. The results show that the inedible husk and shell contained 95.7% 14C, whereas the edible kernel contained 4.3% of the total 14C recovered. The terminal 14C-residue in hazelnut kernel and oil did not contain carbaryl and/or its metabolite naphthol. PMID:16785168

  1. Transform coding of stereo image residuals.

    PubMed

    Moellenhoff, M S; Maier, M W

    1998-01-01

    Stereo image compression is of growing interest because of new display technologies and the needs of telepresence systems. Compared to monoscopic image compression, stereo image compression has received much less attention. A variety of algorithms have appeared in the literature that make use of the cross-view redundancy in the stereo pair. Many of these use the framework of disparity-compensated residual coding, but concentrate on the disparity compensation process rather than the post compensation coding process. This paper studies specialized coding methods for the residual image produced by disparity compensation. The algorithms make use of theoretically expected and experimentally observed characteristics of the disparity-compensated stereo residual to select transforms and quantization methods. Performance is evaluated on mean squared error (MSE) and a stereo-unique metric based on image registration. Exploiting the directional characteristics in a discrete cosine transform (DCT) framework provides its best performance below 0.75 b/pixel for 8-b gray-scale imagery and below 2 b/pixel for 24-b color imagery, In the wavelet algorithm, roughly a 50% reduction in bit rate is possible by encoding only the vertical channel, where much of the stereo information is contained. The proposed algorithms do not incur substantial computational burden beyond that needed for any disparity-compensated residual algorithm. PMID:18276294

  2. Monitoring of pesticide residues in vegetarian diet.

    PubMed

    Kumari, Beena; Kathpal, T S

    2009-04-01

    Samples (28) of complete vegetarian diet consumed from morning till night i.e. tea, milk, breakfast, lunch, snacks, dinner, sweet dish etc. were collected from homes, hostels and hotels periodically from Hisar and analysed for detecting the residues of organochlorine, synthetic pyrethriod, organophosphate and carbamate insecticides. The estimation was carried out by using multi-residue analytical technique employing gas chromatograph (GC)-electron capture detector and GC-nitrogen phosphorous detector systems equipped with capillary columns. The whole diet sample was macerated in a mixer grinder and a representative sample in duplicate was analyzed for residues keeping the average daily diet of an adult to be 1,300 g. On comparing the data, it was found that actual daily intake (microgram/person/day) of lindane in two and endosulfan in four samples exceeded the acceptable daily intake. Residues of other pesticides in all the diet samples were lower than the acceptable daily intake (ADI) of the respective pesticides. The study concluded that although all the diet samples were found contaminated with one or the other pesticide, the actual daily intake of only a few pesticides was higher than their respective ADI. More extensive study covering other localities of Haryana has been suggested to know the overall scenario of contamination of vegetarian diet. PMID:18386151

  3. Selenium speciation in flue desulfurization residues.

    PubMed

    Zhong, Liping; Cao, Yan; Li, Wenying; Xie, Kechang; Pan, Wei-Ping

    2011-01-01

    Flue gas from coal combustion contains significant amounts of volatile selenium (Se). The capture of Se in the flue gas desulfurization (FGD) scrubber unit has resulted in a generation of metal-laden residues. It is important to determine Se speciation to understand the environmental impact of its disposal. A simple method has been developed for selective inorganic Se(IV), Se(VI) and organic Se determination in the liquid-phase FGD residues by hydride generation atomic fluorescence spectrometry (AFS). It has been determined that Se(IV), Se(VI) and organic Se can be accurately determined with detection limits (DL) of 0.05, 0.06 and 0.06 microg/L, respectively. The accuracy of the proposed method was evaluated by analyzing the certified reference material, NIST CRM 1632c, and also by analyzing spiked tap-water samples. Analysis indicates that the concentration of Se is high in FGD liquid residues and primarily exists in a reduced state as selenite (Se(IV)). The toxicity of Se(IV) is the strongest of all Se species. Flue gas desulfurization residues pose a serious environmental risk. PMID:21476358

  4. Vitrification for stability of scrap and residue

    SciTech Connect

    Forsberg, C.W.

    1996-05-01

    A conference breakout discussion was held on the subject of vitrification for stabilization of plutonium scrap and residue. This was one of four such sessions held within the vitrification workshop for participants to discuss specific subjects in further detail. The questions and issues were defined by the participants.

  5. Lamination residual stresses in fiber composites

    NASA Technical Reports Server (NTRS)

    Daniel, I. M.; Liber, T.

    1975-01-01

    An experimental investigation was conducted to determine the magnitude of lamination residual stresses in angle-ply composites and to evaluate their effects on composite structural integrity. The materials investigated were boron/epoxy, boron/polyimide, graphite/low modulus epoxy, graphite/high modulus epoxy, graphite/polyimide and s-glass/epoxy. These materials were fully characterized. Static properties of laminates were also determined. Experimental techniques using embedded strain gages were developed and used to measure residual strains during curing. The extent of relaxation of lamination residual stresses was investigated. It was concluded that the degree of such relaxation is low. The behavior of angle-ply laminates subjected to thermal cycling, tensile load cycling, and combined thermal cycling with tensile load was investigated. In most cases these cycling programs did not have any measurable influence on residual strength and stiffness of the laminates. In the tensile load cycling tests, the graphite/polyimide shows the highest endurance with 10 million cycle runouts at loads up to 90 percent of the static strength.

  6. PHASE CHEMISTRY OF TANK SLUDGE RESIDUAL COMPONENTS

    EPA Science Inventory

    It will not be possible to recover all the contaminated sludge from the bottoms of decommissioned waste storage tanks. This research is directed at providing a credible model for the release of radionuclides from residual sludge. Sludge components that are the prime actors in ret...

  7. Pesticide Residues in Food: Your Daily Dose.

    ERIC Educational Resources Information Center

    Mott, Lawrie

    1985-01-01

    Extensive use of pesticides during food production has created concerns for certain involuntary risks. Examines these concerns: government role in control and monitoring pesticide use, proposals for reform, and how consumer awareness might be an effective pressure for finding remedies. A table listing produce and pesticide residues is included.…

  8. RESRAD. Site-Specific Residual Radioactivity

    SciTech Connect

    Yu, C.

    1989-06-01

    RESRAD is designed to derive site-specific guidelines for allowable residual concentrations of radionuclides in soil. A guideline is defined as a radionuclide concentration or a level of radiation or radioactivity that is acceptable if a site is to be used without radiological restrictions. Guidelines are expressed as (1) concentrations of residual radionuclides in soil, (2) concentrations of airborne radon decay products, (3) levels of external gamma radiation, (4) levels of radioactivity from surface contamination, and (5) concentrations of residual radionuclides in air and water. Soil is defined as unconsolidated earth material, including rubble and debris that may be present. The controlling principles of all guidelines are (1) the annual radiation dose received by a member of the critical population group from the residual radioactive material - predicted by a realistic but reasonably conservative analysis and averaged over a 50 year period - should not exceed 100 mrem/yr, and (2) doses should be kept as low as reasonably achievable. All significant exposure pathways for the critical population group are considered in deriving soil guidelines. These pathways include direct exposure to external radiation from the contaminated soil material; internal radiation from inhalation of airborne radionuclides; and internal radiation from ingestion of plant foods grown in the contaminated soil, meat and milk from livestock fed with contaminated fodder and water, drinking water from a contaminated well, and fish from a contaminated pond.

  9. Potential nitrogen credits from peanut residue

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Availability of residue nitrogen (N) to succeeding crops is dependent on N mineralization rates during decomposition. Following peanut (Arachis hypogaea L.) production, extension currently recommends 22-67 kg N ha-1 credit to subsequent crops, but these recommendations are not supported in the liter...

  10. Chemical Stabilization of Hanford Tank Residual Waste

    SciTech Connect

    Cantrell, Kirk J.; Um, Wooyong; Williams, Benjamin D.; Bowden, Mark E.; Gartman, Brandy N.; Lukens, Wayne W.; Buck, Edgar C.; Mausolf, Edward J.

    2014-03-01

    Three different chemical treatment methods were tested for their ability to stabilize residual waste from Hanford tank C-202 for reducing contaminant release (Tc, Cr, and U in particular). The three treatment methods tested were lime addition [Ca(OH)2], an in-situ Ceramicrete waste form based on chemically bonded phosphate ceramics, and a ferrous iron/goethite treatment. These approaches rely on formation of insoluble forms of the contaminants of concern (lime addition and ceramicrete) and chemical reduction followed by co-precipitation (ferrous iron/goethite incorporation treatment). The results have demonstrated that release of the three most significant mobile contaminants of concern from tank residual wastes can be dramatically reduced after treatment compared to contact with simulated grout porewater without treatment. For uranium, all three treatments methods reduced the leachable uranium concentrations by well over three orders of magnitude. In the case of uranium and technetium, released concentrations were well below their respective MCLs for the wastes tested. For tank C-202 residual waste, chromium release concentrations were above the MCL but were considerably reduced relative to untreated tank waste. This innovative approach has the potential to revolutionize Hanford’s tank retrieval process, by allowing larger volumes of residual waste to be left in tanks while providing an acceptably low level of risk with respect to contaminant release that is protective of the environment and human health. Such an approach could enable DOE to realize significant cost savings through streamlined retrieval and closure operations.

  11. Low cost way to recover logging residues

    SciTech Connect

    Hassler, C.C.; Sinclair, S.A.; Blinn, C.R.

    1983-01-01

    Integration of a residue harvesting component into a traditional harvest system can offer a reasonable alternative to whole-tree chipping of existing natural stands in supplying wood to energy conversion facilitites. Initial attempts at integration should focus on a low cost, incremental expansion that minimizes the impact on productivity for the traditional harvest component, is easily adapted into a traditional harvest system, and has application to a wide range of harvesting firms in practice. Two traditional systems are analyzed - three-person and four-person systems - where chainsaws are used to fell, limb, top, and buck and rubber-tired cable skidders move the wood. Residue recovery is introduced through the addition of a 120-horsepower mobile chipper with self-mounted knuckleboom loader and two used chip vans. The productivity and cost of the residue recovery component is analyzed over a range of stand types and factors affecting productivity and costs. In general, residue recovery for a three-person system is economical only in stands of large sized timber while the four-person system becomes economical in medium sized lumber. (Refs. 12).

  12. Sugarcane rice residue biochars and their applications

    NASA Astrophysics Data System (ADS)

    Wang, J. J.

    2014-12-01

    Sugarcane production in U.S. involves either pre-harvest burning or after-harvest burning of the residue. Approximately 70-90% of the dry matter of harvested sugarcane trash is lost through open field burning. This practice has caused considerable concerns over air quality and soil sustainability. We propose an alternative conservation approach to convert the sugarcane residue to biochar and used as soil amendment to conserve carbon and potentially improve soil fertility. In this study, fundamental properties of biochars made from sugarcane residue along with rice residues were tested for agronomic and environmental benefits. Sugarcane and rice harvest residues and milling processing byproducts bagasse and rice husk were converted to biochars at different pyrolysis temperatures and characterized. In general, sugarcane leave biochar contained more P, K, Ca and Mg than sugarcane bagasse biochar. Rice straw biochar had more S, K Ca but less P than rice husk biochar. Both biochars had higher available fraction of total P than that of total K. Sugarcane leave biochar converted at 450oC was dominated with various lignin derived phenols as well as non-specific aromatic compounds whereas bagasse biochar was with both lignin derived phenol and poly aromatic hydrocarbon (PAH). Rice straw char was dominated with non-specific aromatic compounds. At 750oC, charred material was dominated with aromatic ethers while losing the aromatic C=C structures. These molecular and surface property differences likely contributed to the difference in water holding capacities observed with these biochars. On the other hand, rice straw biochars produced at different pyrolysis temperatures had no significant effect on rice germination. Soils treated with sugarcane leave/trash biochar significantly enhanced sugarcane growth especially the root length. Treating soil with either sugarcane leave or bagasse char also enhanced soil adsorption capacity of atrazine; a common herbicide used in sugarcane

  13. Residual symmetries of the gravitational field

    NASA Astrophysics Data System (ADS)

    Ayón-Beato, Eloy; Velázquez-Rodríguez, Gerardo

    2016-02-01

    We develop a geometric criterion that unambiguously characterizes the residual symmetries of a gravitational Ansatz. It also provides a systematic and effective computational procedure for finding all the residual symmetries of any gravitational Ansatz. We apply the criterion to several examples starting with the Collinson Ansatz for circular stationary axisymmetric spacetimes. We reproduce the residual symmetries already known for this Ansatz including their conformal symmetry, for which we identify the corresponding infinite generators spanning the two related copies of the Witt algebra. We also consider the noncircular generalization of this Ansatz and show how the noncircular contributions on the one hand break the conformal invariance and on the other hand enhance the standard translation symmetries of the circular Killing vectors to supertranslations depending on the direction along which the circularity is lost. As another application of the method, the well-known relation defining conjugate gravitational potentials introduced by Chandrasekhar, which makes possible the derivation of the Kerr black hole from a trivial solution of the Ernst equations, is deduced as a special point of the general residual symmetry of the Papapetrou Ansatz. In this derivation we emphasize how the election of Weyl coordinates, which determines the Papapetrou Ansatz, breaks also the conformal freedom of the stationary axisymmetric spacetimes. Additionally, we study AdS waves for any dimension generalizing the residual symmetries already known for lower dimensions and exhibiting a very complex infinite-dimensional Lie algebra containing three families: two of them span the semidirect sum of the Witt algebra and scalar supertranslations and the third generates vector supertranslations. Independently of this complexity we manage to comprehend the true meaning of the infinite connected group as the precise diffeomorphisms subgroup allowing to locally deform the AdS background into Ad

  14. Experiment specific processing of residual acceleration data

    NASA Technical Reports Server (NTRS)

    Rogers, Melissa J. B.; Alexander, J. I. D.

    1992-01-01

    To date, most Spacelab residual acceleration data collection projects have resulted in data bases that are overwhelming to the investigator of low-gravity experiments. This paper introduces a simple passive accelerometer system to measure low-frequency accelerations. Model responses for experiments using actual acceleration data are produced and correlations are made between experiment response and the accelerometer time history in order to test the idea that recorded acceleration data and experimental responses can be usefully correlated. Spacelab 3 accelerometer data are used as input to a variety of experiment models, and sensitivity limits are obtained for particular experiment classes. The modeling results are being used to create experiment-specific residual acceleration data processing schemes for interested investigators.

  15. Residual Field Correction of Pulsed Bending Magnet

    NASA Astrophysics Data System (ADS)

    Takano, Junpei; Igarashi, Susumu; Kamikubota, Norihiko; Meigo, Shin-ichiro; Sato, Kenichi; Shirakata, Masashi; Yamada, Shuei

    The Japan Proton Accelerator Research Complex (J-PARC) has an accelerator chain, Linac, Rapid Cycling Synchrotron (RCS), and Main Ring (MR). The RCS accelerates the proton beam up to 3 GeV every 40 msec. After the beam is extracted from the RCS, it is delivered to a beam transport line, which is 3NBT for the Material and Life Science Experimental Facility (MLF). Some bunches of the proton beam are bended from the 3NBT to another beam transport line, which is 3-50BT for the MR, by using a pulsed bending magnet (PB) [1]. However, the beam orbit in the 3NBT is kicked by the residual magnetic field of the PB. In order to correct the residual magnetic field, additional coils had been wound on the PB poles. As a result of scanning the current pattern of the correction coils, the orbit distortion in the 3NBT has been reduced.

  16. Residual insecticides and the problem of sorption

    PubMed Central

    Bertagna, P.

    1959-01-01

    Whereas laboratory investigations have elucidated the mechanism of sorption of residual insecticides and demonstrated that their persistency is determined by a number of physico-chemical factors and is therefore theoretically calculable, the variables encountered in the field may produce results in apparent conflict with those theoretically expected. Attempts to enhance persistency through the prevention of sorption, although promising, have so far not been fully successful. It is consequently also necessary to assess the residual effectiveness of insecticides, “effectiveness” here being viewed as a biological effect expressed in terms of the mosquito mortality produced. For this purpose bio-assay tests have been used, but with very variable results, and it is suggested that a study of the bio-assay technique itself is needed. This should be conducted in parallel with chemical determinations of the total amount of insecticide present both on and below the sprayed surface. PMID:13799942

  17. Insecticide residues on weathered passerine carcass feet

    USGS Publications Warehouse

    Vyas, N.B.; Spann, J.W.; Hulse, C.S.; Butterbrodt, J.J.; Mengelkoch, J.; MacDougall, K.; Williams, B.; Pendergrass, P.

    2003-01-01

    Nine brown-headed cowbirds (Molothrus ater) were exposed to turf srayed with either EarthCare? (25% diazinon; 477 L a.i./ha) or Ortho-Klor? (12 .6% chlorpyrifos; 5.21 L a.i./ha.). Birds were euthanized and one foot from each bird was weathered outdoors for up to 28 days and the other foot was kept frozen until residue analysis. When compared to the unweathered feet, feet weathered for 28 days retained 43% and 37% of the diazinon and chlorpyrifors, respectively. Insecticide residues were below the level of detection (1.0 ppm) on control feet. Weathered feet may be used for determining organophosphorus insecticide exposure to birds.

  18. Protein Residue Contacts and Prediction Methods.

    PubMed

    Adhikari, Badri; Cheng, Jianlin

    2016-01-01

    In the field of computational structural proteomics, contact predictions have shown new prospects of solving the longstanding problem of ab initio protein structure prediction. In the last few years, application of deep learning algorithms and availability of large protein sequence databases, combined with improvement in methods that derive contacts from multiple sequence alignments, have shown a huge increase in the precision of contact prediction. In addition, these predicted contacts have also been used to build three-dimensional models from scratch.In this chapter, we briefly discuss many elements of protein residue-residue contacts and the methods available for prediction, focusing on a state-of-the-art contact prediction tool, DNcon. Illustrating with a case study, we describe how DNcon can be used to make ab initio contact predictions for a given protein sequence and discuss how the predicted contacts may be analyzed and evaluated. PMID:27115648

  19. Alkali activation processes for incinerator residues management.

    PubMed

    Lancellotti, Isabella; Ponzoni, Chiara; Barbieri, Luisa; Leonelli, Cristina

    2013-08-01

    Incinerator bottom ash (BA) is produced in large amount worldwide and in Italy, where 5.1 millionstons of municipal solid residues have been incinerated in 2010, corresponding to 1.2-1.5 millionstons of produced bottom ash. This residue has been used in the present study for producing dense geopolymers containing high percentage (50-70 wt%) of ash. The amount of potentially reactive aluminosilicate fraction in the ash has been determined by means of test in NaOH. The final properties of geopolymers prepared with or without taking into account this reactive fraction have been compared. The results showed that due to the presence of both amorphous and crystalline fractions with a different degree of reactivity, the incinerator BA geopolymers exhibit significant differences in terms of Si/Al ratio and microstructure when reactive fraction is considered. PMID:23756039

  20. Recovering recyclable materials from shredder residue

    NASA Astrophysics Data System (ADS)

    Jody, Bassam J.; Daniels, Edward J.; Bonsignore, Patrick V.; Brockmeier, Norman F.

    1994-02-01

    Each year, about 11 million tons of metals are recovered in the United States from about 10 million discarded automobiles. The recovered metals account for about 75 percent of the total weight of the discarded vehicles. The balance of the material, known as shredder residue, amounts to about three million tons annually and is currently landfilled. The residue contains a diversity of potentially recyclable materials, including polyurethane foams, iron oxides, and certain thermoplastics. This article discusses a process under development at Argonne National Laboratory to separate and recover the recyclable materials from this waste stream. The process consists essentially of two stages. First, a physical separation is used to recover the foams and the metal oxides, followed by a chemical process to extract certain thermoplastics. The status of the technology and the process economics are reviewed here.

  1. Recovery of recyclable materials from shredder residue

    SciTech Connect

    Jody, B.J.; Daniels, E.J.; Bonsignore, P.V.; Brockmeier, N.F.

    1994-01-01

    Each year, about 11 million tons of metals (ferrous and nonferrous) are recovered in the US from about 10 million discarded automobiles. The recovered metals account for about 75% of the total weight of the discarded vehicles. The balance of the material or shredder residue, which amounts to about 3 million tons annually, is currently landfilled. The residue contains a diversity of potentially recyclable materials, including polyurethane foams, iron oxides, and certain thermoplastics. This paper discusses a process under development at Argonne National Laboratory to separate and recover the recyclable materials from this waste stream. The process consists essentially of two-stages. First, a physical separation is used to recover the foams and the metal oxides, followed by a chemical process to extract certain thermoplastics. Status of the technology is discussed and process economics reviewed.

  2. Residual ozone determination by flow injection analysis

    SciTech Connect

    Straka, M.R.; Pacey, G.E.; Gordon, G.

    1984-09-01

    It has been proposed that ozone be used to replace free chlorine for the disinfection of drinking water and waste water. For the use of ozone in this capacity, it would be necessary to have a fast accurate and precise method to analyze for the presence of residuals. An automated method for ozone determination based on the indigo reagent method is presented. This method is based on the advantages of flow injection analysis (FIA) techniques. 19 references, 3 tables, 2 figures.

  3. Residual Viremia in Treated HIV+ Individuals

    DOE PAGESBeta

    Conway, Jessica M.; Perelson, Alan S.

    2016-01-06

    Antiretroviral therapy (ART) effectively controls HIV infection, suppressing HIV viral loads. However, some residual virus remains, below the level of detection, in HIV-infected patients on ART. Furthermore, the source of this viremia is an area of debate: does it derive primarily from activation of infected cells in the latent reservoir, or from ongoing viral replication? Our observations seem to be contradictory: there is evidence of short term evolution, implying that there must be ongoing viral replication, and viral strains should thus evolve. The phylogenetic analyses, and rare emergent drug resistance, suggest no long-term viral evolution, implying that virus derived frommore » activated latent cells must dominate. We use simple deterministic and stochastic models to gain insight into residual viremia dynamics in HIV-infected patients. Our modeling relies on two underlying assumptions for patients on suppressive ART: that latent cell activation drives viral dynamics and that the reproductive ratio of treated infection is less than 1. Nonetheless, the contribution of viral replication to residual viremia in patients on ART may be non-negligible. However, even if the portion of viremia attributable to viral replication is significant, our model predicts (1) that latent reservoir re-seeding remains negligible, and (2) some short-term viral evolution is permitted, but long-term evolution can still be limited: stochastic analysis of our model shows that de novo emergence of drug resistance is rare. Thus, our simple models reconcile the seemingly contradictory observations on residual viremia and, with relatively few parameters, recapitulates HIV viral dynamics observed in patients on suppressive therapy.« less

  4. Residual Viremia in Treated HIV+ Individuals.

    PubMed

    Conway, Jessica M; Perelson, Alan S

    2016-01-01

    Antiretroviral therapy (ART) effectively controls HIV infection, suppressing HIV viral loads. However, some residual virus remains, below the level of detection, in HIV-infected patients on ART. The source of this viremia is an area of debate: does it derive primarily from activation of infected cells in the latent reservoir, or from ongoing viral replication? Observations seem to be contradictory: there is evidence of short term evolution, implying that there must be ongoing viral replication, and viral strains should thus evolve. However, phylogenetic analyses, and rare emergent drug resistance, suggest no long-term viral evolution, implying that virus derived from activated latent cells must dominate. We use simple deterministic and stochastic models to gain insight into residual viremia dynamics in HIV-infected patients. Our modeling relies on two underlying assumptions for patients on suppressive ART: that latent cell activation drives viral dynamics and that the reproductive ratio of treated infection is less than 1. Nonetheless, the contribution of viral replication to residual viremia in patients on ART may be non-negligible. However, even if the portion of viremia attributable to viral replication is significant, our model predicts (1) that latent reservoir re-seeding remains negligible, and (2) some short-term viral evolution is permitted, but long-term evolution can still be limited: stochastic analysis of our model shows that de novo emergence of drug resistance is rare. Thus, our simple models reconcile the seemingly contradictory observations on residual viremia and, with relatively few parameters, recapitulates HIV viral dynamics observed in patients on suppressive therapy. PMID:26735135

  5. Deuteration protects asparagine residues against racemization.

    PubMed

    Lowenson, Jonathan D; Shmanai, Vadim V; Shklyaruck, Denis; Clarke, Steven G; Shchepinov, Mikhail S

    2016-09-01

    Racemization in proteins and peptides at sites of L-asparaginyl and L-aspartyl residues contributes to their spontaneous degradation, especially in the biological aging process. Amino acid racemization involves deprotonation of the alpha carbon and replacement of the proton in the opposite stereoconfiguration; this reaction is much faster for aspartate/asparagine than for other amino acids because these residues form a succinimide ring in which resonance stabilizes the carbanion resulting from proton loss. To determine if the replacement of the hydrogen atom on the alpha carbon with a deuterium atom might decrease the rate of racemization and thus stabilize polypeptides, we synthesized a hexapeptide, VYPNGA, in which the three carbon-bound protons in the asparaginyl residue were replaced with deuterium atoms. Upon incubation of this peptide in pH 7.4 buffer at 37 °C, we found that the rate of deamidation via the succinimide intermediate was unchanged by the presence of the deuterium atoms. However, the accumulation of the D-aspartyl and D-isoaspartyl-forms resulting from racemization and hydrolysis of the succinimide was decreased more than five-fold in the deuterated peptide over a 20 day incubation at physiological temperature and pH. Additionally, we found that the succinimide intermediate arising from the degradation of the deuterated asparaginyl peptide was slightly less likely to open to the isoaspartyl configuration than was the protonated succinimide. These findings suggest that the kinetic isotope effect resulting from the presence of deuteriums in asparagine residues can limit the accumulation of at least some of the degradation products that arise as peptides and proteins age. PMID:27169868

  6. Residual strength of thin panels with cracks

    NASA Technical Reports Server (NTRS)

    Madenci, Erdogan

    1994-01-01

    The previous design philosophies involving safe life, fail-safe and damage tolerance concepts become inadequate for assuring the safety of aging aircraft structures. For example, the failure mechanism for the Aloha Airline accident involved the coalescence of undetected small cracks at the rivet holes causing a section of the fuselage to peel open during flight. Therefore, the fuselage structure should be designed to have sufficient residual strength under worst case crack configurations and in-flight load conditions. Residual strength is interpreted as the maximum load carrying capacity prior to unstable crack growth. Internal pressure and bending moment constitute the two major components of the external loads on the fuselage section during flight. Although the stiffeners in the form of stringers, frames and tear straps sustain part of the external loads, the significant portion of the load is taken up by the skin. In the presence of a large crack in the skin, the crack lips bulge out with considerable yielding; thus, the geometric and material nonlinearities must be included in the analysis for predicting residual strength. Also, these nonlinearities do not permit the decoupling of in-plane and out-of-plane bending deformations. The failure criterion combining the concepts of absorbed specific energy and strain energy density addresses the aforementioned concerns. The critical absorbed specific energy (local toughness) for the material is determined from the global specimen response and deformation geometry based on the uniaxial tensile test data and detailed finite element modeling of the specimen response. The use of the local toughness and stress-strain response at the continuum level eliminates the size effect. With this critical parameter and stress-strain response, the finite element analysis of the component by using STAGS along with the application of this failure criterion provides the stable crack growth calculations for residual strength predictions.

  7. SVD analysis of Aura TES spectral residuals

    NASA Technical Reports Server (NTRS)

    Beer, Reinhard; Kulawik, Susan S.; Rodgers, Clive D.; Bowman, Kevin W.

    2005-01-01

    Singular Value Decomposition (SVD) analysis is both a powerful diagnostic tool and an effective method of noise filtering. We present the results of an SVD analysis of an ensemble of spectral residuals acquired in September 2004 from a 16-orbit Aura Tropospheric Emission Spectrometer (TES) Global Survey and compare them to alternative methods such as zonal averages. In particular, the technique highlights issues such as the orbital variation of instrument response and incompletely modeled effects of surface emissivity and atmospheric composition.

  8. Residual Viremia in Treated HIV+ Individuals

    PubMed Central

    Conway, Jessica M.; Perelson, Alan S.

    2016-01-01

    Antiretroviral therapy (ART) effectively controls HIV infection, suppressing HIV viral loads. However, some residual virus remains, below the level of detection, in HIV-infected patients on ART. The source of this viremia is an area of debate: does it derive primarily from activation of infected cells in the latent reservoir, or from ongoing viral replication? Observations seem to be contradictory: there is evidence of short term evolution, implying that there must be ongoing viral replication, and viral strains should thus evolve. However, phylogenetic analyses, and rare emergent drug resistance, suggest no long-term viral evolution, implying that virus derived from activated latent cells must dominate. We use simple deterministic and stochastic models to gain insight into residual viremia dynamics in HIV-infected patients. Our modeling relies on two underlying assumptions for patients on suppressive ART: that latent cell activation drives viral dynamics and that the reproductive ratio of treated infection is less than 1. Nonetheless, the contribution of viral replication to residual viremia in patients on ART may be non-negligible. However, even if the portion of viremia attributable to viral replication is significant, our model predicts (1) that latent reservoir re-seeding remains negligible, and (2) some short-term viral evolution is permitted, but long-term evolution can still be limited: stochastic analysis of our model shows that de novo emergence of drug resistance is rare. Thus, our simple models reconcile the seemingly contradictory observations on residual viremia and, with relatively few parameters, recapitulates HIV viral dynamics observed in patients on suppressive therapy. PMID:26735135

  9. Thin layer chromatography residue applicator sampler

    DOEpatents

    Nunes, Peter J.; Kelly, Fredrick R.; Haas, Jeffrey S.; Andresen, Brian D.

    2007-07-24

    A thin layer chromatograph residue applicator sampler. The residue applicator sampler provides for rapid analysis of samples containing high explosives, chemical warfare, and other analyses of interest under field conditions. This satisfied the need for a field-deployable, small, hand-held, all-in-one device for efficient sampling, sample dissolution, and sample application to an analytical technique. The residue applicator sampler includes a sampling sponge that is resistant to most chemicals and is fastened via a plastic handle in a hermetically sealed tube containing a known amount of solvent. Upon use, the wetted sponge is removed from the sealed tube and used as a swiping device across an environmental sample. The sponge is then replaced in the hermetically sealed tube where the sample remains contained and dissolved in the solvent. A small pipette tip is removably contained in the hermetically sealed tube. The sponge is removed and placed into the pipette tip where a squeezing-out of the dissolved sample from the sponge into the pipette tip results in a droplet captured in a vial for later instrumental analysis, or applied directly to a thin layer chromatography plate for immediate analysis.

  10. Differential spectroscopic imaging of particulate explosives residue

    NASA Astrophysics Data System (ADS)

    Bernacki, Bruce E.; Hô, Nicolas

    2008-04-01

    We present experimental results showing transmission and reflection imaging of approximately 100 μg quantities of particulate explosives residue using a commercial uncooled microbolometer infrared camera and CO II laser differential wavelength illumination. Fine particulates may be generated during bomb-making activities and these particulates can tenaciously adhere to packing material, as well as to the clothing or skin of the bomb maker and could be detectable during transportation. A rapid screening method that detects this residue can serve as a first-line screening method in conjunction with more sensitive, but invasive, approaches. Explosives exhibit absorption features in the mid-infrared molecular fingerprint region that spans 3 to 15 μm, which can be probed with many high-brightness sources such as fixed wavelength and tunable quantum cascade lasers, CO II, CO, and OPO lasers. Commercial uncooled microbolometer cameras typically have detection sensitivity from 7.5 to 13 μm, spanning an absorption region for explosives detection with adequate signal-to-noise ratio. By illuminating a target on and off its absorption wavelengths, ratio images of suspected residue can be obtained without any sample preparation or cooperation and contact with the target. Our proof-of-principle experiment employed tunable CO II lasers, with a tuning range from 9.2 to 10.6 μm, overlapping minor absorption features of RDX and Tetryl.

  11. Diffusion of residual monomer in polymer resins.

    PubMed Central

    Piver, W T

    1976-01-01

    A simplified mathematical model which made use of Fick's laws of diffusion written in spherical coordinates was developed to describe the rate of diffusion of residual monomers from polymer resins. The properties of the monomer-polymer system which influenced the amount of monomer remaining in the polymer as a function of time were the diffusivity and solubility of the monomer in the polymer, and the particle size of the polymer resin. This model was used to analyze literature data on the diffusion of residual vinyl chloride monomer in polyvinyl chloride resins made by the suspension process. It was concluded that particle size of the resin was a significant parameter which should be taken advantage of in process equipment designed to remove residual monomer from PVC resins. The diffusivity of the monomer in the polymer was a function of the solubility of the monomer in the polymer. Monomer solubility can be determined from Henry's law. It was suggested that this model could be adapted to describe diffusion of monomers from any monomer-polymer system, and would be a useful approach to modeling the transport of nonreactive chemical additives from plastics. PMID:1026410

  12. Free Energy Landscape - Settlements of Key Residues.

    NASA Astrophysics Data System (ADS)

    Aroutiounian, Svetlana

    2007-03-01

    FEL perspective in studies of protein folding transitions reflects notion that since there are ˜10^N conformations to scan in search of lowest free energy state, random search is beyond biological timescale. Protein folding must follow certain fel pathways and folding kinetics of evolutionary selected proteins dominates kinetic traps. Good model for functional robustness of natural proteins - coarse-grained model protein is not very accurate but affords bringing simulations closer to biological realm; Go-like potential secures the fel funnel shape; biochemical contacts signify the funnel bottleneck. Boltzmann-weighted ensemble of protein conformations and histogram method are used to obtain from MC sampling of protein conformational space the approximate probability distribution. The fel is F(rmsd) = -1/βLn[Hist(rmsd)], β=kBT and rmsd is root-mean-square-deviation from native conformation. The sperm whale myoglobin has rich dynamic behavior, is small and large - on computational scale, has a symmetry in architecture and unusual sextet of residue pairs. Main idea: there is a mathematical relation between protein fel and a key residues set providing stability to folding transition. Is the set evolutionary conserved also for functional reasons? Hypothesis: primary sequence determines the key residues positions conserved as stabilizers and the fel is the battlefield for the folding stability. Preliminary results: primary sequence - not the architecture, is the rule settler, indeed.

  13. Automotive shredder residue (ASR) management: An overview.

    PubMed

    Cossu, R; Lai, T

    2015-11-01

    On the basis of statistical data, approximately 6.5 million tons of ELVs were produced in Europe in 2011. ELVs are processed according to a treatment scheme comprising three main phases: depollution, dismantling and shredding. The ferrous fraction represents about 70-75% of the total shredded output, while nonferrous metals represent about 5%. The remaining 20-25% is referred to as automotive shredder residue (ASR). ASR is largely landfilled due to its heterogeneous and complex matrix. With a start date of January 1st 2015, the European Directive 2000/53/EC establishes the reuse and recovery of a minimum of 95% ELV total weight. To reach these targets various post-shredder technologies have been developed with the aim of improving recovery of materials and energy from ASR. In order to evaluate the environmental impacts of different management options of ELVs, the life cycle assessment (LCA) methodology has been applied taking into account the potential implication of sustainable design of vehicles and treatment of residues after shredding of ELVs. Findings obtained reveal that a combination of recycling and energy recovery is required to achieve European targets, with landfilling being viewed as the least preferred option. The aim of this work is to provide a general overview of the recent development of management of ELVs and treatment of ASR with a view to minimizing the amount of residues disposed of in landfill. PMID:26294011

  14. Demonstration of catalytic combustion with residual fuel

    NASA Technical Reports Server (NTRS)

    Dodds, W. J.; Ekstedt, E. E.

    1981-01-01

    An experimental program was conducted to demonstrate catalytic combustion of a residual fuel oil. Three catalytic reactors, including a baseline configuration and two backup configurations based on baseline test results, were operated on No. 6 fuel oil. All reactors were multielement configurations consisting of ceramic honeycomb catalyzed with palladium on stabilized alumina. Stable operation on residual oil was demonstrated with the baseline configuration at a reactor inlet temperature of about 825 K (1025 F). At low inlet temperature, operation was precluded by apparent plugging of the catalytic reactor with residual oil. Reduced plugging tendency was demonstrated in the backup reactors by increasing the size of the catalyst channels at the reactor inlet, but plugging still occurred at inlet temperature below 725 K (845 F). Operation at the original design inlet temperature of 589 K (600 F) could not be demonstrated. Combustion efficiency above 99.5% was obtained with less than 5% reactor pressure drop. Thermally formed NO sub x levels were very low (less than 0.5 g NO2/kg fuel) but nearly 100% conversion of fuel-bound nitrogen to NO sub x was observed.

  15. Chemical stabilization of Hanford tank residual waste

    NASA Astrophysics Data System (ADS)

    Cantrell, Kirk J.; Um, Wooyong; Williams, Benjamin D.; Bowden, Mark E.; Gartman, Brandy; Lukens, Wayne W.; Buck, Edgar C.; Mausolf, Edward J.

    2014-03-01

    Three different chemical treatment methods were tested for their ability to stabilize residual waste from Hanford tank C-202 for reducing contaminant release (Tc, Cr, and U in particular). The three treatment methods tested were lime addition [Ca(OH)2], an in situ Ceramicrete waste form based on chemically bonded phosphate ceramics, and a ferrous iron/goethite treatment. These approaches rely on formation of insoluble forms of the contaminants of concern (lime addition and Ceramicrete) and chemical reduction followed by co-precipitation (ferrous iron/goethite incorporation treatment). The results have demonstrated that release of uranium from tank residual wastes can be dramatically reduced after treatment compared to contact with simulated grout porewater without treatment. All three treatments methods reduced the leachable uranium concentrations by well over three orders of magnitude. In the case of uranium and technetium, released concentrations were well below their respective Maximum Contaminant Levels (MCLs) for the wastes tested. For tank C-202 residual waste, chromium release concentrations were above the MCL but were considerably reduced relative to untreated tank waste.

  16. Detection of Gunshot Residues Using Mass Spectrometry

    PubMed Central

    Blanes, Lucas; Cole, Nerida; Doble, Philip; Roux, Claude

    2014-01-01

    In recent years, forensic scientists have become increasingly interested in the detection and interpretation of organic gunshot residues (OGSR) due to the increasing use of lead- and heavy metal-free ammunition. This has also been prompted by the identification of gunshot residue- (GSR-) like particles in environmental and occupational samples. Various techniques have been investigated for their ability to detect OGSR. Mass spectrometry (MS) coupled to a chromatographic system is a powerful tool due to its high selectivity and sensitivity. Further, modern MS instruments can detect and identify a number of explosives and additives which may require different ionization techniques. Finally, MS has been applied to the analysis of both OGSR and inorganic gunshot residue (IGSR), although the “gold standard” for analysis is scanning electron microscopy with energy dispersive X-ray microscopy (SEM-EDX). This review presents an overview of the technical attributes of currently available MS and ionization techniques and their reported applications to GSR analysis. PMID:24977168

  17. Elemental quantification of large gunshot residues

    NASA Astrophysics Data System (ADS)

    Duarte, A.; Silva, L. M.; de Souza, C. T.; Stori, E. M.; Boufleur, L. A.; Amaral, L.; Dias, J. F.

    2015-04-01

    In the present work we embarked on the evaluation of the Sb/Pb, Ba/Pb and Sb/Ba elemental ratios found in relatively large particles (of the order of 50-150 μm across) ejected in the forward direction when a gun is fired. These particles are commonly referred to as gunshot residues (GSR). The aim of this work is to compare the elemental ratios of the GSR with those found in the primer of pristine cartridges in order to check for possible correlations. To that end, the elemental concentration of gunshot residues and the respective ammunition were investigated through PIXE (Particle-Induced X-ray Emission) and micro-PIXE techniques. The ammunition consisted of a .38 SPL caliber (ogival lead type) charged in a Taurus revolver. Pristine cartridges were taken apart for the PIXE measurements. The shooting sessions were carried out in a restricted area at the Forensic Institute at Porto Alegre. Residues ejected at forward directions were collected on a microporous tape. The PIXE experiments were carried out employing 2.0 MeV proton beams with a beam spot size of 1 mm2. For the micro-PIXE experiments, the samples were irradiated with 2.2 MeV proton beams of 2 × 2 μm2. The results found for the ratios of Sb/Pb, Ba/Pb and Sb/Ba do not correlate with those stemming from the analysis of the primer.

  18. Estimators and Characteristics of Logging Residue in California : Final Report.

    SciTech Connect

    Howard, James O.; Bulgrin, Julianne K.

    1985-04-19

    This study, designed to meet the needs of site-specific analysis of logging residue throughout the State of California, has two primary objectives. First was to develop analytical tools for estimating the volume of logging residue for any uniquely defined supply zone in California. Volume estimators developed in this study relate residue volume to both timber harvest volume and acreage. Second was to describe and classify residue by characteristics that affect utilization. Residue materials were classified as to gross and net volume of logging residue by diameter and length, for live, and dead and cull; to number of pieces of residue per acre, by diameter and length; to volume of residue by percent sound (chippability), in cubic feet per acre; to accessibility of residue on cutover areas, by slope and distance to road; and to volume by softwoods and hardwoods. Residue ratios and characteristics data are displayed for eight sample strata in California, based on geographic area, owner class - harvest method, and forest type. Within geographical areas owner class - harvest method strata were selected on the basis of expected differences in residue volume, availability of data, and land management objectives. A separate stratum was selected for the Ponderosa pine forest type in eastern California based on expected differences in residue volume and characteristics. Study results are based on measurements of logging residue on 220 cutover areas allocated across the eight strata. 12 refs., 8 figs., 47 tabs.

  19. Behavior of peptides combining 1 alanine residue and 8 glycine residues on papain associated with structural fluctuations

    NASA Astrophysics Data System (ADS)

    Nishiyama, Katsuhiko

    2011-12-01

    I investigated the behavior of the peptides combining 1 ALA residue and 8 GLY residues on papain associated with structural fluctuations via molecular dynamics and docking simulations. Although the chance of binding to sites near the active center of papain was reduced by replacing the GLY residue in 9GLY with ALA residue, binding stability was improved by the replacement. Furthermore, both the chance and binding stability were greatly affected by positioning of ALA residue in the peptides. Residue in peptides should be replaced in view of the balance between chance of binding to sites near active center and binding stability.

  20. Effects of processing on carbendazim residue in Pleurotus ostreatus.

    PubMed

    Xia, Erdong; Tao, Wuqun; Yao, Xi; Wang, Jin; Tang, Feng

    2016-07-01

    Samples of Pleurotus ostreatus were exposed to fungicide carbendazim to study the effect of processing on the residues. In most cases, processing operations led to a significant decrease in residue levels in the finished products, particularly through washing, drying, and cooking processes. The results indicated that rinsing under running tap water led to more than 70.30% loss in carbendazim residues. When dried under sunlight could remove more than 70.30% residues. There was a 63.90-97.14% reduction after steaming, with processing time extending, the removal rates increased especially for lower initial residue level samples. The residue was almost completely removed by frying combined with microwave heating. Furthermore, boiling the mushrooms reduced the residue in the mushroom and no carbendazim residues were determined in the broth. PMID:27386113

  1. 40 CFR 156.144 - Residue removal instructions-general.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ...) PESTICIDE PROGRAMS LABELING REQUIREMENTS FOR PESTICIDES AND DEVICES Container Labeling § 156.144 Residue... pesticide residues from the container prior to container disposal that are specified in § 156.146 and §...

  2. 40 CFR 156.144 - Residue removal instructions-general.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ...) PESTICIDE PROGRAMS LABELING REQUIREMENTS FOR PESTICIDES AND DEVICES Container Labeling § 156.144 Residue... pesticide residues from the container prior to container disposal that are specified in § 156.146 and §...

  3. 40 CFR 156.144 - Residue removal instructions-general.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ...) PESTICIDE PROGRAMS LABELING REQUIREMENTS FOR PESTICIDES AND DEVICES Container Labeling § 156.144 Residue... pesticide residues from the container prior to container disposal that are specified in § 156.146 and §...

  4. 40 CFR 180.345 - Ethofumesate; tolerances for residues.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... with regional registration as defined in 40 CFR 180.1(l) are established for the combined residues of... commodities: Commodity Parts per million Carrot, roots 7.0 (d) Indirect or inadvertent residues....

  5. 40 CFR 180.345 - Ethofumesate; tolerances for residues.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... with regional registration as defined in 40 CFR 180.1(m) are established for the combined residues of... commodities: Commodity Parts per million Carrot, roots 7.0 (d) Indirect or inadvertent residues....

  6. 40 CFR 180.396 - Hexazinone; tolerances for residues.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... excludes use of hexazinone on sugarcane in Florida, are established for the combined residues of hexazinone... milliom Sugarcane, cane 0.6 Sugarcane, molasses 4.0 (d) Indirect or inadvertent residues....

  7. 40 CFR 180.644 - Cyprosulfamide; tolerances for residues.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... residues of the herbicide safener cyprosulfamide, N- phenyl]sulfonyl]-2-methoxybenzamide, in or on the... established for residues of the herbicide safener cyprosulfamide, N- phenyl]sulfonyl]-2-methoxybenzamide,...

  8. 40 CFR 180.451 - Tribenuron methyl; tolerances for residues.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... residues of the herbicide tribenuron methyl and its metabolites and degradates in or on the commodities in.... Tolerances with regional registration, as defined in § 180.1(l) are established for residues of the...

  9. 40 CFR 180.644 - Cyprosulfamide; tolerances for residues.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... residues of the herbicide safener cyprosulfamide, N- phenyl]sulfonyl]-2-methoxybenzamide, in or on the... established for residues of the herbicide safener cyprosulfamide, N- phenyl]sulfonyl]-2-methoxybenzamide,...

  10. 40 CFR 180.644 - Cyprosulfamide; tolerances for residues.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... residues of the herbicide safener cyprosulfamide, N- phenyl]sulfonyl]-2-methoxybenzamide, in or on the... established for residues of the herbicide safener cyprosulfamide, N- phenyl]sulfonyl]-2-methoxybenzamide,...

  11. 40 CFR 180.451 - Tribenuron methyl; tolerances for residues.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... residues of the herbicide tribenuron methyl and its metabolites and degradates in or on the commodities in.... Tolerances with regional registration, as defined in § 180.1(l) are established for residues of the...

  12. 40 CFR 180.451 - Tribenuron methyl; tolerances for residues.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... residues of the herbicide tribenuron methyl and its metabolites and degradates in or on the commodities in.... Tolerances with regional registration, as defined in § 180.1(l) are established for residues of the...

  13. 40 CFR 180.644 - Cyprosulfamide; tolerances for residues.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... residues of the herbicide safener cyprosulfamide, N- phenyl]sulfonyl]-2-methoxybenzamide, in or on the... established for residues of the herbicide safener cyprosulfamide, N- phenyl]sulfonyl]-2-methoxybenzamide,...

  14. 40 CFR 180.644 - Cyprosulfamide; tolerances for residues.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... residues of the herbicide safener cyprosulfamide, N- phenyl]sulfonyl]-2-methoxybenzamide, in or on the... established for residues of the herbicide safener cyprosulfamide, N- phenyl]sulfonyl]-2-methoxybenzamide,...

  15. 40 CFR 180.569 - Forchlorfenuron; tolerances for residues.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... residues of the plant growth regulator forchlorfenuron; N-(2-chloro-4-pyridinyl)-N′phenyl urea in or on the....06 Kiwifruit 0.04 (2) Time-limited tolerances are established for residues of the plant...

  16. 40 CFR 180.569 - Forchlorfenuron; tolerances for residues.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... residues of the plant growth regulator forchlorfenuron; N-(2-chloro-4-pyridinyl)-N′phenyl urea in or on the....06 Kiwifruit 0.04 (2) Time-limited tolerances are established for residues of the plant...

  17. 40 CFR 180.569 - Forchlorfenuron; tolerances for residues.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... residues of the plant growth regulator forchlorfenuron; N-(2-chloro-4-pyridinyl)-N′phenyl urea in or on the....06 Kiwifruit 0.04 (2) Time-limited tolerances are established for residues of the plant...

  18. In-situ method for treating residual sodium

    SciTech Connect

    Sherman, Steven R.; Henslee, S. Paul

    2005-07-19

    A unique process for deactivating residual sodium in Liquid Metal Fast Breeder Reactor (LMFBR) systems which uses humidified (but not saturated) carbon dioxide at ambient temperature and pressure to convert residual sodium into solid sodium bicarbonate.

  19. In-Situ Method for Treating Residual Sodium

    SciTech Connect

    Sherman, Steven R.; Henslee, S. Paul

    2005-07-19

    A unique process for deactivating residual sodium in Liquid Metal Fast Breeder Reactor (LMFBR) systems which uses humidified (but not saturated) carbon dioxide at ambient temperature and pressure to convert residual sodium into solid sodium bicarbonate.

  20. Utilization of corn residues for production of the polysaccharide schizophyllan

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Abundant corn residues include fiber from wet milling operations and distillers' dried grains from dry grind ethanol plants. Biorefineries of the future will utilize such residues for the production of valuable bioproducts, particularly those traditionally produced from fossil fuels. Schizophyllan...

  1. Assessment of Spectral Indices for Crop Residue Cover Estimation

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The quantification of surficial crop residue (non-photosynthetic vegetation) cover is important for assessing agricultural tillage practices, rangeland health, and brush fire hazards. The Cellulose Absorption Index (CAI) and the Shortwave Infrared Normalized Difference Residue Index (SINDRI) are two...

  2. 40 CFR 180.378 - Permethrin; tolerances for residues.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... residues of the insecticide cis- and trans-permethrin isomers and in/on the following food commodities... residues of the insecticide cis- and trans-permethrin isomers and in/on the following food...

  3. 40 CFR 180.378 - Permethrin; tolerances for residues.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... residues of the insecticide cis- and trans-permethrin isomers and in/on the following food commodities... residues of the insecticide cis- and trans-permethrin isomers and in/on the following food...

  4. 40 CFR 180.378 - Permethrin; tolerances for residues.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... residues of the insecticide cis- and trans-permethrin isomers and in/on the following food commodities... residues of the insecticide cis- and trans-permethrin isomers and in/on the following food...

  5. 40 CFR 180.378 - Permethrin; tolerances for residues.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... residues of the insecticide cis- and trans-permethrin isomers and in/on the following food commodities... residues of the insecticide cis- and trans-permethrin isomers and in/on the following food...

  6. 40 CFR 180.378 - Permethrin; tolerances for residues.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... residues of the insecticide cis- and trans-permethrin isomers and in/on the following food commodities... residues of the insecticide cis- and trans-permethrin isomers and in/on the following food...

  7. Paving the Way To Algebraic Thought Using Residue Designs.

    ERIC Educational Resources Information Center

    Johnson, Iris DeLoach

    1998-01-01

    Presents a brief definition and examples of residue designs while sharing some of the algebraic thought that a student used to form generalizations about the patterns discovered during the investigations of residue designs. (ASK)

  8. Mineralogy of chondritic interplanetary dust particle impact residues from LDEF

    NASA Technical Reports Server (NTRS)

    Barrett, R. A.; Zolensky, M. E.; Bernhard, R.

    1993-01-01

    A detailed structural and compositional analysis of several impactor residues was performed utilizing transmission electron microscopy, energy dispersive spectroscopy, and electron diffraction. Residues from the interior of several craters in gold surfaces were removed with a tungsten needle, mounted in EMBED-812 epoxy, and ultramicrotomed. The presence in these residues of equilibrated ferromagnesian minerals, recrystallization textures, glass, and melted metal and sulfide bodies decorating grain boundaries is indicative of varying degrees of shock metamorphism in all impact residues we have characterized.

  9. 40 CFR 180.116 - Ziram; tolerances for residues.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 24 2014-07-01 2014-07-01 false Ziram; tolerances for residues. 180.116 Section 180.116 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) PESTICIDE PROGRAMS TOLERANCES AND EXEMPTIONS FOR PESTICIDE CHEMICAL RESIDUES IN FOOD Specific Tolerances § 180.116 Ziram; tolerances for residues. (a)...

  10. 40 CFR 180.114 - Ferbam; tolerances for residues.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 24 2014-07-01 2014-07-01 false Ferbam; tolerances for residues. 180.114 Section 180.114 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) PESTICIDE PROGRAMS TOLERANCES AND EXEMPTIONS FOR PESTICIDE CHEMICAL RESIDUES IN FOOD Specific Tolerances § 180.114 Ferbam; tolerances for residues. (a)...

  11. 7 CFR 29.427 - Pesticide residue standards.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 7 Agriculture 2 2014-01-01 2014-01-01 false Pesticide residue standards. 29.427 Section 29.427... REGULATIONS TOBACCO INSPECTION Regulations Miscellaneous § 29.427 Pesticide residue standards. The maximum concentration of residues of the following pesticides allowed in flue-cured or burley tobacco, expressed...

  12. 7 CFR 29.427 - Pesticide residue standards.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 7 Agriculture 2 2013-01-01 2013-01-01 false Pesticide residue standards. 29.427 Section 29.427... REGULATIONS TOBACCO INSPECTION Regulations Miscellaneous § 29.427 Pesticide residue standards. The maximum concentration of residues of the following pesticides allowed in flue-cured or burley tobacco, expressed...

  13. 7 CFR 29.427 - Pesticide residue standards.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 7 Agriculture 2 2011-01-01 2011-01-01 false Pesticide residue standards. 29.427 Section 29.427... REGULATIONS TOBACCO INSPECTION Regulations Miscellaneous § 29.427 Pesticide residue standards. The maximum concentration of residues of the following pesticides allowed in flue-cured or burley tobacco, expressed...

  14. 7 CFR 29.427 - Pesticide residue standards.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 7 Agriculture 2 2012-01-01 2012-01-01 false Pesticide residue standards. 29.427 Section 29.427... REGULATIONS TOBACCO INSPECTION Regulations Miscellaneous § 29.427 Pesticide residue standards. The maximum concentration of residues of the following pesticides allowed in flue-cured or burley tobacco, expressed...

  15. 40 CFR 180.380 - Vinclozolin; tolerances for residues.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 23 2010-07-01 2010-07-01 false Vinclozolin; tolerances for residues. 180.380 Section 180.380 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) PESTICIDE PROGRAMS TOLERANCES AND EXEMPTIONS FOR PESTICIDE CHEMICAL RESIDUES IN FOOD Specific Tolerances § 180.380 Vinclozolin; tolerances for residues....

  16. 40 CFR 180.588 - Quinoxyfen; tolerances for residues.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 23 2010-07-01 2010-07-01 false Quinoxyfen; tolerances for residues. 180.588 Section 180.588 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) PESTICIDE PROGRAMS TOLERANCES AND EXEMPTIONS FOR PESTICIDE CHEMICAL RESIDUES IN FOOD Specific Tolerances § 180.588 Quinoxyfen; tolerances for residues....

  17. 40 CFR 180.433 - Fomesafen; tolerances for residues.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 24 2014-07-01 2014-07-01 false Fomesafen; tolerances for residues. 180.433 Section 180.433 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) PESTICIDE PROGRAMS TOLERANCES AND EXEMPTIONS FOR PESTICIDE CHEMICAL RESIDUES IN FOOD Specific Tolerances § 180.433 Fomesafen; tolerances for residues....

  18. 40 CFR 180.380 - Vinclozolin; tolerances for residues.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 24 2014-07-01 2014-07-01 false Vinclozolin; tolerances for residues. 180.380 Section 180.380 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) PESTICIDE PROGRAMS TOLERANCES AND EXEMPTIONS FOR PESTICIDE CHEMICAL RESIDUES IN FOOD Specific Tolerances § 180.380 Vinclozolin; tolerances for residues....

  19. 40 CFR 180.111 - Malathion; tolerances for residues.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 40 Protection of Environment 24 2011-07-01 2011-07-01 false Malathion; tolerances for residues. 180.111 Section 180.111 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) PESTICIDE PROGRAMS TOLERANCES AND EXEMPTIONS FOR PESTICIDE CHEMICAL RESIDUES IN FOOD Specific Tolerances § 180.111 Malathion; tolerances for residues....

  20. 40 CFR 180.448 - Hexythiazox; tolerance for residues.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 40 Protection of Environment 24 2011-07-01 2011-07-01 false Hexythiazox; tolerance for residues. 180.448 Section 180.448 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) PESTICIDE PROGRAMS TOLERANCES AND EXEMPTIONS FOR PESTICIDE CHEMICAL RESIDUES IN FOOD Specific Tolerances § 180.448 Hexythiazox; tolerance for residues....

  1. 40 CFR 180.110 - Maneb; tolerances for residues.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 40 Protection of Environment 24 2011-07-01 2011-07-01 false Maneb; tolerances for residues. 180.110 Section 180.110 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) PESTICIDE PROGRAMS TOLERANCES AND EXEMPTIONS FOR PESTICIDE CHEMICAL RESIDUES IN FOOD Specific Tolerances § 180.110 Maneb; tolerances for residues. (a)...

  2. 40 CFR 180.261 - Phosmet; tolerances for residues.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 40 Protection of Environment 24 2011-07-01 2011-07-01 false Phosmet; tolerances for residues. 180.261 Section 180.261 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) PESTICIDE PROGRAMS TOLERANCES AND EXEMPTIONS FOR PESTICIDE CHEMICAL RESIDUES IN FOOD Specific Tolerances § 180.261 Phosmet; tolerances for residues. (a)...

  3. 40 CFR 180.225 - Phosphine; tolerances for residues.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 40 Protection of Environment 24 2011-07-01 2011-07-01 false Phosphine; tolerances for residues. 180.225 Section 180.225 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) PESTICIDE PROGRAMS TOLERANCES AND EXEMPTIONS FOR PESTICIDE CHEMICAL RESIDUES IN FOOD Specific Tolerances § 180.225 Phosphine; tolerances for residues....

  4. 40 CFR 180.259 - Propargite; tolerances for residues.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 40 Protection of Environment 24 2011-07-01 2011-07-01 false Propargite; tolerances for residues. 180.259 Section 180.259 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) PESTICIDE PROGRAMS TOLERANCES AND EXEMPTIONS FOR PESTICIDE CHEMICAL RESIDUES IN FOOD Specific Tolerances § 180.259 Propargite; tolerances for residues....

  5. 40 CFR 180.332 - Metribuzin; tolerances for residues.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 40 Protection of Environment 24 2011-07-01 2011-07-01 false Metribuzin; tolerances for residues. 180.332 Section 180.332 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) PESTICIDE PROGRAMS TOLERANCES AND EXEMPTIONS FOR PESTICIDE CHEMICAL RESIDUES IN FOOD Specific Tolerances § 180.332 Metribuzin;tolerances for residues....

  6. 40 CFR 180.412 - Sethoxydim; tolerances for residues.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 40 Protection of Environment 24 2011-07-01 2011-07-01 false Sethoxydim; tolerances for residues. 180.412 Section 180.412 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) PESTICIDE PROGRAMS TOLERANCES AND EXEMPTIONS FOR PESTICIDE CHEMICAL RESIDUES IN FOOD Specific Tolerances § 180.412 Sethoxydim; tolerances for residues....

  7. 40 CFR 180.565 - Thiamethoxam; tolerances for residues.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 40 Protection of Environment 24 2011-07-01 2011-07-01 false Thiamethoxam; tolerances for residues. 180.565 Section 180.565 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) PESTICIDE PROGRAMS TOLERANCES AND EXEMPTIONS FOR PESTICIDE CHEMICAL RESIDUES IN FOOD Specific Tolerances § 180.565 Thiamethoxam; tolerances for residues....

  8. 40 CFR 180.269 - Aldicarb; tolerances for residues.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 40 Protection of Environment 24 2011-07-01 2011-07-01 false Aldicarb; tolerances for residues. 180.269 Section 180.269 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) PESTICIDE PROGRAMS TOLERANCES AND EXEMPTIONS FOR PESTICIDE CHEMICAL RESIDUES IN FOOD Specific Tolerances § 180.269 Aldicarb; tolerances for residues....

  9. 40 CFR 180.206 - Phorate; tolerances for residues.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 40 Protection of Environment 24 2011-07-01 2011-07-01 false Phorate; tolerances for residues. 180.206 Section 180.206 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) PESTICIDE PROGRAMS TOLERANCES AND EXEMPTIONS FOR PESTICIDE CHEMICAL RESIDUES IN FOOD Specific Tolerances § 180.206 Phorate; tolerances for residues. (a)...

  10. 40 CFR 180.262 - Ethoprop; tolerances for residues.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 40 Protection of Environment 24 2011-07-01 2011-07-01 false Ethoprop; tolerances for residues. 180.262 Section 180.262 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) PESTICIDE PROGRAMS TOLERANCES AND EXEMPTIONS FOR PESTICIDE CHEMICAL RESIDUES IN FOOD Specific Tolerances § 180.262 Ethoprop; tolerances for residues....

  11. 40 CFR 180.204 - Dimethoate; tolerances for residues.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 40 Protection of Environment 24 2011-07-01 2011-07-01 false Dimethoate; tolerances for residues. 180.204 Section 180.204 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) PESTICIDE PROGRAMS TOLERANCES AND EXEMPTIONS FOR PESTICIDE CHEMICAL RESIDUES IN FOOD Specific Tolerances § 180.204 Dimethoate; tolerances for residues....

  12. 40 CFR 180.470 - Acetochlor; tolerances for residues.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 40 Protection of Environment 24 2011-07-01 2011-07-01 false Acetochlor; tolerances for residues. 180.470 Section 180.470 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) PESTICIDE PROGRAMS TOLERANCES AND EXEMPTIONS FOR PESTICIDE CHEMICAL RESIDUES IN FOOD Specific Tolerances § 180.470 Acetochlor; tolerances for residues....

  13. 40 CFR 180.328 - Napropamide; tolerances for residues.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 40 Protection of Environment 25 2012-07-01 2012-07-01 false Napropamide; tolerances for residues. 180.328 Section 180.328 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) PESTICIDE PROGRAMS TOLERANCES AND EXEMPTIONS FOR PESTICIDE CHEMICAL RESIDUES IN FOOD Specific Tolerances § 180.328 Napropamide; tolerances for residues....

  14. 40 CFR 180.328 - Napropamide; tolerances for residues.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 25 2013-07-01 2013-07-01 false Napropamide; tolerances for residues. 180.328 Section 180.328 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) PESTICIDE PROGRAMS TOLERANCES AND EXEMPTIONS FOR PESTICIDE CHEMICAL RESIDUES IN FOOD Specific Tolerances § 180.328 Napropamide; tolerances for residues....

  15. 7 CFR 29.427 - Pesticide residue standards.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 7 Agriculture 2 2010-01-01 2010-01-01 false Pesticide residue standards. 29.427 Section 29.427... REGULATIONS TOBACCO INSPECTION Regulations Miscellaneous § 29.427 Pesticide residue standards. The maximum concentration of residues of the following pesticides allowed in flue-cured or burley tobacco, expressed...

  16. 40 CFR 180.574 - Fluazinam; tolerances for residues.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 40 Protection of Environment 25 2012-07-01 2012-07-01 false Fluazinam; tolerances for residues. 180.574 Section 180.574 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) PESTICIDE PROGRAMS TOLERANCES AND EXEMPTIONS FOR PESTICIDE CHEMICAL RESIDUES IN FOOD Specific Tolerances § 180.574 Fluazinam; tolerances for residues....

  17. 40 CFR 180.292 - Picloram; tolerances for residues.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 24 2014-07-01 2014-07-01 false Picloram; tolerances for residues. 180.292 Section 180.292 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) PESTICIDE PROGRAMS TOLERANCES AND EXEMPTIONS FOR PESTICIDE CHEMICAL RESIDUES IN FOOD Specific Tolerances § 180.292 Picloram; tolerances for residues....

  18. 40 CFR 180.581 - Iprovalicarb; tolerances for residues.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 23 2010-07-01 2010-07-01 false Iprovalicarb; tolerances for residues. 180.581 Section 180.581 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) PESTICIDE PROGRAMS TOLERANCES AND EXEMPTIONS FOR PESTICIDE CHEMICAL RESIDUES IN FOOD Specific Tolerances § 180.581 Iprovalicarb; tolerances for residues....

  19. 40 CFR 180.581 - Iprovalicarb; tolerances for residues.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 24 2014-07-01 2014-07-01 false Iprovalicarb; tolerances for residues. 180.581 Section 180.581 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) PESTICIDE PROGRAMS TOLERANCES AND EXEMPTIONS FOR PESTICIDE CHEMICAL RESIDUES IN FOOD Specific Tolerances § 180.581 Iprovalicarb; tolerances for residues....

  20. 40 CFR 180.581 - Iprovalicarb; tolerances for residues.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 40 Protection of Environment 25 2012-07-01 2012-07-01 false Iprovalicarb; tolerances for residues. 180.581 Section 180.581 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) PESTICIDE PROGRAMS TOLERANCES AND EXEMPTIONS FOR PESTICIDE CHEMICAL RESIDUES IN FOOD Specific Tolerances § 180.581 Iprovalicarb; tolerances for residues....